Mustang Mk. I
P-51 (Mustang IA)
P-51 A Mustang (Mustang II)
P-51 B/C Mustang (Mustang III)
P-51 D/K Mustang (Mustang IV)
P-51 H Mustang
F-82 Twin Mustang
When the world needed a hero, the P-51 Mustang was born. Designed and built in less than 120 days it was one of the most famous and beloved fighters that changed the nature of aerial warfare during the Second World War.
Before the P-51 Mustang came into play, bombers on long range missions had to fly unescorted above German soil. Since the fighter planes early in the war had a range of only about 250 miles, this meant that they could not escort the bombers further than Aachen, near the western border of German. For any penetration deeper into the Third Reich, the bombers had to fly on their own.
These unescorted missions had disastrous results for the bombers. During a bombing mission over Schweinfurt, Germany on October 14th , 1943, to bomb the large ball bearing factories so crucial to the German war effort, the U.S. Eighth Air Force were attacked by a large number of Luftwaffe fighter aircraft. Out of 229 bombers, 60 were shot down and 17 more were damaged beyond repair. This loss rate was unacceptable and proved that the allied daylight bombing campaign over Germany could not continue unless the bombers could be accompanied by fighter aircraft.
Originally overlooked by the USAAF, the P-51 did not see action with American forces until April of 1943 (The NA-91 or P-51-NA with the 154th Observation Squadron). Once its full potential had been developed, the USA realized that this aircraft had been ignored for far too long.
With the addition of the British Rolls-Royce Merlin engine to the American airframe, it would be unmatched by any other piston aircraft of World War II.
P-51s became the nemesis of the Luftwaffe, shooting down 4,950 enemy aircraft while achieving a kill ratio of 11:1. It's said that when Hermann Goering learned that long-range P-51s were beginning to escort Eighth Air Force B-17s on bombing runs over Berlin in 1944, he told his staff "The war is over."
© USAAF - 390th Bomb Group B-17s enroute to bomb targets in Germany. The swirling contrails above are those of their P-51 escorts
You can click the corresponding Mustang variant on the top left side or in the overview below to get a detailed description of the development changes of each type.
P-51 / Mustang IA
P-51A / Mustang II
P-51B-C / Mustang III
P-51D-K / Mustang IV
F-6 Photo Reconnaissance Mustang
Cavalier F-51D Mustang
Cavalier F-51D Mustang II
Cavalier Turbo Mustang III (Piper PA-48 Enforcer)
Because the development of the different Mustang variants, ranging from the NA-73X prototype to the final versions of the type, is often intertwined, we have put together a chronological list.
Below is a timeline of major milestones for North American Aviation, regarding the development and evolution of the Mustang:
General Motors decides to rename the General Aviation Manufacturing Corporation (GAMC) holding to North American Aviation
NAA Vice President James Leland “Lee” Atwood was brought in by Kindelberger from Douglas to be Chief Engineer. Both men met whilst working at Douglas earlier in their carreers.
Further recruiting was done by NAA:
USAAC-MD released two open Requests for Proposals (RFP) 35-414:
- X-602: a two-seat, single-engined pursuit airplane with bomb-carrying capability
- X-603: a single-seat, single-engined pursuit airplane.
Further specifications were a profile layout and performance specifications for an all-metal-covered cantilever monoplane with retractable main gear.
The request proved to be originated from a poorly thought-out set of aviation requirements for pursuit and attack airplanes, and was retracted several months later.
NAA had its eye on Allison’s powerful V-1710 engine and thus submitted a proposal for the two-seat, inline engine pursuit competition.
NAA charge number was NA-35 specification, designated the P-198 XP.
General Order NA-16 was issued for an upcoming Circular Proposal for a fixed-gear, two-seat basic trainer.
Chief Engineer Lee Atwood released the detail specification for the P-198.
Before NAA could submit their design, the USAAC canceled the Proposal request.
NAA's two-seat trainer flew for the first time with Paul Balfour at the controls.
A side profile drawing was provided by Atwood for the P-198
NAA completed the XO-47 observation aircraft.
NAA's design beat the Seversky BT-8.
NAA received a contract for 42 BT-9s.
In order to provide funds for the BT-9, NAA opened General Order NA-19.
NAA moves to Mines Field.
NAA begins the construction of a new plant at Inglewood, CA.
President Franklin D. Roosevelt placed a two-year wait on foreign delivery of new aircraft.
The Allison XV-1710-7 engine first flight, installed in a Consolidated XA-11A.
January - March
Two new Requests for Proposals were made by USAAC Materiel Command, via Lt. Benjamin Kelsey and Capt. David Schlatter of the Fighter Projects Office:
- CP37-608: a twin-engined pursuit
- CP37-609: a single-engined pursuit
The request were sent to nine manufacturers, but NAA was not included.
After the Allison V-1710-C5 completed the USAAC-MD Bench Test for 150 hours of continuous operation.
It was ordered to be installed in a P-36, which as a result became known as the XP-40.
NAA opened Charge Number NA-for the construction of a two-seat light bomber variant of the BC-1.
The BC-1 incorporated an all-metal fuselage, which became NAA’s standard for all future designs.
It featured guns and provisions for bomb racks.
USAAC released Request for Proposal CP38-385 for the Light Attack Bomber competition.
NAA entered the competition with charge number NA-40.
The result was a clean, narrow fuselage airframe where the co-pilot sat behind the pilot. The design featured a tricycle landing gear.
Allison and NAA talk about USAAC interest in the V-1710 configuration.
Vance Breese flew the new BC-1 (production version of the NA-26 prototype).
It features a retractable tailwheel landing gear and provision for armament, a two-way radio, and the 550-hp R-1340-47 engine as standard equipment.
Kindelberger contacts Dr. Milikan of the California Institute of Technology to request a study for a "high speed pursuit" based on a 1,050hp inline engine.
This is because he received unofficial information of upcoming USAAC-MD’s Circular Proposals for single- and twin-engined pursuit aircraft.
Kindelberger sends letter to Hap Arnold. He informs Arnold about the high speed pursuit study and that he was preparing to visit European aircraft manufacturers in Germany, Great Britain and Holland.
Technical Report Memo 896 was published by NACA (National Advisory Committee for Aeronautics).
It was basically a translation of B. Gothert’s German report “Drag of Radiator with Special Reference to Heating”
Kindelberger visits various constructors in Europe.
Ernst Udet was his personal guide when he visited the Heinkel, Messerschmitt and Junkers plants.
Kindelberger learned a great deal of German manufacturing techniques and their incorporation of American automobile industry assembly line techniques.
Edward Horkey joins NAA as aerodynamicist.
British Air Ministry orders the Harvard I.
The Millikan report was circulated by Brig. Gen. Arnold to Lt. Col. Echols, Chief Engineering Section of the USAAC-MD at Wright Field.
Kindelberger hoped that NAA would be included in the upcoming Circular Proposals.
NA-44 light bomber first flight.
GMC board of directors authorized funding for the NA-50. This was NAA’s first attempt at building a fighter.
Kindelberger closes the Harvard I production contract with Britain.
First flight of the Harvard I by Louis S. Wait.
The Curtiss XP-40 (with the Allison V-1710-19) flies for the first time.
Lt. Ben Kelsey flies the XP-40 from Dayton to Buffalo at an average speed of 350mph, setting a new USAAC speed record.
XP-38 first flight
NA-40-2’s first flight.
Although the design did not receive any orders by the USAAC, they did sent NAA a list with recommended improvements following extensive flight testing.
This would lead to the future NA-62 (B-25) design.
NAA receives a contract for the NA-50 export fighter. Charge Number NA-68 is opened.
Upon returning from Europe, Kindelberger knew that NAA's NA-53 and lightweight P-500 pursuit concepts would be no match for current European fighters such as the Spitfire of Bf 109.
NAA's aircraft designer, Edgar O. ‘Ed’ Schmued continues to draw and develop designs for a single-engined pursuit from mid-1939 through December of 1940.
Atwood and Schmued initiate sketches to embed the radiator into the fuselage aft of the cockpit later that year.
Sir Henry Self is appointed Director General of the British Purchasing Committee, NY City branch.
He askes Dutch Kindelberger if NAA would consider building Kittyhawk Mark Is (P-40D) under license from Curtiss-Wright.
NAA proposes to build an entirely new fighter for the British in 120 days.
Kindelberger asks Schmued to prepare preliminary design drawings and estimated weight and performance figures for the design of a new pursuit airplane. The pursuit fighter needed to be powered by the F3R version of the Allison V-1710 engine.
Schmued was given two weeks to produce his presentation to the BPC.
Kindelberger instructed Schmued to design a fighter that is the "...fastest airplane we can build around a man that is five feet, ten inches tall and weighs 140 pounds. It should have two 20-millimetre cannon in either wing and it should meet all of the design requirements of the US Army Air Corps."
NAA delivers reports 1592 and 1593, including three-view and side profile drawings of the P-509-1 “High Speed Pursuit” Allison proposal to the BPC in NY.
The US War Department completed its ‘Release of Aircraft Policy’.
This gave authorization to US allies to negotiate contracts for the procurement of the latest US aircraft designs.
Kindelberger holds a meeting with Atwood, Rice and Schmued.
The company begins work on the Company Sponsored Pursuit airplane, dubbed P-509.
Chief aerodynamicist Ed Horkey and key aeronautical engineers Art Chester, John Young, Marc W. Malsby, J. Stan Smithson and Larry Waite also work on the project.
NAA receives a Letter of Intent for the production of 320 P-509 airplanes.
Schmued began detail design on the P-509 prototype.
Work on the P-509 prototype started.
Since NA-73 was the next available NAA Charge Number, the programme was first known as X73 and then NA-73X.
NAA vice president Lee Atwood sends a letter to the BPC in NY.
The company promises initial deliveries of the 320 NA-73 airplanes to begin in January 1941.
Up to 50 airplanes a month will be delivered by October 1st.
NAA signed a ‘Foreign Release Agreement’ with the USAAC.
This authorizes NAA to write formal contracts with the BPC from then on.
Included in the agreement is the release of 2 airframes of the NA-73 to be delivered to the USAAC for testing.
It is decided that the 4th and 10th production airframes will be taken for this.
May 23 - 29th
The BPC signs a formal British Air Ministry contract number (A-250) for 320 NA-73s in Inglewood.
USAAC canceled future P-43 and P-44 pursuit aircraft.
NAA receives official approval from the BPC to proceed with the production of the 320 NA-73 airplanes.
The US War Department issued ‘Authority to Purchase number 165265’ for the BPC to procure 320 NA-73 airplanes, with 2 airframes to be provided to the USAAC at no cost.
The two USAAC NA-73 airplanes are designated XP-51.
USAAC specifies 0.50 cal armament and defensive armor.
Shortly after this changes to four 0.50cals plus one 20mm Hispano II cannon.
First flight of the B-25.
USAAC issued contract for a Pratt & Whitney R-2800 powered version of the XP-47, designated XP-47B (733 production P-47Bs were ordered)
NA-73X rolls out of the factory on AT-6 tyres. It also lacks the Allison engine.
US Assistant Secretary of War, Robert P. Patterson of the US War Department, officially approves the BPC/NAA/USAAC contract for 322 NA-73 airplanes (320 for Great Britain and 2 for the USAAC).
An Allison engine is delivered, but it is not the one that was specified and used during the design of the NA-73X.
Allison delivered a civilian 1,075 hp Allison V-1710-F3R.
As a result, engineers need to make new motor mounts for the engine to fit.
Vance Breese, a freelance engineering test pilot for NAA, prepares NA-73X for its first flight.
- After a few engine run-up tests, Breese took off for the first flight of NA-73X.
- Two short test flights of 5 and 10 minutes respectively are flown.
- Breese completes 6 more functional checkout flights by November 13th.
- NA-73X totals 3 hours, 25 of flying time and was flown at a level attitude flight speed of 382 mph.That was just as fast as a Spitfire, which weighed less and carried half of the amount of fuel of the NA-73X.
NA-73X makes a wheels-down crash landing in a freshly ploughed field.
The aircraft was flown by NAA test pilot Paul B. Balfour, and ends up on its back in the field.
The British send a letter to NAA in which they inform the company that they have chosen "Mustang" as their official name for the fighter.
The RAF adds 300 additional aircraft to their existing order.
Because NAA incorporates several improvements in the design, it opens a new charge number for this order, NA-83. The British still name it the Mustang Mk. I.
Changes included more efficient exhaust stacks and a modified carburetor air scoop.
Mustang Mk I
CAA reissued the Certificate of License for the repared X73.
FAA prepares new test flight.
Vance Breese flight tests the repaired NA-73X out of Mines Field.
In further meetings between the BPC and NAA, the following design changes/request are stated:
- minimum armament is fixed at two 0.50cal cowling-mounted guns
- request for extra fuel to be carried internally in the gun bays (earlier request to permanently put more fuel into the wing were abandoned as it would take up too much time and effort to redesign and strenghten the wings)
Schmued advances the notion of external fuel tanks and racks, but at that time, USAAC regulations forbids aircraft to be equipped with external tanks for combat.
NAA specifies 197,24 gal of internal fuel, with and a cruising speed of 229mph at 10,000ft.
