NTSB Factual Report

On August 13, 2016, about 1300 eastern daylight time, a Cessna 150G, N3666J, was substantially damaged during cruise flight when the left side of the elevator detached from the horizontal stabilizer. The flight instructor and student pilot were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the Title 14 Code of Federal Regulations Part 91 personal flight, which departed Montauk Airport (MTP), Montauk, New York, destined for Brookhaven Airport (HWV), Shirley, New York.

According to the student pilot, he and the flight instructor were on a dual instruction flight when the accident occurred. They had departed MTP and were on their way back to HMV cruising at 4,500 feet above mean sea level, when the student pilot noticed a roughness and vibration coming through the control wheel. He told the flight instructor about it, and then while looking around the airplane he noticed that the left elevator tip was hanging down 6-10 inches from its normal mounting position.

According to the flight instructor, when the student pilot complained that the airplane was handling "funny," he took control of the airplane and noticed that the left elevator was moving up and down uncontrollably. At this point, the airplane was directly in line with runway 24 at HWV, so the flight instructor made a slight power reduction to descend at 150 feet per minute, kept the wing flaps retracted, did not move the flight controls, and made a 7 mile long straight in approach to the runway where the airplane touched down firmly without further incident.

Examination of the elevator and horizontal stabilizer by a Federal Aviation Administration (FAA) inspector revealed that the left outboard elevator attach bolt had backed out of the nut plate. Further examination also revealed that the right elevator attach bolt would move in the nutplate when the elevator was moved up or down.

According to FAA records, the flight instructor held an airline transport pilot certificate with a rating for airplane multi-engine land, and commercial privileges for airplane single-engine land and airplane single-engine sea. He also held a flight instructor certificate with ratings for airplane single-engine, airplane multi-engine, and instrument airplaneHe also held a ground instructor certificate with a basic rating, and a mechanic certificate with ratings for airframe and powerplant, with an inspection authorization from the FAA. His most recent application for a FAA third-class medical certificate was dated January 20, 2015. He reported that he had accrued 8,700 total hours of flight time, 1,300 of which were in the accident airplane make and model.

According to FAA records, the student pilot held a student pilot certificate. His most recent application for a FAA first-class medical certificate was dated November 14, 2013. He reported that he had accrued 56 total hours of flight time, all of which were in the accident airplane make and model.

According to FAA and maintenance records, the airplane was manufactured in 1966. The airplane's most recent annual inspection was completed on February 1, 2016. At the time of the inspection, the airplane had accrued approximately 2,860 total hours of operation.

The elevator attach bolts, nutplates, and bushings, were retained by the NTSB for further examination.