Spitfire V (9/42 – 4/43)
- Crew: one pilot
- Length: 29 ft 11 in (9.12 m)
- Wingspan: 36 ft 10 in (11.23 m)
- Height: 11 ft 5 in (3.86 m)
- Wing area: 242.1 ft² (22.48 m²)
- Airfoil: NACA 2209.4(tip)
- Empty weight: 5,090 lb (2,309 kg)
- Loaded weight: 6,622 lb (3,000 kg)
- Max takeoff weight: 6,770 lb (3,071 kg)
- Powerplant: 1× Rolls-Royce Merlin 45 supercharged V12 engine, 1,470 hp at 9,250 ft (1,096 kW at 2,820 m)
- Maximum speed: 378 mph, (330 kn, 605 km/h)
- Combat radius: 410 nmi (470 mi, 760 km)
- Ferry range: 991 nmi (1,140 mi, 1,840 km)
- Service ceiling: 35,000 ft (11,300 m)
- Rate of climb: 2,665 ft/min (13.5 m/s)
- Wing loading: 24.56 lb/ft² (119.91 kg/m²)
- Power/mass: 0.22 hp/lb (0.36 kW/kg)
- Guns: Mk I, Mk II, Mk VA
- (VA) 8 × .303in (7.7 mm) Browning machine guns, 350 rpg
- (VB on) 2 × 20 mm (0.787-in) Hispano Mk II cannon, 60 rpg (drum magazine); (VC) 120 rpg (belt loaded, box magazine)
- 4 × 0.303 in (7.7 mm) Browning machine guns, 350 rpg
- 2 × 250 lb (113 kg) bombs
- Crew: 1
- Length: 32 ft 3 in (9.84 m)
- Wingspan: 40 ft 0 in (12.19 m)
- Height: 13 ft 1½ in (4.0 m)
- Wing area: 257.5 ft² (23.92 m²)
- Empty weight: 5,745 lb (2,605 kg)
- Loaded weight: 7,670 lb (3,480 kg)
- Max takeoff weight: 8,710 lb (3,950 kg)
- Powerplant: 1× Rolls-Royce Merlin XX liquid-cooled V-12, 1,185 hp (883 kW) at 21,000 ft (6,400 m)
- Maximum speed: 340 mph (547 km/h) at 21,000 ft (6,400 m)
- Range: 600 mi (965 km)
- Service ceiling: 36,000 ft (10,970 m)
- Rate of climb: 2,780 ft/min (14.1 m/s)
- Wing loading: 29.8 lb/ft² (121.9 kg/m²)
- Power/mass: 0.15 hp/lb (0.25 kW/kg)
- Guns: 4 × 20 mm (.79 in) Hispano Mk II cannons
- Bombs: 2 × 250 or 500 lb (110 or 230 kg) bombs
P-47C Thunderbolt (3/43 – 2/44)
Essentially similar to the P-47B, the initial P-47Cs featured strengthened all-metal control surfaces, an upgraded GE turbosupercharger regulator, and a short vertical radio mast. After the initial manufacture of a block of 57 P-47Cs, production moved to the P-47C-1, which had a 13 in (33 cm) fuselage extension forward of the cockpit at the firewall to correct center of gravity problems, ease engine maintenance and allow installation of a new engine mount. There were a number of other changes, such as revised exhausts for the oil coolers, and fixes to brakes, undercarriage, and electrical system as well as a redesigned rudder and elevator balance. The 55 P-47C-1s were followed by 128 P-47C-2s which introduced a centerline hardpoint with under-fuselage shackles for either a 500 lb (227 kg) bomb or a 200 U.S. gal (758 l, 167 Imp gal) fuel tank that conformed to the underside of the fuselage. The main production P-47C sub-variant was the P-47C-5 which introduced a new whip antenna and the R-2800-59 engine with water-methanol injection with a war emergency power rating of 2,300 hp (1,716 kW). With the use of pressurized drop tanks, the P-47C was able to extend its range on missions beginning 30 July 1943.
Republic P-47C-2-RE Thunderbolts of the 61st Fighter Squadron, 56th Fighter Group 41-6265 identifiable, 1943.
