Primary finding
Probable cause
a fatigue fracture of the landing gear axle.
Investigator assessment
Analysis narrative
The airplane was on takeoff run when the right landing gear axle broke. It was not possible to maintain directional control and the gear leg dug into the terrain. The airplane ground looped and the tail impacted the terrain. Subsequent examination of the axle revealed that the failure was due to fatigue cracking, but the source of the fatigue was not determined.
Source record
Factual narrative
On June 2, 1996, at 0830 mountain daylight time, a Cessna 140, N3609V, sustained substantial damage on takeoff from runway 31 (dry turf private strip), near Potter, Nebraska. The right axle broke an the airplane ground looped. The commercial pilot and one passenger reported no injuries. The personal 14 CFR Part 91 flight was operating in visual meteorological conditions. No flight plan was on file. The flight was originating at the time of the accident with the intended destination of Scottsbluff, Nebraska. The pilot stated that the airplane was just about to liftoff when the right axle broke and the landing gear leg dug into the terrain. The airplane ground looped and the tail wheel impacted the terrain. The axle was removed and sent to the NTSB Office of Research and Engineering for examination. The fracture of the axle was found to be indicative of fatigue cracking. No specific determination of the source of the fatigue was determined. -