F4U Corsair Design and Development
An aircraft company better known for producing biplanes hit an aviation home run in 1938
when it unveiled the iconic design of this much-respected WWII fighter/bomber. The Corsair
was the Marine Corps’ workhorse fighter and arguably the best fighter in World War
II. But let’s start from the beginning. On February 1, 1938, the United States Navy
Bureau of Aeronautics requested proposals from American aircraft manufacturers for a
new single-engine, carrier-based fighter airplane. The Navy requested the maximum obtainable
speed, and a stalling speed not higher than 70 miles per hour. A range of 1,000 miles
was specified. The fighter had to carry four guns, or three with increased ammunition.
Provision had to be made for anti-aircraft bombs to be carried in the wing. These small
bombs would, according to thinking in the 1930s, be dropped on enemy aircraft formations.
Development of the F4U Corsair began in early 1938, headed-up by Vought Aircraft’s Chief
Engineer, Rex Biesel, who was a pioneer in the science and industry of aviation. He was
the lead designer of several successful military and civilian aircraft, but his real glory
was creation of the Corsair. The F4U was the first U.S. Navy aircraft to
feature landing gear that retracted into a fully enclosed wheel well. The landing gear
oleo struts—each with its own strut door enclosing it when retracted—rotated through
90° during retraction, with the wheel atop the lower end of the strut when retracted.
A pair of rectangular doors enclosed each wheel well, leaving a streamlined wing.
Reports coming back from the war in Europe indicated that an armament of two .30 inch
synchronized engine cowling-mount machine guns, and two .50 inch machine guns (one in
each outer wing panel) was insufficient. The U.S. Navy's November 1940 production proposals
specified heavier armament, so Rex Biesel redesigned each outboard folding wing panel
to carry three .50 caliber machine guns. These guns displaced fuel tanks installed in each
wing leading edge. To replace this lost capacity, a 237-gallon fuselage tank was installed between
the cockpit and the engine. When the prototype was completed, it had the
biggest and most powerful engine, largest propeller, and probably the largest wing on
any naval fighter to date. The airplane also had another striking feature, an inverted
gull-shaped bent wing. This arrangement gave additional ground clearance for the propeller
and reduced drag at the wing-to-fuselage joint. The Corsair's aerodynamics were an advance
over those of contemporary naval fighters. Test Flights
Vought test pilot Lyman A. Bullard, Jr., first flew the Vought XF4U-1 prototype on May 29,
1940. The R-2800 radial air-cooled engine developed 1,850 horsepower and it turned a
three-blade Hamilton Standard Hydromatic propeller with solid aluminum blades spanning 13 feet,
1 inch. On the Corsair’s maiden flight, she broke the speed record for a single-seat
fighter aircraft by exceeding 400 miles per hour in level flight. When naval air strategists
had crafted the requirements for the new fighter, the need for speed had overridden all other
performance goals. Actually, the cockpit was well back on the fuselage, creating line-of-sight
issues for pilots, and the aircraft had a tendency to bounce on landing, something not
desirable for aircraft carrier use. Landing techniques for the Corsair developed by the
British Navy finally enabled use as a carrier aircraft.
Other problems were encountered in early carrier trials. During landing approaches, it was
found that oil from the opened hydraulically-powered cowl flaps could spatter onto the windscreen,
severely reducing visibility, and the undercarriage oleo struts had bad rebound characteristics
on landing, allowing the aircraft to bounce down the carrier deck. The first problem was
solved by locking the top cowl flaps in front of the windscreen down permanently, then replacing
them with a fixed panel. The undercarriage bounce took more time to solve, but eventually
a "bleed valve" incorporated in the legs allowed the hydraulic pressure to be released gradually
as the aircraft landed. Formal U.S. Navy acceptance trials for the
XF4U-1 began in February 1941. The Navy entered into a letter of intent on March 3, 1941,
received Vought's production proposal on April 2, and awarded Vought a contract for 584 F4U-1
fighters on June 30 of the same year. The planes were given the name "Corsair," inherited
from the firm's late-1920s Vought O2U naval biplane scout, which first bore the name.