The P-47C was sent to England for combat operations in late 1942. The 56th FG was sent overseas to join the 8th Air Force, whose 4th and 78th Fighter Groups were soon to be equipped with the Thunderbolts. The 4th Fighter Group was built around a core of experienced American pilots, volunteers who had served with the British Royal Air Force (RAF) during 1941–43 in the Eagle Squadrons and who flew the Spitfire until January 1943. The 78th FG, formerly a P-38 group, also began conversion to the P-47 in January 1943.
The first P-47 combat mission took place 10 March 1943 when the 4th FG took their aircraft on a fighter sweep over France. The mission was a failure due to radio malfunctions. All P-47s were refitted with British radios, and missions resumed 8 April. The first P-47 air combat took place 15 April with Major Don Blakeslee of the 4th FG scoring the Thunderbolt’s first air victory. On 17 August, P-47s performed their first large-scale escort missions, providing B-17 bombers with both penetration and withdrawal support of the Schweinfurt-Regensburg mission, and claiming 19 kills against three losses.
By mid-1943, the Jug was also in service with the 12th Air Force in Italy, and it was fighting against the Japanese in the Pacific with the 348th Fighter Group flying escort missions out of Brisbane, Australia.
P-47D Thunderbolt (6/43 – 2/44)
- Crew: 1
- Length: 36 ft 1 in (11.00 m)
- Wingspan: 40 ft 9 in (12.42 m)
- Height: 14 ft 8 in (4.47 m)
- Wing area: 300 ft² (27.87 m²)
- Empty weight: 10,000 lb (4,536 kg)
- Loaded weight: 17,500 lb (7,938 kg)
- Max takeoff weight: 17,500 lb (7,938 kg)
- Powerplant: 1× Pratt & Whitney R-2800-59 twin-row radial engine, 2,535 hp (1,890 kW)
- Maximum speed: 433 mph at 30,000 ft (697 km/h at 9,145 m)
- Range: 800 mi combat, 1,800 mi ferry (1,290 km / 2,900 km)
- Service ceiling: 43,000 ft (13,100 m)
- Rate of climb: 3,120 ft/min (15.9 m/s)
- Wing loading: 58.3 lb/ft² (284.8 kg/m²)
- Power/mass: 0.14 hp/lb (238 W/kg)
- 8 × .50 in (12.7 mm) M2 Browning machine guns
- Up to 2,500 lb (1,134 kg) of bombs
- 10 × 5 in (130 mm) unguided rockets
P-51B Mustang (2/44 – 6/44)
In April 1942, the RAF‘s Air Fighting Development Unit (AFDU) tested the Mustang and found its performance inadequate at higher altitudes. As such, it was to be used to replace the Tomahawk in Army Cooperation Command squadrons, but the commanding officer was so impressed with its maneuverability and low-altitude speeds that he invited Ronnie Harker from Rolls-Royce‘s Flight Test establishment to fly it. Rolls-Royce engineers rapidly realized that equipping the Mustang with a Merlin 61 engine with its two-speed two-stage supercharger would substantially improve performance and started converting five aircraft as the Mustang Mk X. Apart from the engine installation, which utilized custom-built engine bearers designed by Rolls-Royce and a standard 10 ft 9 in (3.28 m) diameter, four-bladed Rotol propeller from a Spitfire Mk IX , the Mustang Mk X was a straightforward adaptation of the Mustang Mk I airframe, keeping the same radiator duct design. The Vice-Chief of the Air Staff, Air Marshal Sir Wilfrid R. Freeman, lobbied vociferously for Merlin-powered Mustangs, insisting two of the five experimental Mustang Mk Xs be handed over to Carl Spaatz for trials and evaluation by the U.S. 8th Air Force in Britain.
P-51B in flight showing wing planform
It was decided that the armament of the new P-51B (NA 102) would be the four .50 in (12.7 mm) M2/AN Browning machine guns (with 350 RPG for the inboard guns and 280 RPG for the outboard) of the P-51A, and the bomb rack/external drop tank installation (adapted from the A-36) would also be used; the racks were rated to be able to carry up to 500 lb (230 kg) of ordnance and were also capable of carrying drop tanks. The weapons were aimed using an N-3B optical gunsight fitted with an A-1 head assembly which allowed it to be used as a gun or bomb sight through varying the angle of the reflector glass. Pilots were also given the option of having ring and bead sights mounted on the top engine cowling formers. This option was discontinued on the later Ds.