A proposal is made to the British to retain the 0.50cal fuselage guns and remove the rest of the wing armament and ammunition and replace those with 27gal fuel cells.
GALCIT tests concerning heat rejection data for the cooling system propose an expansion of the intake scoop area to 150in. and to drop the inlet air intake from the bottom surface of the wing. This gives the variable aft plenum exit a range of 65 - 280sq. in.
Rice forwards the memo to NAA Engineering department.
The British Air Ministry is contacted for help in redesigning the scoop.
Rice sends memo to R.C. Costello: the Mustang requires 200US Gallons of fuel for a 1,500 mile flight, including warm-up, take-off and climb to 10,000ft at 75 percent rated power.
Gross weight was estimated at 8,400lb, with a take-off run of 1,600ft to clear a 50ft obstacle.
NAA asks for quotes from the Firestone Tire and Rubber Company for manufacturing and delivering leak-proof fuel cells.
Estimated range for the Mustang I with the auxiliary fuel cells was 1,724 miles with 220gal. The additional fuel cells would augment the cost per aircraft with 125$.
Mustang Mk I
Static test bed airframe XX73 experiences damage to its structural integrity at both its design ultimate angle-of-attack loading and its peak side load.
As a result, the longerons, spar, and some skins are strengthened. These changes were incorporated starting with NA-73 number 11.
Because of this, all earlier airframes (NA-73X, British production airframes AG345 to AG352 and both USAAC examples 41-038 and 41-039 were deemed unsuitable for a combat role). All earlier manufactured airframes were relegated to flight-test status.
XX73 was repaired and turned over to NAA Field Services to produce maintenance and repair instruction manuals.
Atwood and his team explored alternatives to the Allison V-1710.
Dr. B. S. Shenstone of the RAE arrived from Britain to consult with NAA for the cooling and pressure issues.
After examining the data from NACA, he suggests to drop the upper lip of the scoop approximately 1½in. from the bottom of the wing. This was the first of many design changes to the scoop to deal with the so-called "spilling effect",
or effect of boundary-layer separation in front of both the radiator and carburetor scoop.
Results showed significant improvements to the radiator face pressure distribution.
The data was sent to the engineers and a new underbelly scoop was designed and incorporated into production.
The first aircraft to have a Packard Merlin installed is the Curtiss XP-60.
NAA appoints company pilot Louis S. ‘Lou’ Wait to be chief test pilot on the Mustang program.
He replaces freelance pilot Vance Breese.
The BPC asks NAA to reconsider the four-20mm cannon configuration.
NAA opens charge number NA-91 to investigate the changes
British serial number AG347 was the first to be given both the two-gun and four-gun installation to perform drag tests (it was returned to stock NA-73 condition after those tests).
AM190 was the first NA-83 to have the four 20mm cannons installed following examination of the data and drag test results of AG347.
Mustang Mk I
USAAC-MD releases Request for Data R-40C to 13 companies for a High Speed Single-Engine Pursuit.
NAA is, once again, not included.
The Intake scoop design was changed to reduce scoop area from 200sq in. to 110sq in.
Allison reports to NAA that the exhaust power loss was excessive.
They suggest a joint design and test collaboration.
Allison Chairman O.E. Hunt informs Kindelberger of plans to build a two-speed/two-stage supercharger version of the V-1710 engine.
Kindelberger suggests an integral two-speed blower approach. That would minimize modification requirements of the existing Mustang design.
Hunt responds that it would be easier (for Allison) to hang an auxiliary two-stage blower on the back of the engine. This would require extensive redesigning of the airframe for NAA.
Talks between Allison and NAA stagnate.
Kindelberger sends a request to the BPC regarding information on Rolls-Royce engines.
This was against the parent company (GMC) desired and led to serious discussions. about keeping business within the GMC “family”.
Despite GMC's wishesn, Kindelberger carries on talking with Rolls-Royce.
US Army Air Corps’ Captain M. J. Lee, who is on temporary duty from Wright Field, completes seven test flights with NA-73X at Mines Field.
Test pilot Bob Chilton makes his first flight for NAA, piloting an AT-6.
Capt. Lee writes a report to Material Command denigrating the NA-73X and declaring it unsuitable for combat.
His comments lead to the design of the flat-panel windshield and changes to the elevator and aileron control systems.
Bob Chilton takes NA-73X up for a one-hour functional check flight from Mines Field.
J.E. Ellor, a US representative of Rolls-Royce sends an 18-page package of technical details for installing a Merlin XX engine.
These include the radiator cooling and intercooler requirements relating to the P-40F and Bristol Beaufighter II.
NAA found the exhaust stack gas thrust lower than expected.
Rice sends a request for assistance to Dr. George W. Lewis at NACA.
Chilton flies British serial number AG347, which has the prototype three-cell auxiliary fuel tanks installed in the gun and ammuniation bays of each wing.
Mustang Mk I
NAA test pilot Louis Wait completes a successful first flight of the first production RAF Mustang Mark I (AG345) out of Mines Field.
Mustang Mk I
April 23rd - June 30th
NAA resolves various problems, such as:
- stiff controls and roll rate with existing cusped ailerons
- tailwheel shimmy
- engine surge in dives (traced to the carburetor intake)
- Prestone thermostat control
- overheating (solved by new scoop and radiator/oil cooler)
- cockpit illumination with British fluorescent lights.
Sir Henry Self, head of the BPC, pays a visit to the Inglewood NAA headquarters and to the Mustang production facility.
First flight of the XP-47B.
The fourth NA-73 production airframe, 41-038, scheduled to be delivered to Materiel Command, is test flown by Chilton. It sports the flat-panel windshield change, but still has the short carburator intake scoop.
The first flight of the second XP-51 (41-039) soon follows.
Kindelberger writes to Breech that NAA is gaining no progress with Allison. He also sends a memo to the GMC Board stating “grave concerns about both Allison production and service capability”
XP-51 No. 1 (41-038) is deemed ready for USAAC flight testing at Mines Field.
Over 30 Change Engineering Orders have meanwhile been incorporated into the airframe.
The USAAC-MD requests XP-51 delivery to Wright Field on or about July 12th.
Among other requests, it was asked that the first USAAC implementation of the automatic gun charging system be accomplished.
The plan was to also modify the airframe with the long carburator air scoop, but the estimated completion date of August 22nd at the earliest, proves this to be not feasible.
41-038 is therefore sent over with the existing short carb intake.
The decision to incorporate the new production carburetor scoop also delayed transport of XP-51 no. 2 to Wright Field until December.
11,000 NAA employees go on strike to demand an increase in wage, thus halting all NAA aircraft production.
The BAC formally requests that auxiliary tank kits be included with every Mustang I delivery.
They also ask that this change does not cause a delay in delivery of the Mustangs.
Despite this demand, production by the promised date is made difficult because of the discovered wing test structural test failures and the company strike..
The needed changes demand a slowdown of production to allow incorporation of those changes to production airframes.
Also, the Extended Range Modification was still awaiting test results from the Firestone company
Costello and Rice discuss production issues for delivery of airframes with the additional fuel cells.
The kits would be provided starting with aircraft number 143 to 320, and also for the second contract of 300 NA-83 Mustangs.
Rice reiterates the 1,500-mile range guarantee, and summarizes the price per kit of $245.35 per airplane.
Those additional fuel cells were however not installed and delivered in the Mustangs. If they would have been installed, the Mustang I would have been the longest-range armed, single-engined fighter-reconnaissance aircraft of World War II using only internal fuel until 1943.
Mustang Mk I
To end the strik, US President Franklin D. Roosevelt issues a presidential order for US Army troops to secure the plant and protect managerial workers who remained on the job.
The US Army Air Corps (USAAC) became the US Army Air Forces (USAAF) to better deal with its growing numbers of branched air forces throughout the US and territories.
On this date, the USAAF has seven air forces or branches listed from the First Air Force (1st Air Force or 1AF), up to the Seventh Air Force (7th Air Force or 7AF).
During the strike, NAA receives a Department of the Army contract (DA-140) on behalf of the BPC for 150 P-51 airplanes under its NA-91 programme.
These are designated as Mustang Mark IAs by the RAF and will range from serial number FD418 to FD567.
As stipulated in this contract, two of these airplanes will be set aside to serve as XP-51B Merlin conversion prototypes. These would be the 33rd and 102nd NA-91 airplanes built.
Mustang Mk IA
The 27-day strike was peacefully ended and NA-73 Mustang Mark I production resumed.
NAA chief engineering test pilot Bob Chilton completes the first flight of the second production production Mustang Mark I (AG346) out of Mines Field.
Mustang Mk I
NAA begins work on its NA-91 program.
150 P-51 Mustang Mark IA airplanes will be built under the new Lend-Lease agreement for the RAF under Department of the Army/USAAC contract DA-AC-140.
US Serial numbers 41-37352 and 41-37421 will be taken aside as the two prototype XP-51B airframes.
This engine change was the result of the highly successful Mustang Mark X programme in Great Britain
NA-73X makes its last flight.
Between May 1st and this date, Chilton flight tested AG345 17 times much in part to evaluate ongoing radiator and air scoop performance at different speeds and altitudes.
He also makes the first flight of AG347, the 3rd production Mustang Mark I.
Mustang Mk I
Chilton just completed functionality tests of AG346 when he is introduced to RAF Squadron Leader Michael N. Crossley, an ace with nine kills, and RAF Wing Commander Christopher Clarkson.
Both gentlemen came over from the UK to complete acceptance testing of AG346.
The Packard Motor Company received the first drawing package for the Merlin XX/1650-1 two-speed, single-stage engine from Rolls-Royce
Mustang Mk I
Battle of Britain ace Sqn Ldr Michael Crossley makes the first “official” RAF flights in the Mustang I.
Mustang Mk I
The BPC orders 320 long-range fuel tank kits.
The first XP-51 (41-038) leaves Mines Field and is ferried to Wright Field for official USAAF performance evaluations.
The RAF accepts two NA-73 airplanes.
Only another 136 airplanes will be delivered until the end of the year.
Packard completes its first Merlin V-1650-1/Merlin 28 destined for Canadian-built Lancasters and Moquitoes.
Curtiss arranges for the V-1650-1 to be delivered for its P-40F fighters.
The USAAF orderes 733 P-47B/Cs from Republic.
The FW-190A-1 becomes operational with Jagdgeschwader (JG) 26.
The Curtiss XP-60 makes its first flight with a Packard Merlin.
Chilton initiates functional flight tests of AG349 (Mustang Mk. I number 5).
AG349 is later sent to Russia for evaluation by its air force.
Mustang Mk I
Contract DA-140 is officially approved for the NA-91.
The RAF accepts its first Mustang Mk. I (AG346) at Inglewood.
Mustang Mk I
Performance tests of XP-51 41-038 are flown out of Wright Field between October 8th and December 22nd.
Carrying a full load of ammunition and 170 gallons of fuel and weighing 7,934 lb, it is clocked at 382mph at 13,000ft.
Its range was 750 miles at 325 mph cruise speed.
Kindelberger and Atwood look for opportunities to keep the Mustang in production.
Learning of USAAC funding available for dive-bombers, they study to rework the NA-83 design as a low-altitude attack pursuit aircraft as described in Army FM 1-15.
Chilton arrives at Wright Field to evaluate a Spitfire Mark V and Hurricane Mark II.
Whilst at Wright Field, he notices 41-038 tied down on the ramp and checks the aircraft log.
He is surprised to learn that it was only flown for 1 hour after its arrival on August 24th.
He questions the designated Project Officer, 2nd Lt. Winthrop Towner, who simply states: "It’s a low priority program and we’re not done testing it."
XP-51 is readied for its ferry flight to Langley, Virginia, to be evaluated by NACA.
Chilton performs test flights with AF347, which has four dummy 20-mm cannons installed for drag testing.
Structures chief Richard Schleicher tells Rice that approximately 700hrs of structural analysis is required to examine the necessary modifcations needed to transform the NA-83 into a dive-bomber.
The necessary changes include strengthening the wing to carry the additional load of bombs and dive brakes, as well as designing the dive brakes.
Mustang Mk I
AG346 is the first Mustang Mk. I which is shipped to Britain.
After arriving in Liverpool, it is transported by road to Speke, is uncrated and assembled by No.1 Aircraft Assembly Unit.
It is now ready to begin Service Trials by the Aeroplane and Armament Experimental Establishment (A&AEE) at Boscombe Down, Wiltshire.
Mustang Mk I
Allison informs NAA about its new “high-altitude” engine, with an auxiliary second-stage supercharger attached to the V-1710 basic design.
Kindelberger requests a design study to get a grasp of the changes required to the NA-73/83 airframe to accommodate the new engine.
Britain's first Mustang Mk. I AG346 makes its first flight in the UK.
The commander of the Air Fighting Development Unit (AFDU) describes the airplane as an "...excellent low- and medium-altitude fighter ... pleasant to fly ... extremely stable ... far smoother in all manoeuvres than the Spitfire". Other test pilots said the Mustang is "...definitely the best American fighter yet that has reached Great Britain".
Mustang Mk I
In late November/early December, pilots from the 79th Pursuit Squadron (PS)/20th Pursuit Group (PG) of the 4th Interceptor Command are allowed to fly a P-51.
They fly it against a P-38D, P-40E and a Vultee P-66.
Commander of the 20th PS at that time was Col. Ira Eaker.
