What happened
On 10 June 2021, a Piper PA-31-350 Chieftain, registration ZS-NDN, was preparing for a maintenance acceptance flight at Wonderboom National Airport (FAWB). After being cleared for takeoff from Runway 11, the pilot initiated the takeoff roll. As the aircraft reached rotation speed, the pilot experienced heavy resistance in the control column. Attempting to pull the column back with constant pressure, the pilot realized the aircraft would not lift off in time.
In an effort to stop, the pilot retarded the throttles to idle and applied the brakes. Due to insufficient remaining runway, the pilot applied heavy braking and shut down both engines to halt the aircraft. The aircraft subsequently exited the runway and came to rest on a grass area near the threshold of Runway 29. The heat from the main landing gear brake assemblies ignited the dry grass, though airport fire and rescue services extinguished the flames before any damage occurred to the aircraft. There were 0 fatalities and no injuries.
The investigation
SACAA AIID examined the circumstances surrounding the heavy control column and the subsequent excursion. The investigation established that the aircraft was mechanically sound and capable of normal operation. The pilot identified that the elevator trim tap was not correctly configured for takeoff. Specifically, the elevator trim was set in a reverse position, resulting in a nose-down attitude that prevented effective rotation.
Findings
- The primary cause of the failure to rotate was the elevator trim being set to a nose-down attitude.
- The incident was driven by the pilot's failure to perform a thorough pre-flight inspection prior to the flight.
- The aircraft experienced a runway excursion and a localized grass fire due to the heat from the braking system.