Primary finding
Probable cause
Fatigue failure in a weld on the right main landing gear oleo strut tubing.
Investigator assessment
Analysis narrative
The pilot reported that he flared about 3 feet above the ground, then he 'cut' the throttle & the airplane 'dropped' onto the tundra. Both landing gear assemblies collapsed as the airplane touched down. The pilot reported there was a fracture in the welded section of the right oleo strut tubing. The airplane was equipped with 30 inch tundra tires.
Source record
Factual narrative
On October 5, 1993, at 1715 Alaska daylight time, a wheel equipped Piper PA-18 airplane, N5285J, owned and operated by the commercial rated pilot-in-command, crashed during a landing attempt at a remote landing site located approximately 4 miles north of Haines, Alaska. The pilot, the sole occupant, was not injured and the airplane sustained substantial damage. The personal flight, operating under 14 CFR Part 91, last departed Haines, Alaska, at 1700 and the destination was the remote landing site. Visual meteorological conditions prevailed and a VFR flight plan was not filed. The pilot told the investigator-in-charge, during a telephone conversation, that he was surveying the area looking for mountain goats. During the landing attempt on the saddle back of the mountain, he flared too high and the airplane "dropped" onto the ground from a height estimated to be three to five feet. The airplane did not bounce. Both main landing gear structural assemblies collapsed. The airplane was equipped with 30 inch tundra tires. The pilot reported that his post accident inspection of the landing gear found a fracture in the welded section of the right oleo strut tubing. An inspection of the fuselage by the NTSB investigator-in-charge found a fracture in a longeron tube (a major structural member) in the area where the left forward landing gear ear attaches to the fuselage. -