Cessna R182 N292LC accident near Farmingdale, New York

Probable cause

The failure of the aluminum nipple fuel supply line fitting, which resulted in an engine compartment fire.

NTSB analysis

The private pilot departed for the personal cross-country flight. The pilot reported that, after leveling off the airplane at 5,000 ft mean sea level (msl), he noted a fuel pressure drop and a fuel flow rate increase. The pilot requested a priority return to the departure airport, and when the airplane was on a high, right downwind leg of the traffic pattern, smoke appeared in the cockpit along with an "acrid, insulation smell." The pilot then declared an emergency and requested that fire rescue equipment be standing by at the airport.

The pilot added that, as the airplane descended through 1,400 ft msl and with the engine still running "normally," he observed flames entering the cockpit near the rudder pedals. The pilot completed the landing, stopped the airplane on the taxiway, and after he and the passenger disembarked, firefighters extinguished the fire.

Subsequent examination of the airplane revealed that the aluminum nipple fitting that connected the fuel line "T" to the carburetor was fractured and had separated, which allowed fuel to be pumped into the engine compartment. The nipple fitting was likely original to the airframe, which had about 4,010 total hours of operation.

The airframe manufacturer indicated that the fitting was likely cracked for some time before the complete separation occurred and that the crack should have been detectable during ground inspection before the failure through either fuel staining and/or a strong fuel odor. However, the investigation could not determine the condition of the fitting before the accident flight or at the time of the airplane's most recent annual inspection, which was performed 150 hours (about 6 months) before the accident.

Text from the NTSB. Open the NTSB docket for ERA14LA390 for the full record.