Brève Histoire du Corsair (3)


Shown above is a F4U Corsair from US Marines VMA-323, circa 1952.


The F4U-4 was one of the more important variants of the Corsair. Seven prototypes were built, anticipating the many problems which would arise from the proposed changes. Five F4U-1s were pulled from the production line to be modified into the XF4U-4A, ‘4B, ‘4C, ‘4D and’4E. Two more "FG-1" aircraft (identical to the Vought F4U-1) were pulled from Goodyear’s production line. They were all fitted with the Pratt-Whitney R-2800-18W engine which produced 2,100 hp (1,567 kW) and sported a new four blade prop. The engine also had methanol-water injection which boosted the war emergency power rating to 2,450 hp (1,828 kW) for about five minutes. The 18W engine necessitated changes in the basic airframe to handle the extra power and the turbo air intake was mounted on the inside bottom of the engine cowling (it was called a "chin scoop") while air for the intercooler and oil cooler continued to be drawn from the wing slots. The F4U-4 was clocked at a top speed of 446 mph (717.75 kph) at 26,200 ft (7,985.76 m).

Although it wasn’t designated by the Navy as such, the dash four was a fighter-bomber for all intents and purposes. It had 6 Colt-Browning .50 cal. (12.7 mm) wing mounted machine guns (the F4U-4C substituted four 20 mm cannon), plus it could carry two 1,000 lb (453.6 kg) bombs or eight 5 inch (127 mm) rockets. The first 300 of the production F4U-1Cs were assigned to Marine Air Group 31 and were taken into the Battle for Okinawa aboard the escort carriers Sitko Bay and Bereton. The Army and Marine riflemen who fought that battle on the ground remember the F4U-4 as the "Sweetheart of Okinawa" and it undoubtedly saved many hundreds of their lives.

The prototype "Dash Five" was flown in December 1945, a few months after World War Two had ended. It utilized all the knowledge built up over the war years and major changes were made to upgrade the F4U-5 Corsair. First, the engine was changed to the Pratt-Whitney R-2800-32W. This was called a "Series E" engine and featured a dual supercharger to boost engine power to 2,350 hp (1,753.7 kW) at 26,200 ft (7,985.8 m). War emergency power was boosted to 2,760 hp (2,059.7 kW). The dual supercharger necessitated removing the chin scoop and installing two "cheek" scoops inside the engine cowling.

Due to the higher horsepower, the fuselage was lengthened by 5 inches (127 mm) and the engine angled down about 2º to provide more stability. Until the dash 5, the outer top wing panels and the control surfaces of the Corsair had been fabric covered. At speed, the fabric tended to deform and slow the aircraft by a few miles per hour. The F4U-5 had all fabric surfaces replaced with sheet duralumin to minimize this problem. Armament was the same as the F4U-4.

  

Shown above is the F4U Corsair of Lt. J.G. Ira Kepford from US Navy VF-17, circa 1944.

 
A few improvements were made solely for pilot comfort. Cockpit heating was redesigned, controls were made easier to operate and/or automatic. Armrests were installed on the seat, which reclined slightly. With the improvements and the -32W engine, the dash five could operate very comfortably at altitudes approaching 45,000 feet (13,716 meters).

The AU-1 project began life as the F4U-6 but was quickly redesignated by the Navy to reflect its ground attack role. The dash six was never built. The AU-1 was produced solely for the US Marines during the height of the Korean War. Deliveries began in January 1952 and a total of 111 were supplied during the year. The AU-1 was powered by an R-2800-83W Double Wasp with a single stage supercharger, developing 2,300 hp (1,716.4 kW) for take off and 2,800 hp (2,089.6 kW) for War Emergency. Extra armor was added for protection from the small arms fire which would be encountered at the lower altitudes where the AU-1 would be working. It’s ground attack role was underlined by the statistics; max take-off weight was almost 10 tons (9071.9 kg) while the service ceiling was only 19,500 ft (5,943.6 m) and the maximum speed was a mere 238 mph (383 kph)! Ground attack required only enough speed to present a difficult target for ground fire and only enough altitude to properly aim it‘s weapons.

The AU-1 was armed with 10 rockets or 4,000 lbs (1,814.4 kg) of bombs, in addition to four wing mounted 20 mm cannon with 230 rounds per gun. A fully armed AU was an awesome war machine!

