What happened
On July 6, 2003, at approximately 19:00 UTC, a Tecnam P92 E Super, registration CS-ULX, was performing a visual flight rules (VFR) navigation flight from Valdonas to Pias Long and Vila Nova de Ourém. The aircraft was carrying a pilot and one passenger.
During the approach to runway 30 at Pias Longas, the pilot initiated a direct approach from a significant distance. Due to the aircraft's descent and the influence of mountain waves caused by northwesterly winds, the aircraft's altitude dropped below the elevation of the runway. As the pilot realized the low altitude, they applied maximum engine power in an attempt to climb, but the aircraft was already in a high-drag landing configuration with full flaps.
Recognizing the imminent collision, the passenger—who was also a rated pilot—took control of the aircraft and attempted a 180-degree turn to the left to return to the valley and regain altitude. This maneuver caused the aircraft to reach its minimum controllable airspeed, leading to a loss of lift. The aircraft struck a small olive tree and subsequently crashed into the ground, approximately 500 meters from the runway threshold. The impact triggered a fire that partially consumed the airframe, resulting in a total loss of the aircraft.
The investigation
The GPIAAF investigation examined the flight path, meteorological conditions, and the aircraft's performance. Investigators noted that the pilot was familiar with the terrain and frequently operated this route. However, the investigation established that the pilot began configuring the aircraft for landing too early, before the runway was even in sight.
Meteorological data indicated that while the weather was generally good, visibility was significantly reduced due to high humidity, suspended particulates in the air, and the sun's position near the horizon directly in the pilot's line of sight. This glare and reduced visibility made it difficult to perceive the aircraft's height relative to the terrain and the runway.
Findings
- The primary cause of the accident was deficient piloting technique, which allowed the aircraft to descend below the proper approach profile and enter a state where it could no longer trade airspeed for altitude.
- The aircraft entered the power-inversion zone, making it impossible to recover altitude while in a high-drag configuration.
- Contributing factors included reduced horizontal visibility and the sun's position, which hindered the pilot's ability to judge altitude and distance.
- The pilot failed to implement timely corrections to the anomalous flight conditions, necessitating the passenger's intervention.
- The passenger's attempt to execute an emergency turn at low speed led to a loss of lift and the subsequent impact.