The first production F4U-1 performed its initial flight a year later, on June 24, 1942. It
was a remarkable achievement for Vought; compared to land-based counterparts, carrier aircraft
are "overbuilt" and heavier, to withstand the extreme stress of deck landings. The Corsair,
even with its streamlining and high speed abilities, could fly slowly enough for carrier
landings with full flap deployment of 60°. Carrier qualification trials on the training
carrier USS Wolverine and escort carriers USS Core and USS Charger in 1942 found that,
despite visibility issues and control sensitivity, the Corsair was "...an excellent carrier type
and very easy to land aboard. It is no different than any other airplane." Two Navy units,
VF-12 (October 1942) and later VF-17 (April 1943) were equipped with the F4U. By April
1943, VF-12 had successfully completed deck landing qualification. At the time, the U.S.
Navy also had the Grumman F6F Hellcat, which did not have the performance of the F4U, but
was a better deck landing aircraft. Combat in the Pacific
The Corsair was declared "ready for combat" at the end of 1942, though qualified to operate
only from land bases until the last of the carrier qualification issues were worked out.
VF-17 went aboard the USS Bunker Hill in late 1943, and the Chief of Naval Operations wanted
to equip four air groups with Corsairs by the end of 1943. The Commander, Air Forces,
Pacific had a different opinion, stating that, "In order to simplify spares problems and
also to insure flexibility in carrier operations present practice in the Pacific is to assign
all Corsairs to Marines and to equip FightRons [fighter squadrons] on medium and light carriers
with Hellcats." Because of this, the first Corsairs into combat were flown with great
success by land-based Marines who later named it the "Angel of Okinawa." The land-based
Marines were the first U.S. forces to fly the Corsair in combat. It was not until the
British proved that the Corsair could safely operate from carriers that the Navy put the
type into service in January of 1944. From February 1943 onward, the F4U operated
from Guadalcanal and ultimately other bases in the Solomon Islands. The first recorded
combat engagement was on February 14, 1943, when Corsairs of VMF-124 under Major Gise
assisted P-40s and P-38s in escorting a formation of Consolidated B-24 Liberators on a raid
against a Japanese aerodrome at Kahili. Japanese fighters contested the raid and the Americans
got the worst of it, with four P-38s, two P-40s, two Corsairs, and two Liberators lost.
No more than four Japanese Zeros were destroyed. A Corsair was responsible for one of the kills,
albeit due to a midair collision. The fiasco was referred to as the "Saint Valentine's
Day Massacre." Despite the debut, the Marines quickly learned how to make better use of
the aircraft and started demonstrating its superiority over Japanese fighters. By May,
the Corsair units were getting the upper hand, and VMF-124 had produced the first Corsair
ace, Second Lieutenant Kenneth A. Walsh, later a Medal of Honor recipient, who would rack
up a total of 21 kills during the war. One particularly unusual kill was scored by
Marine Lieutenant R. R. Klingman of VMF-312 (the "Checkerboards") over Okinawa. Klingman
was in pursuit of a Japanese twin-engine aircraft at high altitude when his guns jammed due
to the gun lubrication thickening from the extreme cold. He flew up and chopped off the
enemy's tail with the big propeller of the Corsair. Despite missing five inches off the
end of his propeller blades, he managed to land safely after this aerial ramming attack.
