Lockheed F-94 Starfire

The Lockheed F-94 Starfire was the United States Air Force's first operational jet-powered all-weather interceptor aircraft. It was a development by Lockheed from the twin-seat T-33 Shooting Star trainer aircraft.

Design and development
Built to a 1948 USAF specification for a radar-equipped interceptor to replace the aging F-61 Black Widow and North American F-82 Twin Mustang, it was specifically designed to counter the threat of the USSR's new Tupolev Tu-4 bombers (reverse-engineered Boeing B-29). The Curtiss-Wright XF-87 Blackhawk had been designated to be the USAF first jet night fighter, but its performance was sub par, and Lockheed was asked to design a jet night fighter on a crash program basis. The F-94 was derived from the TF-80C (later T-33A Shooting Star) which was a two-seat trainer version of the F-80 Shooting Star. A lengthened nose area with guns, radar and automatic fire control system was added. Since the conversion seemed so simple, a contract was awarded to Lockheed in early 1949, with the first flight on 16 April 1949. The early test YF-94s used seventy-five percent of the parts used in the earlier F-80 and T-33As.

The fire control system was the Hughes E-1, which incorporated an AN/APG-33 radar (derived from the AN/APG-3 which directed the Convair B-36's tail guns) and a Sperry A-1C computing gunsight. This short-range radar system was useful only in the terminal phases of the interception. Most of the operation would be directed using ground-controlled interception as was the case with the earlier aircraft it replaced.

The added weight of the electronic equipment required a more powerful engine, so the standard J-33 turbojet engine, which had been fitted to the T-33A, was replaced with an afterburning Allison J33-A-33. The combination reduced the internal fuel capacity. The F-94 was to be the first US production jet with an afterburner. The J33-A-33 had standard thrust of 4,000 lbf, and with water injection this was increased to 5400 lbf and with afterburning a maximum of 6,000 lbf thrust. The YF-94A's afterburner had many teething problems with its igniter and the flame stabilization system.



The initial model was the F-94A. Its armament was four .50 in (12.7 mm) M3 Browning machine guns mounted in the fuselage with the muzzles exiting just behind the radome. Two 165 US Gallon (1,204 litre) drop tanks, as carried by the F-80 and T-33, could be carried under the wingtips. Alternatively, these could be replaced by 1,000 lb (454 kg) bombs, giving the aircraft a secondary fighter bomber role. 109 were produced. The subsequent F-94B, which entered service in January 1951, had upgraded and more reliable electronics and engines, as well as a new Instrument Landing System (ILS). 356 of these were built.

The F-94C Starfire was extensively modified from the early F-94 variants. In fact, it was initially designated F-97, but it was ultimately decided to treat it as a new version of the F-94. USAF interest was lukewarm, so Lockheed funded development themselves, converting two F-94B airframes to YF-94C prototypes for evaluation. To improve performance, a completely new, much thinner wing was designed, along with a swept tail surface. The J33 engine was replaced with a more powerful Pratt & Whitney J48, a license-built version of the afterburning Rolls-Royce Tay, which dramatically increased power, producing a dry thrust of 6350 lbf and with afterburning, approximately 8750 lbf. The fire control system was upgraded to the new Hughes E-5 with an AN/APG-40 radar in a much larger nose. The guns were removed and replaced with all-rocket armament consisting of four flip-up panels in a ring around the nose, each containing six rockets. According to test pilot Tony LeVier, the F-94C was capable of supersonic flight.

The F-94C was the only variant to be officially named Starfire. With time, the entire F-94 family has adopted the name.

An F-94D model was proposed as a single-seat fighter bomber, with bombs and rockets under the wings. A single prototype was built, but the model was not accepted for production. The prototype was later used as a testbed for the 20 mm (.79 in) M61 Vulcan cannon subsequently used on the F-104 Starfighter and many others.

