What happened
On 24 June 2006, a Dornier 28 D2 Turbo Skyservant, registration HA-ACO, was performing a private flight near Brigg, North Lincolnshire. Having completed a parachute lift operation, the aircraft was on final approach to Runway 2cap 26 at Hibaldstow Airfield. At the time of the incident, visibility was approximately 10 km with light winds from 280 degrees at 3 knots.
During the approach, the pilot adjusted the propeller pitch to the flight beta range, which is controlled via the power levers. As the aircraft approached the runway threshold, it began to lose altitude more rapidly than anticipated. In an attempt to correct this, the pilot deselected flight beta, which caused the aircraft to balloon upward slightly. However, once the aircraft crossed the threshold, flight beta was re-selected. This action resulted in a faster than expected sink rate that the pilot could not arrest before touchdown.
The resulting landing was heavy, with the aircraft maintaining a relatively level wing attitude but a slightly tail-down posture. The impact caused damage to the right wing stub and the right wheel hub. There was no damage to the engines or propellers, and the pilot exited the aircraft via the door without injury.
The investigation
The investigation was based on the aircraft accident report form completed by the pilot. The examination focused on the aircraft's configuration and the pilot's management of the propeller pitch settings during the landing phase. The investigation confirmed that the aircraft's engines are mounted on wing stubs beneath the cockpit, and the landing gear is a fixed tail-dragger configuration.
Findings
- The primary cause of the heavy landing was the abrupt re-selection of flight beta after passing the runway threshold.
- This adjustment led to a descent rate that exceeded the pilot's ability to compensate.
- The impact caused structural over-stressing to the right wing stub and damage to the right undercarriage hub.