Left in a Huff

The NTSB has released its preliminary report on a 25 June 2023 accident in which a Mooney M20R, registration N13LV, was destroyed and its pilot—the aircraft’s sole occupant—lost his life.

The accident-aircraft was operated as a personal flight under Part 91 of the Federal Aviation Regulations.

According to a mechanic at Oak Island, North Carolina’s Cape Fear Regional Jetport (SUT), the accident-aircraft had been undergoing maintenance since October 2022. The Mooney’s Private Pilot certificated owner had tasked the mechanic with troubleshooting the aircraft’s interior lighting, servicing its brakes, installing a standby vacuum hose, and repairing an exhaust leak. The mechanic had not completed the specified work insomuch as the airplane could not be started on account of dead batteries.

Inspection of the accident-aircraft’s main batteries revealed an unairworthy condition. Specifically, the Mooney M20R was designed with a 24-volt electrical system comprising a pair of 24-volt batteries. The mechanic found, however, that the accident-aircraft had been modified, and retrofitted with four 12-volt batteries.

Upon reporting the discrepancy to the Mooney’s owner, the mechanic was summarily instructed to return the quartet of non-standard 12-volt batteries to the aircraft and reconnect such.

The mechanic refused, however, as the requested installation was at once unapproved, unairworthy, and in violation of Federal Aviation Regulations.

Aggrieved, the Mooney’s owner demanded to take possession of the aircraft.

The mechanic explained the plane was not in an airworthy condition—as he had yet to complete the originally-specified repairs—and noted as much on the work invoice.

As the Mooney’s owner taxied the aircraft from the SUT maintenance facility, witnesses observed excessive white smoke emitting and oil leaking therefrom.

Shortly after the Mooney departed SUT Runway 23, the pilot took to the airport’s Common Traffic Advisory Frequency (CTAF) to report the aircraft’s engine had failed. The pilot went on to state his intention to return to the airport and attempt a landing on Runway 23.

Review of ADS-B data revealed the accident-aircraft departed SUT Runway 23 at approximately 16:17 EDT and attempted to fly a left circuit back to Runway 23.

The Mooney came to ground in a residential area one-half-mile short of the SUT Runway 23 threshold.

The aircraft impacted the yard of a single-family home. A post-accident fire ensued but spread to neither the home nor adjacent structures.

First responders discovered the accident-aircraft lying on its starboard side with its longitudinal axis oriented on an approximate magnetic heading of 090-degrees. A 125-foot debris-path began with the Mooney’s starboard aileron suspended in a forty-foot tree on a southeast bearing from the main wreckage.

The left-wing—its aileron and flap intact—remained partially attached to the accident-aircraft’s fuselage. The left-wing flap was observed in an extended position; the cockpit flap-control, however, could not be identified.

The accident-aircraft’s right wing separated from the fuselage and was discovered resting beneath the left wing, with its aileron and flap detached. The right-wing flap was recovered near the right-wing, and the right-wing aileron was recovered from the aforementioned tree.

The Mooney’s landing gear was observed in the extended position. The empennage remained intact and oil streaks were discovered on the underside of such.

Flight control continuity was confirmed from the cockpit via push-pull tubes to all flight control surfaces, excepting the separated right wing—the aileron continuity of which was confirmed only to the wing root.

The Mooney’s cockpit and cabin were consumed by fire.

The accident-aircraft’s engine came to rest, inverted, in the vicinity of the main wreckage. The propeller remained attached to the engine.

An engine oil sump accessory port plug was observed loose, with oily blue-stained baffling material resting beneath it. Additionally, the engine’s number-four piston connecting-rod had protruded through the top of the engine case. A check of the engine’s oil dipstick revealed no measurable oil in the sump.

FMI: www.ntsb.gov