| Continued from above… were also much the same except for their propellers. |
As an escort fighter, the P-51 played a decisive role in achieving the final Allied victory over Germany. The wartime Luftwaffe's supreme commander, Hermann Goering, said that: "When I saw Mustangs over Berlin, I knew the war was lost." The first Mustangs (at this stage, P-51 Bs/Cs with the high "razorback" rear fuselage) reached the 8th Air Force in Great Britain in January 1944, and two months later aircraft of the 4th Fighter Group became the first to accompany USAAF bombers all the way to the German capital.
The Mustang was one of World War II's finest fighters, and one of the few aircraft conceived after the start of that conflict to see large-scale service before its termination. Utilizing a laminar-flow wing section, the Mustang was the first American fighter to incorporate the lessons of air combat in Europe, and owed its existence to the insistence of a British Purchasing Commission that these lessons should be heeded.
The North American P-51 Mustang
The general requirement for a fighter of more advanced design and with better operational performance than any then available in the United States was put to North American Aviation early in 1940 by the British Commission.
To match British practice, the aircraft was required to have an in-line engine and an armament of eight machine-guns. Of inspired design, the Mustang was built, tested, and placed in production in record time. Under the pressure of need, a prototype was built in 117 days and tested within seven months of the British request.
The P-51D was to become the most widely produced variant of all Mustangs. It was quickly delivered to squadrons in both Europe and the Pacific.
Right: US Pilots of 380th Fighter Squadron, 363rd Fighter Group with P-51D Mustang "Fools Paradise IV" at Maupertus Airfield, Cherbourg, France, Jul-Aug 1944.
The Mustang was built, tested, and placed in production in record time
A prototype was to be completed within 120 days of go-ahead. North American bettered the target by three days when the prototype of their NA-73 was rolled out in the late summer of 1940, but delays in delivery of the 1,100-hp Allison V-1710-F3R engine kept the aircraft on the ground for another six weeks. Striking features of the NA-73 were seen to include its angular lines -simplifying production - and its wide-track inward-retracting landing gear.
British contracts established the Mustang (the name bestowed by the RAF) in production at the North American plant in Los Angeles, the US Army Air Corps sanctioning export of the new type in return for an opportunity to evaluate two early production models, which were designated XP-51 for this purpose. The first order was for 320 Mustang Is, two later contracts - increasing the initial P51s total to 620; the first of these arrived in Britain in November 1941. They were armed with four 0-50-in and four 0-30-in machine-guns and were faster than any fighter then in service with the RAF. However, their low-altitude Allison engines limited their operational effectiveness, and most were modified for Army Co-operation duties, with an oblique camera behind the cockpit.
Of the total of Mustang Is ordered, 20 were lost at sea, 10 were re-shipped to Russia and a number of these P-51s were used for armament and power plant experiments in the UK. In the latter category were four fitted by Rolls-Royce with high-altitude Merlin 60-series engines, leading to a major re-design of the Mustang by North American late in 1942, to take advantage of the performance gain offered by the Merlin.
Meanwhile, the USAAF had placed its first production contract for the type, using lend-lease funds to order 150 P-51s in September 1940. These had four 20-mm cannon in the wings but were otherwise similar to the Mustang Is. All were intended for the RAF, which called them Mustang IAs, but the USAAF re-possessed 55 for modification to F-6As, with two oblique cameras for tactical reconnaissance duties. Two others were used for prototype installation, in August 1942, of Packard Merlin V-1650-3s, after the Rolls-Royce work noted above. Known briefly as XP-78s, they were redesignated XP-51 Bs.
The experiment which was to bring the P-51 Mustang to excel as an all-round fighter
In the R.A.F. the P-51A was known as the Mustang II , and fifty were delivered late in 1942. Apart from the engine and armament, the P-51A differed principally from the first production model in having two underwing racks for carrying either 500-lb. bombs or 75- or 150-gallon drop-tanks. The latter load brought the take-off weight up to 10,600 lb., but provided a ferrying range of no less than 2,350 miles.
