What happened
On September 8, 1998, a Piper PA-28-180 attempted a takeoff from the grass runway 24R at the Langeoog airfield (EDWL). The aircraft, which had recently landed to pick up passengers for a private flight to Bad Neuenahr-Ahrweiler, began its takeoff roll on a runway that had become heavily saturated due to recent intense rainfall.
The pilot rotated the aircraft in the middle of the runway and lifted off at 55 knots. However, the aircraft failed to achieve an adequate rate of climb to clear the trees and shrubs located at the end of the runway. Realizing that clearing the obstacles was impossible, the pilot attempted to land the aircraft in the treetops. The aircraft struck the vegetation with its tail first before pitching forward and impacting the ground at an angle of approximately 30 degrees. The impact caused the wings to separate from the fuselage and resulted in a fire in the engine compartment, which the pilot managed to extinguish using a handheld fire extinguisher. The accident resulted in two serious and two minor injuries.
The investigation
The BFU investigation examined the aircraft's maintenance records, weight and balance calculations, and the runway conditions. The investigation found that the aircraft was properly maintained and airworthy, though a non-relevant defect in the magnetic compass was noted.
Investigators analyzed the takeoff performance requirements based on the aircraft's flight manual. They determined that because the runway surface was heavily sodden, a 60% increase in the required takeoff distance should have been applied. The investigation also scrutinized the pilot's weight calculations, discovering that the pilot had used an outdated empty weight from 1991 instead of the current 1997 record, leading to an incorrect calculation of the aircraft's center of gravity and takeoff performance.
Findings
- The aircraft was overloaded by approximately 75 kg, exceeding the maximum allowable takeoff mass of 1090 kg.
- The pilot used an incorrect empty weight for takeoff calculations, as the flight manual contained an obsolete weighing record from 1991.
- The insufficient runway length prevented a safe takeoff, as the required distance to clear 15-meter obstacles under the prevailing wet conditions was approximately 792 meters, while only 645 meters of runway were available.
- The saturated condition of the grass runway significantly reduced acceleration during the takeoff roll.
- The aircraft likely entered an aerodynamically stalled or near-stalled state during the climb due to insufficient airspeed at liftoff.