Incident Overview
On March 20, 2008, at approximately 1026 Pacific daylight time, a Piper PA-31-350, registration N4098A, landed with the right main landing gear retracted at Portland International Airport in Portland, Oregon. The aircraft was operated by Ameriflight LLC under 14 Code of Federal Regulations Part 135 and was owned by UAS Transervices, Inc. The certificated commercial pilot was not injured. The airplane sustained substantial damage to the aileron.
Flight Sequence
The cross-country cargo flight departed Portland en route to Roseburg, Oregon. Visual meteorological conditions prevailed, and an instrument flight rules flight plan had been filed. While preparing to land at Roseburg, the pilot noted that the right main landing gear failed to extend. Ground personnel confirmed the gear was retracted during a flyby. The pilot then diverted back to Portland. Ameriflight personnel alerted the Portland tower that the airplane was returning for an emergency landing with one main wheel retracted.
Emergency Response
Maintenance personnel discussed the problem with the pilot, who attempted various remedial actions without success. A subsequent flyby confirmed that the wheel remained retracted. The pilot declared an emergency and landed. There was no fire and no injuries. The right propeller, right flap, right wing outboard of wing station 190, and right aileron sustained damage.
Recovery and Examination
During recovery efforts, the airplane was jacked up to extend the right main landing gear, which then locked in place. The airplane was towed to a hangar. Examination revealed that the upper pivot bolt had not been installed through the pivot hole in the upper end of the actuating rod during recent maintenance. The mechanic who performed the repair and the inspector who signed off on the repair did not detect this discrepancy.