Accident Details
On January 1, 2018, about 1725 eastern standard time, a Costruzioni Aeronautiche Tecnam P2006T airplane, registration N594MA, sustained substantial damage during a landing accident near Lynchburg, Virginia. The flight instructor and the pilot receiving instruction were not injured. The airplane was being operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
The instructor reported that the flight was a cross-country instructional mission with the pilot receiving instruction acting as the pilot flying. On final approach, the pilot maintained a descent rate of about 500 feet per minute and confirmed with the instructor that the airspeed was 70 knots. Immediately after touchdown, the left main landing gear (MLG) assembly separated from the airplane. The airplane then skidded for approximately 100 feet, departed the runway to the left, and came to rest on grass. The fuselage sustained substantial damage.
The instructor noted that no wind gusts were present during the approach and landing, and no side loading occurred at touchdown. Based on his experience, he did not believe the landing was hard enough to cause damage.
Maintenance History
The Airplane Maintenance Manual (AMM) required replacement of the MLG every 4,000 landings. Review of maintenance records showed that several previous owners and operators had not tracked the number of landings. After purchasing the airplane, the owner worked with the Federal Aviation Administration (FAA) to estimate the number of landings and determine compliance with the AMM replacement requirement. At the time of the accident, the estimated number of landings had still not been determined, and maintenance records indicated that the MLG had never been replaced.
Metallurgical Examination
The separated left MLG assembly and the intact right MLG assembly were recovered and sent to the NTSB Materials Laboratory for examination. The outer area of the arm's fracture surface exhibited a slanted morphology and rough surface texture, consistent with a fracture through the weld filler. The inner area of the arm's fracture surface was shinier and flatter, indicating an area that had not been welded. Most of the flange's exterior had not been welded. The flange's upper area showed fracture features consistent with progressive cracking that propagated from the interior unwelded area outward through the weld filler. A complete copy of the NTSB materials laboratory report is included in the public docket for this accident.