Piper PA-18A N4581A accident near Nikolai, Alaska

Probable cause

The pilot’s improper decision to load the airplane beyond its allowable takeoff weight and center of gravity limits, which resulted in a loss of control during the initial climb. Contributing to the accident was the external load and the downwind takeoff.

NTSB analysis

Before departure, caribou antlers were attached externally to the airplane's left wing lift struts, the airplane's main wing fuel tanks were refueled, the airplane was loaded with two butchered caribou and hunting gear, and the passenger's rifle was strapped onto the right wing. The passenger reported that, after taking off toward the east, the pilot stated that he "should have taken off the other way." A witness stated that the airplane departed downwind and began a shallow climb, followed by a gradual left turn, before descending into the trees just beyond the departure end of the runway.

No restricted airworthiness certificate had been issued by the Federal Aviation Administration authorizing external load operations. Further, the airplane's estimated gross weight at the time of the accident was about 642 pounds over its approved maximum takeoff weight and its center of gravity was significantly beyond the aft-most limit. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. It is likely that the pilot took off downwind and inadvertently stalled the airplane at a low altitude due to the exceedance of its allowable weight and center of gravity limits and the effect of the external load (antlers) and was unable to recover.

Text from the NTSB. Open the NTSB docket for ANC13FA091 for the full record.