F-89 to F-94
A refined version, the F-89C, ordered June 20, 1950, and first flown September 18, 1951, replaced the external elevator mass balances with internal ones. Of 163 F-89Cs, the first 64 were delivered with J35-A-21A engines, the next 45 (beginning February 1952) with J35-A-33s, and the rest completed with J35-A-35s by November 1952. The F-89C entered service in January 1952, but after several aircraft were lost to fatigue failure of wing fittings due to aero elasticity, all Scorpions were grounded September 22, 1952, until the wing structure could be changed. All had to be returned to the factory to be reworked, until 194 F-89A/B/Cs were returned to service beginning on February 23, 1953.
The wings, tail, and landing gear were those of the F-80; only the fuselage was new. There were 940 pounds of APG-33 radar in the nose and a radar operator sitting behind the pilot. Four .50-caliber guns were directed by the Hughes E-1 fire control, and two 1,000-pound bombs could be added. An Allison J33-A-33 of 4,600-pounds dry thrust had a Solar afterburner to boost this to 6,000-pounds for brief moments of climb and dash, but that devoured fuel so fast that it could be used only sparingly. The F-94A was the first production job with an afterburner; which have since become standard on fighters in which short bursts of power are more important than range.
One F-94A was modified to the YF-94B configuration in September 1950, and 356 F-94Bs first ordered March 3, 1950, were delivered from January 1951 to January 1952 and appeared with center-mounted 230-gallon tanks on each wing tip, instead of the 165-gallon tanks on the F-94A. A Sperry Zero Reader instrument was added to aid blind landings.
Lockheed F-94s entered USAF service in May 1950 with the 325th Fighter-Interceptor Group at McChord AFB, and then with the 52nd Group at McGuire AFB in New Jersey. The former group’s 319th Squadron was transferred to Korea in March 1952.
At first its missions were limited to local defense, so the radar equipment would not be captured, but more aggressive tactics were allowed in 1953 to support B-29 operations. An F-94B made the first night kill, a prop-driven La-11, on January 30, 1953, and the squadron claimed two MiGs and a Po-2 biplane in the spring, while an F-94B collided with a Po-2 on June 12, destroying both aircraft. Three F-94s were lost in action and six to non-enemy operational causes.
The most specialized escort fighter was the McDonnell Model 27D, offered March 19, 1945, as a parasite fighter to be carried inside a B-36. On October 9, a letter contract ordered two XP-85 prototypes. When big bombers on a mission were menaced, the concept was that some might open their bomb bay, lower parasites on a trapeze, launch them and at the end of the engagement recover any survivors. These fighters would have to be small enough to fit inside bomb bays, yet equal enemy interceptors in performance.
McDonnell’s answer to the unique problem was short enough to fit a 16-foot long bay, and its swept wings folded to only 5 feet,5 inches in width, and 10 feet,3 inches in height. The pilot straddled a 3000-pound thrust Westinghouse J34-WE-22 with about 32 minutes of fuel, and preliminary estimates promised a top speed of 664 mph. Four .50-caliber guns were grouped about the nose intake. Instead of landing wheels, there was a retractable hook for the trapeze of the carrier plane. Tail span was reduced by dividing the tail into six odd-shaped surfaces.
A mockup of the parasite fighter and the B-36 bay and trapeze was inspected at St. Louis in June 1946, and a definitive contract approved February 5, 1947. Since a B-36 would not be available on time, an EB-29B was modified as a carrier plane. As the XF-85 Goblin descended on its trapeze from the mother plane, it looked like a fat little bug.
Edwin F. Schoch made the first XF-85 test flight on August 23, 1948, but when he attempted to return to the mother plane, the trapeze smashed the canopy, and he was forced to make an emergency landing on a belly skid. Another attempt on October 14 succeeded, but the difficulty of recovering the parasites had been demonstrated.