The Chance Vought F4U Corsair
By Chuck Hawks
The Chance Vought F4U Corsair proved to be the most capable carrier based fighter of the Second World War. This big, fast, and manuverable Navy and Marine fighter was designed around the Pratt and Whitney XR-2800 Double Wasp engine, which promised to be the most powerful aircraft engine in the world at that time. This very successful twin row 18 cylinder radial engine initially produced about 1850 HP, and ultimately produced about 2,450 HP with water injection by the end of the war.
In February 1938 the U.S. Navy requested proposals for new carrier based fighter. A Vought design team led by Rex Beisel was assembled to create the Vought proposal that ultimately became the Corsair. Beisel's basic idea for the new fighter was a fairly simple concept: he wanted the smallest airframe that would allow use of the proposed 1,850 HP Pratt and Whitney Double Wasp radial engine. The Navy preferred air-cooled radial engines due to their greater reliability and ability to absorb battle damage and still function (compared to liquid-cooled engines).
The most distinctive feature of the new Vought fighter was its "cranked" or inverted gull wing. It gave the V-166B (as it was known inside the company) a unique look among WW II fighters, a look that is still popular today. I was recently told by a model airplane retailer that the P-51 Mustang and F4U Corsair are by far the most popular WW II fighter models.
The inverted gull wing was designed to raise the nose of the airplane farther from the ground without unduly lengthening the undercarriage. The reason was to allow the use of the largest possible diameter propeller in order to make most efficient use of the engine's high power. It also allowed the wing's hinge point to be a little closer to the ground, and the tips consequently a little lower when folded, giving a little more hanger deck roof clearance on board aircraft carriers. The wings, by the way, were power folded by the pilot, unlike most earlier carrier planes whose wings had to be folded manually by the deck crew. The propeller selected was a three-bladed Hamilton-Standard Hydromatic constant speed model.
The Navy ordered a prototype of the proposed Vought fighter in June 1938, which first flew in May 1940. In October the XF4U-1, as the Navy called it, achieved a speed of 404 MPH in level flight, the first U.S. made aircraft to do so. Armament was a mix of .30 and .50 caliber machine guns mounted in the wings and cowl.
The XF4U-1 also became the first Navy fighter to encounter shock stall. This insidious problem affected the first generation of U.S. fighters to achieve high mach numbers in a dive and was due to their lack of laminar flow wings. In other words, the F4U, P-38 and P-47 all had wings that were thick in cross section, which provided high lift, but caused the early formation of shock waves as the air flow over them reached supersonic speeds in high altitude, high speed dives. These standing shock waves degraded the lift normally provided by the wings, resulting in an increasingly steeper and faster dive from which the pilot could not pull out until the plane reached the thicker air of lower altitudes, where drag increased enough to slow the plumeting aircraft and gradually return control to the pilot. Such uncontrolled dives were terrifying and could be fatal if they happened over mountainous terrain where the pilot might run out of altitude before enough speed bled away to permit recovery.
A series of revisions were implemented as problems were identified. These included a more powerful 2,000 HP R-2800-8 engine and a revised fuel system, which required moving the cockpit 3 feet back to maintain a correct center of gravity. This had the unfortunate side effect of reducing the pilot's forward visibility in nose high attitudes, as when landing. The armament was revised and became 6-.50 caliber wing mounted machine guns (3 per wing). The improved Corsair F4U-1 was ordered into production in the Autumn of 1941.
The first production F4U-1's were delivered in June 1942. By September 1942 Marine Squadron VMF 124 had been equipped with the new fighter, which was declared combat ready that December.
F4U-1's reached the Marines fighting desperately to hold Guadalcanal, in the Solomon Islands, in February of 1943. Just in the nick of time, as the saying goes, as the outcome of that crucial turning-point battle was balanced on a razor's edge.