The first XP-51B flew on 30 November 1942. Although flight tests confirmed the potential of the new fighter, with the service ceiling being raised by 10,000 feet and the top speed improving by 50 mph at 30,000 ft (9,100 m), it was soon discovered that the radiator duct airflow was breaking up at high speeds, generating a rumble as the exit shutter was closed. Testing at the Ames Aeronautical laboratory led to a redesign of the radiator scoop culminating in a forward slanted upper lip. After sustained lobbying at the highest level, American production was started in early 1943 with the B (NA-102) being manufactured at Inglewood, California, and the C (NA-103) at a new plant in Dallas, Texas, which was in operation by summer 1943. The RAF named these models Mustang Mk III. In performance tests, the P-51B reached 441 mph (709.70 km/h) at 30,000 ft (9,100 m). In addition, the extended range made possible by the use of drop tanks enabled the Merlin-powered Mustang to be introduced as a bomber escort with a combat radius of 750 miles using two 75 gal tanks.
The range would be further increased with the introduction of an 85 gal (322 l) self-sealing fuel tank aft of the pilot’s seat, starting with the B-5-NA series. When this tank was full, the center of gravity of the Mustang was moved dangerously close to the aft limit. As a result, maneuvers were restricted until the tank was down to about 25 gal (95 l) and the external tanks had been dropped. Problems with high-speed “porpoising” of the P-51Bs and Cs with the fuselage tanks would lead to the replacement of the fabric-covered elevators with metal-covered surfaces and a reduction of the tailplane incidence. With the fuselage and wing tanks, plus two 75 gal drop tanks, the combat radius was now 880 miles.
Despite these modifications, the P-51 Bs and Cs and the newer Ds and Ks experienced low-speed handling problems that could result in an involuntary “snap-roll” under certain conditions of air speed, angle of attack, gross weight, and center of gravity. Several crash reports tell of P-51Bs and Cs crashing because horizontal stabilizers were torn off during maneuvering. As a result of these problems, a modification kit consisting of a dorsal fin was manufactured.
“Unless a dorsal fin is installed on the P-51B, P-51C and P-51D airplanes, a snap roll may result when attempting a slow roll. The horizontal stabilizer will not withstand the effects of a snap roll. To prevent recurrence, the stabilizer should be reinforced in accordance with T.O. 01-60J-18 dated 8 April 1944 and a dorsal fin should be installed. Dorsal fin kits are being made available to overseas activities”
These kits became available in August 1944 and were fitted to Bs and Cs and to Ds and Ks. Also incorporated was a change to the rudder trim tabs, which would help prevent the pilot over-controlling the aircraft and creating heavy loads on the tail unit.
P-51Bs and Cs started to arrive in England in August and October 1943. The P-51B/C 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.
P-51D Mustang (6/44 – 12/44)
- Crew: 1
- Length: 32 ft 3 in (9.83 m)
- Wingspan: 37 ft 0 in (11.28 m)
- Height: 13 ft 8 in (4.17 m)
- Wing area: 235 ft² (21.83 m²)
- Empty weight: 7,635 lb (3,465 kg)
- Loaded weight: 9,200 lb (4,175 kg)
- Max takeoff weight: 12,100 lb (5,490 kg)
- Powerplant: 1× 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 WEP
- Zero-lift drag coefficient: 0.0163
- Drag area: 3.80 ft² (0.35 m²)
- Aspect ratio: 5.83
- Maximum speed: 437 mph (703 km/h) at 25,000 ft (7,620 m)
- Cruise speed: 362 mph (580 km/h)
- Stall speed: 100 mph (160 km/h)
- Range: 1,650 mi (2,755 km) with external tanks
- Service ceiling: 41,900 ft (12,770 m)
- Rate of climb: 3,200 ft/min (16.3 m/s)
- Wing loading: 39 lb/ft² (192 kg/m²)
- Power/mass: 0.18 hp/lb (300 W/kg)
- Lift-to-drag ratio: 14.6
- Recommended Mach limit 0.8
- 6 × 0.50 in (12.7 mm) machine guns; 400 rounds per inboard gun; 270 per outboard gun
- 2 × hardpoints for up to 2,000 lb (907 kg) of bombs
- 10 × 5 in (127 mm) rockets
P-51K Mustang (12/44 – end)