Chance-Vought F4U / F2G Corsair
A design team headed by Rex Biesel and lgor Sikorsky set out to tackle a February 1938 US Navy requirement for a single seat carrier borne fighter; the challenge being to build the smallest possible fighter around the most powerful air cooled engine then under development.
Such a huge propeller was required for the world's first 2000 horse power engine - a Pratt and Whitney 18 cylinder two row Double Wasp radial - that the team followed Junker's lead in using an inverted gull wing to provide sufficient ground clearance for the 4.1 metre (13 feet 4 inch) three bladed Hamilton constant speed propeller.
The wing design also enabled the use of short and strong oleo legs capable of withstanding operational carrier landings and, as an added benefit, the wings folded from the lowest part of the wing to provide a low overall height when the wings were in folded configuration. On retraction the gear rotates through 89 degrees and then folds backwards into the wing. As the weight is taken off the oleos the legs are prevented from extending by cables. The distinctive gull wing shape was used to allow the very large diameter propeller to be used and still keep a relatively short strong undercarriage for aircraft carrier operations.
In 1938 the Navy became involved in three new fighter projects - the Grumman XF5F-1 and similar USAAF XP-50, the Bell XF1-1 and the Vought XF4U-1. The long term intention was to bolster the Navy's sagging carrier forces whose squadrons flew the Grumman F3F-2 biplane fighter harking back to the mid-1930s.
Chance Vought won the contract and the project was under way. The Corsair's first test flight on 29 May 1940 - the delay being largely the result of engine development problems - resulted in the elevator tabs tearing loose during a high frequency oscillation just above 200 mph. Lyman Bullard Jnr, Chance Vought test pilot, landed the prototype successfully despite the damage to the control surfaces. By October the aircraft had recorded a ground speed of over 400 mph, the first US military aircraft to exceed that speed.
Some 12,681 of them were built over the following 10 years.
US Navy pilots were enthusiastic about the aircraft's rate of climb and speed but had reservations about inadequate forward vision during takeoff and landing, a marked tendency to torque stall in carrier approach configurations and a lack of directional stability following touchdown. There appears no doubt that, had the necessity for a high speed carrier-borne fighter not been paramount, the Corsair could well have become an also ran. Instead the US Navy issued a contract for 584 units and the first production example flew on 25 June 1942.
The production machines featured the cockpit moved rearwards to make room for the fuel tankage, shifted from the wings to make way for six .50 Browning machine guns, and the even further impaired forward view - plus the still unsolved directional instability after landing and the threat of torque stall on approach - led the US Navy to decide that the Corsair was unsuitable for combat in the hands of average carrier pilots.
Instead the production delivery was re-allocated to the US Marines for land-based operations; the first unit (VMF124) flying its first operational mission from Guadalcanal on 1 February 1943 and, within six months, all Marine squadrons in the Pacific had been equipped with the Corsair.
The Marine Corsairs provided immediate protection for the bombing raids on Rabaul, usually flown at 20,000 feet with the P-40s flying below and the P-38 Lightning as top cover above 30,000 feet.
Some 688 F4U-1s were built before a bubble canopy and undercarriage modifications led to the F4U-1A model.
By August 1943 both Goodyear (FG-1) and Brewster (F3A1) had joined Chance Vought in the production of Corsairs. Goodyear-built FG-1Ds were distinguished from the F4U-1D by clear blown canopies, underwing rocket launching stubs and starting courtesy of a electric battery cart rather than cartridges.
It was at this time that the British Royal Navy gladly accepted 95 early F4U-1 models, designated Corsair Mk.1s, for carrier service. The Royal Navy, after clipping eight inches off each wing to enable the fighters to be fitted underneath the flight deck, operated the Corsair in the European theatre alongside their Fleet Air Arm Wildcats, Hellcats and Seafires. A notable operation was the attack by HMS Victorious-based Corsairs on the German pocket battleship Tirpitz in Kaa Fjord. By April 1944 Royal Navy Corsairs were in operation in the Pacific.
The US Navy accepted the F4U-1D in April 1944 for carrier trials - the new designation covering a multitude of modifications such a full plexiglass canopy to replace the metal braced flat sided canopy of the -1, a higher placed pilot's seat for improved visibility, longer stroked oleos, modified aileron mechanism to improve control at low speeds, and more power from a water injected P&W R2800-8W. The Corsair remained a difficult aircraft for US carrier operations.
