N51774

On January 29, 1997, at 2045 central standard time, an Enstrom F-28C helicopter, N51774, registered to and operated by a private owner under Title 14 CFR Part 91, was destroyed by fire following a forced landing at the Brazoria County Airport near Lake Jackson, Texas. The flight instructor and the student pilot were not injured. Visual meteorological conditions prevailed and a flight plan was not filed for the local night instructional flight.

According to the flight instructor, he and his student were practicing takeoffs and landings at Brazoria County Airport and were "on the second or third takeoff," approximately 400 feet agl, when the helicopter "began to lose power." The instructor turned the helicopter back towards the airport and "proceeded to descend while losing engine power." Before the helicopter "reached the ground, the engine lost all power." After the touchdown on a taxiway, the instructor "noticed flames from the engine compartment" and, after shutting down the engine, attempted unsuccessfully to put out the fire with a hand held fire extinguisher. The helicopter was destroyed by the fire.

Examination of the engine, a Lycoming HIO-360-E1AD, by the operator revealed a "hole melted out above [the] exhaust port" of the number 2 cylinder. According to the operator, the resulting exhaust gas leak "severed the number 4 cylinder oil line and started a fire." The cylinder, part number ECLW 12988CP, had accumulated 568 hours since overhaul. The operator reported experiencing two previous "similar" failures of these cylinders on this engine with the first one occurring 421 hours after overhaul. In the section of the NTSB Pilot/Operator Aircraft Accident Report entitled "Recommendation (How Could This Accident Have Been Prevented)," the operator stated that "these cylinders should be restricted from use in helicopters due to high temp. and RPMs common to these machines."

A search of the FAA's Service Difficulty Report database for the time period from January 1990 to the present using the selection criteria, Lycoming HIO360E1AD and Enstrom F28, did not reveal records of any other failures of part number ECLW 12988CP cylinders.