Accident Overview
On April 15, 2015, about 1530 eastern daylight time, a Piper PA-28-140, registration N7598R, experienced a total loss of engine power during takeoff from Buffalo-Lancaster Regional Airport in Lancaster, New York. The private pilot, who was the sole occupant, was not injured during the forced landing on airport property. The airplane was substantially damaged. The aircraft was registered to and operated by a private individual under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which was originating at the time.
Pilot Actions and Preflight
The pilot reported conducting an extremely thorough preflight inspection while the airplane was in the hangar, as it had not been flown since January 2015. She checked the fuel and oil, then pulled the aircraft out. She stated the total fuel on board was 39 gallons—20 in the left tank and 19 in the right—and believed the fuel selector was on the left tank position. After engine start, she performed an engine run-up and reported everything was fine, noting a 50-rpm drop during each magneto check. She checked the ATIS, which favored runway 08, taxied, completed pre-takeoff checks, and applied full power on the runway, with the tachometer indicating full red-line rpm. She rotated at 60 mph.
Engine Power Loss and Forced Landing
At the end of the runway, at an estimated altitude of 200 feet, the engine coughed and the airplane began losing altitude. Power was restored briefly, and she considered turning to land on runway 26, but the engine quit again. She elected to land straight ahead in an abandoned field with high grass. The airplane touched down on the main landing gear, but the nose gear hit rising terrain, causing it to collapse. The airplane came to rest in a nose-low, tail-high attitude. After stopping, the pilot heard the electric fuel pump operating. She secured the airplane, found her cell phone, and called the mechanic/airport manager to report the accident.
Engine and Carburetor Inspection
Following recovery, the Lycoming O-320-D3G engine (serial number L-11402-39A) was inspected by an FAA airworthiness inspector. Crankshaft, camshaft, and valve train continuity was confirmed for all cylinders. Magnetos were tightly installed, but magneto-to-engine timing was not checked. P-leads were secure with no evidence of grounding, and spark plugs indicated a lean running condition by color. The carburetor bowl assembly could be moved by hand pressure relative to the throttle body assembly. The carburetor (model MA-4SPA) was removed and sent to the NTSB for dynamic and teardown inspection. Tachometer time at the accident was 781.4 hours.
At a FAA-certified repair station under NTSB oversight, inspection revealed a washer was installed beneath each of the four screws securing the throttle body to the bowl. Three of the four screws could be moved by hand, but movement was restricted by the washers. The single tight screw was adjacent to the lean mark on the carburetor bowl assembly. Looseness between the bowl and throttle body was noted on the side with the data plate. No impact damage was observed, but blue fuel stains were found on the faying surfaces of both assemblies and near certain screws. Each washer was inspected and documented.
Carburetor Bench Testing
During bench testing, the carburetor was placed on a dynamic test bench that applied downward clamping force on the top. The accelerator pump worked satisfactorily, and fuel flow was richer than specified. After shims were installed between the bowl and throttle body (to compensate for the clamping force), a second test showed slightly different fuel flow but still richer than specified. Test results are in the NTSB docket.
Maintenance Records
Engine records showed the carburetor was last overhauled on June 25, 1998, and installed July 6, 1998, with no subsequent removal, replacement, or repair. The last annual inspection was completed on June 12, 2014, at a tachometer time of 741.3 hours. The airplane had accrued approximately 40 hours since that inspection.
Service Bulletin Reference
Service Bulletin (SB)-17, dated August 12, 2010, titled "Body to Bowl Fuel Leaks," reported loose body-to-bowl joints with potential leakage past the gasket, possibly accompanied by loose screws. The SB recommends visual inspection for fuel stains and checking for bowl looseness; if detected, the carburetor must be removed, threads inspected, and a new gasket and lock tab washers installed, followed by testing per the service manual.