Aero Vodochody L-39ZO Albatros, G-OTAF
During a ‘run and break’ rejoin to the circuit at Duxford, the pilot turned crosswind, reduced the throttle to IDLE and extended the speed brakes. After lowering the landing gear he increased the throttle but then noticed “a change in the usual sound” of the engine. As the aircraft was descending below circuit height he added full power but the engine did not spool up. After making a MAYDAY call he considered that the aircraft was too low to attempt an engine restart and that he was also outside the safe ejection envelope. The pilot therefore decided to carry out a forced landing into a field. The landing was successful but the nose landing gear collapsed during the ground roll. An examination of the engine revealed that the inlet directing body of the high pressure compressor had seized. This could have caused a sub-idle engine surge when the throttle was rapidly retarded to IDLE. A service bulletin calling for a torque check of the inlet directing body had not been carried out. In addition, there was no record of the engine having been overhauled since its manufacture in 1982. Four safety recommendations were made concerning this service bulletin and engine calendar life limits.
G-OTAF.pdf (160.81 kb)
Published 10 December 2014