Rice responds that only the two-speed F11 or single-speed F3R are suitable for installation in the NA-73/83 without major design changes to the wing and fuselage to accommodate the altered center of gravity.
Along with the Curtiss Kittyhawk, the Mustang is shown to the British press at Liverpool’s Spekes Airport.
The US officially enters World War 2 following the attack on Pearl Harbor by Japan.
After reading the report of the test flights by the 20th PS pilots, Col. Ira Eaker flies from Hamilton Field to visit the NAA plant at Inglewood.
He flies the XP-51 and expresses great admiration for its handling qualities and speed.
He subsequently calls Arnold and recommends that he visits NAA to inspect the P-51 personally.
The second XP-51 is delivered at Wright Field.
Testing of XP-51 41-038 continues at Wright Field.
Materiel Command issues a report with several comments on the XP-51. Those comments include:
- improved forward view with the new flat windscreen
- issues with engine surges during high-speed dives (already known to NAA)
- the canopy layout made it difficult to open in flight
- a tendency for the right gear fairing to try to open during flight
- issues with right gear full extension at temperatures below freezing
- binding/scarring of the main right gear door oleo strut and an adjacent wing rib.
The issues with the right gear were probably caused by an extraordinarily bad landing by Capt. Lee on November 26th, which damaged the right main gear and destroyed the tailwheel and lower rudder surface.
Following that landing, the Mustang was inspected by NAA Structures and was deemed safe.
Maj. Ralph P. Swofford at Wright Field remarked that all pilots who flew the Mustang were favorably impressed with its performance and handling characteristics.
XP-51 41-039 is flown to test any improvements when installing the Allison V-1710-61. The Mustang is flown in a normal combat configuration and with its gun ports taped.
Multiple speed runs are made to evaluate the critical altitudes and top speed averages.
Results showed an improvement in critical altitude from 13,000ft to 16,300ft and an increase in top speed from 370mph to 383mph.
Chilton makes first testflight of Mustang Mk. I AG347 equipped with extended-range wing fuel kits.
Mustang Mk I
Pilots of the 79th Pursuit Squadron write their report on the XP-51 comparison test flight against the P-38D, P-40E and P-66 which they made in December 1941.
The report is forwarded to Gen. Ord Ryan, CO of 4th Interceptor Command, who attached it to a letter addressed to "Chief, Air Corps", which is Gen. "Hap" Arnold.
Ryan’s letter to Arnold is sent approximately three weeks after Col. Ira Eaker flew the Mustang during a visit to NAA, on his way to HQ-AAF for his VIII Bomber Command assignment. Eaker states: “I thought that the Mustang was the best fighter that I had flown. It was somewhat underpowered, but I knew it was possible to correct that with bigger engines coming along.”
He later mentions his impression of the Mustang when he arrives at HQ-AAF to meet with Spaatz. The latter notifies Eaker that he will be made CO of VIII Bomber Command.
USAAF ordered 1,050 P-47Ds and 354 P-47Gs.
After receiving the Mustang report earlier this month from Gen Ryan, Arnold and Spaatz visit NAA and come to the conclusion that “the Air Force should have P-51s.”
NAA completes Report NA-1778-A “Design Data Ground Attack Airplane”.
Basis for the report was a NA-73 Mustang, modified with Vultee-supplied A-31 dive brakes and 20mm armament from the NA-91 design.
The engine used was a single-speed, single-stage Allison V-1710-87.
Mustang Mark I production and deliveries continued.
No. 26 Squadron based at RAF Lympne becomes the first operational squadron to receive Mustang Mark I airplanes. Most of these have an F24 camera installed aft of the pilot’s seat for armed reconnaissance with the Army Cooperation Command.
The RAF accepts 84 Mustang Mark Is during this month.
Mustang Mk I
Kindelberger sends a letter to Wright Field.
Subject of the letter is: "Production of P-51 Mustang Fighter Airplanes".
Kindelberger expressed his concerns of what would follow NAA's current Mustang contracts: "...a total of 620 airplanes had been ordered by the RAF at this time. Under the Defense Aid program, 150 additional were ordered by the Army, making a total of 770 aircraft ... approximately 220 airplanes had been delivered and that the production rate is now 78 airplanes per month. Starting about March 1, the production rate will be 104 per month. At this rate the fighters will all be delivered by August 1942 and no additional orders have been indicated.
If production was not extended, the P-51 tooling would be stored and manufacturing capacity would be diverted to the B-25."
The USAAF abandones the production plans for the P-60A because they do not want to interrupt the P-40 production program.
Instead, they want Curtiss to build 1,400 more P-40s and introduce the P-47 on their production line.
NAA is still getting no progress with Allison regarding better engines and are looking for alternatives.
Schmued draws preliminary engineering and profile drawing D-111 for the Continental V-3420 “X” engine.
Rice’s team start an analysis for the increased intercooler requirements and airframe changes needed for the extreme forward center of gravity.
Col. K.B. Wolfe, Assistant Chief, USAAF-MD, Production Engineering, sends a memo to HQ-AAF, MM&D recommending cancellation of the Vultee A-35 Vengeance dive-bomber.
They continue to seek a “low altitude, dive bomber-capable, attack fighter to meet Directive – Close Air Support requirements.
U-boat U-108 sinks the British freighter "Ocean Venture" off Cape Hatteras, Virginia, killing most of its crew and destroying the twelve Mustang Mark Is it was transporting.
Fourteen survivors are rescued the following day. In another U-boat attack just a few days later, yet a further eight Mustang Mark I airplanes would be lost.
RAF Chief of General Staff of the British Army asks for the re-equipment of Army Co-operations Command squadrons with Mustangs.
Those Mustangs should be equipped with oblique and vertical cameras.
NA-83 AL958 makes its first test flight, with Chilton at the controls.
Gen. Arnold holds a Fighter Conference with the Air Staff to discuss priorities for delivery of a long-range escort fighter to accompany heavy bombardment aircraft to their assigned targets.
The Air Staff continues to offer development of a twin-engined fighter as the best solution, with possible “bomber convoy escort to be investigated.”
Increasing the internal fuel capacity of fighters, and development of pressurized, high-altitude-capable, external combat tanks also emerge as the highest priorities.
On an update to examine the installation of the Continental engine in the Mustang, Rice writes to Atwood: “Cooling requirements for Continental engine require far larger radiator/intercooler, significant redesign of the airframe, and unsuitable for incorporation in the Mustang.”
Atwood writes to Allison Chairman, O.K. Hunt, to once more lobby for the two-speed/single-stage supercharger in lieu of Allison’s proposed two-speed/two-stage supercharged V-1710-45, because the latter's extra lenght can not be installed in the NA-73 airframe without moving the wing further forward to accommodate the extra nose length from the firewall to the propeller.
Packard receives design drawings for the Rolls-Royce Series 60 Merlin two-speed/two-stage supercharger.
Packard designates it the Packard Merlin V-1650-3.
The USAAF states the need for a very fast fighter and attack bomber to perform both close air support and tactical reconnaissance missions, equipped with cameras.
In mid-february, Brig Gen. Fairchild proposes the Mustang as the USAAF battlefield fighter for CAS.
Following the armament/gun charging tests at Eglin Field, the USAAF sends XP-51 41-038 to the Langley Field NACA facility in Virginia where it is turned over for its flight test evaluations.
Lockheed deliveres the first P-38F. It also concludes testing of external racks, pylons and internal plumbing for 165gal and 310gal ferry tanks.
The USAAF also accepts the first production P-47B.
R.C. Costello receives a report from Rice detailing the primary differences between the NA-73 and the NA-83:
- the addition of flame dampening exhausts
- a redesigned windshield assembly
- changing from the Air Research radiator to a Harrison-designed radiator
- changing the forward coolant scoop fairing air scoop (which is not interchangeable with the NA-73)
- addition of the N-1 gun camera to replace the W-7B
- redesigned hydraulic and fuel lines
- elimination of the wing-mounted floodlights.
In a bid to increase the ferry range of its fighters, Gen. Bennett Myers, Chief Fighter Procurement, Materiel Division, proposes that:
- the P-38E is modified to carry 175gal tanks
- that the P-47 carry two 100gal and one 410gal external tanks to increase ferry range to 3,000 miles.
Although the P-38E/F could already carry two 310gal ferry tanks when this request was made, the P-47D-15, delivered to the Eighth in January of 1944, was the first production version of the Thunderbolt capable of having wing pylons and plumbing from external fuel tanks to the engine installed.
At that stage of the war, fighters were still not allowed to carry ferry tanks for combat operations.
NAA issued contract AC-27396 for 500 A-36 dive-bombers.
Charge number NA-97 is opened for project accounting.
Production engineering begins to transform the NA-83 airframe and the Vultee company is contacted for permission to use their A-31 dive brake design.
Work begins swiftly in the NAA Experimental Department on NA-83 AM118, which will serve as the test bed for the A-36.
NAA plans to produce its 500 A-36As during the last three months of 1942 and the first two months of 1943.
No other Mustangs will be built during this time frame.
Up till now (not counting the NA-73X prototype), NAA has built 1,272 Mustangs.
Rolls-Royce chief test pilot, Ronald T. ‘Ronnie’ Harker, makes a test hop in an Allison-powered Mustang Mark I (RAF serial number AG422) at RAF Duxford in Great Britain.
He was intrigued by reports coming from other RAF units and pilots familiar with the Allison-powered Mustang.
Upon landing, he is very pleased with the Mustang's performance, but also noticed the lack of power above 15,000ft. He suggests that it would perform way better at altitude if a Merlin 61 was installed in the Mustang.
First test flight of the NA-83 AM118 with dive brakes installed. That this test flight is already done at this date shows the advanced stage of design and fabrication that had already been reached before the contract was issued.
Harker sends a letter to Rolls-Royce to suggest the installation of a Merlin 61 in the Mustang
First Mustang Mk. I combat sorties start with Army Co-operation Command’s No.26 Squadron.
Informal discussions begin between NAA and Material Command regarding the intent to acquire the Mustang IA as a replacement for the P-39 for the tactical reconnaissance role.
Estimates are made to install a Merlin engine of unspecified type into a Mustang airframe.
RAF No. 2 Squadron is the first to fly the Mustang Mark I into battle when RAF Flight Officer Graham Newstead Dawson flies a solo tactical reconnaissance mission over northern France.
Following Harker’s suggestion, Rolls-Royce general manager Ernest Walter Hives sends a secret memo to the British Air proposing the installation of several Merlin engines in Mustang Mark I airplanes for flight test evaluations.
The USAAF speeds up its desire to acquire Mustang IA for the CAS and reconnaissance roles.
It also states a priority for the first Packard Merlin 1650-3 engines for test purposes.
Rice and Atwood conclude that the Merlin Mustang project would advance faster if it is specified as a “modification” rather than a new design which will be burdened by Material Command’s specification cycle.
The Merlin program is first referred to as the XP-78.
An agreement is reached to set aside two P-51-NA airframes (41-37352 and 41-37421) for the Merlin Mustang conversion
Col. John Sessums, Fighter Projects Officer, Material Command, calls Atwood to inform him that the first two production Packard Merlin 1650-3s will be delivered to NAA following bench tests at Wright Field.
The USAAF decided to acquire 57 NA-91s of the 150 scheduled for delivery as Mustang Ias for the RAF.
They are redesignated P-51-NA.
The decision to install a vertical and oblique camera in the new P-51s is made. Those Mustangs are redesignated F-6As.
The eighth production P-51, 41-37327, is modified in the Experimental Department with a K-24 camera.
In the UK, NA-73 AG518 is the Mustang Mk. I to be allocated to Rolls-Royce for the Merlin program, which the British name the Merlin X.
AG518 would never be converted.
AM121, a NA-83 Mustang, takes its place as the first to be converted.
Louis Wait flies NA-91 P-51-NA 41-37320 for the first time.
Chilton starts bomb-dropping trials with AM118.
Bob Chilton completes a successful test flight in the first US P-51 Mustang (USAAF serial number 41-37320, RAF serial number FD418) from Mines Field. This Mustang will be retained by the USAAF and will have two F-24 cameras installed.
It is later redesignated P-51-1-NA and will go on to serve as the prototype F-6 tactical reconnaissance version of the Mustang.
The RAF would designate these aircraft as Mustang Mk. IAs.
Chilton also performs dive brake tests on a modified NA-73, the first one built for the upcoming A-36 program.
NAA increases design work on the Merlin modification:
- to meet the higher pressure by the two-speed/two-stage supercharged Merlin, a complete redesign of the coolant system is necessary
- the carburator intake duct needs to be moved beneath the engine for the Merlin updraft design.
- a new four-bladed Hamilton Standard propeller will be used
- additional structural changes are needed to meet the additional loads imposed by the increased aileron throws and the extra 350lb weight of the Merlin
The BAC formally requests that NAA should install Malcolm Hoods on all Mustangs destined for the RAF.
The Directorate of Air-Ground Support further clarifies the selection of 57 of the 150 Mustang IAs:
- the first 20 are destined for the USAAF
- 35 will be used for assignment to Training Command for crew training in preparation for A-36 deliveries
- 2 are assigned to the construction of the NA-101 XP-78.
The first 20 are to be modified as F-6A reconnaissance versions.
