Cessna 414 N40NY accident near New York, New York

Probable cause

The improper rigging of the right main landing gear, which resulted in ovestress fractures of a bolt and aft lug on the trunnion assembly.

NTSB analysis

The pilot stated that before landing, he confirmed all landing gears were down and locked. He performed a normal landing on runway 6 about 100 knots, and during the landing roll he applied the brakes. After rolling about 200 to 300 feet, while traveling about 70 to 75 knots, he began to apply right rudder to turn onto runway 10. During the turn, the right main landing gear slowly began to collapse causing the right wing to contact the runway. The airplane departed the runway and collided with a runway marker sign. Postaccident examination of the airplane revealed that the bellcrank was separated from the attach point on the right trunnion assembly, the aft lug of the right trunnion assembly was fractured, and the bolt that secures the bellcrank to the right trunnion assembly was also fractured in overstress. The fractured components were submitted to the NTSB’s Materials Laboratory for further examination, and the parts revealed no evidence of preexisting cracking. While the bolt diameter was less than the minimum specified, that condition did not contribute to the fracture trunnion aft lug or the bolt. Several days before the accident, a serviceable right trunnion assembly was installed during an annual inspection, and the airplane was approved for return to service. The airplane had been operated for about 2 hours since the serviceable trunnion assembly was installed. Cessna engineering personnel reported that overstress fracture of the trunnion aft lug can occur when the landing gear is improperly rigged such that the upper and lower side links of the main landing gear are not over center, which transmits the load path from the main landing gear to the trunnion lugs.

Text from the NTSB. Open the NTSB docket for ERA11LA191 for the full record.