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AIRCRAFT
 
north american p-51 mustang
 
 
 
 
 

The P-51 was designed (as the NA-73) in 1940 at Britain's request. In April 1938, the British government established a purchasing commission in the United States, to organize the manufacturing and supply of American fighter aircraft for the RAF. At the time, the choice was very limited as no U.S. aircraft already flying met European standards, with only the Curtiss P-40 Tomahawk coming close. The Curtiss-Wright plant was running at capacity, so even P-40s were in short supply.

 

North American Aviation (NAA) approached the RAF to sell a new medium bomber, the B-25 Mitchell. Instead, RAF asked if NAA could manufacture the P-40 Tomahawk under license from Curtiss. North American felt that they could produce a better aircraft with the same engine in the air in less time than it would take to set up a production line for the P-40. The Commission stipulated armament of four .303 in (7.7 mm) machine guns, the Allison V-1710 liquid-cooled engine, a unit cost of no more than $40,000, and delivery of the first production aircraft by January 1941, in March 1940, 320 aircraft were ordered.

 

The prototype NA-73X was rolled out in early August and first flew on 26 October 1940 respectively just 117 and 178 days after the order had been placed. The design showed such promise that in 7 July 1941 the Army Air Forces placed an order for 150 P-51s. After the attack on Pearl Harbor priority had to be given to building as many of the existing fighters - P-38s, P-39s and P-40s. The 150 NA-91s were designated P-51 by the newly formed USAAF and were initially named Apache, although this was soon dropped, and the RAF name, Mustang, adopted instead. The USAAF did not like the mixed armament of the British Mustang Is and instead adopted an armament of four long-barreled 20 mm (.79 in) Hispano Mk II cannon, and deleted the .50 cal engine cowling mounted weapons. The British designated this model as Mustang Mk IA. A number of aircraft from this lot were fitted out by the USAAF as F-6A photo-reconnaissance aircraft. The British would fit a number of Mustang Mk Is with similar equipment.

 

 

The first version of the P-51 to see operation service in the US was the A-36 Apache dive-bomber that first flew in 1942. About 500 of these "near-Mustangs" were built and saw action in the Italian campaign and in India. The US used the A-36 in the Mediterranean theatre with first deliveries beginning in early 1943. When not in the ground attack role, the A-36 was essentially a low-altitude P-51A and was used as a fighter. The A-36 scored 101 air-air victories during WWII. The A-36 proved to be a very stable platform for accurate weapons delivery, 177 were lost in action mostly due to the dangerous mission of low-level operations.

 

The next versions to see service was the P-51 B /C built in Inglewood, CA and Dallas, TX which was to manufacture P-51Cs. The P-51B and P-51C were essentially identical, with the only distinguishing feature being the serial numbers. The engines were supplied by the Packard Company, which had reached an agreement with Rolls Royce to license produce the Merlin under the American designation V-1650. The NAA P-51B/C represented a quantum leap in high altitude performance and range, allowing them to escort the heavy bombers all the way to their targets deep into enemy territory. The first P-51B exited the assembly line and flew in May of 1943 with the P-51C model flying 3 months later. In search of even more range, an 85-gallon fuselage tank was installed behind the pilot's seat. This began with the P-51B-7NA (taken from -5 lines) and the P-51C-3NT versions (taken from the -1 line). With this added range came a price of directional stability.

 

Problems for the P-51B and C models included poor visibility towards the rear and gun jamming during high G maneuvers. The RAF found the best solution (at the time) for the visibility issue was installing a "Malcolm Hood" which was a bubble type canopy around the pilot's area of the birdcage. The new hood was on rails sliding rearward for an easy in and out. The old canopy was hinged and more difficult for egress. The "Razorback" Merlin Mustangs P-51B and P-51C remained in service until the end of the war.

