The North American F-82 Twin Mustang was the last American piston engine fighter ordered into production by the United States Air Force. Based on the P-51 Mustang, the F-82 was originally designed as a long-range escort fighter in World War II, its postwar role changed to that of night-fighting. Radar-equipped F-82s were used quite extensively by the Air Defense Command as replacements for the P-61 Black Widow night fighter. During the Korean War, Japan-based F-82s were among the first USAF aircraft to operate over Korea. The first three North Korean aircraft destroyed by U.S. forces were shot down by F-82s.
Initially intended as a very long-range (VLR) escort fighter, the F-82 was designed to escort B-29 bombers on missions exceeding 2,000 miles from the Solomons or Philippines to Tokyo, missions beyond the range of the P-38 and conventional P-51s. Such missions were part of the planned U.S. invasion of the Japanese home islands, which was forestalled by the surrender of Japan days after the atomic bombings of Hiroshima and Nagasaki.
In October 1943, the North American Aircraft design team began work on a fighter design that could travel over 2,000 miles without refueling. It consisted of a two fuselage design, somewhat similar to the experimental German Messerschmitt Bf 109Z "Zwilling". Although based on the lightweight experimental XP-51F, which would later become the P-51H Mustang, it was actually an entirely new design. North American Design Chief Edgar Schmued incorporating two P-51H Mustang fuselages lengthened by the addition of a 57-inch fuselage plug located behind the cockpit where additional fuel tanks and equipment could be installed. These were mounted to a newly-designed center wing section containing the same six .50-caliber Browning M2 machine guns as a single-engine Mustang, but with more concentrated fire. The outer wings were strengthened to allow the addition of hard points for carrying additional fuel or 1000 pounds of ordnance. The two vertical tails were also from the XP-51F, but incorporated large dorsal fillets for added stability in case of an engine failure. The aircraft had a standard landing gear with both wheels retracting into bays under the each fuselage center section.
The XP-82 was to be powered by two Packard-built Rolls-Royce V-1650 Merlin engines. Initially, the left engine was a V-1650-23 with a gear reduction box to allow its left propeller to turn opposite to the right engine, which was the more conventional V-1650-25. In this arrangement both propellers would turn upward as they approached the center wing, which in theory would have allowed better single-engine control. This proved not to be the case when the aircraft refused to become airborne during its first flight attempt. After a month of work North American engineers finally discovered that rotating the propellers to meet in the center on their upward turn created sufficient drag to cancel out all lift from the center wing section, one quarter of the aircraft's total wing surface area. The engines and propellers were then exchanged, with their rotation meeting on the downward turn, and the problem was fully solved. The first XP-82 prototype (44-83886) was completed on 25 May 1945, and made the type's first successful flight on 26 June 1945. This aircraft was accepted by the Army Air Force on 30 August 1945. AAF officials were so impressed by the aircraft while still in development that they ordered the first production P-82Bs in March 1945, fully three months before the aircraft's first flight.
Prototype XP-82s, P-82Bs and P-82Es retained both fully equipped cockpits so that pilots could fly the aircraft from either position, alternating control on long flights, while later night fighter versions kept the cockpit on the left side only, placing the radar operator in the right position.
Although some P-82B airframes were completed before the end of World War II, most remained at the North American factory in California waiting for engines until 1946. As a result, none saw service during the war.
Like the P-51 Mustang, the first two prototype XP-82s, as well as the next 20 P-82B models were powered by British designed Rolls-Royce Merlin engines, built under licence by Packard. These provided the fighter with excellent range and performance, but political pressurefrom the U.S. Procurement Office , as well as the increased licence fees demanded by Rolls-Royce, forced North American to switch subsequent production P-82C and later models to the lower powered Allison V-1710-100 engines. Allison powered P-82 models demonstrated a lower top speed and poorer high altitude performance than the earlier Merlin powered versions.The earlier P-82B models were designated as trainers, while the "C" and later models were employed as fighters, making the P-82 one of the few aircraft in U.S. military history to be faster in its trainer version than the fighter version.
On 11 June 1948 the newly-formed United States Air Force eliminated the P-for-pursuit category and replaced it with F-for-fighter. Subsequently, all P-82s were re-designated F-82. The F-82E was the first model to reach operational squadrons and its initial operational assignment was to the 27th Fighter Wing at Kearney Air Force Base, Nebraska in 1948. The 27th used the F-82E to fly long-range escort missions for SAC B-29 bombers. F-82Es continued to fly actively until 1953 escorting B-29s, B-50s and B-36s becoming Strategic Air Command's last operational piston-engined fighters.
The cessation of hostilities in World War II ended the need for a long-range bomber escort, though the F-82 continued as a replacement for the aging P-61 Black Widow night fighter.
The night fighter versions, designated the F-82F/G, required numerous modifications. The right side cockpit was replaced with a radar operator's position without flight controls. A long radar pod, resembling a sausage and irreverently known as a "long dong", was attached to the underside of the center wing, below the six .50 caliber machineguns and with its dish in front of the propellers to prevent signal interference. This unconventional arrangement was found not to affect the aircraft's performance seriously. Additionally the unit could be jettisoned in an emergency, or for belly landings; it was sometimes lost during high-G maneuvers.
