ERA14LA390

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.

On August 17, 2014, about 1430 eastern daylight time, a Cessna R182, N292LC, was substantially damaged when it caught fire while returning to Republic Airport (FRG), Farmingdale, New York. The private pilot and the passenger were not injured. Visual meteorological conditions prevailed, and the flight was operating on an instrument flight rules flight plan between FRG and Dutchess County Airport (POU), Poughkeepsie, New York. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, the airplane took off about 1415, and was cleared to 5,000 feet mean sea level (msl). Shortly after leveling off, the pilot noted a fuel pressure drop and a fuel flow rate increase. The pilot requested a priority return to FRG and kept the airplane at 5,000 msl feet until he believed that he could land at the airport in the event of an engine failure, then descended it to 3,000 feet msl for a visual approach to runway 32. 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. As the airplane descended through 1,400 feet msl, and with the engine still running "normally," flames were observed entering the cockpit in the vicinity of the rudder pedals. The pilot subsequently lowered the flaps and completed the landing to runway 32. He then turned the airplane onto a taxiway and stopped it where he and the passenger disembarked, and firefighters extinguished the fire. According to a responding Federal Aviation Administration (FAA) inspector, the AN911-2D nipple fitting that connected the fuel line Tee (AN917-2D) to the carburetor was fractured and had separated, which allowed fuel to be pumped into the engine compartment. The inspector subsequently suggested through FAA channels that an Airworthiness Directive (AD) be issued to change the AN911-2D aluminum nipple fitting to an MS fitting made of steel. He also noted that the nipple fitting was likely original to the airframe, which had about 4,010 hours of operation. In response, the FAA Aircraft Certification Office (ACO) stated that they reviewed National Transportation Safety Board accident/incident and Monitor Safety Analyze Data databases for the last 15 years for other like occurrences and/or failures and found no additional reports to support the issuance of an AD. The response further noted that the AN911-2D nipple fitting was an industry standard part which was used in numerous fuel, hydraulic and pneumatic systems, throughout the aerospace industry, including in the fuel systems of many other Cessna airplanes. Cessna indicated that they had not received any other reports wherein an AN9l1-2D nipple cracked and caused a fuel leak, and that it was "very likely the nipple was cracked for a time prior to complete separation. Evidence of this crack should have beendetectable during ground inspection prior to complete failure of the nipple in the form of fuel staining and/or a strong fuel odor…" Both Cessna and the FAA ACO did not agree to the proposed fitting material change to steel. The pilot reported that the airplane had been operated for 150 hours since its most recent annual inspection, which was performed on February 15, 2014.