 

P-51Bs and P-51Cs started to arrive in England in August and October 1943. The P-51B/P-51C versions were sent to 15 fighter groups that were part of the 8th and 9th Air Forces in England and the 12th and 15th in Italy (the southern part of Italy was under Allied control by late 1943). Other deployments included the China Burma India Theater (CBI). Allied strategists quickly exploited the long-range fighter as a bomber escort. It was largely due to the P-51 that daylight bombing raids deep into German territory became possible without prohibitive bomber losses in late 1943. A number of the P-51B and P-51C aircraft were fitted for photo reconnaissance and designated F-6C.

 

The shortcomings of the B/C models were well known and evolved into a new model of P-51, the P-51D. The new line, designated NA-109, P-51D, was started after the USAAF ordered 2,500 in July 1943. Interesting is that the XP-51D did not have a test flight until November 17, 1943, well after the first order was placed. Deliveries to fighter units began March of 1944 and a good supply was on hand for the Normandy Invasion, or D-Day.

 

The signature change in the P-51D line was the new bubble canopy. The U.S. was behind the British in canopy development. A British company had designed and built the "Malcolm Hood" which improved visibility to the rear of the P-51B/C models. The U.S. was not unaware of the advantages of a bubble canopy design. NAA had built a wooden model of the P-51 with a bubble canopy for wind tunnel testing. The technology to build large curves of Plexiglas "distortion free" at that time was being invented and developed. The cut-down back for the new bubble canopy lead to a loss of surface area. This caused the P-51D to have directional problems (especially with full fuel in the fuselage tank creating an aft CG) for all but the most proficient pilots. The solution was to add a fillet (often called the "dorsal fin") to the vertical stabilizer that extended down and towards the front. The fillet was also added to other P-51 models already in the field.

 

The addition of the 85 US gallon (322 l) fuselage fuel tank, coupled with the reduction in area of the new rear fuselage, exacerbated the handling problems already experienced with the B/C series when fitted with the tank, and led to a fillet being added to the base of the vertical tailfin. The new model Mustang also had a redesigned wing; alterations to the undercarriage up-locks and inner-door retracting mechanisms meant that there was an additional fillet added forward of each of the wheel bays, increasing the wing area and creating a distinctive "kink" to the leading edges of the inner wings.

 

The armament was increased with the addition of two more .50 in (12.7 mm) M2 Browning machine guns, bringing the total to six. The inner pair of machine guns had 400 rpg, and the others had 270 rpg, for a total of 1,880. The wing racks fitted to the P-51D/P-51K series were strengthened and were able to carry up to 1,000 lb (450 kg) of ordnance, although 500 lb (230 kg) bombs were the recommended maximum load. Later models had removable under-wing 'Zero Rail' rocket pylons added to carry up to ten T64 5.0 in (127 mm) H.V.A.R rockets per plane. The gunsight was changed from the N-3B to the N-9 before the introduction in September 1944 of the K-14 or K-14A

The P-51D became the most widely produced variant of the Mustang. During 1945–48, P-51Ds were also built under license in Australia by the Commonwealth Aircraft Corporation. A Dallas-built version of the P-51D, designated the P-51K, was equipped with an 11 ft (3.4 m) diameter Aeroproducts propeller in place of the 11.2 ft (3.4 m) Hamilton Standard propeller. The hollow-bladed Aeroproducts propeller was unreliable, due to manufacturing problems, with dangerous vibrations at full throttle and was eventually replaced by the Hamilton Standard. By the time of the Korean War, most F-51s were equipped with "uncuffed" Hamilton Standard propellers with wider, blunt-tipped blades.

 

The photo reconnaissance versions of the P-51D and P-51K were designated F-6D and F-6K respectively. The RAF assigned the name Mustang Mk IV to the P-51D model and Mustang Mk IVA to P-51K models. The P-51D/P-51K started arriving in Europe in mid-1944 and quickly became the primary USAAF fighter in the theater. It was produced in larger numbers than any other Mustang variant. Nevertheless, by the end of the war, roughly half of all operational Mustangs were still P-51B or P-51C models.