One will be sent to the Air Proving Ground at Eglin Field for performance trials.
The block of P-51-NAs modified to carry only the oblique camera (the vertical camera installation being deemed unsatisfactory) are designated P-51-2-NAs at the Memphis Depot.
20mm cannon firing tests using NA-83 AM190 start in an effort to improve both the fairings and belt feed chutes for the NA-91 P-51.
In the UK, the Hucknall drawing office devotes its time assessing the changes required to install the Merlin 61.
The first P-51-NA, 41-37327, was delivered to USAAF Palm Springs by Chilton.
The USAAF Materiel Command authorized its own Merlin engine-powered project after witnessing the most promising Rolls-Royce efforts in Great Britain. With this, it issued the designation MX-278 to the secret project and ordered two prototypes designated XP-78 (MX meaning Materiel, Experimental).
Hucknalls drawing office releases design engineering drawings for the new hybrid Mustang X.
Fabrication of the cowling, engine mounts, the engine aftercooling system, etc., begins shortly hereafter.
One very distinct difference between NAA and the Rolls-Royce design team’s approach to the installation of the Merlin is the placement of the intercooler radiator under the engine, in the same space as the carburetor intake.
NAA design combines the intercooler with the engine radiator into the same radiator frame (square).
the Rolls-Royce team keeps the “donut’ combination of engine radiator surrounding the oil cooler matrix, similar to the existing Mustang I (round) design. The result is “P-40-type” lower cowl, adding extra drag to the Mustang X.
Rice sends a memo to Brig. Gen. Charles E. Branshaw at Materiel Command citing a major improvement in roll performance due to the 50 percent increase in aileron movement, plus the internal seal balance being tested.
These features will be incorporated starting with the XP-78.
NAA initiates its NA-99/AC-30479 programme for the manufacture of 1200 P-51A (Mustang Mark II) airplanes in Inglewood.
Several tests with AL958 are flown to test new inlet scoop geometry for pressure distribution in front of the radiator and oil cooler of the new A-36 coolant system.
Following these tests the adjustable alligator scoop is discarded for the A-36 and all subsequent Mustang models.
The BAC follows up on the Malcolm Hood request with further details.
NAA analyzes the requirements and the design, and decides that the Malcolm Hood is an interim solution to the various options already being discussed, namely a sliding canopy similar to that of the Mitsubishi A6M or a bubble/teardrop canopy of clear Plexiglas.
In either case the modifications require a complete redesign of the rear upper fuselage deck to permit the necessary aft travel of the canopy.
The first conceptual “Packard Merlin” profiles for both a wind tunnel model and sliding-canopy version of the aircraft already began in June and will be completed in July and September, respectively.
Using the company-owned number one NA-73 airplane, modified with A-36 type bomb shackles, Chilton performs initial seventy-five-US gallon drop tank tests.
Between July 4th and 31st, AM118, serving as the test aircraft for A-36 modifications, is used for dive-bombing trials and the first 75 gal combat tank drop tests.
NAA wind tunnel model drawing X-73-01123 “Packard Pursuit” is released for construction.
The first redesign for a “greenhouse” sliding canopy and lowered rear deck are immediately noticeable.
Col William Ball, Director of Intelligence Services, writes a letter to Kindelberger.
The subject of the letter is “Information Regarding the North American Mustang Fighter".
It contains elements of RAF Report No. 48,117: "The Mustang is considered an excellent low and medium altitude fighter, being faster than a Spitfire 5B at all altitudes up to 25,000ft. The rate of climb is inferior. At 5,000ft the Mustang is 40mph faster than the Spitfire, at 15,000ft, 35mph faster, and at 25,000ft, 1 or 2 mph faster. The Merlin engine in the Spitfire 5B delivers 950hp at 25,000ft and the Allison engine delivers only 660hp at that same altitude. The Spitfire thereby draws 290 more hp to get slightly less speed. The conclusion is inescapable that the drag of the Mustang is considerably less than that of the Spitfire. This is in spite of the fact that the Mustang weight of 8,000 pounds is considerably more than the 6,475 pounds of the Spitfire. Though the poor climb of the Mustang is a disadvantage, it is more than made up for in greater speed and dive ability. It is recommended that the Mustang be speedily equipped with the Merlin 61 engine now being used in the Spitfire IX. It is estimated by Rolls-Royce people that the Mustang equipped with the 61 engine will have a top speed of 440mph and a speed curve of somewhat more than 20mph faster than the Spitfire IX."
The formal Letter Agreement between Material Command and NAA for two P-51s to be modified to accept the Packard Merlin 1650-3 is made.
In the ETO, the very first loss of a Mustang in combat occurrs during a high-speed ground target strafing pass. As reported, this Mustang Mark I had flown straight in to the ground. The reason for this remains unclear.
Mustang Mk I
An Army Air Forces Technical Report entitled Final Report of Inspection, Performance and Acceptance of NAA Model XP-51 (Report No. 4801) is released.
For the upcoming XB-51B flight test programme, a four-bladed propeller is evaluated on a Mustang Mark I (RAF serial number AL975).
NAA starts its NA-101 programme to produce two Merlin engine-powered Mustangs
As stipulated, NAA set aside two NA-91 P-51 (Mustang Mark IA) airplanes for this project: serial numbers 41-37352 and 41-37421 (NAA factory serial numbers 91-12013 and 91-12082).
The formal contract number is AC-32073.
A letter contract for an XP-78 (Merlin Mustang) design is issued.
S.B. Gates, Technical Office, BAC, notes in a letter to Rice the “desirability of improving rate of roll at low speed by increasing aileron travel, combined change from concave cross-section of aileron to attain 45-degree bank at 400mph in 1 sec”
At that time, Rice already received the test results of XP-78s roll tests from Langley Field and was already in the midst of making modifications.
By order of Brig Gen Gordon Saville, Chief, Air Defense Directorate, P-51s 41-37323, -37324, and -37325 are dispatched to the Air Forces Proving Ground at Eglin Field to undergo Tactical Trials.
These trials are the first steps in removing certain test and evaluation tasks from Materiel Command at Wright Field.
Kindelberger requests supplementary production line funding from the Chief, Material Command, at Wright Field to accelerate delivery of the Merlin Mustang.
He also notes that it is agreeable to NAA to ship engineless Merlin Mustangs to Britain so that the RAF could install Merlin engines should priorities for Packard Merlin 1650-3s not be made available.
USAAF contract number AC 27396 is approved for the manufacture of 500 A-36A-1-NA airplanes at Inglewood.
These are NAA factory serial numbers 97-15881 to 97-16380 and will be given USAAF serial numbers 42-83663 to 42-84162.
The testing of the three P-51s sent to Eglin begins. They would continue untill November 1st.
Two P-51 airframes, 41-37352 and 37421, are released from the lend-lease contract for Merlin Mustang installation.
Gen. F.O. Carroll, Chief Experimental Engineering, Materiel Command, Wright Field, orderes the Technical Executive to “Proceed full speed on the installation of the Merlin 61 in two P-51 airplanes”
In Europe, the first aerial victory is recorded by a Mustang when a Fw 190 is shot down by a Mustang Mark I over Dieppe, France. This Mustang of No. 44 Squadron (Canadian) was flown by Pilot Officer Hollis H. Hills from Pasadena, California, who had joined the Royal Canadian Air Force prior to America’s entry into the war.
Mustang Mk. I
The USAAF contract for 500 production airplanes is officially approved.
Gen. K.B. Wolfe, Chief, Production Division, writes to Maj. Gen. Echols, Chief of Staff, Materiel Command, suggesting that NAA be awarded a contract for 400 P-51Bs, and that the P-51B Mustang be put in the Priority Preference Group.
The eighth production P-51, 41-37327, is modified in the Experimental Department to take the K-24 camera.
It is designated P-51-1-NA and is first flown on this day by Chilton.
US War Department approves USAAF contract number AC 30479 for the production of 310 P-51A airplanes in Inglewood, to be delivered in three production blocks:
P-51A-1-NA – USAAF serial numbers 43-6003 to 43-6102 (100 ac)
P-51A-5-NA – USAAF serial numbers 43-6103 to 43-6157 (55 ac)
P-51A-10-NA – USAAF serial numbers 43-6158 to 43-6312 (155 ac)
Even before the first XP-51B took to the skies, NAA starts its NA-102 programme to set into motion its P-51B-1-NA production programme at Inglewood.
Kindelberger sends a letter, hand-delivered by NAA’s Alex Burton, to Colonels Chidlaw and James Phillips, Materiel Command. Philiips in turn sends Chidlaw a memo stating “the first flight of XP-78 should be October 1st if Packard meets commitment to deliver two engines on September 1st”.
Enlosed in the letters to Materiel Command were the preliminary performance estimates for the XP-78.
Preliminary results from a report entitled “Tactical Employment of Mustang P-51” are released by Air Forces Proving Ground Command at Eglin Field.
In states that “The subject aircraft is the best low altitude American fighter aircraft yet developed and should be used as the criterion for comparison of subsequent types. The P-51 Mustang is the best fighter tested by this Command to date.”
Col. Chidlaw sends a letter to Brig. Gen. A.J. Lyons, Commanding General Eighth Air Force Air Technical Services, regarding the status of the XP-78, Packard 1650-3, stating “reject Griffon as too difficult to install”.
Maj. Gen. Fairchild directs Maj. Gen. Echols, “The Merlin should be introduced into the P-51 production as early as that airplane engine combination is determined practical.”
First NAA sliding-hood concept for Merlin Mustang is shown in Drawing D-12011.
The windscreen and aft section are fixed and the middle canopy travels to the rear.
First test of the balanced, sealed aileron is undertaken on AM118 by Chilton, who noted dramatic improvements in both high- and low-speed roll rates compared with the Mustang I.
XP-78 is re-designated XP-51B.
First flight of the A-36A Mustang (USAAF serial number 42-83663) by Bob Chilton.
September - October
The first P-47C-2-Res are being delivered, having the first provision for attachment of a centerline 200gal ferry tank. They become the first of the P-47 series to be sent to the ETO.
XP-51B airframe is complete and is awaiting its Packard Merlin 1650-3 to enable fitment of fuel supply system, engine controls and instrumentation
NA-103 program (contract AC-33940) is initiated to produce 350 P-51C Mustangs at its Dallas, Texas, plant.
(950 more were subsequently added to NA-103 when order NA-107 P-51D-1 was cancelled in the fall of 1943)
Lt. Col. Tommy Hitchcock writes a lengthy memo to Assistant Ambassador John Stettinius, in which he summarized: "(1) the history of the NAA Mustang as a unique joint British/NAA project independent of Materiel Command; (2) the virtues of the airframe’s performance with respect to comparisons with the Spitfire V and Fw 190 fighters; and (3) the very high level of support from Ambassador Winant and Assistant Secretary of War Robert A. Lovett, as well as very senior Air Ministry and RAF leaders to prioritize the development of the Merlin Mustang. "
He goes on to recount the extreme level of indifference from the American side, pointing to the possibility of a “not invented here” syndrome, particularly with respect to no visible champion at HQ-AAF or Materiel Command.
Rolls-Royce chief test pilot Ronald Thomas Shepherd, a former Captain in the Royal Flying Corps (RFC), makes the first flight test of a Merlin-powered Mustang, a Mustang Mark I (RAF serial number AL975/G).
The suffix ‘G’ meant that this was a top secret airplane that had to be closely guarded at all times.
Mustang Mk I
The first Packard Merlin 1650-3 is delivered to NAA on the 18th, but it fails two days later during ground tests of the installation in XP-51B 41-37352.
Following successful changes to improve both reliability and power, the 1650-3 would be the standard engine supplied with all P-51B-1s and B-5-Nas as well as the P-51C-1-NT. (the standard Packard Merlin for all Inglewood Mustang deliveries, beginning with P-51B-10-NA 42-106739 and P-51C-1-NT 42-103329 in February 1944, was the 1650-7 (equivalent to Merlin 65))
NAA charge number NA-104 is opened for the P-51B.
In Europe, German airspace is penetrated for the first time by a Mustang when four Mark I airplanes of No. 268 Squadron fly from their RAF base at Bury St. Edmunds in Great Britain into Germany and back.
These aircraft were performing tactical reconnaissance to mark future bombardment targets.
Col. D.M. Schlatter, Chief Air-Ground Support Directorate, issues a request titled “Fighter Aircraft for Observation”.
This led Brig. Gen. Gordon Saville, Chief, Air Defense Directorate, to order that all P-51 production allocations are to be for Reconnaissance and CAS units. (this would change in the fall of 1943, when Gen. Arnold intervened to redirect both P-38 and P-51B units to the ETO)
Chilton accelerates testing of A-36 41-83663 to analyze performance for the new Allison V-1710-87F21R engine.
Gen. Arnold reports to President Roosevelt that 2,200 Mustangs have been ordered.
The first flight of the second Mustang Mark X (AM208) is successfully concluded, piloted by Shepherd.
More functional testing is done for the new pitot-tube/airspeed calibration, dive-brake testing with full bomb loads, and wing de-icing for the A-36.
Brig. Gen. Gordon Saville expresses his written opinion in Fighter Conference 11/28-11/29 that he has “serious doubts that a single-engine fighter could have enough sealing gas to go to deep targets and fight”.
