What happened
On July 3, 2012, a Piper PA-34-200T, registration G-TAIR, was conducting a training flight at Cascais Aerodrome (LPCS) with an instructor pilot and a student pilot. The flight plan included local maneuvers and a simulated engine inoperative (OEI) training exercise.
During the training, the student pilot configured the aircraft for a simulated failure of the right engine by extending the landing gear and 25° flaps, and reducing the right engine's throttle to minimum. After completing a go-around maneuver, the aircraft was in a climbing turn to the left. During this phase, the left engine experienced an abrupt drop in RPM and a subsequent loss of thrust. This caused the aircraft to yaw sharply to the left with a steep nose-down attitude, initiating a rotation around its longitudinal axis.
The instructor pilot took control, attempting to maintain the aircraft's nose and level the wings by applying maximum power to both engines. However, the aircraft's low airspeed led to a collision with large trees and the ground, resulting in the destruction of the aircraft. The student pilot sustained minor injuries, while the instructor pilot suffered serious injuries.
The investigation
The GPIAAF investigation examined the aircraft wreckage, flight control surfaces, and engine components. Investigators confirmed that all flight control surfaces were intact and connected, and the landing gear and flaps were in the retracted position at impact. Both propellers were found in a fine pitch configuration, not feathered, which is consistent with low engine power at the time of impact.
While the aircraft was equipped with satellite navigation, no flight data recorder was present. The investigation also noted that the cockpit's structural disruption may have altered the position of the engine control levers during the crash sequence. Meteorological conditions at the time were clear with good visibility.
Findings
- The instructor pilot likely prioritized maintaining the climb profile, which allowed the aircraft's airspeed to decrease dangerously.
- The failure to feather the propellers after the left engine power loss prevented the optimization of the aircraft's performance.
- The instructor's attention may have been fixated on maintaining the aircraft's attitude, reducing his ability to identify the loss of airspeed and the resulting degradation in climb performance.
- The emergency procedure for an engine failure requires maintaining a specific control speed (89 KIAS) and configuring the aircraft for maximum continuous power and drag reduction, which was not fully achieved.