Accident Summary
On June 8, 2017, at about 2110 eastern daylight time, a Piper PA-44-180 airplane, registration N3020M, was substantially damaged during the landing rollout at Montgomery County Airpark (GAI) in Gaithersburg, Maryland. The flight instructor and two student pilots on board were not injured. The instructional flight was conducted under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight.
Sequence of Events
According to the flight instructor, the airplane was returning to home base after a training flight that consisted of basic maneuvers and two takeoffs and landings to a full stop. During final approach, the instructor configured the airplane for landing and briefed the student pilot. The touchdown was uneventful. During the landing roll, the airplane began veering to the right of the centerline. After coming to a full stop, the instructor performed an engine shutdown before exiting.
Damage and Inspection
Upon inspection, the flight instructor noted that the right main landing gear had collapsed and was bent backwards toward the aft of the airplane. A Federal Aviation Administration inspector examined the airplane and found that the aft right wing spar web was damaged during the landing sequence. Further examination of the landing gear revealed that the right aft main landing gear trunnion bracket had failed.
Material Analysis
The NTSB Materials laboratory conducted a visual examination of the fracture surfaces of the trunnion bracket. The examination revealed no signs of fatigue failure within the trunnion; the bracket failed during an overstress event.
Maintenance History
A review of the aircraft logbooks did not reveal any recent maintenance to the landing gear assembly.