 

During  May 1944, the 317th, 318th and 319th Fighter Squadrons of the 325th Fighter Group nicknamed "The Checkertail Clan" transitioned out of the rugged P-47 Thunderbolt into the Mustang. With their new Mustangs, the squadron was able to fly missions farther into enemy territory, and to escort bombers from a pre-target rendezvous point, over the target, and well along the course back to base. This meant that one group flying P-51s would be able to supply the cover that had previously required two or three groups flying P-47s. On 7 May 1945, hours before the end of the war in Europe the 325th flew its last combat sortie, an mission escorting Halifax bombers of the Royal Air Force's 148 Squadron, when the propellers of the five P-51's came to a halt, the war ended for the Checkertail Clan. The final record for the 325th in the P-51 was 342 missions, 10,596 sorties flying 45,370 combat hours with 246 aerial victories vs. 75 losses.

 

At war's end, 5,541 Mustangs were on hand. Surplus machines were sold or given to Australia, China, Cuba, Denmark, the Dominican Republic, France, Indonesia, Israel, Sweden, Korea, Switzerland, Italy and Canada were the Mustangs served in Reserve Air Defense units . Many were also passed on to the USAF Air National Guard units, locally flown by the WA ANG's 116th Fighter Squadron (1947-1950 & 1952-1954) at Felts Field near Spokane WA. Other Squadrons in the region,  Oregon's 123d Fighter Squadron (1946-1951 & 1952-1953) Montana's 186th Fighter Squadron (1946-1953) and the 190th Fighter Squadron (1946-1953) were assigned the Mustang at their home base and other bases during their activation during the Korean War in the early 50's.

 

During the Korean War, F-51Ds (as they were redesignated in 1948) were used by active duty units primarily for close support of ground forces until the type was withdrawn from combat in 1953. Mustangs have been popular for many years on the unlimited racing circuit. In 1984, the Piper Enforcer, a turboprop design based on the P-51, was marketed to smaller air forces as a light attack aircraft although none was bought.


 
SPECIFICATIONS
 
 
north american p-51D mustang
  • TYPE:  Long range Interceptor

 

  • POWER:  One Packard V-1650-7 liquid-cooled supercharged V-12, 1,490 hp (1,111 kW) at 3,000 rpm; 1,720 hp (1,282 kW) at military power

 

  • SPEED:  Max - 437 mph at 25,000 ft   Cruise speed: 362 mph

  • RANGE:  1,650 mi with three external tanks

 

  • SERVICE CEILING: 41,900 feet

  • WEIGHT: Empty - 7,635lbs, Combat - 9,200 lbs, Max T/O 12,100 lbs.

 

  • DIMENSIONS:  Wingspan 37 ft 0 in, Length 32 ft 3 in, Height 13 ft 4.5 in

 

  • ARMAMENT: 6× 0.50 caliber (12.7mm) M2 Browning machine guns with 1,880 total rounds (400 rounds for each on the inner pair, and 270 rounds for each of the outer two pair);  2× hardpoints for up to 2,000 lb (907 kg) of bombs; 6 or 10× T64 5.0 in (127 mm) H.V.A.R rockets (P-51D-25, P-51K-10 on).

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  • CREW:  One

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  • PRODUCTION TOTALS: 150 (P-51); 310 (P-51A); 1,988 (P-51B); 1,750 (P-51C); 8,156 total (P-51D - 6,502 at Inglewood, 1,454 at Dallas and 200 by CAC at Fisherman's Bend, Australia);  3 (XP-51F); 2 (XP-51G); 555 (P-51H); 2 (XP-51J);  1,500 (P-51K); 1 (P-51M); 620 (Mustang Mk I); 852 (Mustang Mk III); 281 (Mustang Mk IV); 595 (Mustang Mk IVA).

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  • COST: $50,985 in 1945


318th FIGHTER-INTERCEPTOR SQUADRON SERVICE: 

 
29 March 1944 at Lesina, Italy
5 March 1945 at Rimini, Italy
April 1945 Mondolfo, Italy
July 1945, Vincenzo, Italy
 
COURTESY OF THE McCHORD AIR MUSEUM