The famous "Black Sheep" squadron of book and TV series fame immortalized the Corsair in the blue South Pacific skies. The Marines found that the new fighter at last gave them superiority over the Zero, as long as they did not try to turn with the lighter Japanese plane. The Corsair was much faster than the Zero, had a better roll rate and could dive away to safety when necessary. Corsair pilots established a very satisfactory kill ratio against Japanese fighters and helped turn the tide in the Solomons (and later battles). The F4U-1 had a top speed of 393 m.p.h. at 25,000 ft. Later water injection was added to the radial engine, raising the top speed to 415 m.p.h.
Although U.S. Navy and Marine pilots operated the Corsair from a multitude of airfields hewn from Pacific atolls, it wasn't until April 1944 that the Navy cleared the powerful fighter for shipboard use. This delay was primarily due to the Corsair's high (for the time) landing speed and the pilot's limited forward visibility over the big radial engine when landing. By that time the British Royal Navy had been operating Corsair fighters from aircraft carrier decks for nine months.
The Corsair was continuously modified and improved throughout the war. By 1945 over 3000 minor and major improvements had been made, including a four-blade propeller.
The F4U-2 was a night fighter variant adapted from some dozen F4U-1's. An A1 airborn radar was fitted to the right wing and two guns deleted to compensate for the increased weight. An autopilot was also added. Two specialized night fighter units were formed. Six of the F4U-2's were sent to Munda Island and the other six assigned to the famous aircraft carrier Enterprise, thus becoming the first specialized night fighter unit to operate at sea.
The XF4U-3 was a high altitude version of the Corsair based on the F4U-1 airframe fitted wth a two stage supercharged engine that could deliver 2,000 HP up to 40,000 feet. Only a few were completed. The project was never fully implemented due to the press of other affairs.
The definitive Corsair was the F4U-4. Major improvements evident in the F4U-4 included a four-bladed Hamilton Standard Hydromatic propeller, a new cockpit layout, a clear view sliding hood, a two stage supercharged engine and under wing attachment points for 8-5 inch rockets or bombs. The new engine pumped out 2,450 HP with water injection and that, plus the four-bladed propeller, improved both speed and climb rate. Most F4U-4's retained the standard armament of six .50 caliber wing mounted machine guns, but some 297 F4U-4B's were produced with 4-20mm cannons in place of machine guns. Specifications for the F4U-4 follow.
The last U.S. Navy version of the Corsair was the F4U-5, which first flew in April 1946. The F4U-5 used an F4U-4 airframe and an R-2800-32W (2,675 HP) engine. The principal difference was the new standard armament of 4-20mm wing mounted cannons and an increased bomb load of 5,200 pounds. The F4U-5 was produced in fighter, fighter bomber, reconnaissance and night fighter variants.
The final order for 94 Corsair fighter-bombers came from the French Navy and were designated F4U-7. They were similar to the fighter bomber variant of the F4U-5. Many of these aircraft saw combat in Indo-China. The final F4U-7 Corsair was completed on 31 Jan 1953.
Unlike most American piston engine fighters, but like the P-51, the Corsair continued to serve long after the end of WW II. Corsairs served in three major wars, the Second World War, the Korean War and with the French in Indochina (Vietnam). It also served as a carrier based fighter with the British Royal Navy during and after the war and with the navies and air forces of a number of minor powers. In the post WW II years it was employed primarily as a ground attack fighter, a role for which it was well suited.
One Corsair, piloted by the redoubtable Charles Lindbergh, delivered 4,000 pounds of bombs in an attack at Wotje Atoll. My Dad spent a couple of weeks with Lindbergh during the Korean War, showing him around the latest Air Force projects and trading aviation stories late into the night. Dad said that Lindbergh was a most interesting and likable person and a terrific pilot.
Another Corsair received an official citation for flying 100 combat missions and 80,000 miles in service. Interviews conducted after the war revealed that Japanese fighter pilots considered the F4U to be the best all-around American fighter.
The Corsair was, without a doubt, one of the great fighters of WW II and just about the first carrier based fighter that could hold its own with the best land based fighters. The respect shown it by its adversaries and its key role in the Pacific Theater of the Second World War, not to mention its later service during the Korean War, are really all the testimonials this great fighter plane needs.
Copyright 2003, 2012 by Chuck Hawks. All rights reserved.