Before production of the Merlin-engined versions began, the USAAF acquired 500 A-36As and 310 P-51As. The former were dive-bombers with six 0-50-in guns, underwing bombs and speed brakes above and below the wing. The P-51As also had bomb racks; distinguishing features were the 1,200-hp V-1710-81 engine, provision for drop tanks, and an armament of only four 0-50-in guns. Fifty went to the RAF on lend-lease as Mustang IIs and 35 were converted into F-6Bs with cameras. While these versions were being delivered, the XP-51Bs were demonstrating a top speed of 441 mph at 30,000 ft, and a major production effort began.
The experiment which was to bring the Mustang to fruition as an all-round fighter par excellence, however, was made by Rolls-Royce . Major Thomas Hitchcock reported to Washington in the autumn of 1942 that the P-51 was one of the best, if not the best, fighter airframes developed at that date, and advised its development as a high-altitude fighter by cross-breeding it with the Merlin 61 engine. This opinion was endorsed by such authorities as Eddie Rickenbacker and Air Marshal Sir Trafford Leigh-Mallory, and four Mustangs were delivered to Rolls-Royce for conversion.
A Mustang I (AM 208) was fitted with a Merlin 65, and a Mustang IA (AL 975-G) received a Merlin 61. These aircraft, together with AM203 and AL963, had four-bladed airscrews to absorb the extra power, and featured small "chin"-type radiators of varying shape while retaining the ventral radiators originally fitted. These four machines were known as Mustang Xs. A Rolls-Royce project which called for the installation of a Griffon engine aft of the pilot's cockpit, driving the airscrew via an extension shaft, progressed no further than the mock-up stage. The Merlin installations were completed and the Mustang Xs successfully flown within six weeks, and the data provided by flight tests with these machines was sufficient for the North American company to initiate a complete redesign of the Mustang for production with the Packard-built 1,520 h.p. Merlin 61, the V-1650-3, with two-speed, two-stage supercharger and intercooler.
The most important thing to a fighter pilot is speed; the faster an aircraft is moving when he spots an enemy aircraft, the sooner he will be able to take the bounce and get to the Hun. If you have any advantage on him, keep it and use it. When attacking, plan to overshoot him if possible, hold fire until within range, then shoot and clobber him down to the last instant before breaking away. The P-51 made achieving this a sport.
P-51 pilot - Duane W. Beeson, 4th Fighter Group
The Mustang was proving itself even before the introduction of the Merlin-powered P-51B
The Mustang's inherent versatility was beginning to manifest itself even before the introduction of the Merlin-powered P-51B , and a number of the earlier production models delivered to the U.S.A.A.F. were modified for tactical reconnaissance, following the R.A.F. precept. In 1942 some fifty-seven P-51s were each fitted with two K-24 cameras under the designation F-6A, and these became the first of a substantial series of photo-reconnaissance Mustangs, including thirty-five F-6Bs modified from P-51As.
The time was then November 1942, and it was to be a year before the first group of P-51B Mustangs (this name having also been adopted by the U.S.A.A.F. in preference to the Apache) were to be available for combat. In the meantime a new version of the P-51A had been evolved specifically for dive-bombing in the spring of 1942, fitted with wing-mounted airbrakes, a 1,325 h.p. Allison V-1710-87 engine, and designated A-36A. Five hundred of these were delivered to the U.S.A.A.F., with which they were the first Mustangs to see combat, equipping two groups in Sicily and Italy in 1943. The dive-bombing equipment of the A-36A increased gross weight to 10,700 lb. and reduced maximum speed to 356 m.p.h., and the type was only moderately successful. The dive brakes proved unsatisfactory and were eventually wired shut. Many fighters were subsequently to be adapted for the dive-bombing role, and some (notably the Spitfire) proved highly successful, but only without the weight of extraneous equipment and by retaining their versatility. One A-36A (EW998) was supplied to the R.A.F, in March 1943 for experimental purposes.
