North American F-82 Twin Mustang
The North American F-82 Twin Mustang is an American long-range escort fighter. Based on the North American P-51 Mustang, the F-82 was designed as an escort for the Boeing B-29 Superfortress in World War II, but the war ended well before the first production units were operational. The F-82 was the last American piston-engined fighter ordered into production by the United States Air Force.
In the postwar era, Strategic Air Command used the aircraft as a long-range escort fighter. Radar-equipped F-82s were used extensively by the Air Defense Command as replacements for the Northrop P-61 Black Widow as all-weather day/night interceptors. 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, the first being a North Korean Yak-11 downed over Gimpo Airfield by the USAF 68th Fighter Squadron.
Design and development
Initially intended as a very long-range escort fighter, the F-82 was designed to escort Boeing B-29 Superfortress bombers on missions exceeding from the Solomon Islands or Philippines to Tokyo, missions beyond the range of the Lockheed P-38 Lightning and conventional P-51 Mustangs. Such missions were part of the planned U.S. invasion of the Japanese home islands, which was forestalled by the surrender of Japan after the atomic bombings of Hiroshima and Nagasaki and the opening of Soviet attacks on Japanese-held territory in Manchuria.Development of the Twin Mustang began in October 1943. Two new-design fuselages based on the XP-51F were lengthened by a fuselage plug inserted behind the cockpit and joined by a center wing section mounting six.50 caliber M3 Browning machine guns. The prototype XP-82 carried an eight-gun pod beneath the center wing, but this was not included as an option for the production aircraft. A different gun pod, fitted with a cannon, was also proposed. The outer wings were fitted with four hardpoints rated for up to of ordnance each. The landing gear was of conventional type; the main wheels retracted into the fuselage center sections. Power was provided by two Packard-built Rolls-Royce V-1650 Merlin engines.
The XP-82 prototypes, and production 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.
The first flight of the prototype took place in June 26, 1945; a production order for P-82B Twin Mustangs had been placed in March 1945. 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 most versions of 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, re-engineered for increased durability and mass-production, and built under license by Packard. These provided the fighter with excellent range and performance; however, the Army had always wanted to give the Twin Mustang a purely American and stronger engine than the foreign-designed P-51's V-1650. In addition, the licensing fees paid to Rolls-Royce for each V-1650 were being increased by Britain after the war. It therefore negotiated in August 1945 with the Allison Division of the General Motors Corporation for a new version of the Allison V-1710-100 engine. This forced North American to switch subsequent production P-82C and later models to the lower-powered engines. It was found that 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.
In 1948, the 3200th Proof Test Group at Eglin AFB, Florida, fitted the 4th F-82B Twin Mustang with retractable pylons under the outer wings capable of mounting 10 High-Velocity Air Rockets each, which folded into the wing undersurface when not in use. This installation was not adopted on later models, the standard "tree" being used instead. The 13th aircraft was experimentally fitted with a center wing mounted pod housing an array of recon cameras, and was assigned to the 3200th Photo Test Squadron, being designated, unofficially, the RF-82B.
Record-setting
On February 27, 1947, P-82B, 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 in 14 hr 32 min. It averaged. This flight tested the P-82's range. The aircraft carried a full internal fuel tank of, augmented by four tanks for a total of. Colonel Thacker did not drop three external tanks when their fuel was expended, either because of an oversight, or because they were stuck due to a mechanical glitch. This remains the longest nonstop flight ever made by a propeller-driven fighter, and the fastest time in which such a distance has ever been covered in a piston-engine aircraft. The aircraft chosen was an earlier "B" model powered by Rolls-Royce Merlin engines.Operational history
The Twin Mustang was developed at the end of the prop-driven fighter era and at the dawn of the jet age. Its designed role as a long-range fighter escort was eliminated by the end of World War II. With the rapid draw-down of the armed forces after the war, the newly established United States Air Force had little money for new prop-driven aircraft, especially since jets, such as the Messerschmitt Me 262, had been faster than P-51 Mustangs in the skies of Germany in late 1944. The completed airframes of the P-82 pre-production aircraft already manufactured went into storage, with an uncertain future.However, during the 1947 Soviet Aviation Day display at Tushino Airport, a surprise appearance was put in by what looked like three Boeing B-29s, followed by a fourth, passenger version, the Tu-70. The first three were examples of the Tupolev Tu-4, which was a reverse-engineered B-29 Superfortress, three examples of which were known to have been interned in the Soviet Union after having been forced to land there during bombing raids against Japan in WWII. Since the USSR was expected to have nuclear weapons sooner or later, the appearance of the Soviet Tu-4 was a shock to U.S. military planners, since it meant that the U.S. mainland might be vulnerable to a Soviet nuclear attack from the air.
Until jet interceptors could be developed and put into service, the Twin Mustangs already built were seen as an interim solution to SAC's fighter escort mission for its strategic bomber force and also as an all-weather air defense interceptor.
