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Aviation History
1971
1971 - 0123.PDF
114 FLIGHT International, 28 January 1971 F-14A accident cause found An investigation by Grumman into the loss of the prototype F-14A fighter on December 30, during its second test flight, has shown that a total hydraulic failure occurred as the result of loss of fluid from the system. The aircraft had been scheduled for a 90min flight, but 20min after take-off the crew radioed back that they had encoun tered a hydraulic problem and were returning to the Grumman test air field at Calverton, New York. The undercarriage was extended by a nitrogen emergency system, but dur ing the final stages of approach to the airfield the aircraft began to porpoise and finally entered a nose-down pitch which could not be corrected. The rear-seat pilot, Mr Robert Smyth, ejected so low that his parachute opened directly over the crash. The thermal generated by the ensuing con flagration wafted him away from the vicinity and he and Mr William Miller, his front-seat colleague (who also ejected), landed unhurt. The initial indications that a leak had occurred in the system were sub stantiated by Grumman's inquiry team, and their findings are expected to be confirmed by the US Navy board whose official report is expected shortly. Examination of the wreckage dis- Japan's Vtol Tests continue with Japan's first Vtol test-bed at the National Aerospace Laboratory, Kakuda City- Powered by two 3,3731b, !5kN Ishikawajima-Harima JR-IO0F lift engines, the rig made its first tethered flight in November 1969 and its first free flight late last year. Two 66 Imp gal fuel tanks allow for a maximum endurance of lOmin closed that both main hydraulic supply pipes had fractured, allowing hydraulic fluid to leak away and thus cutting off power to (among others) the vital flight-control system. Subsequent tests disclosed that the cause of the fracture was a severe high-frequency pressure fluctuation, or ripple, which caused the hydraulic fines to resonate and ultimately fatigue. Unfortunately the electrical back-up flight-control system, which provides power to the rudders and differential tailplane, also failed to operate satisfactorily, either be cause of lack of hydraulic fluid or be cause of an internal leak, which resulted in insufficient output pressure. The corrective measures to be adopted on the second F-14A proto type, due to fly in March, are described by Grumman as "straightforward mechanical system modifications and will not entail any re-design effort." At the time of the accident the F-14 programme was running one month ahead of schedule, but the loss of the first aeroplane is not expected, accord ing to Grumman, to have an adverse effect on either the US Navy trials or delivery to the Fleet. The Mirage G Crash It appears that a total electrical failure may have been the cause of the accident to the experimental Mirage G demonstrator, which crashed five miles from Istres on January 13 (see Flight last week, page 76). An unofficial report says that the electrically signalled wing-mounted spoilers were asymmetrically ex tended, and that the aircraft entered an uncontrolled roll. M Jean Coureau, Dassault's chief test pilot, ejected at 400ft and was saved. The Mirage G has full-span trailing- edge flaps and leading-edge slats for maximum low-speed lift augmenta tion. Roll control under these condi tions is obtained by the use of spoilers plus the differential tailplane. At high speeds, when the wings are fully swept, the spoilers are locked out and the entire rolling moment is supplied by the tailplane. Apollo 14 Countdown The next American manned flight to the Moon, Apollo 14, is due to be launched from Cape Kennedy, Fla, next Sunday, January 31. Mission commander will be Astronaut Alan B. Shepard, who is 47 and was one of the original seven Mercury astronauts. He is due to land on the Moon with Astronaut Edgar D. Mitchell, the pilot of the lunar module. The third mem ber of the crew is Astronaut Stuart A. Roosa, who will continue in lunar orbit while the other astronauts are on the Moon. Apollo 14's return to Earth is scheduled for February 9 (see Spaceflight, page 136). Stretched 125 Flies The HS.125-600 made its first flight on January 21 from the Hawker Sidde- ley airfield at Hawarden. After a flight lasting over two hours the aircraft was landed at Hatfield where flight testing will continue. Mr M. Goodfellow, 125 project test pilot, reported that the air craft was fully serviceable at the end of the flight. The HS.125-600 is powered by two Rolls-Royce Viper 600 engines which are being developed jointly by Rolls-Royce Bristol and Fiat, Turin. For the early stages of test flying the -600 prototype carries a nose- mounted venturi and air-temperature probe; a dorsal aerial caters for telemetry (see photograph opposite). Swedish AF Safety Six Swedish Air Force pilots were killed in flying accidents during 1970, the same number as in 1969. Twelve aircraft were lost, compared with nine in the previous year. Gen Stig Noren, C-in-C, SAF, commented on January 21 that no pilots had been lost owing to equipment failures; the greatest risk level arose in combat training in operational units. TF34 Engine Airborne The 9,0001b, 40kN-thrust General Electric TF34 turbofan engine under development for the US Navy's new ship-borne Lockheed S-3A made its first flight on a modified Boeing B-47
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