Two P-51s were fitted with the Packard-built Merlin in the U.S.A., and after a brief period as XP-78s were eventually redesignated XP-51B . Their airframes were strengthened in order to make full use of the increased power available; the ventral radiator was deepened; the carburetor intake was moved from above to below the nose for the Merlin's up-draught induction system; new ailerons were fitted and the underwing racks increased in capacity to take two 1,000-lb. bombs or their equivalent weight in fuel. Before the two XP-51Bs, which were to show a level speed improvement of 51 m.p.h. to 441 m.p.h., had even flown, General Arnold was able to report to President Roosevelt that approximately 2,200 Merlin-powered P-51Bs had been ordered for the U.S.A.A.F.
We soon found out that the P-51 Mustang was indeed a different breed of airplane. It was fast, for one thing. ... The P-51 was redlined at 505 and, though it was no Spitfire, its turning ability wasn't bad at all - especially if you sneaked down 10 degrees of flaps. It was pretty good in the climbing department too, and accelerated very fast in a dive. But the thing that really set the Mustang apart from any other fighter, friend or foe, was its range. With a 75-gallon tank slung under each wing, it could perform the unheard-of: It could fly six-hour missions.
Physically, it was pleasing to the eye and looked fast, even sitting on the ground. Power was provided by a V-1650 Rolls-Royce Merlin engine built under license in the States by Packard, the luxury automobile company. The V-1650 was a fine engine and could be taken up to 61 inches of manifold pressure at 3,000 RPM for take-off or, if needed in combat, 67 inches for up to five minutes in Emergency Power. Normally aspirated engines tended to run out of power as altitude increased, usually between 15,000 and 20,000 feet.
The P-51 had a two-stage blower in the induction system that was controlled automatically with a barometric switch. Around 17,000 feet, when the throttle had been advanced almost all the way forward just to maintain normal cruise, the blower would kick into high, the manifold pressure would jump up, and the climb could be continued to 30,000 feet. The P-51 could be taken a lot higher than that, but above 30,000 feet the power was way down and the controls had to be handled gingerly.
Robert Goebel, 31st Fighter Group, based at San Severo, Italy 1944
The Mustang's extreme range made it a natural choice for bomber-escort and fighter
Two production lines for the Merlin-engined P-51 Mustangs began to roll in 1943, building identical aircraft at Inglewood, California (P-51B), and Dallas, Texas (P-51C). The first Merlin-Mustangs were delivered to the U.S. Eighth Air Force in the United Kingdom on December 1, 1943, and, with two 92 U.S. gallon wing tanks and either two 75-gallon or 150-gallon external tanks, flew their first long-range escort mission on December 13 was 490 miles to Kiel and back, which established a record at that time.
Until the Mustang came on the scene, American confidence had been placed in the P-47 Thunderbolt and P-38 Lightning. It was not until late 1943 that Mustangs marked with the star and bar went into action. The airplane was a winner from the first. High altitude escort and combat was its forte. And it had extreme range. Also, Mustang speed and maneuverability was superior to every piston-engine plane the Germans flew against it.
Whatever shock this was to the Luftwaffe was nothing compared with that a few months later when, in March 1944, Merlin-powered Mustangs accompanied B-17 Fortress and B-24 Liberator bombers all the way on the 1,100-mile round trip to Berlin. It is true to say that the introduction of the P-51B and C, capable of accompanying bombing formations to their targets and still meeting the Luftwaffe on equal terms after jettisoning nearly empty external tanks, imposed a severe tactical problem on the German defense system, while adding tremendous impetus to the American daylight offensive. The long-ranging fighters, weaving over the massed formations of bombers, were soon christened "little friends" by the hard-pressed crews of the Fortresses and Liberators, and many crippled bombers owed their return to the protection of escorting Mustangs.
Drawing upon the Mustang's talents beginning in March, 1944, the Eighth Air Force severely shook German morale by using Mustangs to escort mass formations of B-17 Fortresses and B-24 Liberators to Berlin and back. The days when Luftwaffe interceptors could attack daylight bombers beyond the range of the Allied escort fighters were over.
A latecomer to European skies...
