What happened
On May 5, 2010, at approximately 15:45 UTC, a Land África aircraft, registration I-7563, was performing a simulated forced landing at the Águeda Municipal Aerodrome. The pilot was practicing a maneuver intended to improve proficiency in handling engine failure scenarios. During the approach, the pilot performed several sideslips to manage altitude and airspeed. However, the aircraft approached the runway threshold with excessive speed.
In an attempt to achieve a precise touchdown at a specific target point, the pilot executed a final sideslip followed by a high flare. This maneuver was unsuccessful, resulting in the aircraft striking the runway with a high sink rate. The impact caused the nose gear to collapse and resulted in the breakage of two blades on the three-bladed propeller. There were no injuries to the single occupant.
The investigation
The GPIAAF investigation noted that the report of the accident reached the agency four months after the occurrence, which limited the scope of the investigation. The investigators examined the mechanics of the flight maneuvers, specifically the transition from sideslips to the landing flare. The investigation focused on how the aerodynamic changes during the maneuver influenced the pilot's ability to control the descent rate and touchdown point.
Findings
- The pilot was conducting the simulation with the engine stopped, which is contrary to standard practice for a simulated forced landing (SAF). Standard procedures dictate that the engine should remain running at low RPM to allow for immediate power application if necessary.
- During the successive sideslips, the pilot used crossed controls, which increased drag and required higher speeds to maintain lift. As the pilot leveled the wings for the landing, the lift-to-drag (L/D) ratio increased, meaning the aircraft did not lose speed as effectively as anticipated.
- The pilot attempted to correct the approach by increasing the angle of attack to hit a specific touchdown point, which led to a loss of lift and an aggressive descent.
- The primary cause of the accident was the excessive load placed on the nose gear during the high-sink-rate touchdown.