After the Flight Test Department had conducted ground tests of the second Packard Merlin 1650-3, Chilton performs a successful first flight with the very first Merlin engine-powered XP-51B (USAAF serial number 41-37352).
Chilton performs a functional flight test on with the XP-51B and it is deemed a complete success.
Following test flights with the XP-51B had to be aborted due to overheating.
Significant fouling of the radiator cooling tubes due to electrolytic reactions between the glycol coolant and the dissimilar metals in the Merlin cooling system are discovered.
Flights tests are suspended briefly after December 31st in order to solve the problem.
Schmued consults with the Bureau of Standards: the recommended solution is “take your radiator and slosh in some Keg Liner (a lacquer used in beer cans to isolate the metal from the beer).
Continued flight tests during December include:
- the first A-36 dive test with 1,000lb bombs and dive brakes extended for different dive angles up to 70 degrees.
- radiator scoop pressure testing
- evaluating performance variation between the current Curtiss Electric 10ft 6in. no-cuff propeller and the new Hamilton Standard 11ft 2in. cuffed Hydromatic propeller (it is concluded that the Hamilton, despite being heavier, proves to be more efficient in converting horsepower into blade thrust)
A fatal A-36 accident occurs at the Eglin Field bombing and gunnery range. A witness described the aircraft in a vertical dive “past the target” with dive brakes extended and two 1,000lb bombs “trying to get back on target to the point of being near inverted.” It was then observed to roll as if to perform a “reverse Immelmann,” followed by a violent over-control as the pilot tried to recover from the dive, whereupon the wing separated. The airframe and wing crashed in the same area. Following this accident to 43-83666, both Materiel Command and NAA investigated the crash scene and found that the separation occurred at wing station 75, the root cause being a combination of the rolling moment with dive brakes extended at near-terminal speeds, plus the acceleration loads on the wings carrying unreleased 1,000lb bombs.
After a detailed review of the structural analysis and wind tunnel data, NAA issued placard instructions in April 1944 limiting level flight speeds with extended dive brakes to 275mph at sea level and maximum bomb load to 550lb for each bomb rack.
The Commanding General of the USAAF, Henry H. “Hap” Arnold visits Inglewood.
He and a number of VIPs are treated to a special airshow flown by Chilton to demonstrate the performance of the Merlin-powered XP-51B. Just before Chilton lands, he makes a low-level, high-speed run over Mines Field runway at over 400mph leaving the general and the other guests in awe.
The sealed aileron changes are incorporated into the first production P-51B-1-NA, followed by insertion in both P-51B-5 and C-1 (and subsequent) models.
The B-5 and C-1 introduced several changes that were not interchangeable with the B-1. A notable one was to provide three attachment points per aileron, which stiffened the aileron span-wise to provide a more effective aerodynamic surface.
The A-36 testing continues with 1,000lb bombs and dive brakes extended for different dive angles up to 70 degrees.
January - February
In the last three months of 1942, and the first two months of 1943, no P-51 Mustang or Mustang Mark I/IA deliveries During those months, A-36A production was given top priority. Those were the only Mustang airplanes produced in Inglewood during this time.
NAA opens Charge Numbers NA-105, NA-105A and NA-105B.
These are for the Lightweight Mustang program.
By USAAF contract, there will be seven of these aircraft built: three XP-51Gs, two XP-51Fs and two XP-51Js. These are similar to the other Lightweight Mustang, the forthcoming P-51H, but with a number of differences. This program is classified secret by the USAAF Materiel Command and is given designation MX-356.
Testing with XP-51B continues after changes are made to the orientation of the Harrison radiator and following the introduction of the Keg Liner to protect the inner cooling tubes from chemical reactions.
The P-51A is ready to fly. Two extra days are spent in order to test instrumentation.
The second XP-51B is successfully flown by Chilton from Mines Field.
The fourth Mustang X conversion, AL963, has been modified with a dorsal fin fillet and is awaiting first flight at Duxford.
Chilton completes a successful flight of the first P-51A (43-6003) from Mines Field. It is retained for a time by NAA for ongoing evaluations while the second example (43-6004) is delivered to Wright Field. This airplane is nicknamed ‘Slick Chick’ due to its lack of installed armament.
Maj. Gen. Barney Giles, Chief, Air Staff, and Col. William E. Kepner (future CO of VIII Fighter Command) direct that teams at NAA, Lockheed and Republic study solutions to create added fuel capacity for both the wings and fuselage.
NAA had already been thinking about this in 1941, with the idea of auxiliary ammuniation/gun-bay fuel tank kits. This was deemed impractical, so wing locations were considered a no-go.
The Merlin 61 sent by Rolls-Royce to Wright Field for bench tests is transported to NAA so that the company can consider differences in installation between the 1650-3 and the Merlin 61.
Two related actions are initiated to drive the development of external combat tanks pressurized for high altitude:
- Gen Chidlaw, Assistant Chief, Air Staff, Materiel Division, queries the Materiel Center regarding the status of self-sealing combat tanks
- He requests that provision for external leak-proof combat tanks be a design requirement for all current fighters
Combined, these directives from HQ-AAF and Materiel Command reversed pre-WWII restrictions prohibiting the attachment of external fuel tanks to combat aircraft.
In the ETO, only short-range Spitfires are currently providing fighter cover for bombers, but they could only go as far as mid-France. The longer range P-47C-2 will not be operational for another two months.
The contract for the P-51D is executed as NA-106 AC-30479.
Shortly after, the same Mustang is announced to be built in Dallas as NA-107 P-51E.
Introducing the bubble canopy into production is deemed too far in the future for inclusion in the first block of P-51Ds.
The initial plan is to insert this configuration at aircraft 43-6713 (No.401), and build the rest as NA-106 P-51Ds with the new wing.
The Dallas P-51E, with the same configuration, is to start at 42-103379 (No. 351 of the old NA-103 contract). This is later changed to 43-6913.
Continuing efforts are made to solve the “rumble” and loud “banging/vibration” noises emanating from below the cockpit in the XP-51B.
A single A-36A airplane (42-83685) is delivered to Great Britain for evaluations by the RAF and is given RAF serial number EW998.
Also, more importantly, combat operations for the A-36A begin in North Africa.
Materiel Command approves the first purchase order for Materiel Change Request C-258 to the NA-102 P-51B-1-NA Specification.
MCR C-258-1 provides the authority to start on the “Cockpit Enclosure – Sliding P-51D) Bubble Canopy” for the NA-106 P-51D-NA airframe.
Three-View General Arrangement drawing 106-00001 is released, showing both the bubble canopy and the increased aileron movement of +/- 10,12 and 15 degrees.
March 9th & 11th
Chilton flies XP-51B No. 2 41-37421.
After the latter test flight, NAA dismantles the aircraft and ships it, minus its propeller, to NACA’s Moffet Field full-scale Ames wind tunnel.
The root cause determined by NACA is “the resonant vibration of the coolant radiator at high speed, evidently caused by pulsation of the flow through the duct”. As a result, the lower inlet duct geometry to the oil cooler and oil cooler exit scoop are made.
This modification of the lower inlet duct geometry to the oil cooler and the oil cooler exit scoop improves the bypass air below the oil cooler. These improvements are achieved by dividing the intake plenum by extending the upper oil cooler plenum surface all the way to the front scoop.
The first attempt at lowering the upper scoop lip further from the wing to create a boundary-layer bypass gutter between the wing and scoop further improves the situation, but does not completely solve the problem.
Additionally, changes to increase and decrease the area of the radiator rear scoop are tried. Several configuration changes eventually solve the “rumble/vibration” phenomenon, but result in either too much drag or too little cooling efficiencies in climb configuration.
Project Change Order C-258, states “Covers design of a sliding enclosure to replace the hinged canopy. As the enclosure will consist entirely of an external canopy fairing, this change includes reduction in height and re-fairing of the fuselage from the cockpit aft”.
USAAF Dive Bomber Evaluation Board issues a final report of the “Proceedings of a Board of Officers for the Purpose of Evaluating Current Dive Bombers Now in Production”.
The title P-51D and P-51E is removed from the 106-9000002 Title Block and replaced by P-51D.
The first production P-51B-1-NA airframe (43-12093) is completed (before any changes to the radiator inlet scoop arising from the wind tunnel experiments were finalized).
In C-258 project logs, it is noted that the engineering for Cockpit Enclosure-Sliding (P-51D) is complete.
April 8th - 10th
After shop modifications based on feedback from Horkey and Ashkenas from tests of XP-51B No.2 at Ames, final changes are made to the scoop inlet geometry that were then tested by Chilton on XP-51B No.1.
The rumble issue is finally solved.
The first USAAF Mustang, a P-51-2-NA (41-37328 later designated F-6A), is used in combat in the MTO.
It is flown by Lt Alfred Schwab of 12th Air Force, 68th Observation Group, 154th Observation Squadron, based in North Africa. He fllies a tactical reconnaissance sortie over Tunisia.
NAA opens charge number NA-107.
This is a cancelled production program where 950 P-51Cs were to be built in Dallas, Texas.
These airplanes are built however under NA-103 in Dallas
Design NA-109 for the P-51D-5-NA is executed on April 13th.
The new block is virtually identical to the P-51D and P-51D-1, except that many of the parts and subassemblies are NA-106 and new NA-109 designs, with fewer residual NA-102 and NA-104 parts.
The USAAF issues a Letter of Intent to procure 2000 NA-109s. This is later augmented to 2500.
Charge Number NA-111 for the last block of 400 P-51C-10-NTs and the 600 P-51D-5-NTs is executed.
The Australian contract for 100 P-51D kits plus one completed P-51D-5-NA is executed .
NAA charge number NA-110 commences for the Australian Government that wants to procure 100 P-51D airplanes.
NAA charge number NA-126 originates for the P-51H Lightweight Mustang.
It calls for the production of three XP-51F and two XP-51Gs.
NAA assigns its NA-106 Charge Number to the P-51D program.
Two P-51B-10-NA airplanes (42-106539 and 42-106540) are set aside for modification to the P-51D configuration.
NAA charge number NA-111 originates.
The P-51E is to be the Dallas-built P-51D, but these will become NA-111 P-51Ks.
The first production P-51B-1-NA (43-12093) is flight tested at Mines Field. It is subsequently ferried to Wright Field where it establishes official Merlin-powered P-51B performance figures.
Experiments with the carburetor intake continue on airframe 41-37421.
It is moved back to a position ahead of the wing under the Merlin 1650-3 carburator and flush with the cowl.
It has its four 20mm cannon reinstalled to match the configuration of 41-37352 and both are delivered to the USAAF on May 12th.
NAA opens charge number NA-112.
This later results in a canceled order for 2000 P-51Ds to be built at Inglewood.
It will be transferred to the NA-109 program.
XP-51B 41-37421 subsequently has the four 20mm cannon reinstalled to match the configuration in 41-37352, and both are delivered to the USAAF.
41-37352 is sent to Eglin Field and then to Wright Field for testing, and it remains at the latter location until June 1944, when it is assigned to the 340th AAF Base Unit (AAFBU), Combat Crew Training School, at Bartow, then Hillsborough Field, both in Florida. The aircraft will be surveyed on July 28th ,1944.
41-37421 is assigned to Eglin Field, returns to NAA for modifications and flight tests, and is then sent to Wright Field in August of 1943. In June 1944 it is assigned to the 2000th AAFBU, Air Training Command, where the fighter remains until mid- September 1945. After serving for two months at the 3502nd AAFBU (Technical School, Air Training Command) in Chanute Field, Illinois, it is surveyed on August 2nd, 1946.
P-51D mockup work begins.
The first of two XP-51B airplanes (41-37352) is ferried to Wright Field for additional evaluations.
Packard-Merlin can not keep up the production of its engines with the number of aircraft being produced.
Materiel Command makes this situation worse by 2 actions:
- it approves Air Services Commands request for a block of spare parts for the Packard Merlin 1650-1 engine.
- by adding 3,000 more Merlin 1650-1 engines and spares for FY44.
The shortage of Merlin 1650-3 deliveries owing to the shift in production priority to spare parts for the 1650-1 costs an immediate 100 Packard Merlin 1650-3 engines destined for the P-51B, starting in March.
As a result, NAA is forced to push the delivery date for the 100th aircraft forward nearly 60 days into June.
The order by Materiel Command was revoked when Col. John Sessums sends a letter to Echols, reminding him that the shift in priorities to the 1650-1, as he authorized, would cost 1,200 engines for the P-51B.
Design NA-107 is executed for the P-51 manufacturing plant in Dallas.
It is basically the same aircraft as the P-51D-NA scheduled for Inglewood, but is give designation P-51D-1-NT.
Many changes to the schedule and configuration of the P-51D lead to consolidation of NA-107 funding and its relocation to NA-103 and NA-104 and, possibly, NA-110 for the Australian contract.
Sometime in July, references to both NA-107 and P-51E will be removed as the funding for NA-106 is reduced to two P-51Ds, and funding from NA-106 and NA-107 is redistributed to NA-103 and NA-104.
The 27th and 86th Fighter-Bomber Group, equipped with the A-36A, initiate attacks upon German and Italian air bases in Italy for the first time. This is the first operational A-36A mission.
