Narrative:On final approach approximately 10 miles from the airport, the flight crew received an aft cargo bay fire warning. The flight crew followed checklist procedures, activated the cargo bay fire extinguishers and declared an emergency. The fire indication went out some 20 to 30 seconds after activation of the fire
|Date:||13 MAY 2002|
|C/n / msn:|| 24948/380|
|First flight:|| 1991-07-02 (10 years 11 months)|
|Total airframe hrs:||46830|
|Engines:|| 2 Pratt & Whitney PW4060|
|Crew:||Fatalities: 0 / Occupants: 8|
|Passengers:||Fatalities: 0 / Occupants: 177|
|Total:||Fatalities: 0 / Occupants: 185 |
|Airplane damage:|| Substantial|
|Airplane fate:|| Repaired|
|Location:||Toronto-Pearson International Airport, ON (YYZ) (Canada)
|Phase:|| Approach (APR)|
|Nature:||Domestic Scheduled Passenger|
|Departure airport:||Vancouver International Airport, BC (YVR/CYVR), Canada|
|Destination airport:||Toronto-Pearson International Airport, ON (YYZ/CYYZ), Canada|
extinguishers, but a slight smell of smoke was noticed by the cabin crew and flight crew. Flight 116 landed and stopped on the runway to allow airport
firefighters to inspect the aircraft for fire. Firefighters, using infrared sensing equipment, did not detect any sign of fire. The flight crew taxied the aircraft to the terminal but stopped approximately 40 feet back from the gate to allow firefighters to open the aft cargo compartment for a detailed inspection. When the cargo door was opened, a significant amount of smoke was observed. Firefighters entered the cargo compartment and confirmed that the fire had been extinguished.TSB investigators discovered that an intense but relatively small fire had occurred, causing significant structural damage in the floor area of the aft
cargo compartment. Before it was extinguished, the fire had progressed approximately 18 inches up the right side wall of the aircraft, outside the aft cargo compartment. The cargo bay fire-extinguishing system, a Halon-based system, effectively suppressed the fire before it could spread further. The fire appears to have been a direct result of an electrical failure of a heater tape used to prevent water lines from freezing. The electrical failure of the heater tape ignited the covering of the insulation blankets installed below the open cargo floor and some debris found in the area.
FINDINGS AS TO CAUSES AND CONTRIBUTING FACTORS: "1. The B110 heater ribbon attached to the water supply line failed at the site of a recent water line repair, which allowed the elements of the heater ribbon to electrically arc, providing a source of ignition to surrounding materials; 2. The polyethylene terephthalate (PET) covering material of the thermal acoustic insulation was contaminated. The contaminated material provided an ignitable source of fuel for a self-sustaining fire; 3. The open cargo floor provided a trap that collected contaminants and debris in the bilge area of the cargo compartment; the debris and contaminants were an ignitable source of fuel to sustain a fire; 4. Circuit protection devices are designed to protect aircraft wiring and not aircraft components. The lack of circuit protection of the heater ribbon system permitted the heater ribbon failure to result in an arcing event."
Official accident investigation report
Follow-up / safety actions
During the inspection of this and other aircraft, additional examples of overheated and burned heater tapes were discovered. Affected systems were deactivated.
On June 7, 2002 the FAA issued Airworthiness Directive AD 2002-11-11 applicable to certain Boeing Model 767-200, -300, and -300F series airplanes. This action requires an inspection of visually accessible areas for indications of overheating of the heater tape attached to the potable water fill and drain lines in the forward and aft cargo compartments, exposed foam insulation or missing or damaged protective tape around the potable water fill and drain lines, and debris or contaminants on or near the potable water fill and drain lines. It also requires corrective action, as necessary. This action is necessary to prevent overheating of the heater tape on potable water fill and drain lines, which may ignite accumulated debris or contaminants on or near the potable water fill and drain lines, resulting in a fire in the airplane. This action is intended to address the identified unsafe condition.
TSB issued 2 Safety Recommendations
Show all AD's and Safety Recommendations
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from Vancouver International Airport, BC to Toronto-Pearson International Airport, ON as the crow flies is 3321 km (2076 miles).