NIKOLAI, AK, USA
N504FS
Short Brothers SC.7
THE PILOT WAS DELIVERING A LOAD OF CARGO THAT INCLUDED BARRELS OF 100LL OCTANE AVIATION FUEL TO A REMOTE AIRSTRIP. THE PILOT REPORTED FIRE AND SMOKE IN THE CARGO COMPARTMENT. HE BEGAN AN IMMEDIATE DESCENT AND LANDED AT THE DESTINATION AIRSTRIP. AFTER LANDING, THE PILOT NOTICED THAT FUEL WAS LEAKING FROM ONE OF THE BARRELS. THE FIRE WAS LOCATED BETWEEN THE CARGO AREA FLOORING AND THE BOTTOM BELLY OF THE AIRPLANE. THERE WAS FIRE AND HEAT DAMAGE TO THE CARGO BAY AND MELTING OF THE AIRFRAME ASSEMBLY, INCORPORATING THE REAR SPAR AND SEVERAL AIRFRAME STATIONS. AN AREA OF SOOTING AND A CHARRED SECTION OF ELECTRICAL WIRING WAS FOUND BELOW THE FLOORING, ADJACENT TO THE MOUNTING POSITION OF A LOWER FUSELAGE BEACON THAT HAD BEEN REMOVED SOMETIME IN THE PAST. THE CIRCUIT BREAKER PROTECTING THE ELECTRICAL LOADS FOR THE AIRPLANE'S ROTATING BEACONS WAS FOUND POPPED. APPLICATION OF ELECTRICAL POWER TO THE ROTATING BEACON CIRCUIT RESULTED IN PROPER FUNCTIONING OF THE UPPER FUSELAGE BEACON AND THE PRESENCE OF ELECTRICAL POWER TO THE CHARRED WIRING.
On August 11, 1995, about 1030 Alaska daylight time, a Short SC- 7, N504FS, experienced an in-flight fire about 20 miles from its planned destination at a private airstrip near Nikolai, Alaska. The airplane was being operated as a visual flight rules (VFR) cargo flight under Title 14 CFR Part 135 when the accident occurred. The airplane, registered to and operated by F.S. Air Service Inc., Anchorage, Alaska, sustained substantial damage. The certificated airline transport pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. Company flight following procedures were in effect. The flight originated from the Anchorage International Airport at 0927. The operator reported that the cargo included barrels of 100LL octane aviation fuel. The pilot reported fire and smoke in the cargo compartment. He began an immediate descent and landed at the destination airstrip, located in a remote area. After landing, the pilot noticed that fuel was leaking from one of the barrels and from the belly of the airplane. The fire was extinguished by the pilot and ground personnel. The fire was located between the cargo area flooring and the bottom belly skin of the airplane. Examination of the airplane on August 17, 1995, revealed fire damage to the flooring and heat damage to the overhead areas of the cargo bay. In addition, the airframe assembly incorporating the rear spar, the airframe formers between the rear and front spar, and airframe stations 211, 226, and 244, received fire damage and melting. An area of sooting and a charred section of electrical wiring was found below the flooring near the aft end of the cargo bay. It was adjacent to the mounting position of a lower fuselage beacon that had been removed sometime in the past. The wire was connected to a 5 amp circuit breaker in the cockpit that was found popped. The breaker protected the electrical loads for the airplane's rotating beacons. Application of electrical power to the rotating beacon circuit resulted in proper functioning of the upper fuselage beacon, and the presence of electrical power to the charred section of lower fuselage wiring.
IGNITION OF HAZARDOUS CARGO (AVIATION FUEL) BY AN EXPOSED ELECTRICAL WIRE, AFTER LEAKING FROM A CONTAINER OF FUEL THAT WAS BEING TRANSPORTED ON THE FLIGHT. FACTORS RELATING TO THE ACCIDENT WERE: INADEQUATE INSPECTION OF THE AIRPLANE BY COMPANY MAINTENANCE PERSONNEL, AND FAILURE OF COMPANY PERSONNEL TO IDENTIFY THE LEAKING FUEL CONTAINER.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
