P 39 Cobra - The P-39, known as the "Cobra II", was a Bell P-39Q-10BE, AAF 42-20869, assigned to the 430th Army Air Force Base Unit, Combat Crew Training Station, Ephrata AAB, Washington, in April 1944. To the 4th Air Force of training to fight. When training ended in February 1945, 42-20869 was transferred to the Reconstruction Finance Corporation at Ponca City Air Field, Oklahoma, and then to the War Assets Administration for storage and disposal.
Bell's swept-wing L-39 project, based on the P-63, required 400-pound three-blade props that were lighter than the 460-pound four-blade P-63 props. In 1946, it was cheaper to buy an entire plane than a prop. So Bell bought two P-39Qs from the WAA in February 1946 for $750.00 each. AAF 42-20733 became the dead "Cobra I" and AAF 42-20869 became the famous "Cobra II".
P 39 Cobra
In the spring of 1946, it was announced that the National Air Races would return to Cleveland, Ohio, for a regular Labor Day weekend event that had not been held since September 1939. In addition to the Thompson trophy, the winner of the contest receives $20. 000 in prize money (approximately $262,968 in 2020 US dollars). Also, each leg leader had $2,000 in prizes. The competitor who sets the world record during the race will receive the Allegheny-Ludlum Trophy and $2,000. These were serious sums in 1946, and they bought out serious contenders.
Bell P 39q 10 Be Airacobra Archives
It was clear that no one could build their own racing aircraft as they had done before the war. Several fighters will dominate the field, available in flying condition for as little as $500. In Buffalo, two P-39s, stripped of propellers purchased by Bell, were sold to Skylanes Unlimited for one dollar each to be converted into Cleveland racers. Three pilots were involved, Bell chief test pilot Jack Woollams and Bell experimental test pilots Alvin "Tex" Johnston and Chalmers "Slick" Goodlin. They believed the lighter P-39 was a better choice than the newer but heavier P-63.
All unnecessary equipment was removed: ammunition, ammunition racks, 227 kg of armor plate, radios and oxygen system. Self-sealing fuel tanks were replaced with lightweight neoprene tanks, which increased fuel delivery by 10%. Each now weighs 4,500 pounds, with 1,000 pounds removed. Fabric-covered control points are reinforced with aluminum to prevent ballooning at high speeds. A 36 volt battery was installed to retract the landing gear in five seconds. Twelve exhausts were installed. Adjustable trim tabs are off. Gyroscopic devices have been removed. The pitot tube was removed from the left wing and mounted on a long boom projecting through the propeller hub. Floor-to-ceiling windows were replaced with permanent Plexiglas panels.
The most significant change was the replacement of the P-39Q's 1,325 hp Allison V-1710-85. Engineers at Allison recommended that a modified Allison XV-1710-135 (E31) engine be used for the two runners. The revised engines used an increased diameter supercharger impeller and smaller pistons to reduce cylinder wall friction. They produced 2,000 horsepower at 3,200 rpm using 140-octane Mobil aviation gasoline. It has a maximum pressure of 86 inches. High power output requires a continuous supply of precisely metered water and ethyl/methyl alcohol solution to the engine while operating above 57 inches of manifold pressure. An 85-gallon tank of the injection mixture is placed in the nose. It also required a large oil cooling radiator, which was mounted in the lower center of the main gear. The increased power of the XV-1710-135 required a four-bladed propeller from the P-63 Kingcobra. It was an Aeroproducts A624S constant speed propeller with metal holes.
Flight tests showed that a speed of 430 mph was possible. For Thompson in 1946, Jack Woolums would fly the red and black "Cobra I" (NX92847), while Johnston flew the yellow and black "Cobra II" (NX92848).
P 39 Airacobra
Among the participants in the 1946 competition were well-known aviators, test pilots and fighter pilots: Cook Cleland, US dive bomber; Woodrow W. ("Woody") Edmondson, pilot; Howard Clifton ("Tick") Lilley, test pilot for the National Advisory Committee for Aeronautics (NACA); Alvin Melvin ("Tex") Johnston, test pilot for Bell Aircraft Corporation; Anthony W. ("Tony") Levier, chief engineering test pilot for Lockheed Aircraft Corporation, and veteran pylon racer (second winner of the 1939 Thompson Race, the last of the military events); Earl Hill Ortman, a test pilot for the Douglas Aircraft Company, was also a veteran of pre-war Thomson Racing; Howard L. Pemberton; Bruce Raymond; Robert Swanson; Charles ("Chuck") Tucker, former "Flying Tiger" in China and USAAF test pilot; George S. Welch, Air Corps hero of Pearl Harbor and test pilot for North American Aviation. and Sylvester Joseph ("Steve") Whitman, an aircraft designer and air racer.