The F3A-1 was produced by the Brewster Aeronautical Corporation and was identical to the F4U-1. Internal management problems at the corporation caused the Navy to end Brewster production in 1944 after over a year in which only 735 aircraft rolled off the Brewster assembly line.

Goodyear produced a number of Corsair models identical to the Vought models. But since it was easier to interrupt Goodyear production than Vought, some experimental models were also constructed. Most notably the F2G series which featured an entirely new engine; the Pratt-Whitney R-4360-4 "Wasp Major". The airframe received significant alterations in order to mount this engine. The Wasp Major could deliver 3,000 hp (2,238.8 kW) for take-off and 2,400 hp (1,791 kW) at 13,500 feet (4,114.8 m). Top speed was 431 at 16,400 ft (4,998.7 m). It was armed with four .50 cal. (12.7 mm) Browning machine guns with 300 rounds per gun, and could carry two 1,600 lb (725.8 kg) bombs on wing pylons. The F2G-1 was the land based version, while the F2G-2 was the carrier model. Although hundreds were on order by August 1945, only 5 examples of each were built due to cancellations at the end of hostilities. All ten of these were sold as surplus, and a few could be found at various air races around the country after the war.

The entire production run of the F4U-7 was tailored specifically for the French Navy (the "Aeronavale"). Ninety-four copies were built and all were sold to the Aeronavale. The dash seven was an upgrade of the AU-1 built specially for ground attack. Production of the dash seven began in June, 1952 and when the last one was delivered to the French in December of that year, the long production run of the Vought F4U Corsair came to an end.

 

When the Korean conflict began, VMF(N)513 was sent from MCAS (Marine Corps Air Station) El Toro with twelve F4U5(N)s to Atsugi, Japan. They flew night interdiction missions from Atsugi until southern South Korea was cleared. VMF(N)513 then moved to K-1 airfield near Pusan. By that time the 38th parallel was secured as a front. VMF(N)513 then covered three roads coming from North Korea during night hours. A navy PB4Y2 flew from Japan and dropped flares over these roads so that the F4Us could work underneath, attacking trucks, tanks, trains, and troop movements. The F4U5(N)s were equipped with 20mm cannons in the wings, four bomb/rocket racks under each wing. Additionally they could carry, one drop fuel tank and two napalm tanks. A radar dome was mounted in the right wing. Radar was extremely useful in these operations. These flights were very effective in slowing down traffic to the front lines.

Additional duties included night time scramble alerts at K-14 (Kyongsong) to meet aircraft intrusions from the North. There were some "In Close" air support flights to the front line units. A few planes were equipped with special equipment for MPQ flights during day light hours. In late 1950, VMF(N)542 transferred twelve Grumman F7Fs Tigercats to VMF(N)513 which then gave the squadron twelve F4Us and twelve F7Fs.

In late 1951, VMF(N)513 moved to K-6 (P'Yong'taek) and remained there until Douglas F3D Skynights replaced all the F4Us and the F7Fs to the end of the conflict.

"WF" were the letters painted on the vertical stabilizers.

I Raymond M. Smith Major, USMC retired, flew the F4U-4B and the F4U5(N) at MCAS Cherry point NC and MCAS El Toto as well as in Korea with VMF513 during 1950 and 1951. I flew all the different missions mentioned above. Decorations I received in Korea included the Air Medal with three gold stars, and one Distinguished Flying Cross.

 

Dimensions:

Wing span:

41 ft

Length:

33 ft 8 in

Height:

16 ft 1 in

Wing Area:

314 sq ft

Weights:

Empty:

9 835 lb

Gross:

12 420 lb

Maximum Take-Off:

19 398 lb

Performance:

Maximum Speed:

446 mph at 26 200 ft

Service Ceiling:

41 500 ft

Normal Range:

1 120 miles

Maximum Range:

1 560 miles

Powerplant:

One Pratt-Whitney R-2800-18W Double Wasp eighteen-cylinder radial engine, developing 2 100 hp (1 567 kW) for take-off, 1 950 hp (1 455 kW) at 23 300 ft (7 101.8 m)
2 450 hp (1 828.4 kW) for "War Emergency".

Armament:

Six .50 cal (12.7 mm) Colt-Browning M2 machine guns (some variants had four 20mm cannon) and two 1 000 lb bombs or eight 5 in (127 mm) rockets.