Report on aviation accident at Maarud farm in Sør-Odal municipality, Innlandet on 24 June 2024 with Piper L-4j, LN-SAI

LN-SAI was performing landings with an instructor and a student on board. During the last landing, something went wrong. As the aircraft touched down, the pilots noticed that it braked abruptly before the aircraft tipped onto its nose and stopped. The plane then fell back, settling on its landing gear. Both pilots were unharmed and were able to exit the aircraft on their own. They observed that the left main wheel was missing and that there was additional damage to the aircraft.

The Norwegian Safety Investigation Authority (NSIA) chose to investigate the main wheel axle at the Armed Forces' Laboratory Service to see if there were any specific factors that could explain the breakage of the wheel axle. The conclusion was that fatigue cracks had started at the spot welds in the axle. This may be due to the welding process itself and impurities in the base material.

LN-SAI is a historical aircraft built in 1944, which means the aircraft is now 80 years old. There is no complete history for all the parts, and the NSIA was unable to determine how long the wheel axle has been installed on the aircraft. A contributing factor that may have accelerated the breakage of the axle could be that the aircraft has operated on both skis and floats.

The NSIA does not issue any safety recommendations in this case. The aircraft is 80 years old, and it is impossible to determine the age of the wheel axle. LN-SAI is a historical aircraft, and there are no inspection requirements for the wheel axle on this aircraft. However, the NSIA encourages owners of Piper aircraft with similar landing gear to perform internal inspections of the axle periodically. The check can be done with flashlight and possibly with a borescope.

This report is in Norwegian only.

Published 03.12.2024