Aviation Accident Summaries

Aviation Accident Summary NYC04IA037

Windsor Locks, CT, USA

Aircraft #1

N14CG

Dassault-Breguet Falcon 50

Analysis

Shortly after takeoff, at 500-600 feet AGL, the flight crew noticed smoke in the cabin, declared an emergency, and returned to land without incident. After landing, crash fire rescue extinguished a fire in the overhead paneling of a coat closet, which was located directly behind the cockpit. Examination of the airplane revealed extensive heat damage to the overhead paneling around a closet light fixture in the aircraft cabin. Visual examination of the damaged area revealed that electrical wiring and an oxygen line were installed in close proximity to each other in the area of the light fixture. Additionally, examination of the oxygen line revealed a pin-size hole through the circumference of the line with signatures consistent of electrical arcing. Further examination of the light fixture revealed areas of severe localized heating and melting. Examination of maintenance records revealed two entries in the past 12 months, which described the closet light circuit breaker popping during illumination of the light. This occurred as a result of an electrical arcing between the light assembly and an oxygen line. Both instances included installing Teflon tape to protect interference between the assembly and the oxygen line.

Factual Information

On November 18, 2003, at 1700 eastern standard time, a Dassault Falcon 50, N14CG, received minor damage during an in-flight fire during climbout from the Bradley International Airport (BDL), Windsor Locks, Connecticut. The two certificated airline transport pilots and three passengers were not injured. Night visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed, for the flight which was destined for the Westchester County Airport (HPN), White Plains, New York. The company training flight was conducted under 14 CFR Part 91. According to the pilots, shortly after takeoff from runway 33 at BDL, at 500-600 feet AGL, the check airman who was sitting in the jumpseat, informed the crew that there was "smoke in the cabin." The first officer advised air traffic control (ATC) of the situation, and declared an emergency, as the captain initiated a left turn to return to runway 33. A passenger, who was also a company pilot, reported that shortly after takeoff he smelled an odor of "electrical smoke," coming from the left side [aux] galley area, and then noticed a large amount of smoke pouring out of the glass storage area located at the top of the [aux] galley. He announced to the cockpit crew, "we have a fire," and immediately turned off all galley power and pulled all circuit breakers on the galley power panel. The smoke seemed to subside for several seconds and then began to "pour out with force." The passenger then noticed bright, white burning particles and smoke being expelled from the coat closet and galley on the opposite side of the cabin, followed by a "stream of flames." He discharged the cabin fire extinguisher into the coat closet until it was expelled, and then he and the additional passenger moved toward the right wing exit in preparation for landing. After the airplane came to a stop on the runway, the passengers evacuated from the right over wing exit. Crash fire rescue then extinguished the fire in the overhead paneling of a coat closet, which was located directly behind the cockpit. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed extensive heat damage to the overhead paneling around a closet light fixture in the aircraft cabin. Visual examination of the damaged area revealed that electrical wiring and an oxygen line were installed in close proximity to each other in the area of the light fixture. Additionally, examination of the oxygen line revealed a pin-size hole through the circumference of the line. The light fixture and oxygen line were sent to the Safety Board Materials Laboratory in Washington, D.C. for further examination. According to the Materials Laboratory Factual Report: "The outer surface of the [oxygen] line was deeply pitted and cratered around the perforation consistent with electrical arcing. Further energy-dispersive x-ray spectra (EDS) from within the pits at the perforation detected aluminum in local areas in addition to the previously detected elements on the line surface. The electrical wires connected to the curtain strip and the light fixture showed evidence of high temperature exposure, and the insulation was missing from all wires. The outer housing of the light fixture and the aluminum fuselage attachment bracket had areas of severe localized heating and melting." Examination of maintenance records revealed an entry dated September 14, 2002, which stated, "Closet light circuit breaker trips whenever closet light switch is turned on." The corrective action described in the entry stated that the closet light fixture was removed and inspected, and a fixture mount screw was found to be contacting an oxygen line and allowing the circuit breaker to pop. The oxygen line was inspected and no damage was observed. The screw tip was then protected with Teflon tape to prevent it from shorting any further, and the light fixture was reinstalled. A second entry dated August 15, 2003, stated, "forward closet light circuit breaker popped." Again, the corrective action noted was that the closet light assembly was arcing on an oxygen line. Teflon tape was again installed between the light assembly and the oxygen line, and no further damage was observed. The fixture mount screw was used to bond the fixture to the airframe, and served as an electrical ground. During the course of the investigation, Dassault Falcon issued a Service Bulletin to all Falcon 50 operators, which recommended that the aircraft be inspected for any indication of interference between the closet light fixture or its wiring and the surrounding structure or equipment, particularly oxygen lines. One additional Falcon 50 aircraft was identified as needing a clamp to improve the oxygen line attachment. No interference between wiring and oxygen lines was noted in any of the inspected Falcon 50 aircraft.

Probable Cause and Findings

An in-flight fire, originating from electrical arcing, which subsequently created a hole in an oxygen line.

 

Source: NTSB Aviation Accident Database

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