20240805020819A

The pilot was performing a post-inspection flight after annual inspection. Upon liftoff from runway 34, the aircraft gained minimal altitude, began to porpoise, and struck the runway nose down. The nose landing gear (NLG) collapsed and both propellers contacted the runway. The aircraft departed the runway, onto a taxiway under its own momentum. The pilot exited the aircraft. There were no injuries and no post crash fire.

The FAA investigation found substantial damage to the nose area of the aircraft. The NLG wheel assembly was sheared at the NLG fork and strut tube. Structural crumpling was found on both sides of the fuselage, forward of the leading edge of the wing, extending diagonally to the nose bowl and upwards to the windscreen.

The interior inspection found the stabilator trim indicator full forward in the "nose down" position. Attempts to operate the stabilator trim by hand revealed that the manual trim wheel was bound. Considerable effort was required to break the trim wheel free. Once free, the stabilator trim operated normally from stop to stop. Travel and correct orientation of the stabilator trim tab was verified by another inspector. An attempts to bind the manual trim wheel into full forward position was successful on numerous attempts. The stabilator electric trim system was verified as operable and the electric trim servo was audible to the inspector. However, with the manual trim wheel bound in the full forward position, the stabilator electric trim servo was unable to produce the necessary force to overcome the binding and release the stabilator trim system. The stabilator servo clutch released allowing the servo motor to turn freely. The stabilator trim drum and cable was inspected in the aft tailcone. The stabilator trim drum jackscrew was not properly lubricated.

The technician that performed the annual inspection was interviewed. The technician, who holds an FAA inspection authorization, stated that the inspection had been performed in accordance with the manufacturer's maintenance manual and applicable regulations. When asked about the trim system, the technician stated that a non-certificated technician was supposed to have lubricated the stabilator trim jackscrew while the technician operated the manual trim wheel from stop to stop. The technician stated the aircraft had been maintained by their shop for a number of years.

The pilot was interviewed and stated that the aircraft was operating well during the takeoff roll, but once the yoke was pulled aft, the aircraft became difficult. The pilot stated that there was heavy forward/nose down pressure on the control yoke. The electric trim was operated in an attempt to correct the nose down pressure with no success. At that point the decision was made to abort the takeoff. Both throttles were brought back to idle, at which point the nose pitched down and the aircraft began to porpoise. The NLG contacted the runway and collapsed. Differential braking was utilized to steer the aircraft off the runway to a taxiway, where the aircraft came to rest. The pilot attempted to exit the main door, which was jammed, but was able to exit the aircraft through the aft door. The pilot was asked if the preflight checklist was followed and whether the trim position was physically verified before takeoff, to which the pilot replied that the electric trim switch was operated, but did not visually or physically verify the stabilator trim position. When asked how they knew if the trim was set for takeoff, the pilot replied that they only ever checked electric trim for operation.

The FAA, NTSB investigator, and a representative from Piper aircraft disassembled the tail section to reveal the stabilator trim assembly. It was discovered that the stabilator trim drum barrel mount bearings were worn excessively. When the stabilator trim wheel was operated to the full forward position, the bearing would bind in the bracket assembly.