Beech A24 N400LE accident near Manteo, North Carolina

Probable cause

The failure of maintenance personnel to properly secure wiring during an electrical component installation, which resulted in arcing and smoke in the cockpit. Contributing to the outcome was the flight instructor's failure to attain a proper descent rate during the forced landing.

NTSB analysis

Shortly after takeoff on the instructional flight, the pilot receiving instruction heard a "pop" sound; the flight instructor saw smoke coming from the right lower portion of the instrument panel and felt a melted wire contact her leg. The pilot receiving instruction continued to fly the airplane briefly, then the flight instructor took the controls. With inadequate runway remaining ahead on which to land, the instructor initiated a turn to return to the runway. The airplane impacted the ground and slid about 500 ft, coming to rest upright and resulting in substantial damage to the airframe.

Postaccident examination of the cockpit revealed that electrical wires of a recently-installed avionics switch had arced against the top aft edge of the adjacent autopilot control unit and also at the edge of a vertical support member. The wires did not have circuit protection, nor was there any mechanical protection or supports present along the length of the wires to prevent chafing, contrary to FAA guidance. The pilots' failure to secure the electrical system from memory in response to the cockpit smoke would not have mitigated the hard landing, but may have decreased the smoke in the cockpit and lessened the urgency to land.

Text from the NTSB. Open the NTSB docket for ERA18LA010 for the full record.