The Mustang nevertheless accounted for more enemy aircraft than any other American fighter in the European Theater of Operations. In two months in the spring of 1944, a single Mustang Group shot down 235 enemy planes and destroyed more than half as many more on the ground.
The P-51 Mustang is considered to be one of the greatest single seat fighters to be used in WWII. Its original design called for the use of a 1,100 hp Allison V-1710-39 engine, but this version proved to have limitations in combat operations at higher altitudes. When the Allison was replaced by the British Rolls Royce Merlin engine the Mustang leapt into prominence as an excellent fighter. Its ability to fly long distances in the escort fighter role earned it fame during the long missions to Germany and over the expanses of the Pacific.
The P-51 remained with the U.S.A.A.F. until beyond 1950, and was the only World War II piston-engined fighter to survive so long with the USAF Service - long enough to see operational service in the Korean War. Post-war, the Mustang was built under license in Australia by Commonwealth Aircraft Company, which supplied 60 to the RAAF; while large numbers of surplus USAF machines - mostly P-51 Ds - passed into service with many other nations, including Canada, Sweden, Switzerland, China and most of the South American and Asian countries within the US sphere of influence.
In a surprise move in 1967, the USAF ordered the F-51D back into production for counter-insurgency duties. Assembled by Cavalier Aircraft Corporation from component parts (some newly manufactured, others from war surplus stocks), these Cavalier F-51Ds have two seats in tandem, updated systems and electronics, reinforced wing spars, a taller tail-fin and improved armament.
Left: Inside the Cockpit of the North American P51D Mustang.
Starting in December 1943, the P-51B was in operation with the US Eighth Air Force
For production, the P-51B had increased fuel, four 0-50-in guns in the wings, and wing racks for two 1,000-lb bombs or 150-US gallon drop tanks. At Los Angeles, North American built 1,988, while a new factory at Dallas turned out 1,750 similar P-51Cs. The RAF received 274 Bs and 636 P-51Cs, designating them Mustang III and fitting a new cockpit canopy with bulged sides. The USAAF converted 91 assorted B and C models into F-6C reconnaissance fighters.
Starting in December 1943, the P-51B was in operation with the US Eighth Air Force, escorting bomber formations; and its combination of speed, maneuverability and range made it not only the most popular but also the most effective fighter operational over Europe in the last two years of the war. For the loss of 2,520 P-51s in combat in Europe, the USAAF claimed the destruction, by this type, of 4,950 enemy aircraft in the air and 4,131 on the ground - a better ratio than any other US fighter.
Despite the highly favorable ratio of successes in the European theatre against the Luftwaffe, the U.S.A.A.F. was evincing as much concern as the R.A.F. about rearward view. The Malcolm hood was but a temporary measure to improve this fault, and by 1944 a major re-design was under way in order to fit a beautifully streamlined "bubble" canopy on a cut-down rear fuselage. A new version of the Mustang, the P-51D, was already on the production lines, having the more powerful Packard Merlin V-1650-7 and six 0.5-in. machine-guns with 270 or 400 r.p.g., and after the completion of the first four aircraft the new "bubble" hood was introduced onto the production line.
A redesigned rear fuselage, with a new "tear drop" canopy providing all-round vision, distinguished the P-51D, which occupied the production lines in 1944. Totals were 6,502 at Los Angeles, and 1,454 at Dallas, plus 1,337 similar aircraft built at Dallas with an Aero-products propeller and designated P-51K. The RAF received 281 P-51Ds and 595 P-51Ks under lend-lease and designated them Mustang IV, while the USAAF increased its reconnaissance force with 136 F-6Ds and 163 F-6Ks converted from the fighters. The RAF's Mustang IIIs and IVs, operational from early in 1944, flew bomber escort duties from the UK, and fighter-bomber sorties with 2nd TAF from France and with the Desert Air Force. They also scored notable successes against German V-l flying-bombs over Southern England.
By the end of the War all but one of the 8th Air Force Fighter Groups (the 56th) had converted to P-51's, and the graceful Mustang is credited with having destroyed more enemy aircraft than any American fighter in the European Theatre of Operations. After converting to Mustangs, the famous 4th Fighter Group became the top-scorer in the ETO ending the war with a total of 1,016 enemy planes destroyed.