He was awarded the Navy Cross. Corsairs also served well as fighter-bombers in the Central
Pacific and the Philippines. By early 1944, Marine pilots were beginning to exploit the
type's considerable capabilities in a close-support role in amphibious landings. The Corsair proved
versatile, able to operate everything from Bat glide bombs to 298 mm Tiny Tim air-to-ground
rockets. The F4U had an immediate impact on the Pacific
air war. Unprotected by armor or self-sealing fuel tanks, no Japanese fighter or bomber
could withstand for more than a few seconds the concentrated volley from the six .50 caliber
machine guns carried by a Corsair. Marine and Navy pilots flew 64,051 operational sorties,
54,470 from runways and 9,581 from carrier decks. During the war, the British Royal Navy
accepted 2,012 Corsairs and the Royal New Zealand Air Force accepted 364. The demand
was so great that the Goodyear Aircraft Corporation and the Brewster Aeronautical Corporation
also produced the F4U. On September 2, 1945, the Navy credited Corsair pilots with destroying
2,140 enemy aircraft in aerial combat. The Navy and Marines lost 189 F4Us in combat and
1,435 Corsairs in non-combat accidents. "Pappy" Boyington and "Lucky" Lindbergh
On September 7, 1943, Major Gregory "Pappy" Boyington assumed command of Marine Corsair
squadron VMF-214, nicknamed the "Black Sheep" squadron. In fewer than five months of action,
Boyington received credit for downing 28 enemy aircraft. The Corsairs flown by VMF-214 were
seldom flown by the same pilot every day. In fact, Pappy would always fly the plane
in the poorest condition on every mission, just so a pilot under his command wouldn’t
have to do so. Enemy aircraft shot him down on January 3, 1944, but he survived the war
in a Japanese prison camp. In May and June 1944, Charles A. Lindbergh
(nicknamed "Lucky Lindy"), the first person to fly solo acorss the Atlantic, flew Corsair
missions with Marine pilots at Green Island and Emirau. On September 3, 1944, Lindbergh
demonstrated the F4U's bomb hauling capacity by flying a Corsair from Marine Air Group
31, carrying three bombs, each weighing 1,000 pounds. He dropped this load on enemy positions
at Wotje Atoll. On September 8, Lindbergh dropped the first 2,000-pound bomb during
an attack on the atoll. For the finale five days later, the trans-Atlantic flyer delivered
a 2,000-pound bomb and 1,000-pound bombs. Lindbergh went ahead and flew these missions
after the commander of MAG-31 informed him that if he were forced down and captured,
the Japanese would almost certainly execute him.
Korea and Beyond During the Korean War, the F4U was used mostly
in a close-support role. The Corsair could loiter over an area longer when providing
low-level close air support. The versions of the Corsair used in Korea from 1950 to
1953 were the AU-1, F4U-4B, -4P, -5N, and 5-NL. There were dogfights between F4Us and
Soviet-built Yakovlev Yak-9 fighters early in the war, but when the enemy introduced
the Mikoyan-Gurevich MiG-15, the Corsair was outmatched.
F4U-5N and -5NL Corsair night fighters were used to attack enemy supply lines, including
truck convoys and trains, as well as to interdict night attack aircraft such as the Polikarpov
Po-2 "Bedcheck Charlies," which were used to harass United Nations forces at night.
Lieutenant Guy Bordelon of VC-3 Detachment D, off USS Princeton, become the Navy's only
ace in the war, in addition to being the only American ace in Korea that used a piston-engined
aircraft. Bordelon, nicknamed "Lucky Pierre," was credited with three Lavochkin La-9s or
La-11s and two Yakovlev Yak-18s between June 29 and July 16/17, 1952. Navy and Marine Corsairs
were credited with a total of 12 enemy aircraft. The Corsair was nicknamed "whistling death"
by ground troops because of its distinctive sound when in attack mode at lower altitudes.
F4Us, the last to be produced, also saw an anti-communist role when they were used by
France during the First Indochina War, and some remained in French military service to
the 1960s. From the first prototype delivery to the U.S. Navy in 1940, to final delivery
in 1953 to the French, 12,571 F4U Corsairs were manufactured in 16 separate models. Their
1942–1953 production run was the longest of any U.S. piston-engined fighter.
