What happened
On September 19, 2017, a Van's Aircraft RV-4, registration LN-ABF, was conducting a sightseeing flight from Hamar Airport Stafsberg with one pilot and one passenger. The aircraft had been purchased by the pilot only one month prior to the accident, and he had just four hours of flight time in this specific model following a self-conducted familiarization process.
During the return leg of the flight, the aircraft approached runway 15 on a long final. Video surveillance from the airport tower indicated that the descent profile became unstable, with the aircraft leveling off or even slightly climbing. At an altitude of approximately 300 feet above the ground, the aircraft entered a stall. This was immediately followed by a significant right wing drop and a roll that brought the aircraft nearly inverted. The aircraft then entered a spin with a belly-down attitude, rotating approximately 330 degrees before impacting the ground with a steep nose angle. Both occupants of the Van's Aircraft RV-4 were killed in the crash.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined various elements of the flight, including GPS track logs, video recordings from the airport tower, and the aircraft's wreckage. The investigation noted that the passenger had been using a mobile phone to take photos and videos during the flight, with the final transmission occurring seconds before the loss of control.
Investigators also reviewed the pilot's experience and the aircraft's documentation. It was discovered that the Aircraft Flight Manual (AFM) present on board was incomplete, consisting only of loose, individual sheets of paper. Furthermore, there were no existing routines during annual aircraft certifications to verify that a complete, approved manual is carried on board.
Findings
- The pilot had not acquired sufficient flight experience on the LN-ABF to manage the aircraft during a loss of control.
- The aircraft's descent profile was unstable during the final approach, leading to a stall at low altitude.
- The pilot's self-conducted familiarization on the new aircraft model was inadequate for the complexities of the aircraft's handling.
Safety action
- The NSIA recommended that the Civil Aviation Authority Norway evaluate whether current regulations allowing pilots to perform self-familiarization on new aircraft models without documented minimum requirements for content or duration are safe. The board suggested that authorities provide specific criteria or checklists for such training.
- A recommendation was made to implement routines during annual aircraft certifications to ensure that a complete and approved Aircraft Flight Manual is present on board.