Chuck Yeager joined the Army Air Force at the age of 18 in 1941. He is most noted for not only becoming a revered Ace of WWII, but also for shooting down at least 2 of his multiple kills being German jet-fighters. He became an Ace in one day, giving birth to the term that is consistently referenced to Yeager, Ace in a Day. He was unfortunately shot down over France, where he eluded the enemy, returned to the states and then flew many high-danger and high-priority campaigns over Europe. Chuck Yeager went on to become a test pilot for the Air Force in post-war years. He is the first person to break the sound-barrier. He was flying the Flying Bell X-1 when performing this feat. Chuck Yeager's plane that he will forever be tied to was the Glamorous Glen. He is also renowned for being a test pilot for the 357th fighter group.
P-51 Mustang pilot - Chuck Yeager
The main production model: The P-51D Mustang
The following spring the main production model appeared, the P-51D. The RAF had experimented with its Mustang Mk.III to improve visibility, and a structure-less round hood was introduced, the Malcolm (named after its inventor). North American also tackled the problem. In the P-51D the rear of the cockpit fairing was removed and a fin was added to the rudder to make up for the loss of lateral surface. The cockpit was given a teardrop-shaped, fully transparent hood. It was powered by a 1,695-h.p. Packard Merlin engine and had a top speed of 437 m.p.h. at 25,000 feet.
The P-51D was to become the most widely produced variant of all Mustangs , 6,502 being built at Inglewood and 1,454 at Dallas. It was quickly delivered to U.S.A.A.F. squadrons in both Europe and the Pacific, and P-51Ds were to make the first land-based fighter strikes against Tokyo on April 7, 1945. The fuselage fuel tank had by this time become standard, and the underwing racks were augmented by twin zero-length launching stubs for 5-in. rocket missiles on the last 1,100 P-51D-25-NA fighters. Some Mustangs in Europe had previously carried a cluster of three Bazooka-type rocket-launching tubes beneath each wing and on returning from fighter escort frequently engaged in ground-strafing sorties, using either rockets or machine-guns. An enormous number of vehicles, trains and dispersed aircraft were destroyed by marauding Mustangs before and after D-Day in France and Germany.
The Mustang's extreme range made it a natural choice for bomber-escort and fighter sweeps over the broad wastes of the Pacific, and after the capture of Iwo Jima, in February 1945, P-51Ds began aiding the B-29 Superfortress force in its assault against Japanese targets. With external tanks giving a total of 489 U.S. gallons of fuel, the P-51D was comparatively light at 11,600 lb., and had an absolute range of no less than 2,080 miles, an endurance of 8 1/2 hours.
Following immediately on the P-51D, and differing only in the replacement of the Hamilton-Standard airscrew by one of Aeroproducts type, came the P-51K, 1,337 of which were built at Dallas. Weighing 11,000 lb. loaded, the P-51K was not fitted with rocket stubs and had a slightly inferior performance to that of the P-51D. Its tactical reconnaissance variant was the F-6K, 163 being converted from P-51Ks. Meanwhile at Inglewood development continued with the XP-51F, which represented the first attempt to produce a lightweight Mustang. With the same Packard Merlin V-1650-7 engine, the XP-51F was an extensive re-design in which loaded weight had been reduced to 9,060 lb. through the simplification of the structure, the deletion of some equipment, and the use of new materials, including plastics. A new low-drag wing was employed, and by fitting smaller wheels, with the new disc brakes, to a simplified undercarriage the "cranked" inner wing that had characterized all previous Mustangs was eliminated. To reduce drag a longer "bubble" hood was fitted, together with a modified radiator fairing, the oil cooler being replaced by a heat exchanger. Two of the six 0.5-in. guns were removed, and the fuel system was re-designed around two 105 U.S. gallon wing tanks, while more weight was saved with the three-bladed Aeroproducts hollow-steel airscrew. The net result was the saving of about one ton in weight and the attainment of a maximum speed of 466 m.p.h. Three XP-51F Mustangs were built, one (FR409) being supplied to the R.A.F.