The first F-82F/G models began to reach operational squadrons in late 1948. By the middle of 1949 the F-82 was in widespread service with some 225 E/F/G models being in use by the USAF at Bergstrom, Hamilton, McChord, Mitchel and McGuire AFB. F-82Gs were also deployed to the 347th Fighter Group in Japan. Modified F-82s for cold weather (F-82Hs) were assigned to Ladd AFB, Alaska, and make a brief but memorable appearance in the movie "Top of the World. (1955)
Although not operational during World War II, the F-82G was effective during the Korean War. In June 1950, U.S. forces in Seoul, South Korea were attempting to evacuate U.S. civilians, including many women and children, from the advancing North Korean Army. A total of 682 civilians had been evacuated on the 26 June aboard the Norwegian freighter Reinholte, then visiting Inchon Harbor and transported to Sasebo, Japan. The remaining civilians were to be evacuated the following day by an Air Force C-54. Fearing that the North Korean Air Force might try to shoot down the transport (a C-54 had been destroyed on the ground at Kimpo by North Korean fighters on June 25th) the Air Force requested air cover to protect the aircraft during takeoff. The F-80 Shooting Star was available, but its thirsty jet engine meant it could only remain over the airfield for a few minutes before having to return to base and no P-51 Mustangs were available.
Fortunately, the 4th and 339th Fighter All Weather Squadrons F(AW)S with their F-82Gs were based in Japan and Okinawa at Misawa and Yokota Airfields, and the 68th F(AW)S was based at Itazuke airfield. With Lt. Col. John F. Sharp in command, 27 F-82Gs of the 35 in the theater answered the call. Arriving in the early morning, they orbited Kimpo Airfield in three flights, each above the other. Suddenly, at 1150 hours, a mixed lot of five North Korean fighters (Soviet-built Yak-9s, Yak-11s and La-7s) appeared, heading for the airfield. One of the Yak-9s immediately scored several hits on 68th F(AW)S pilot Lt. Charles Moran's vertical stabilizer. Moments later, Lt. William G. "Skeeter" Hudson, also of the 68th F(AW)S, initiated a high-G turn to engage the Yak. Soon Hudson was closing in on the Yak's tail. He then fired a short burst at close range, scoring hits with his six .50 caliber machine guns. The Yak banked hard to the right, with the F-82G in close pursuit. A second burst hit the Yak's right wing, setting the gas tank on fire and knocking off the right flap and aileron. The North Korean pilot bailed out, but his observer, who was either dead or badly wounded, remained in the doomed aircraft. Parachuting down to Kimpo Airfield, the North Korean pilot was immediately surrounded by South Korean soldiers. Surprisingly, he pulled out a pistol and began firing at them. The South Korean soldiers returned fire, killing the pilot. Moments later, Lt. Moran shot down an La-7 over the airfield, while a few miles away, Maj. James W. Little, commanding officer of the 339th F(AW)S, shot down another La-7. The C-54 was able to escape safely. Of five North Korean fighters, only two returned to their base. In the process, Lt. William G. "Skeeter" Hudson, with his radar operator Lt. Carl Fraiser had scored the first aerial "kill" of the Korean War.
It is generally believed that the aircraft Hudson and Fraiser flew that day was an F-82G named "Bucket of Bolts" (s/n 46-383), as their usual aircraft was down for repairs. "Bucket of Bolts" would survive the Korean War and eventually be reassigned to escort duty in Alaska. It is believed to have been scrapped at Ladd AFB, Alaska in 1953.
1951 was the last full year of F-82 operations in Korea, as they were gradually replaced by the jet-powered F-94 Starfire. Twin Mustangs destroyed 20 enemy aircraft, four in the air and 16 on the ground during the conflict.
By summer 1952, the last surviving Korean War veteran F-82s were flown to Tachikawa, Japan to be upgraded to F-82H models with the addition of cold weather equipment and additional de-icers. Many of these fighters later operated with Strategic Air Command from airfields in Alaska where they served as escorts for the massive Convair B-36 bombers during long flights over the Arctic, finally fulfilling their original mission as a bomber escort. The F-82 did not disappear from USAF inventory until 1953, when a lack of parts made it impossible to keep the aging airframes flying. Many were ultimately scrapped in Alaska.
On 27 February 1947, a P-82B (44-65168) named Betty Jo and flown by Colonel Robert E. Thacker made history when it flew nonstop from Hawaii to New York without refueling, a distance of 5,051 miles in 14 hr 32 min (347.5mph). To this day, it remains the longest nonstop flight ever made by a propeller-driven fighter, and the fastest such a distance has ever been covered in a piston-engined aircraft (the record for the longest nonstop flight by a propeller-driven aircraft of any type is held by the Rutan Voyager). The aircraft chosen was an earlier "B" model powered by Rolls-Royce Merlin engines (see "Survivors" below).