NAA starts its NA-105 programme to build seven Lightweight Mustang prototypes: three XP-51Fs (43-43332/-43334), two XP-51Gs (43-43335 and 43-43336) and two XP-51Js (43-7027 and 43-76028).
Two of these airplanes are cancelled and are temporarily assigned USAAF serial numbers 43-43337 and 43-43338 (believed to be two cancelled XP-51Hs or XP-51Js)
Regarding the situation with the Packard-Merlin engine production, Echols sends a letter to Arnold in which he states that the ultimate effect of the Packard strike on the production of Merlin 1650-3s is estimated at 600,000 hours lost, and a loss of 240 two-speed/single-stage (1650-1) and 100 two-speed/two-stage (1650-3) engines scheduled for delivery that month.
The lack of Merlin 1650-3 priority allocation and the Packard strike are the most important factors delaying the introduction of the Merlin Mustang into combat operations from as early as September 1943 to the beginning of October 1943.
Maybe the 14 October Schweinfurt raid would have ended differently if P-51B Mustangs would have been delivered to the ETO by then?
Further consequences are the delayed formation of the Mustang-equipped 363rd and 357th FGs from mid-December to mid-February.
The 4th, 352nd and 355th FGs will also not be equipped with Mustangs before “Big Week”.
Australia issues Provisional Specification No.4/43 (DTS 382/43) for the P-51E-1-NT, NAA model NA-107.
The specification evolved from the six-gun/birdcage P-51D but was modified to specify one 20mm cannon and one 0.50cal guns as wing armament, then changes again to agree to the NA-109 specs.
First mention in project log C-258 for P-51B-1-NA modification as C-258-2 “Rework P-51B-1-NA ship No.10 (43-12102), Installation of Sliding enclosure."
It also states the tasks required to complete the installation of the cockpit enclosure, namely: A new enclosure being developed to provide rear vision for the pilot. This involves a complete change in structure above the upper longeron from the firewall aft to the empennage fillet, with a new windshield and a one-piece Plexiglas canopy with a travel of about 22in. This necessitates removal of the radio equipment and some changes to the electrical system, and relocation of propeller anti-icing tank.
Regarding the long-range fuel task force, Gen. Arnold writes to Maj. Gen. Giles, saying, in part: "This brings to mind very clearly the absolute necessity for building a fighter airplane that can go in and out with the bombers. Moreover, this fighter has to go into Germany. Perhaps we can modify some existing type to do the job. The P-38 has been doing a fine job from North Africa in escorting our B-17s 400 hundred miles or so. Whether this airplane can furnish the same escort against the GAF (German Air Forc)] on the Western Front is debatable. Our fighter people in the UK claim they can’t stay with the bombers because they are too slow (in cruise mode) and because they (the fighter escort) must have top speed by the time they hit the bombers. The P-38 is not notable for great acceleration, so perhaps it too will not be able to meet the FW’s and 109’s. About six months remains before deep penetrations of Germany begin. Within this next six months, you have got to get a fighter that can protect our bombers. Whether you use an existing type or have to start from scratch is your problem. Get to work on this right way because in January, ’44, I want a fighter escort for our bombers from the UK into Germany."
NAA’s Field Service News note that improved self-sealing fuel cells will be installed in every P-51B.
The last Allison Mustang, P-51A-10-NA 43-6312 is completed.
The P-51A contract was originally for 1,200 aircraft, but this was changed after P-51A No. 350 so that funds could be shifted to 400 NA-102 P-51B-1-NAs in October of 1942
The remainder went into NA-104 P-51B-5-NAs.
Gen. Fairchild publishes the Fighter Airplane Range Extension Program (FAREP) report, which directs the fighter manufacturers to provide maximum fuel internally. In summary, the report and recommendations focus on extending the combat radius of fighters, contemplating that only remaining internal fuel is useful for combat and return home after external tanks have been jettisoned.
C-258 entry states “Cockpit Enclosure – Sliding (P-51D). Rel. Sched. Rev. to work required on ships Nos. 1-600 for old type enclosure for Inglewood Drawing Release P-51D, Nos. 1-600 original type enclosures.
Gen .Giles sends a telex to NAA, Lockheed and Republic stating, “Provide maximum combat range at earliest possible time”.
Lockheed advises that two 55gal fuel tanks can be installed in the wing leading edges of the P-38J: “Estimate four months to complete installation in 100 aircraft”.
Materiel Command telexes Rice at NAA: “Request additional tankage for fighter airplane. Dimensions 54”x25”x16”
NAA Representative Hellman sends a memo to Rice: “Telephone conversation with Col. Bradley, Maj. Price and Maj. Towner. Action immediately on calculating the aft CG travel. They very desirous of having a test flight made, also desire feasibility of making changes to service airplanes.”
P-51B-1-NA 43-12113 is accepted by the USAAF and is given serial FX848 for the RAF.
A new design of the P-51B/C engine mount, which permits the Merlin to be removed without detaching the engine mount from the firewall is noted.
Col. M.E. Bradley, Chief, Fighter Projects, calls Gen. Echols to report the dangerous flight characteristics of the XP-75 and recommends that the focus be directed to adding more fuel in the Mustang.
Brig. Gen. Charles E. Branshaw sends telex to NAA:
"AAFRR NAA, Inc. Inglewood, CA
PEST-T-1320, Fighter Airplanes, Extra Tankage Program Desired as Follows:
Letter follows through Requirements Division request.
Brid. Gen. Branshaw
That same day, NAA, per Materiel Command instructions, issues the following Change Orders to the P-51B-1 Specifications: “MCR C-326 Fuel Tank and Kits-85-gallon Fuselage Tank, Rework P-51B-1 43-12212 to include 93-gallon steel tank for Flight Test. Rework three more P-51B (43-12388-390) with tanks per S.O. 16591 per MCR C-326-2 and -3”.
Release of Specifications for Combat Tanks: “Aircraft equipped with combat tanks must be controllable on instruments, ratio of 75% capacity of combat tank to internal fuel capacity, must be able to extract 95% of combat tank fuel capacity at critical altitude of the fighter”.
Around this date, NAA plans an installation of the 85gal tank into P-51B-1 43-12304 in the Experimental Department for three reasons:
- to determine and document the modifications required to remove the existing radio, radio shelf, and oxygen supply, and installing the plumbing and control switch, etc.
- to coordinate the design changes between engineering and field services, additional parts fabrication, and the processes to assemble kits for future depot installation.
- to carefully document each stage of the modification work in Field Service Bulletin 73-95.
Chilton tests 43-12112 with both the new internal fuel tank and 75gal combat tanks during a 1hr 20min functional test.
Chilton makes a long-range 1,200-mile cruise test at 30,000ft with full internal fuel, simulating combat for 20 minutes at military power. His total flight time was 4hrs 45 min.
Bradley flies Mustang 43-12112 with a full load of fuel, including 75gal combat tanks and the 93gal steel fuselage tank, and a full load of ammunition, from Muroc Field to Albuquerque, New Mexico: “I took off and flew to Albuquerque at 25,000ft, simulated full power over that city for 15 minutes, and then flew back to Muroc Field with plenty of gas left."
The simulated mission to Berlin had been accomplished.
C-258-2 notes “Re-work of P-51B-1-NA ship No.10 in process Dept. 9”, and for C-258-3, “Rework NA-102 Fuselage for NA-106 Static test. Fuselage delivered to Dept. 9 on July 19.”
Both C-258-1 (P-51D) and C-258-3 (P-51D-1) are extracted from NA-102 spares assemblies for the complete base fuselage, coupled with NA-106 six-gun P-51D wings fabricated in Advanced Production (also as “separate assemblies), and assigned aircraft serial numbers 42-106539 and 42-106540 from the future P-51B-10-NA series.
The bubble canopy modification will not be included into the existing P-51B/C production lines, primarily owing to the delivery slowdown this would cause from P-51B-5-NA No.400 (43-6713, projected No. 1 for NA-106 P-51D).
NAA engineering begin production design tasks for a self-sealing 85gal-capacity fuel tank, the removal and rearrangement of existing radio, battery, and IFF to accommodate the fuel tank, a new fuel line, a five-position fuel tank cockpit selector switch, the fuel filler system, fuel gage, and extra oxygen capacity for longer range.
During flight testing of 43-12112, Change Order MCR C-348 is issued to have the 85gal tank installed also in the NA-106 and NA-109 P-51D.
This influences the bubble canopy project in Experimental Hangar 9, namely, to install the fuselage fuel tank “when available into P-51D 42-106539 and P-51D-1 42-106540.
The April 13th Letter of Intent for NA-109 is replaced by an official contract, AC-40064 for 2000 Mustangs: 800 P-51D-5-NA, 800 P-51D-10-NA and 400 P-51D-15-NA (addendum on November 3rd, 1943).
Another contract, AC 40063, is approved for the Texas plant to build 200 P-51D-5-NT airplanes (amended on November 5th, 1943)
The first P-51B-1-NA, 43-12103, is ready for K-24 camera installation at the Modicication Center as the first F-6C.
A number of A-36As fitted with 75 US gallon drop tanks escort B-26 Marauder medium bombers to targets in Italy. This is a record-setting mission for single-engine aircraft as they fly a round trip of over 800 miles.
Eaker and Emmons cable Arnold from HQ Eighth Air Force during the beginning of “Blitz Week” in the ETO to “request P-51B this theater”.
This is the first request received from top USAAF leadership to deploy the P-51B for escort duties.
NAA almost loses its chief test pilot Bob Chilton, when he and NAA flight test engineer Roy Ferrin are forced to bale out of their stricken XB-28A while flying rolling manoeuvres over the Pacific Ocean just west of Balboa, California. The airplane suffers a structural failure, but both men are rescued by the US Coast Guard.
Col. Bradley’s NAA report of flight tests of P-51B-1-NA 43-12304 fitted with fuselage and combat tanks is extremely positive.
First flight of the P-51C-1-NT.
Chilton flies 43-12112 with the production Firestone 85gal self-sealing fuselage fuel tank in place of the prototype steel test tank.
Field Services Bulletin (FSB) 73-95 is released, which will accompany all 85gal fuselage tank modifications for all P-51B-1, B-5 and C-1 Mustangs dispatched to the ETO prior to the tanks being installed during production.
Materiel Command contacts NAA to request an “immediate” change point for early P-51B-5-NA production, but this is deemed to be impossible by the company without significant delay in the construction of the P-51B-5 and C-5. Accordingly, the change point is set for the first P-51B-10, which is the major reason for the block change.
Materiel Command issues Order NA-117 for the production of 3,500 P-51Hs.
The order is based on performance projections for the XP-51G with the R.M. 14 S.M. engine (an extension of the Rolls-Royce Merlin 100).
NAA cancels the production program and transfers it to the P-51H NA-126 program.
The first P-51C-1-NT (42-102979) is delivered from Dallas plant to the USAAF.
It will remain there for testing until November 1st
Fighter Branch Engineering Section recommends that NAA not continue seeking additional fuel capacity in the P-51B wing, specifying “Fuselage tank only”.
Gen A. E. Jones, Chief, Procurement Division, Materiel Command, by order of Brig Gen Branshaw, issues instructions to "provide three P-51B aircraft with hand-made 85 gal fuselage tanks to AAFSAT [AAF School of Applied Tactics] for Flight Testing,” plus “install 55 gal tank for P-51D-1 aircraft at the factory prior to delivery”.
The latter instruction is later amended to 85 gal tank.
The order also confirms previously issued Materiel Change Request C-348 for NA-102 for P-51B-1-NAs 43-12388,-12389, and-12390.
The instructions also provide for a “Purchase Order for fabrication of 800 kits to be furnished for P-51B-1, P-51B-5, and P-51C-1.
FSB 73-95 is revised several times to reflect the progressive reduction in total labor requirements from 450hrs to 150hrs, as the last block of P-51B-5s and C-1s roll off the assembly line with most of the infrastructure for incorporation of the fuselage fuel tank already included.
Ultimately, 1600 kits are contracted to provide for all P-51B-1s and P-51B-5-NAs, P-51C-1s, and the first 50 P-51C-5-NTs.
Chilton flies 43-12304 with an 85gal production self-sealing fuselage tank installed to begin stability testing before 43-12388, -12389 and -12390 are scheduled to arrive at Eglin for further testing.
The P-51A enters service with the 14th Air Force in China. The P-51As primarily serve as fighter-bombers but also as bomber escorts while they are based in China.
Brig. Gen. Branshaw sends another cable to NAA ordering “convert Packard Merlin 1650-3 to -7 as soon as possible. Packard to produce supercharger kits as required in the field”
Experimental Department project logs note C-258-1 (P-51D-1) and C-258-2 (P-51B-1) are reworked to prepare for flight tests.
NAA Engineering states they are 10% complete for addition of the 85gal fuse tank.
In the bubble canopy modification project, P-51B-1 43-12102 (C-258-2) is closer to completion than P-51D-1 42-106539 (C-258-1) because the 85gal fuselage tank installation has just begun for the D-model Mustang but is not necessary for 43-12102.
Important Change Orders incorporated on the NA-102 fuselages: they include dropping the firewall slightly to accommodate the new P-51D windscreen assembly, as well as modifying the leading edge of the wing between station 61 and the fuselage with a new sub-spar to accommodate the new landing gear well and wheel door.
