NTSB Factual Report

On April 24, 2009, about 1600 eastern daylight time, a Mooney M20J, N201JT, registered to and operated by a private individual, collided with a fence during an aborted takeoff from Berkeley County Airport (MKS), Moncks Corner, South Carolina. Visual meteorological conditions prevailed at the time and an instrument flight rules (IFR) flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 personal flight from MKS to Zephyrhills Municipal Airport (ZPH), Zephyrhills, Florida. The airplane was substantially damaged and the private certificated pilot and one passenger were not injured. The flight was originating at the time of the accident.

The pilot stated that after landing following an uneventful 3 hour flight, he fueled the airplane and then performed a preflight inspection, but he did not check the fuel tanks for contaminants. After engine start he taxied to the approach end of runway 23 where he performed an engine run-up which included checking the magnetos and cycling the propeller one time. With the flaps set to the takeoff position he taxied onto the runway, applied the brakes, set the directional gyro, and applied full power noting 2,600 to 2,700 rpm static. He estimated the takeoff roll was 1,500 feet, and he rotated between 65 and 70 knots. When the flight was 20 feet above ground level (agl), he noticed the engine began to “miss.” He verified by touch that the mixture, propeller, and throttle controls were full forward, and confirmed the magneto switch was set to the both position. He also looked at the engine gauges and did not notice anything unusual. The engine then smoothed out and he continued the flight climbing to a maximum of approximately 50 feet agl. At that time the engine began to run rough and the airplane was not climbing. He again verified the engine controls were full forward and saw a clearing to his left. He told the passenger he was aborting the takeoff, reduced power, and maneuvered the airplane towards the clear area. With the landing gear down he landed approximately 1/8 to 1/4 mile past the departure end of the runway. The airplane continued on the ground and collided with the airport perimeter chain link fence.

The passenger stated that when the flight was approximately 10 to 15 feet agl, he heard a noise that sounded to him like the engine was missing. A few seconds later he heard another miss sound and asked the pilot if he heard the same thing. The passenger reported the airplane was not climbing and he braced after the pilot reported they were landing.

According to an FAA inspector who was on-scene later that evening and again the following morning, he inspected fuel samples taken from the source that fueled the accident airplane. The samples were free of contaminants. Additionally, the airport manager reported to him that there were no complaints from pilot’s and owner’s of other airplanes fueled from the same source. The FAA inspector visually checked the accident airplanes’ fuel tanks and noted both were nearly full.

Recovery of the airplane was performed by cutting the empennage aft of the wings leaving the fuel supply system intact.

Examination of the airplane and engine following recovery was performed by a National Transportation Safety Board (Safety Board) investigator and a Federal Aviation Administration (FAA) inspector. Visual inspection of the fuel tanks revealed both were near full and no contaminants were noted either inside the tank or from samples taken from each tank. The fuel was light blue in color consistent with 100 low lead and was not cloudy. The gascolator did not contain any contaminants and the screen was clean.

In preparation for the attempted engine run on airframe with Safety Board and FAA oversight, the impact damaged propeller was removed and replaced, and the impact damaged exhaust was cut off. During the first run using fuel contained in the tanks at the time of the accident, the engine was noted to run rough and a magneto check produced a 250 rpm drop for the left and 50 rpm drop for the right. The engine was secured and the Nos. 2 and 4 bottom plugs were oil soaked. The plugs were cleaned, reinstalled, and the engine was restarted but still continued to operate rough. The engine was secured and the No. 4 bottom spark plug was still oil soaked. The spark plugs were swapped (top to bottom and vice versa). The engine was restarted and operated to 1,800 rpm (safety concerns precluded higher operation). The magnetos were checked and the left magneto drop was between 50 and 75 rpm and the right magneto drop was approximately 100 rpm. Following the engine run all spark plugs were removed and inspected; all were light gray and no oil soaked plugs were noted. Additionally, all cylinders were borescoped and no discrepancies were noted. The engine was run with the fuel selector positioned to the left and right positions with no changes noticed.

NTSB Probable Cause

The reported partial loss of engine power for undetermined reasons.