Incident Overview
On April 14, 2011, at approximately 1755 Alaska daylight time, a Piper PA-32 airplane, registration N81052, was substantially damaged during an encounter with turbulence while in cruise flight. The incident occurred about 13 miles west of Cold Bay, Alaska. The aircraft was operated by Peninsula Airways, Inc., of Anchorage, Alaska, as a visual flight rules (VFR) cargo flight under 14 Code of Federal Regulations Part 135. The solo airline transport pilot was uninjured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight had departed False Pass, Alaska, around 1745.
Pilot Account
In a written statement to the National Transportation Safety Board (NTSB) dated April 29, the pilot reported that while descending toward his destination, the airplane encountered severe up and down drafts. During this encounter, the pilot struck his head on the sun visor, despite his seatbelt and shoulder harness being snug and secure. After the turbulence, he continued to his destination and landed without further incident.
Weather and Mechanical Condition
The wind at the destination airport at the time of the incident was reported as 300 degrees at 9 knots. The area forecast valid for the time of the incident forecast no significant turbulence during the reporting period, and no pilot reports of turbulence in the area were received. The pilot stated that there were no preaccident mechanical problems with the airplane.
Damage Examination
A postaccident examination revealed substantial damage to the stabilator. Inspection by the NTSB investigator-in-charge showed that the right half of the stabilator was bent downward 5 to 10 degrees outboard of the fuselage attachments. The bottom skins adjacent to the bend were wrinkled. Removal of the skins revealed downward bending of the stabilator main spar. No signs of fatigue or corrosion were found.