When the race got underway, Tex Johnston came out on top with his yellow Cobra II. The average speed was 409.091 mph. George Welch finished second with his P-51D, No. 37. Jack Woollams and Cobra I third at 392.71 mph.
Jack Woollams was killed on August 30, two days before the race, when the "Cobra I" crashed into Lake Ontario while returning to the Bell plant for an engine change.
The Thompson Trophy Race has always been one of the most popular events in air racing, as it is flown in front of large crowds. Sponsored by the Thompson Products Company (a predecessor of TRW), it was a ten-lap pylon race flying at low altitude around a 30-mile course. With the advent of the jet revolution, two sectors were established. The R division was for reciprocating engines and the J division was for jet powered aircraft. Although the R Division was a civilian aircraft, the J Division showed P-80s from the USAAF - among the Air Force "racers" World War II ace Major Robin Olds, who would finish second in the "race". The race course is laid out as a parallel track with two 10-mile sections and two 5-mile sections. There were two 75 degree and two 105 degree turns. Among the twelve aircraft competing in the 1946 Thompson Race was a P-39Q Airacobra; four P-63 Kingcobras; an FG-1D Corsair; a P-38L Lightning; and five P-51D Mustangs.
Air International 1982 02
The Thomson Trophy match was played on Sunday, September 1, 1946. Tex Johnston gets up and gets to 300m. On reaching the first level, he made the "Cobra II" turn 4G at an angle of 75.5 degrees and dove to 60 feet. Coming out of the army, he was already far ahead of others. George Welch crashed when the engine caught fire. Tony Levier's P-38 took second place. By lap nine, Johnston was hitting runners at the back of the field.
In the final turn, Johnston rolled into a 90-degree bank, passed the P-63 by only 50 feet, and flew at 430 mph to win the race. The average speed of the 10 runs was 373.908 mph. Tony Levier was second at 370.193 mph. The third, fourth and fifth were P-51Ds. Sixth was the FG-1D and third was the P-51 in seventh place. The last three were P-63s.
Johnston won first prize of $20,000, top prize of $2,200 and record prize of $2,000. Today he walked away with almost half a million dollars.
In the 1947 competition, Bell test pilot Gerald A. "Cobra II" finished third behind two F2G Super Corsairs flown by Cook Cleland and Dick Becker, flown by "Jay" Demming. He drove race number 11 and averaged 367.625 mph.
File:bell P 39n 1 Be Airacobra '28740' (n81575) (25894610281).jpg
In 1948, Charles Brown, a test pilot for Allison engines, flew the "Cobra II". Sponsored by Kaiser-Frazier dealer Stewart Motor Sales, it was designated the "KR-1" and flew at a speed of 438 mph in a test flight. The race was 20 laps of a short 15 mile course. By burning special high-octane fuel and turning a three-bladed prop, Brown reached 418.3 mph, ahead of Cook Cleland's XF2G-1 at 417.424 mph. Cook Cleland and Dick Becker's F2Gs withdrew from the morning race after their cattle caught fire. Brown's top lap speed was 413 mph. Before the race, Allison experienced airlock on lap 19 and was forced to land. Anson Johnson hung on for the win in the P-51D at 383.77 mph.
In November 1948, it was damaged while being transported to Indianapolis, ending NX92848's racing days. It remained unorganized until purchased by Ed Maloney in 1960. In 1967, Maloney sold it to Michael D. Carroll, owner of Signal Trucking Company. Now registered N9824, Carroll decided to go for the world piston engine speed record.
He installed a highly modified V-1710 rated at 2,850 hp, trimmed the wings, cleaned up the airframe, and changed the three-blade prop to a four-blade prop. On August 10, 1968, Carroll took off from Long Beach Airport to Orange County Airport on its first test flight. The race broke off at 11:15
Fms p 39 airacobra, e flite p 39 airacobra, p 39 aircraft, p 39 airacobra rc, bell p 39 king cobra, cobra 39 plus, p 39 air cobra, p 39, p-39, p 39 airacobra model, p 39 king cobra, p 39 aircobra
0 Comments