Additionally the six 0.50cal AN/M2 machine guns are installed in the upright position, rather than using the slanted design which originated in the A-36.
Col W. M. Morgan, Acting Chief, Production, Materiel Command, approves funding for the internal pressurization system to support combat tank pressurization independent of “B-12 Vacuum Pump” if "possible.”
He also instructs NAA to assemble kits and incorporate into the production of all Mustangs the external fuel tank pressurization system "per NAA Drawing 102-948008.”
Planned insertion point for production is P-51B-5 (No. 400) 43-6713, but this is later changed to 43-6913.
NAA completes engineering for the 104-48013 “Equipment Installation - Fuse. Fuel Tank,”
The system will be inserted into the P-51B-10 No. 1 (43-7113) block.
Engineering on the NA-106 P-51D-1-NA’s "Installation Cockpit Enclosure” for the bubble canopy is also released to both the Production and Experimental Departments.
Allison, NAA and Materiel Command conduct a meeting at Wright Field to discuss and agree to build the XP-51J with the new Allison V-1710-119F27 two-speed/two-stage supercharger.
The first P-51B-1-NAs arrive in the ETO.
Some are diverted to the RAF, beginning with FZ100.
NAA completes engineering for the 104-48013 “Equipment Installation – Fuse. Fuel Tank”, and releases the system for insertion into P-51B-10 No.1 (43-7113) block.
Engineering on the NA-106 P-51D-1-NA’s “Installation Cockpit Enclosure” for the bubble canopy is also released to both the Production and Experimental Departments. This initiates the final bubble canopy fabrication for both the P-51D-1 and P-51B-1 as per MCR C-258-1 and -2.
Allison’s GM, K.B. Newell, writes to Brig. Gen. Branshaw, informing him of the availability of the two-speed/two-stage Allison for spring 1944, and noting that the projected capacity for Allison engines is greater than the projected production orders.
The 311th Fighter-Bomber Group (Single Engine) of the Tenth Air Force equipped with two squadrons of A-36As and one squadron of P-51As begin operations at Dinjan Airfield, India.
It is the first Mustang-equipped group to see combat against the Japanese.
P-51D No. 1 42-106539 is delivered to the flight test department.
The cockpit enclosures for both P-51B-1-NA 43-12102 and P-51D-NA 42-106539 are complete.
The P-51D is now 90% complete regarding the 85gal tank installation.
The P-51B-1 is in the Flight Test Department, being readied for its first test flight the following week.
All three bubble canopy conversions are from the same NA-106 design cockpit enclosures.
During October, the USAAF accepts a grand total of 382 Mustangs.
This is the highest one month total of deliveries since Mustang production started.
Addendum is added to the 21 July 1943 AC 40064 contract, adding 500 P-51D-15-NA airplanes to the NA-109 line.
Addendum is added to the 21 July 1943 AC 40063 contract, adding 369 P-51D-NT.
Chilton successfully completes the first flight of the P-51D prototype (a modified P-51B-1-NA 43-12102) out of Mines Field.
This Mustang has been referred to as the XP-51D, although no official documentation exists to substantiate this.
It is also believed that a second prototype P-51D (43-12101) – from another P-51B-1-NA – is also created, but again, no official documentation exists.
Chilton successfully completes the maiden flight of the first service test P-51D-NA 42-106539.
These were created from two P-51B-10-NA airplanes (42-106539 and 42-106540), the 111th and 112th P-51B-10-NA airplanes, under NAA Charge Number NA-106.
They feature the large bubble-type canopy tested earlier on a P-51B-1-NA (43-12102). They also lack the 85-gallon fuel tank and their wings are moved slightly forward.
They come with six wing-mounted .50 calibre machine guns in lieu of four, and a Type D-2 pitot tube with flush static vents in lieu of the Type G-2 airspeed tube.
At a 9th AF HQ meeting, P-51 project engineer George Gehrkens confirms the decision that “1st 75 P-51Bs will go operational without 85 gal tank, but kits are being installed at US- and UK-based Depots retroactively.”
He also reporsd that “1st UK inst'l due 1st week Dec. Sliding Balloon Hoods being manufactured for all P-51B/C in ETO".
Because of the massive stream of B-17s and P-47s arriving in the ETO, the new P-51B/C deliveries from Liverpool/ Speke are moved to BAD2 Warton for all future Mustang variants.
The first USAAF P-51B Mustangs begin to arrive in the ETO at RAF. They are initially assigned to the 9th Air Force, 354th Fighter Group.
The 357th FG of the 9th AF is second to get P-51Bs.
Chilton makes the first flight of P-51D-NA 42-106539.
On performing dive tests, things are uneventful until speeds exceeded 450-505mph true airspeed.
Chilton notes severe buffeting of the left elevator, including signs of the fabric covering ballooning. Also noted were fogging of the windscreen and the “drafty cockpit.” The left elevator fabric on 43-12102 was ruptured and had to be replaced to enable flight tests to continue. There are also vague references to the fabrication processes for the new -2 canopies introduced into the P-51D-5-NA production series first flown in January 1944, from draping over a mold to a vacuum-forming process. The results from these tests initiated a series of design and wind tunnel projects to solve the problems, which turn out not to be solely due to the bubble canopy changing the airflow over the top deck.
The solutions necessitated both a change of the horizontal stabilizer’s angle of incidence (down) and replacement of the elevator fabric covering with thin aluminum sheet.
The changes are tested by Materiel Command in the fall of 1944 and are approved for production insertion in the P-51D-20 block.
NAA issues kits for combat tank pressurization for all P-51As, all P-51Bs through 43-6712, and all P-51Cs through 42-103378. All subsequent Mustangs departing Inglewood and Dallas have the pressurization modification installed as a production feature.
Brig. Gen. Branshaw directs that all Depots install the 85gal fuselage kits.
All Mustangs receiving the fuselage fuel tank kits will be marked with a white 6in. x 6in. cross beneath the data block on the left side of the fuselage. The main reason is to identify these Mustang for the pilots, to warn them that they are to be flown with care when fully fueled due to the aft movement of the CG limit.
Some aircraft are identified by the designation P-51B-7 and C-7, but this practice is not consistent.
NAA incorporates the requested identification in the top 102-000010 drawing for the P-51B-10-NA 43-7113 and subsequent P-51C-5-NT 42-103379. In addition to the fuselage tank stencil, the first P-51B/Cs to be specified to have natural metal finish are P-51B-5-NA 43-7082 and P-51C-1-NT 42-103179, but in actual practice the olive drab/gray camouflage is continued past January 1944.
43-6913 (4th FGs future VF-T flown by Capt. Don Gentile) emerges from the Buffalo Depot. It has the 85gal fuselage tank modification, and is also the first P-51B-5-NA with the production combat tank pressurization system.
It is the first airframe of the last 200-ship P-51B-5 block and is re-identified at Buffalo as a P-51B-7-NA.
At least two P-51B-5-NA/Mustang IIIs (FZ 100 and FZ 101 ) assigned to the RAF are dispatched to R. Malcolm to have the hood installed. These are the first two so identified on their individual craft record cards, but it is probable that earlier P-51B-1-NA/Mustang III FX893 was modified with the Malcolm Hood by the RAF for service acceptance trials.
Mustang Mk. III
First P-51B-10 (43-7313, No 1 of Block One) is completed and is flown.
It is the very first complete long-range escort production Mustang to feature all the necessary change orders covering the installation of the 85gal fuselage tank, extra oxygen, new internal fuel tank pressurization, etc.
Fabrication of XP-51F 43-43332 begins in the Experimental Department.
More dive tests and six gun-firing trials are flown with 43-12102 and 42-106539.
The 354th Fighter Group of the Ninth Air Force flies its first combat sortie from RAF Boxted. On this very same day the Eighth Air Force receives its first P-51B Mustangs.
Construction of the B-25 is moved to Kansas City in 1943 to make room for an increased Mustang production at Inglewood.
The 357th Fighter Group, the Yoxford Boys of the Ninth Air Force, receives its first Mustangs.
Army Air Force Proving Ground Command Eglin Field releases Report 4-43-23-1 “Test to Determine the Effect of an Additional 85 Gallons of Internal Fuel on Performance and Handling of the P-51B Airplane.”
The flight trials on P-51B-1-NA 43-12388,-12389, and -12390 commenced on November 22nd and were concluded on December 8th.
NAA received preliminary results and USAAF recommendations in early December, and began work to design internal baffles for the 85 gal fuselage tank.
Materiel Command instructs all aircraft companies that camouflage paint should no longer be applied, effective January 1st, 1944.
On December 29-30th, the P-51D-1 is completed in Advanced Production. It comprises an NA-102 P-51B-1-NA fuselage modified with an NA-106 cockpit enclosure and bubble canopy, a revised firewall, and a six-gun wing.
The second service test P-51D-1-NA (42-106540) is accepted by the USAAF and is subsequently transferred to the 347th Army Air Forces Base Unit Combat Crew Training Squadron.
With regard to the decision to drop camouflage on all aircraft, NAA provides specific details as follows: "Both aircraft and spares to cease application of camouflage paint. External surfaces, fabric, plywood, magnesium and Dural shall require protective primers and aluminized coating.
Alclad and stainless steel shall require no covering. Anti-glare paint shall be applied on top of fuselage forward vision areas. Wing leading edges will be smoothed as outlined on P-51B/C Series Maintenance Repair Manual, Report No. NA-5742 except camouflage replaced with aluminized lacquer applied. Estimated 16 pounds weight reduction".
The decision to remove the camouflage on combat aircraft only effected NAA in the usage of paint versus aluminized lacquer to be applied as a final coat. The top and bottom surface of each wing, from the leading edge to approximately 40 percent chord was still puttied, sanded, and sealed to smooth the wing over all rivets and butt joints.
Details of a P-51B-5 empennage failure during a high-speed slow roll are relayed from Maj. Charles Krouse of VIII Air Force Service Command to Frank Lyons, NAA Field Services manager.
A variety of other problems experienced by 354th FG Mustangs are reported, which include:
- external combat tanks failing to feed at various altitudes above 20,000ft
- propellers throwing oil
- glycol reserve tank leaks spraying windshields and freezing
- cooling system overheating due to radiator corrosion, combined with leaks in the system
- radios failing
- alarming control response issues due to sloshing fuel in the 85gal tank
- poor spark plug performance
- excessive oil loss
- ammunition feed failures causing gun jams.
P-51B-1 43-12102, which was modified with a bubble canopy for tests in November 1943, is fitted with the new canopy design intended for the production P-51D-5-NA and the first example of the metal-covered elevator modifications to fix the issues discovered during dive tests two months earlier.
Contract NA-120 is executed for the XP-82 Twin Mustang very-long-range escort fighter.
US Army Air Forces Commanding General Henry H. ‘Hap’ Arnold visits NAA’s Inglewood plant to see first-hand what the ‘Twin Mustang’ was all about. His opinion was that this aircraft would be able to escort 20th Air Force B-29s on Very Long Range (VLR) missions to Japan and back.
He therefore gives NAA the ‘green light’ on its NA-120 programme and the prototype Twin Mustang program was born. Four XP-82 examples are ordered but the order is soon reduced to two examples.
The first P-51D-NA 42-106539 is lost in an accident due to a structural failure at Redondo Beach, California.
Major James H. Howard of the 356th Fighter Squadron, 354th Fighter Group 9th Air Force, whilst flying P-51B-5-NA (43-6315) (‘Ding Hao!’), single-handedly defends a stricken B-17 that was undergoing multiple attacks from Luftwaffe fighters. A former Flying Tiger, Col. Howard will be awarded the Congressional Medal of Honor on June 5th, 1944 for his valour during this mission.
The 357th Fighter Group of the 8th Air Force flies its new P-51Bs into combat for the first time.
The first production P-51D-5-NA, 44-13253 is flown by Chilton.
The kits to install baffles into the 85 gal fuselage tanks are shipped to the ETO in January, arriving at BAD2 Warton and 4th Air Depot Charmy Down later that same month.
Ongoing testing of different dorsal fin fillet modifications in an attempt to mitigate the Merlin Mustang yaw issues identified by Rolls-Royce continued at NAA.
The Office of the Assistant Chief of the Air Staff, Materiel, Maintenance and Distribution forwards a memo dated January 2nd from Materiel Command to the Technical Executive.
It notes that the installation of baffles in the 85 gal fuselage tank to prevent fore-and-aft movement of fuel, have indeed been fitted in all production tanks. The memo further stated that, in the opinion of Materiel Command, this installation sufficiently retarded the motion of fuel, and that the fitment of a longitudinal baffle would be a waste of labor and materials.
P-51B-10-NA 42-106538 (No. 110 of P-51B Block Two), immediately preceding the serial number to P-51D 42-106539, is delivered
The new P-51B dorsal fin fillet is tested by Chilton on 43-12095, which is subsequently sent to NACA Langley Field for further testing. While at Langley, 43-12095 is also used to test a modification for the new rudder fin cap.
The premier Lightweight Mustang makes its debut when Bob Chilton successfully gives the first of three XP-51F airplanes (43-43332) a one hour test hop out of Mines Field.
The first long-range bomber escort mission to Berlin and back is flown by 121 8th and 9th Air Force P-51 Mustangs. These Mustangs, in addition to eighty-six P-38s and 563 P-47s, escort 502 B-17s.