Operational history


In March 1951, F-94Bs were sent into combat in the Korean War, where they equipped the 339th, 68th, 4th, and 319th FIghter Interceptor Squadrons. The type was credited with several air to air victories, including the first jet-vs.-jet night victory against a MiG-15. One F-94 was listed as lost due to enemy action, six more to non-enemy causes on combat missions, two were declared as missing on a combat mission and three were lost in accidents. One F-94 was lost when it slowed to 110 mph during pursuit of a Po-2 biplane.

Another early detachment was the 59th Fighter Interceptor Squadron, (all-weather, night-fighter interceptor,) which was sent to Goose Bay, Labrador in November, 1952 and placed under the control of Northeast Air Command (NEAC). One flight from the 59th FIS was kept at Thule Air Base to back up the DEW Line.

The F-94B remained in USAF service through 1954 before being transferred to the Air National Guard. In ANG service, some were modified with a pod under each wing for two additional .50 in (12.7 mm) machine guns, bringing the total to eight.

The first production F-94C aircraft were delivered in July 1951, 387 examples being delivered before May 1954. The largest problem discovered in service was the nose-mounted rockets, which blinded the crew with their smoke and fire. The most severe problem associated with firing the nose-mounted rockets was that the exhaust could cause a flameout of the jet engine, which could lead to loss of the aircraft. Mid-wing fuel and rocket pods were added, each holding 12 rockets. Most of the time, the nose rockets were not installed, and the mid-wing pod rockets were the sole armament. This version of the aircraft was extensively used within the Semi Automatic Ground Environment (SAGE) air defense system.

The F-94C was retired from USAF service in 1959, as newer and more capable interceptors entered service. Air National Guard units retired their F-94s a year later.

Variants



 * YF-94
 * TF-80Cs converted into YF-94 prototypes, two built.


 * F-94A
 * Initial production version, 109 built.


 * YF-94B
 * One F-94A modified on the production line with new flight director, modified hydraulic systems and two enlarged wingtip tanks.


 * F-94B
 * Production model based on YF-94B, 355 built.


 * YF-94C
 * F-94Bs modified with Pratt and Whitney J48 engine, leading edge rocket pods and swept tailplane, originally designated YF-97A, two modified.


 * F-94C Starfire
 * Production version of the YF-94C with longer nose, gun armament replaced with nose mounted rockets and provision for underfuselage JATO rockets, originally designated F-97A, 387 built.


 * EF-94C
 * Test aircraft for proposed reconnaissance variant


 * YF-94D
 * Prototype single-seat close support fighter version based on the F-94C, one partly built but construction was abandoned when program was cancelled.


 * F-94D
 * Production version of the YF-94D, 112 on order cancelled, none built.


 * YF-97A
 * Original designation of the YF-94C.


 * F-97A
 * Original designation of the F-94C.

Operators

 * United States Air Force
 * Air National Guard
 * Air National Guard

Aircraft on display

 * F-94A
 * 49-2498 - National Museum of the United States Air Force at Wright-Patterson Air Force Base near Dayton, Ohio. It was transferred from active inventory to the Museum in May 1957.


 * 49-2517 - Burlington Air National Guard Base at Burlington International Airport in Burlington, Vermont. Formerly displayed at the Pima Air and Space Museum adjacent to Davis-Monthan Air Force Base in Tucson, Arizona.


 * YF-97C/F-94C
 * 50-0877 - Syracuse, New York airport.


 * 50-0980 - National Museum of the United States Air Force at Wright-Patterson Air Force Base near Dayton, Ohio. It is displayed as 50-1054.


 * 50-1006 - Peterson Air & Space Museum at Peterson Air Force Base in Colorado Springs, Colorado.


 * 51-5623 - Pima Air and Space Museum adjacent to Davis-Monthan Air Force Base in Tucson, Arizona


 * 51-5671 - Erie County Memorial Gardens cemetery at Erie, Pennsylvania. It was first put on display in 1971 and subsequently left to deteriorate. It was refurbished in 2005.


 * 51-13560 - Minnesota Air National Guard Museum at Minneapolis, Minnesota.


 * 51-13575 - Evergreen Aviation & Space Museum in McMinnville, Oregon. It was previously on display at the New England Air Museum in Windsor Locks, Connecticut and moved to Evergreen in 2010.