This is the prototype Mustang, the NA-73 being readied for a test flight. Note the absence of all markings except the rudder stripes, which is unusual as the plane was ordered by the British.
This is the prototype Mustang, the NA-73 being readied for a test flight.
Note the absence of all markings except the rudder stripes, which is unusual
as the plane was ordered by the British.
In late 1939, with the likelihood of full scale war in Europe a major concern, the British Royal Air
Force was looking seriously at methods of quickly increasing its fighter strength. In April 1940,
the British Air Purchasing Commission approached North American Aviation with the intent of
having them build
P-40's
for the R.A.F. Instead, North American offered to build an
entirely new fighter using the same
Allison V-1710-39 engine as the
P-40.
The British agreed only on the stipulation that a prototype be on hand within 120 days. North American designers
Raymond Rice and Edgar Schmued immediately set about meeting the requirements. Schmued
had been a part of Willy Messerschmitt's design group in Germany; no doubt the somewhat
angular lines of the new fighter came from this relationship.
The Allison-powered
prototype NA-73 was assembled within the specified period, but the engine
was not yet ready, causing a delay of some six weeks before the NA-73 could fly. In the
meantime, on May 4, 1940, the U. S. Army released the design for export sales with the condition that two of the planes be delivered to them for evaluation. At this time the NA-73 was assigned the XP-51 designation. The first and tenth airframes were sent to the Army for testing; these were given the serial numbers 41-38 and -39. An order for 150 P-51's followed. These planes were named "Apache" for a short time, but later the name "Mustang" was adopted for the P-51.
The Merlin engine installed in this P-51B, improved the performance
of the Mustang.
The P-51 was an immediate success. It outperformed even the
Spitfire, but the
Allison
engine placed limitations on the performance. In England, a
mock-up was devised to use the Rolls Royce Merlin in the P-51 airframe.
One concept was to locate the new engine behind the cockpit, but this idea
was rejected and the Merlin was mounted in the conventional position in
the nose. Four airframes were adapted in England to take the
Merlin
engine. These planes had deep intakes below the engine for carburetor air.
In the meantime, North American had undertaken a similar conversion project
and was building two Packard Merlin-powered Mustangs. The results of the
British tests were passed on to North American; and even before the Army's
Merlin
-powered Mustangs had flown, the U. S. Army ordered 2,200 of the more
powerful fighters. For a short time, this model was designated P-78, then
reclassed as P-51B.
To say the
Merlin
Mustangs were successful would be an understatement. The P-51 became one
of the aviation world's elite. The total number of 14,819 Mustangs of all types were built for the
Army. American Mustangs destroyed 4,950 enemy aircraft in Europe to make them the highest
scoring U. S. fighter in the theater. They were used as dive-bombers, bomber escorts,
ground-attackers, interceptors, for photo-recon missions, trainers, transports (with a jump-seat),
and after the war, high performance racers.
A new bubble-topped P-51D begins its delivery flight to a combat unit.
The Merlin
-powered P-5lB and its Dallas-built twin, the P-51C, began operations in December
1943. A further improvement to the Mustang was introduced when a graceful teardrop canopy
was installed to eliminate the dangerous blind area created by the faired cockpit. First tested on
two P-51B's, they became standard on the P-51D and all later models. The P-51D became the
version produced in the greatest quantities, 7,954 being completed. The "D" model carried six .50 cal. machine guns instead of the four mounted in the "B's"; and other refinements, such as moving the wing forward slightly and providing for rocket launchers, were included. The first "D" types were delivered without dorsal fins but this feature was added to compensate for keel-loss when the bubble canopy was adopted.
Later developments to the P-51 series included the final production type, the P-51H with several
changes which made it the fastest production variant with a maximum speed of 487 mph at
25,000 feet. Five hundred fifty-five P-5lH's were delivered before VJ Day led to cancellation of
the P-51 production program.
The P- 51 D represents the typical Mustang configuration. It had a 37-foot
wingspan with an area of 233 square feet and was 32 feet 3 inches long.
Height was 13 feet 8 inches. The
Packard-built Merlin V-1650-7 was capable
of delivering 1,695 hp which provided a speed of 437 mph at 25,000 feet.
Weights were 7,125 lbs. empty and 10,100 lbs. normal gross, but an
additional 2,000 lbs. could be carried. Internal fuel capacity was 105
gallons, giving a range of 950 miles at 362 miles per hour at 25,000 feet.
Armament was six .50 cal. wing-mounted machine guns with 1,880 total rounds.
The P-51 was one of the first fighters to use a laminar-flow airfoil, a high-speed shape which
became standard on most later high performance fighters.
The North American P-51H Mustang single-seat fighter.
(Packard V-1650-11 Merlin engine.)
Specifications: North American P-51D Mustang
Powerplant:
Rolls Royce - Packard-built V-1650-7 Merlin 1,590 hp 12 cylinder
Vee engine.
Dimensions:
Length: 32 ft 2.5 in (9.82 m)
Height: 13 ft 8 in (4.17 m)
Wing span: 37 ft .5 in (11.3 m)
Weights:
Empty: 7,125 lb. (3,232 kg)
Operational: 11,600 lb (5,266 kg)
Performance:
Maximum speed: 437 mph (703 km/h)
Service ceiling: 41,900 ft. (12,780 m)
Range: 1,300 miles (2,092 km)
Armament: Six .50 calibre guns, external bomb load of 2,000 lbs.
(908 kg.) or drop tanks.