Of the 121 P-51s launched, sixteen are lost, one is damaged beyond repair and another is damaged. One pilot is KIA and another fifteen are MIA.
NAA initiates its NA-123 programme for the production of eighteen P-82B, one P-82C and one P-82D Twin Mustang aircraft. The P-82C and P-82D airplanes would be completed as radar-equipped night fighter aircraft while the P-82B would serve as long-range fighter aircraft.
Several significant problems are encountered with the P-51B. The most serious are structural failures of the empennage, wing and engine mounts. All aircraft are grounded between March 10 and 15th.
Chilton makes several important test flights in 43-12105 and 43-12102. The P-51B-1 43-12095 had been modified with a wind tunnel-tested dorsal fin fillet and reverse rudder boost tab for flight tests beginning February 11th through March 7th. After deeming the combination beneficial, and with no attendant maneuverability issues, NAA turns 43-12095 over to the USAAF for acceptance testing. The metal elevator tests, plus the first changes to elevator incidence, are made with the bubble canopy-converted P-51B 43-12102. After March 11th this aircraft ceased to be the initial test bed for the future modification of the horizontal stabilizer and metal elevator.
NAA opens charge number NA-122.
USAAF test pilot Maj Ritchie submits "AAF Memo Report ENG-47-FR- TC2 re: Stability Tests on P-51B-1 43-12095 equipped with new DFF [dorsal fin fillet] and Reverse Rudder Boost.”
The dorsal fin fillet and reverse rudder boost reduce yaw oscillation dampening with improved stability due to hard rudder input, and improve dive stability.
NAA engineering drawings 104-25001 (P-51B/C) and 109-25001 (P-51D) for the dorsal fin fillet are released for production that week (March 31st and March 25th respectively). The P-51B dorsal fin fillet and reverse rudder boost tab are fabricated and installed on 43-12105 in early February.
Chilton begins initial trials of 100/150-octane fuel in P-51B-10-NA 43-7113. Performance testing is undertaken to determine the effects of boosting manifold pressure to 75inHg for the Packard Merlin 1650-7.
As expected, the full-throttle horsepower for the engine/ fuel combination was reduced, but the top sea-level speed and overall rate of climb at 75in. improved dramatically.
Chilton makes a run with a P-51A modified with the V-1710-F20R engine equipped with water injection.
During this same period P-51D-5-NAs 44-13255 (No. 3 ) and 44-13258 continue testing of the dorsal fin fillet design which was just released for production insertion at 44-13903 in July.
Ed Schmued files for a US patent as inventor on his design of the P-82 Twin Mustang.
Chilton flies 43-7113 to test the 100/150-octane fuel. The aircraft is found to have exceptional climb rates.
The 15th Air Force in the MTO receives its first P-51B airplanes. These are allocated to the 31st Fighter Group based in Italy.
NAA opens charge number NA-124 for a single P-51M-1-NT.
The new P-51B-10s and C-5s in natural metal finish begin to arrive in quantity from BAD2 Warton.
In April NAA release kits to be applied following Tech Order 01-60J-18 and Field Service News, dated April 8th, 1944, to install the dorsal fin fillet and the reverse rudder boost tab. These changes improve airflow past the empennage and increased rudder control input resistance, assisting the pilot in reducing rudder deflection under high loading (i.e., during a dive).
The dorsal fin fillet and reverse rudder boost tab kits begin to arrive, along with the Technical Order 01-60J-18 specifications to install the former on the P-51B/C, as well as on all P-51Ds through 44-13902.
NA-111 P-51C-10-NT dorsal fin fillets are installed during the production stage.
The first P-51D-5-NAs arrive at the Eighth Air Force’s BAD2 Warton and the Ninth Air Force’s 4th Tactical Air Depot Charmy Down in late April. A few would reach the 4th, 352nd, 354th, 355th, and 357th FGs before D-Day.
Lt Col Thomas Hitchcock perishes in a P-51B crash near Salisbury while making practice dive- bombing runs. Hitchcock was arguably one of the most, if not the most, important figures in pushing the hybrid NAA/Rolls- Royce Mustang into USAAF service.
The P-51H contract under NA-117 is reduced from 3,500 aircraft and absorbed into the NA-126 contract execution.
Although Materiel Command was very pleased with the results of the XP-51F flight tests, its future production was in jeopardy, because it was not equipped with a fuselage fuel tank.
The XP-51F, XP-51G and J were not designed structurally to allow extra fuselage fuel to be accommodated, which prevented them from having the same combat radius as either the P-51B or the new P-51D. Incorporation of the 50 gal fuselage tank into the P-51H is the major reason for its weight increase over the XP-51F and G.
Furthermore, the concept of the P-82 Twin Mustang, with its even greater range to provide escort distances for projected attacks against Japan, seems to place the XP-51F/G into the category of interceptor or middle-range escort.
When design of the P-51H began, the critical specifications were:
- range and firepower equivalent to that of the P-51D
- better maneuverability and climb rate
- higher top speeds
- reducing yaw issues
The first Commonwealth Aircraft Corporation-assembled Mustang, the Model CA-17 designated Mk.17, makes its first flight in Australia.
It was created from a previously unassembled RAF P-51D-5-NA (Mustang Mark IV).
It is allocated Royal Australian Air Force serial number A68-1001. At this time, CAC was receiving 100 crated P-51D-1-NA airplanes for its CA-17 programme. CAC built eighty production CA-17s and the twenty other NA-110 P-51Ds remained crated and unassembled to be used as spares.
First flight of the 3rd XP-51F (43-43334) is made by Chilton.
Chilton completes the first flight on XP-51F number two (44-43333).
Under USAAF contract AC 2378, NAA built 1,000 P-51D-20-NAs, 600 P-51D-20-NAs, 1,600 P-51D-25-NAs and 800 P-51D-30-NAs, for a total worth of 4,000 P-51Ds at Inglewood.
Another 1,000 P-51Ds (44-75027 to 44-76026) are ordered, but later cancelled, which most likely would have been block 30s or block 35s.
Operation Matterhorn – the strategic bombardment of Japan by B-29s – is initiated when XX Bomber Command commander, Major General Kenneth B. Wolfe, launches sixty-eight B-29s that bomb the Yawata Steel Works.
This is the first bombardment of the Japanese homeland since the Doolittle Raid on April 18th, 1942. Since the Mustang had demonstrated its long legs in Europe, it is called upon to escort the B-29s.
Some of the Mustang Mark IIIs of No. 112 Squadron are transferred to No. 249 Squadron. In a test of maximum range, after a 1,470-mile flight from a south-eastern air base in Great Britain, sixty-five Mustangs land in Russia.
The third of three XP-51F airplanes is shipped to Great Britain for RAF Fighter Command evaluations.
NA-124 is approved by USAAF with contract number AC 2400 for the manufacture of 1001 NA-124s at Dallas.
The 15th Air Force in the MTO now had four of its seven fighter groups fully equipped with Mustangs.
The RAF received 274 P-51B and 626 P-51C airplanes to complete its fleet of 900 Mustang Mark III airplanes.
The dorsal fin fillet is introduced on production Mustangs, both for the P-51C-10-NT (no. 1 of NA-111 block) and P-51D-5-NA (No 650 of N-109 block)
NAA test pilot Ed Virgin completes the first flight of the number one XP-51G (43-43335) at Mines Field.
NAA opens charge number NA-127, but is later cancelled. It had been for the production of 1400 P-51Ds. Under USAAF contract number AC 3449 it was transferred to the NA-126 (P-51H) production program.
NA-104 contract AC 2400 is amended to include additional airplanes under Fiscal Year 1945.
The computing K-14 gunsight is incorporated into P-51D-20-NA Mustangs and in all subsequent block numbers of the P-51D.
The second XP-51G (43-43336) is initially flight tested by NAA test pilot Joe Barton.
The top P-51 Mustang ace, Major George E. Preddy, Jr., is killed by friendly ground fire over Belgium.
1944 was the highest production year for the Mustang as NAA turned out no fewer than 6,900 P-51 airplanes from its Inglewood and Dallas production facilities.
RAF Flight Lieutenant A. Mercer is credited with the last confirmed kill of a Luftwaffe aircraft by an Allison-powered Mustang. He was flying a Mustang Mark IA (RAF serial number FD560) during Operation Bodenplatte near Zeist, the Netherlands, when he downed a Junkers Ju 88.
Mustang Mk. I
Captain William Arthur (Bill) Shomo, flying with the 71st Tactical Reconnaissance Group, 82nd Tactical Reconnaissance Squadron, 5th Air Force, shoots down seven Japanese aircraft in a single mission, while flying his F-6D-10-NA (44-14841) named ‘Flying Undertaker’.
Based at Hill Field, Mindoro, he is later awarded the Congressional Medal of Honor for his actions.
NAA charge number NA-138, USAAF contract AC 8387 is terminated, which originally called for the production of 629 P-51D and P-51Es to be built in Dallas.
NAA charge number NA-139 for the P-51H originates, for the production of 2500 P-51H airplanes, but is also cancelled.
The 8th Air Force had earlier set a goal to equip fifteen long-range bomber escort groups solely equipped with P-51s. That goal is met on this date.
The premier P-51H Mustang (44-64160) accomplishes a successful first flight at Inglewood with Bob Chilton at the controls.
For the first time, Iwo Jima-based 7th Fighter Command Mustangs begin operations over Japan when they fly their first Very Long Range/VLR mission escorting B-29s to Tokyo.
These P-51s shoot down twenty-one enemy aircraft with the loss of only one Mustang. There will be numerous subsequent escort missions for the B-29s from the captured islands of Guam, Saipan and Tinian. The B-29s also navigate for the Mustangs before late model P-51D-30-NT Mustangs were fitted with the much improved Uncle Dog/Brother Agate navigation system featuring twin radio antennas.
The Uncle Dog/Brother Agate antennas work in conjunction with the four-channel SCR-522 ultra-high frequency (UHF) radio.
Newly acquired P-51 Mustangs 15th Fighter Group begin to arrive on Iwo Jima on March 6th, 1945 when the commander of 7th Fighter Command, Brigadier General Ernest M. ‘Mickey’ Moore, lands the first Mustang on the island.
The Sunsetters, as 7th FC was nicknamed, will add two more groups later on.
The 21st Fighter Group, 46th, 72nd and 531st Fighter Squadrons, begin to arrive on Iwo Jima.
The 506th Fighter Group is the third and last Mustang-equipped fighter group to base itself on Iwo Jima in mid-May 1945.
These three fighter groups would be ‘the little friends’ escorting B-29s to Japan.
NAA test pilot Joe Barton successfully flight tests the first of two XP-51J Lightweight Mustang prototypes.
Hitler commits suicide during the Battle of Berlin.
VE-day, victory in Europe.
An F-6C photo reconnaissance Mustang is the last Allied fighter to shoot down a Luftwaffe aircraft in the ETO.
The premier XP-82 is ready for its first flight, but it refuses to take off.
NAA test pilot, Joseph F. ‘Joe' Barton, makes several take-off attempts but the tail wheels seem to be glued to the runway: they lift slightly but then drop back on to the runway.
XP-82 finally makes its first flight.
The last operational Allison-powered Mustang, a RAF Mustang Mark II of No. 268 Squadron, returns to Great Britain from its base at Hustedt in Germany.
In Alamogordo, New Mexico, a test called Trinity takes place. It is the world’s first explosion of the atomic bomb.
The Manhattan Project had spawned the deadliest weapon known to mankind and wheels are set in motion to get several of these bombs to the 20th Air Force in the Mariana Islands, namely the island of Tinian where the Silverplate B-29s are based.
B-29 "Enola Gay" drops atomic bomb on Hiroshima.
B-29 "Bockscar" drops atomic bomb on Nagasaki.
On this day the last combat missions are flown by Mustangs in the Second World War.
Firstly, 160-plus P-51s from Iwo Jima escort 145 B-29s that bomb the Osaki Army Arsenal and alternate targets.
The Mustangs also strafe airfields in the Nagoya area with a loss of one P-51.
Lastly, Far East Air Forces P-51s attack Japanese shipping in North Korean and Kyushu, claiming several vessels destroyed and damaged with no losses.
A final tally found that the three fighter groups equipped with Mustangs based on Iwo Jima had flown some 1,700 sorties between April 7th and August 14th, 1945, and had produced four aces.
Respectively, the 15th FG, 506th FG and 21st FG got 111, 24, and 71 kills during their VLR escort missions.
VJ-Day, victory in Japan.
The official Japanese surrender is signed aboard US battleship USS Missouri.
The NA-144 programme is initiated by NAA for the production of 100 P-82E Twin Mustang night (all weather) aircraft. These are to be powered by 1,930 hp Allison V-1710 engines with water injection and auxiliary stage superchargers.
From January 1st, 1945 to August 31st, 1945, NAA delivered 5,111 Mustangs:
3,276 P-51Ds and P-51Hs from Inglewood
1,835 P-51Ds, F-6Ds, P-51Ks, F-6Ks, TP-51Ds - and a single P-51M from Dallas
Subtotals for both production facilities:
Grand total: 15,586 (this total includes the single NA-73X and the 320 NA-73 and the 300 NA-83 Mustang Mark I airplanes built under contracts for the RAF and the 100 P-51D airplanes built for Australia).