Accident Summary
On December 30, 2018, at 1553 Pacific standard time, a Piper PA46-350P, registration N4161X, was substantially damaged during a landing accident near San Diego, California. The private pilot and three passengers were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
The pilot reported that the approach and flare to runway 28R were normal, with a smooth touchdown. Shortly after the nose landing gear contacted the ground, the airplane began pulling left. Despite corrective control inputs, the airplane continued turning left, departed the runway surface, and the landing gear collapsed. Both wings and the aft cabin structure sustained substantial damage. All occupants egressed unaided via the aft cabin door.
Post-Accident Examination
Due to the 2018–2019 federal government shutdown, the NTSB could not respond immediately. An examination was performed on February 19, 2019. Photographic evidence showed the airplane came to rest about 1,300 ft beyond the displaced threshold of runway 28R and 50 ft left of the runway edge. Runway 28R was 4,598 ft long and 150 ft wide. The main landing gear had collapsed, and three black tire transfer marks formed a sweeping arc from the runway centerline to the infield.
Examination of the landing gear revealed that both left and right actuators were in the extended position. The left actuator had detached from its mounting points at the wing spar and landing gear trunnion. The right actuator remained attached to the trunnion but its piston was bent, and the upper section detached from the wing spar. All failure areas exhibited grainy surface features with no corrosion or beach markings.
The nose landing gear had partially retracted and rotated, with the wheel hanging below the open gear doors. The oleo strut and trunnion assembly remained attached; the scissor link appeared undamaged, and the steering horn remained attached. The down spring was intact, the tire firm, with scuffing on the left side of the tire lip. The lower section of the nose landing gear actuator remained attached to the trunnion, while the upper section broke free from its engine mount attach point and impinged against the firewall. The actuator’s internal locking system appeared engaged, with 7 1/8 inches of piston extension, consistent with full extension.
Control continuity was established from the foot pedals to the rudder and steering components. Movement of the foot pedals resulted in appropriate steering arm movement. With the actuator removed, the nose landing gear trunnion fell forward and locked into place with the down spring; steering arm contact with the steering horn and rollers showed no significant play, and foot pedal movement resulted in appropriate nose wheel steering.
Brake lines were damaged, preventing a full assessment, but both wheels rotated freely and rotors showed no thermal discoloration.
Service Bulletins
Five Piper service bulletins (SB) applied to the accident airplane:
- SB 1060: Removal of a spring washer in the brake pedal pin to prevent binding brakes and inconsistent steering. Complied with November 2001.
- SB 1075: Modification of the steering horn to prevent contact with the engine mount during towing. Complied with November 2001.
- SB 1256: Replacement of nut and bolt orientation for nose landing gear torque links. Complied with August 2013.
- SB 1103F: Repetitive fluorescent penetrant inspection of the engine mount for fatigue cracks at the nose landing gear actuator attach point, at 100-hour intervals unless upgraded. The airplane had the original engine mount; inspection was performed during the last annual inspection on January 26, 2018, 52.2 flight hours before the accident.
- SB 1193: Replacement of the nose landing gear down spring due to tendency to develop permanent set. Replaced at the last annual inspection.
NTSB Materials Laboratory Examination
The actuator and damaged engine mount components were sent to the NTSB Materials Laboratory. Examination showed the engine mount fractured in the area specified by SB 1103F: at the right attachment foot for the actuator and at one of the support tubes on the left attachment foot. The nose landing gear actuator remained bolted to pieces of the attachment feet. Fractures exhibited a uniform matte-gray appearance on slant angles, consistent with ductile overstress fracture.
At the time of the accident, the wind was from 210° at 8 knots.