After six months the US Navy cleared the Corsair for combat duty, the first operation unit (VF17) flying from New Georgia as a shore-based squadron. It was not until late in 1944 that a Corsair-equipped Marine squadron (VMF124) joined the USS Essex and proved highly successful against Kamikaze attacks. By the end of the Okinawa campaign all US Navy carriers were equipped with Corsairs.
An early night-fighter version, the XF4U-2 was operated by an American specialist unit flying out of Munda on New Georgia with two machine guns removed and an early mark of airborne interception radar (an APS-4) mounted on the wing leading edge and an autopilot fitted. The six aircraft were the first radar carrying single seat fighters.
Charles Lindberg, acting as a civilian technical representative for United Aircraft in the Pacific combat area, pioneered the process of doubling the Corsair bomb load from 2000 to 4000 lbs.
Re-introduced in the early -1D were wing leading edge fuel tanks, small 62 gallon unprotected units outboard of the gunbays. Most later F4U-1Ds differed in having the outboard-wing leading edge fuel tanks deleted and hard points for bombs or external fuel tanks installed under the centre section.
The RNZAF was issued with 424 of these aircraft; thirteen squadrons eventually used the aircraft. Corsairs in RNZAF service did have their problems - predominately centering on the complex hydraulic system, the engine, bombracks, brakes, and ailerons - the main spar of which rotted out after about a year due to water. The F4U-1 wing tanks on the leading edges wept petrol through rivet holes after a few months service due to the vibration of the Brownings, and caused these tanks to be sealed off. This was the primary difference between the F4U-ls and the -1Ds in the RNZAF. FG-1D’s were similar to F4U-1Ds but introduced a clear blown pilot canopy and rocket launching stubs underwing.
With dive brakes extended, the airspeed would stabilise at about 300 knots, but in the clean condition, the aircraft was permitted to indicate 420 knots between 7,500 feet and sea level, which was 470 knots true airspeed.
As early as 1941 the US Navy had requested better high altitude performance from Chance Vought and, in July 1944, the F4U-4 with an uprated Pratt and Whitney R2800-18W engine with water/methanol and driving a four bladed propeller, made its first test flight. The -4 proved to have a top speed of 425 mph (680 kph) at 28,000 feet, compared with the -1 of 392 mph (630 kph) at 24,000. The first F4U-4 went into service in January 1945, being operated until the end of the Korean War as a carrier borne fighter bomber.
The F4U-5 was developed to meet a high altitude fighter requirement for the United States Navy in 1947. It differs from the F4U-1 and FG-ID series in a number of respects; a four bladed propeller, twin cheek inlets on the cowling for the side mounted superchargers, metal covered outer wing rear panels (instead of fabric aft of the main spar) to reduce drag and a slightly more bulged canopy to improve rearward vision. The uprated 2850 hp R-2800-32W engine was titled downward 2.75' to improve stability and forward vision.
Although most contracts for fighters were cancelled at the end of WW2 the Corsair remained in production. Only 5 F4U-5 were built in 1947, 61 in 1948, and 69 in 1949.
The last of 14 F4U-5N was delivered to the US Navy on 22 October 1951. The winterised F4U-5NL had a production run of 100 during 1950-51.
The F4U-5N night fighter variant differs significantly from the -1 model in having different engines, propeller, cowls and exhaust system as well as a later style canopy with a raised section aft.
The XF4U-5 first flew on 4 April 1946 and introduced a new engine. The wings were totally skinned in metal and ailerons were given spring tabs. Heaters were provided for the windshield, gun bays and pitot head. A similar low altitude version with the R-2800-83W engine and increased armour was originally designated F4U-6, and later AU-1. Some 101 F4U-5Ns were winterised for service in Korea as F4U-5NLs with wing and empennage boots, propellor de-icer shoes and windshield de-iceing. The F4U-5N had the APS-19A radar. The last operational Corsairs in United States Navy services were withdrawn in December 1955 and the last of the Reserve Squadron F41J-5s were retired in June 1957.
During the Korean War the US Navy used 27 F4U day squadrons. In addition VC-3 flew F4U-5NL night fighters with attachments on every carrier.
The F2G-1 was the “Sprint” Corsair developed by Goodyear in 1945 using the Wasp Major engine. Only 17 were built. The Goodyear F2G is distinguishable from the Chance-Vought Corsair by having a clear blown canopy.
The last Corsairs to see actual air to air combat were those of the Honduran Air Force during the 11-19 border war between Honduras and El Salvador. On 17 July 1969 a Honduran pilot flying an F4U-5 shot down a P-51D Mustang and two FG-1 Corsairs. The Honduran Corsairs were subsequently sold to collectors in the USA.