The Mustang was pleasant and forgiving to fly. Best of all, it went like Hell. The Merlin had great gobs of power, and was equally at home high or low, thanks to a two-stage, two-speed supercharger. The Mustang carried fuel enough to pursue and destroy the enemy once you'd flown to the target, and it could turn on a dime. It was crucial to keep it it trim but, as we gained experience with the plane, that became automatic. We sensed it was special, even before we measured it against what the enemy pilots were flying.
Bud Anderson, Another Famous P-51 Mustang pilot
Mustangs served in nearly every combat zone, including the Pacific
From its inception, the plan to seize Iwo Jima had two goals: providing a haven for damaged B-29s and establishing a base for AAF fighters that could escort the bombers. The Marianas gave the Superforts a home 1300 miles from Tokyo. But no fighter of that day could make such a round trip. It was, however, theoretically possible for the North American P-51D to fly from Iwo Jima to Tokyo and other southern cities in Honshu, but it was by no means a routine flight. The Mustang had proved itself over Europe on five and six hour missions that covered 1200 to 1300 miles. However, the Empire run was entirely over water. After navigating nearly 650 miles to the coast of Japan on rigid cruise control, these pilots would be expected to drop their auxiliary tanks, engage an enemy, and return over the same empty ocean to find Iwo Jima. A mistake of a degree in navigation spelled disaster. Engine trouble, fuel starvation or battle damage requiring a parachute jump would, likewise, force a pilot into the vast Pacific.
In the Pacific, 7th Air Force Mustangs based on Iwo Jima were the first Army fighters to operate over the Japanese home islands, while the 5th Air Force Mustangs scourged the skies over the Philippines in combat which nearly equaled the savagery of the air fighting in Europe.
Mustangs escorted B-29s to Japan from Iwo Jima. Two P-51 groups were ready to move into Iwo just as soon as facilities could be readied for them. The Mustang's seven-league boots were legendary in the European Theater, where the war was almost over, as Eighth and Ninth Air Force P-51 s easily flew from southeastern England to Berlin and back, nearly 1,200 statute miles. A few 1,500-mile shuttle missions from England to the Ukraine had also been undertaken, but once P-51s were based on Iwo they would fly round-trips of that distance as a matter of routine.
The P51 Mustang had an astonishing success rate. Its ratio for kills to losses was said to have been 19 kills for every 1 Mustang lost. The P51 Mustang is credited with the destruction of 4,950 German planes - more than any other Allied fighter - and some of these kills included the jet powered Me 262.
Such was the success of the Mustang, that the Senate War Investigating Committee set up by Harry Truman in 1944, called it "the most aerodynamically perfect pursuit plane in existence".
The pilots called themselves the 'Tokyo Club'
The pilots called themselves the 'Tokyo Club'. It was a simple task to become a member. All you had to do was strap yourself into a heavily loaded P-51 Mustang, take off from Iwo Jima (a postage-stamp sized volcanic island in the middle of the Pacific Ocean), fly 650 miles north over the sea - often through monsoon storms - in your single-engined aircraft to Japan, attack a heavily defended target in the vicinity of the enemy's capital city and then turn around and fly home while fretting over your shrinking fuel supply and perhaps battle damage as well. If your gas held out and you were not blown off-course on your return trip, you landed back at 'Iwo' after an eight-hour flight. Do it once and you earned membership in the club. Do it 15 times and you earned a trip home. But make one mistake or have one touch of bad luck, and you had a very good chance of ending up dead.
Without question, one of the finest fighters to see service during World War II
Many things have been said and written about the Mustang - that it was the best combat plane of World War II, that it was the plane that marked the transition from piston-engine fighters to jet fighters, that it was the plane that gave the Allies final supremacy in the skies. The truth is perhaps slightly obscured by all these claims.