Early attempts to develop jet-powered all-weather fighters ran into a series of delays. The Curtiss-Wright XF-87 Blackhawk was ordered in December 1945, but it ran into development difficulties and the project was abandoned in October 1948. The Northrop P-89 Scorpion had greater promise, but it too had teething troubles and was not expected to enter service until 1952 at the earliest. Due to the lack of a suitable jet-powered replacement, the wartime Northrop P-61 Black Widow night fighter was forced into this role, and in order to fill in the gap until the Scorpion became available, night fighter adaptations of the Twin Mustang were developed and deployed.
On June 11, 1948, the newly formed United States Air Force replaced the P-for-pursuit category with F-for-fighter. All P-82s were then re-designated F-82.
Strategic Air Command
The F-82E was the first operational model and its initial operational assignment was to the Strategic Air Command 27th Fighter Wing at Kearney Air Force Base, Nebraska in March 1948.During World War II, the P-51 Mustang had escorted Boeing B-17 Flying Fortress and Consolidated B-24 Liberator bombers from bases in England and Southern Italy to targets in Nazi-occupied Europe. However, the Cold War brought on the challenge of B-29, Boeing B-50 or Convair B-36 missions into the Soviet Union. The size of the Soviet Union dictated long bombing missions there and back from bases in Europe or Alaska, most of it over Soviet territory. Also the weather, which was bad enough in Western Europe, would make bombing missions exceptionally difficult between October and May. With no long-range jet fighters to escort the strategic bomber force, the 27th FEW was to fly these missions in F-82Es.
The F-82E had a range of over, which meant that with external fuel tanks it could fly from London to Moscow, loiter for 30 minutes over the target, and return, the only American fighter which could do so. It also had an operational ceiling of, where it could stay close to the bombers it was designed to protect. The first production F-82Es reached the 27th in early 1948, and almost immediately the group was deployed to McChord AFB, Washington, in June, where its squadrons stood on alert on a secondary air defense mission due to heightened tensions over the Berlin Airlift. It was also believed that the 27th would launch an escort mission, presumably to the Soviet Union, if conflict broke out in Europe. From McChord, the group flew its Twin Mustangs on weather reconnaissance missions over the northwest Pacific, but problems were encountered with their fuel tanks. Decommissioned F-61 Black Widow external tanks were found at Hamilton AFB, California, which could be modified for the F-82; fitted on the pylons of the Twin Mustang, these solved the problem. With a reduction in tension, the 27th returned to its home base in Nebraska during September.
Four F-82s were deployed from McChord to Alaska, where the pilots provided transition training to the 449th Fighter Squadron, which used Twin Mustangs in the air defense mission. They remained in Alaska for about 45 days, returning to rejoin the rest of the group at the beginning of November 1948.
File:523d FES North American F-82E Twin Mustang Adak AK.jpg|thumb|One of four 27th Fighter Escort Wing F-82Es deployed to Davis AFB, Aleutians in December 1948 for the transition of the 449th Fighter Squadron from P-61 Black Widows to the Twin Mustang.
In January 1949, Eighth Air Force planned a large celebration at Carswell Air Force Base. All of its assigned units were to participate in a coordinated flyover. Most of the Strategic Air Command's bombers were to participate, along with its only "Long Range" fighter group, the 27th. The weather in Nebraska was horrible, with most airports in the Midwest forced to close on the day of the display. Kearney Air Force Base was hit with a blizzard, and paths were cut through the snow allowing the F-82s to take off and rendezvous with the bombers. This was seen as proof of the F-82's capabilities in bad weather.
In early 1949, the 27th began carrying out long-range escort profile missions. Flights to Puerto Rico, Mexico, the Bahamas and nonstop to Washington, D.C. were carried out. For President Truman's 1949 inauguration, the 27th FEW launched 48 aircraft to fly in review, along with several other fighter units, in formation down Pennsylvania Avenue. Another flyover of the newly dedicated Idlewild Airport in New York City soon followed, with the aircraft flying non-stop from Kearney AFB.
In March 1949, Kearney AFB was closed and the 27th FEW was reassigned to Bergstrom Air Force Base, Texas. Other long-range missions were flown cross-country, including simulated dogfights with Lockheed F-80 Shooting Stars. The 27th FEW began transitioning to the Republic F-84 Thunderjet in March 1950, and the F-82Es were largely surplus, with the last examples being phased out by September. A few were sent to Far East Air Forces for combat in Korea and some were sent to Alaska for bomber escort missions over the Arctic from Ladd AFB until 1953. The majority went to reclamation and were gone by 1952.
With the appearance of the Mikoyan-Gurevich MiG-15 over North Korea in late 1950, the B-29, as well as all of the propeller-driven bombers in the USAF inventory, were rendered obsolete as strategic offensive weapons. The straight-winged F-84Gs were ineffective against the MiG, and it took the swept-wing North American F-86 Sabre to counter them. It would take a new generation of swept-wing jet bombers, able to fly higher and faster, to survive the MiG-15 and subsequent Soviet interceptors. The era of large formations of bombers flying to a strategic target ended after the Korean War. Strategic bombing became a one-plane, one target mission, with the jet-powered Boeing B-52 Stratofortress flying higher and faster than most enemy interceptors. The escort fighter became redundant, and by 1957 SAC had inactivated the last of its strategic fighter escort wings.