The aircraft was used by the French naval air arm during the Suez operations in 1956.
In production from 1941 to 1952, a total of 12,571 were built.
XF4U-1 - Prototype
VS-317 Modifications on XF4U-1
F4U-1 – Production, seat moved aft 3 ft
VS-321 Modifications on F4U-1
VS-323 F4U-1 with Wright R-3350 engine
VS-324 Modifications on F4U-1
VS-325 Modifications on F4U-1
F4U-1B – Production for British Royal Navy
F4U-1C – Four 20 mm cannon
F4U-1D – Twin pylons for fuel tanks or bombs
F4U-1P – Photographic equipment
XF4U-2 – Special night fighter, radar gear
F4U-2 – modified by Navy as night fighter
VS-331 XF4U-3 – projected turbosupercharger version
XF4U-4 – new engine, propeller, cowling, carberator
V-334 F4U-4 – basic production version
V-336 F4U-1WM (F4U-1 with P&W R-4360 Wasp Major)
V-342 F4U with E engine
F4U-4B – Produced for Royal Navy
F4U-4C – Four 20 mm cannon
F4U-4N – night fighter version
F4U-4P – Photographic version
F3A-1 – Manufactured by Brewster
F3A-1D – Mrewster model of F4U-1D
FG-1 – Manufactured by Goodyear (F4U-1)
FG-1D – Goodyear version of F4U-1D
FG-1E – Radar equipped
FG-3 – Turbosupercharger version
F2G – 3000 hp engine version
XF4U-5 – New P&W engine, supercharger
V-351 F4U-5 – R-2800-32(e) engine, max speed 480 mph
V-354 F4U two seat advanced trainer
V-376 F4U for Perú
V-361 F4U-5 variant
F4U-5N - Night fighter version
F4U-5P – Photographic version
F4U-5NL – Winterised version for Korea
AU-1 – Low altitude attack version, Korean war
F4U-7 – Same as F4U-4 for French Navy
Vought F 4 U Corsair
Engine: Pratt & Whitney R 2800 18W Double Wasp, 2416 hp
Length: 33.661 ft / 10.26 m
Height: 14.764 ft / 4.5 m
Wingspan: 40.912 ft / 12.47 m
Wing area: 313.986 sqft / 29.170 sq.m
Max take off weight: 14672.1 lb / 6654.0 kg
Weight empty: 9205.9 lb / 4175.0 kg
Max. speed: 388 kts / 718 km/h
Service ceiling: 41503 ft / 12650 m
Wing load: 46.74 lb/sq.ft / 228.00 kg/sq.m
Maximum range: 1356 nm / 2511 km
Range: 873 nm / 1617 km
Armament: 6x cal,.50 mg (12,7mm), 2x 454kg Bomb./ 8x 5"-Rocket
Engine: Pratt & Whitney R2800-8W Double Wasp, 2250 hp.
Wing span: 41 ft.
MAUW overload: 14,000 lb.
Engine: Pratt & Whitney R2800-8W Double Wasp, 2000 hp.
Length 33.3 ft. (10.15 m.).
Wing span 41 ft. (12.5 m.).
Weight empty 8,980 lb. (4,070 kg.).
Max wt: 5,465kg (12,039 lb).
Crew 1 pilot.
Armament 6 x 0.50 in. machine-guns, 2 x 1,000 lb. (450 kg.) bombs; or 8 x 5 in. (13 cm.) rockets.
Max speed 417 mph (670 kph).
Range 1,015 miles (1,630 km.).
Engine: Pratt & Whitney R2800-32W Double Wasp, 2850 hp.
Engine: P&W R2800-8W Double Wasp 18-cylinder radial, 2,000 hp
Wing span: 41’0”
Length of 33’4.5”.
Sevice ceiling: 37,000 ft.
Range: 1015 sm.
Engine: Pratt & Whitney R2800 Double Wasp, 2850 hp.
Max speed: 470 mph.
Range: 1120 mile.
Engine: Pratt & Whitney R2800 Double Wasp, 2850 hp.
Max speed: 470 mph.
Range: 1120 mile.
Engine: 2,100 h.p. R2800
Span: 40 ft. l1.75 in
Weight: 13,300 lb.
Max. Speed: 470 m.p.h.
Armament: 4x20 mm. Cannon
Engine: Pratt & Whitney R-2800-83W Double Wasp.
Engine: Pratt & Whitney R-4360 Wasp Major, 3000 hp.
Engine: Pratt & Whitney R-2800-8W.