Cubcrafters Inc CC11-160 N55JV accident near Findlay, Ohio

Probable cause

The pilot/mechanic’s inadequate inspection of the faulty horizontal stabilizer trim switch, which resulted in an uncommanded trim movement during the takeoff roll, which resulted in an aborted takeoff, and subsequent nose over.

NTSB analysis

The pilot, who was also a mechanic, purchased the airplane after it had been involved in an accident. The pilot completed major repairs and a conditional inspection on the airplane and planned to complete the first test flight from a soybean farm field near his residence. He taxied the airplane to the field and completed a normal run-up. He then operated the electric horizontal stabilizer trim, via the rocker switch on the control stick, to the takeoff position (full nose up) as indicated on the primary flight display (PFD).

When the trim indicator reached the takeoff position, he removed his thumb from the trim switch and initiated the takeoff roll. The airplane accelerated normally, and he moved the control stick aft to rotate however, a heavy nose down pressure was felt. He immediately aborted the takeoff and, in his effort to slow the airplane, it nosed over. The left wing and empennage sustained substantial damage.

Examination of the horizontal stabilizer trim position found that it was set to a full nose down position, as observed at the control surface and on the PFD trim indication.

Examination of the trim rocker switch found that it would operate the trim actuator; however, when the switch was released, it would not return to the neutral position as designed. In order to stop the trim movement from continuing to run until it reached its maximum nose up/down limit, the switch was required to be moved to the center position, which would stop the trim movement.

It is likely that the stabilizer trim continued to operate towards the nose down position during the takeoff roll, after the pilot had released his thumb from the switch, which resulted in the pilot feeling a heavy nose down force during the takeoff.

There was no evidence that the pilot/mechanic evaluated the rocker switch’s proper operation during the major repairs and recent conditional inspection. Had he inspected the switch for proper movement, it is likely that he would have detected the faulty condition of the switch, and the accident likely would have been prevented.

Text from the NTSB. Open the NTSB docket for ERA22LA310 for the full record.