CEN21LA147

The instructional flight included numerous landing gear extension and retraction cycles. During the flight, the nose landing gear indication showed that the gear was in the down and locked position but then indicated that the gear was in the unsafe position. The flight instructor performed several touch-and-go landings to “lightly move” the nosewheel into the down-and-locked position. According to the flight instructor, the contact with the runway pavement was “firm enough” to indicate that the nose landing gear was down and locked. After touching down on the accident landing, the airplane began yawing to the right with an “unusual noise.” The application of left brake prevented the airplane from leaving the runway pavement; however, the nose landing gear collapsed during the rollout. The substantial airframe damage precluded functional testing of the nose landing gear. Visual examination revealed that the nose landing gear lower drag link was fractured. Metallurgical examination revealed the presence of fatigue cracking in the wrought material and a lack of fusion in the welded areas. Although postaccident examination of the actuator arm determined that it was fully extended at the time the nosegear collapsed, it is likely that the nose gear was not fully extended before landing. The lack of full extension compromised the nosewheel steering system and affected directional control during the rollout. The subsequent failure of the landing gear link resulted in the collapse of the nose gear. The extent to which the fatigue and lack of fusion had compromised the structural integrity of the link before the accident flight could not be determined from the available information.

On February 27, 2021, about 1030 central standard time, a Piper PA-23 airplane, N1460P, was substantially damaged when it was involved in an accident in Oshkosh, Wisconsin. The flight instructor and the pilot receiving instruction were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor reported that the flight included numerous landing gear extension and retraction cycles. About 45 minutes before the accident, the nose landing gear indication showed that the gear was initially in the down-and-locked position and then was in the unsafe position. The flight instructor subsequently performed several touch-and-go landings to “lightly move” the nosewheel into the down-and-locked position. According to the flight instructor, the contact with the runway pavement was “firm enough” to indicate that the nose landing gear was down and locked. After touching down, the airplane began yawing to the right with an “unusual noise.” The application of left brake (by the pilot receiving instruction because the brakes were on that side of the airplane) prevented the airplane from leaving the runway pavement, but the nose landing gear collapsed during the rollout. The airplane traveled an additional 100 to 200 ft with its nose on the runway before coming to a stop. Poastaccident examination of the airplane revealed substantial airframe damage including multiple fuselage frames and skin panels and the nose landing gear wheel well structure. The damage precluded functional testing of the gear. Visual examination revealed that the nose landing gear lower drag link had fractured and that the left and right tubes had separated from the bracket. The nose landing gear strut and wheel assembly appeared intact. The actuator was in the extended position. The arm was bent about 90°, consistent with it being fully extended at the time of the landing gear collapse. Metallurgical examination of the nose landing gear lower drag link revealed the presence of fatigue cracking in the welded areas and the wrought material of the left and right tubes. In addition, the weld metal had areas that exhibited a lack of fusion.