What happened
On January 27, 1998, a Beechcraft A 36, registration OH-BBL, was conducting a training flight at Pori Airport when it sustained substantial damage. The flight, operated by the Finnair Flight Academy, was intended to practice engine failure procedures during the takeoff phase.
During the maneuver, the instructor simulated an engine failure by reducing power to idle at an altitude of approximately 100 ft (QNH). The student pilot attempted to maintain an airspeed of 85 knots by pitching the nose down; however, the airspeed dropped to 75 knots. The student also promptly deployed full flaps. Although the crew later applied full power to arrest the descent, the aircraft could not recover sufficient airspeed in time. This resulted in a heavy landing approximately 735 meters from the runway threshold. The impact caused the aircraft to bounce and veer toward the left runway light line. The left main gear tire burst, and the left wing's trailing edge structure was damaged, with the wing angle of incidence shifting downward. No fatalities or serious injuries were reported, though the instructor sustained back pain.
The investigation
OTKES examined the training syllabus, the instructor's experience, and the specific parameters of the maneuver. The investigation established that the training procedure for simulated engine failures after takeoff was a relatively new addition to the curriculum for this aircraft type. Investigators found that there was significant ambiguity regarding the required starting altitude for the maneuver. While the flight manual provided emergency airspeeds, the training manual did not specify a minimum altitude for initiating the simulated failure.
Furthermore, the investigation revealed that the instructor had mistakenly believed the required altitude was measured relative to mean sea level (QNH) rather than the airfield elevation. This error meant the maneuver was initiated at only about 65 feet above the runway surface, leaving insufficient margin to manage the descent. The investigation also noted that the instructor's familiarity with the specific handling characteristics of the Beechcraft A 36 during such high-workload maneuvers was limited, as it was only his fourth flight in this type.
Findings
- The primary cause of the damage was insufficient airspeed and an inadequate starting altitude during the simulated engine failure maneuver, which prevented the crew from maintaining a controlled descent.
- The training syllabus lacked clear, standardized instructions regarding the minimum altitude for initiating the procedure.
- The instructor miscalculated the actual altitude above the runway due to a misunderable distinction between QNH and airfield elevation.
- The student pilot's rapid deployment of full flaps contributed to the loss of airspeed.
- There was a lack of standardized instructor training and coordination regarding the risks associated with this specific new training task.