When the American air force introduced the Mustang long-range escort fighters over Europe at the beginning of 1944, after months of disastrous losses and inaccurate bombing, the 8th Air Force gained air superiority over the Luftwaffe in a matter of weeks.
P-51 Mustang fighter being serviced at an airfield near Frankfurt, Germany, Mar Apr 1945;
note the wrecked German Fw-190 aircraft in foreground.
| Summary: |
The North American P-51 Mustang was the product of two highly advanced technologies: the American aircraft industry, which in 117 days designed a plane body that was extremely advanced in structure and aerodynamics; and the British engine industry, which, with its prestigious Rolls-Royce Merlin, provided the ideal complement. The Mustang would not have become immortal without the British engine, the same engine that had already made the Supermarine Spitfire famous. Beyond this, all is history. A total of 15,686 Mustangs were built. Mustangs destroyed 4,950 enemy aircraft in combat and 4,131 on the ground in the course of 213,873 missions in Europe alone. Mustangs also saw duty during the Korean War, and they served in the air forces of some 20 other countries.
In April, 1940, the visiting British purchasing commission suggested to North American that they build Curtiss P-40 fighters on license for the RAF. The president of North American, J. H. ("Dutch") Kindelberger, was not enthusiastic. He said his company could produce a combat plane that was better than the P-40, even using the same engine, the V-12 Allison V-1710. The British accepted Kindelberger's counterproposal, but they made it a condition that the prototype be ready in no more than 120 days because the situation in Europe was extremely serious.
Two North American designers, Raymond Rice and Edgar Schmued, got to work at once, and the prototype, the NA-73X, was ready three days ahead of schedule, albeit without an engine and with wheels borrowed from an AT-6 trainer. The first flight took place on October 26, 1940. The plane had exceptionally clean lines, and its performance was outstanding. It flew about 25 m.p.h. faster than the Curtiss P-40.
Meanwhile the U.S. government had approved the RAF order for 320 planes, provided that the USAAC was supplied with two planes for testing. The first production fighter took to the air on May 1, 1941, and remained at North American for technical evaluation. The second reached Great Britain in November and was officially designated the Mustang Mk.l. These planes, which were considered far superior to any other American fighter, were put into service in April, 1942, as tactical reconnaissance planes. About the same time, the British ordered 300 more planes, which differed only in equipment and armament.
The idea that led to the P51 Mustang's full development came to British and American technicians almost simultaneously. In Great Britain four Mustangs were given to Rolls-Royce for testing with the Merlin 61 engine. In the United States two bodies were consigned to North American for testing with the Merlin that' the Packard company built on license, the V-1650-3. Thus, in September, 1942, the first P-51B prototype was born. Only minor changes were made in the forward part of the fuselage, to accommodate the new engine. But performance was radically different. Now the plane could reach a speed of 440 m.p.h. at 30,000 feet, and an ascent to 20,000 feet required only five minutes and 54 seconds. This was a remarkable advance over the P-51A's top speed of 390 m.p.h. at 20,000 feet and more than nine minutes in ascent.
The P-51 went into mass production in the summer of 1943. It was built at the Inglewood factory as the P-51B (1,988 aircraft) and in the new Dallas plant as the P-51C (1,750 aircraft). Great Britain received about 1,000 and called them Mustang Mk.III.
British-operated Mustangs saw first action in July, 1942, nobly acquitting themselves supporting assault troops at Dieppe the next month, and earning the distinction of being the first England-based single-engined fighter to thrust beyond the German border.
The first Merlin-engine Mustangs were delivered to the 354th Fighter Group of the 9th Air Force in Great Britain on December 1, 1943. The P-51B first went into action as a fighter on December 17, 1943 and on January 15, 1944 P-51Bs with drop tanks made their first long-range mission as fighter escort to heavy bombers of the 8th Air Force over Germany. Like the Thunderbolt, the P-51 could be a formidable fighter-bomber. Flying at roof-top level or below (one P-51 returned to its English base with a turnip in its air-scoop), the plane could deal rapid, stunning blows to enemy armor and troop concentrations and get away faster than the anti-aircraft guns could track.