Checklists and Procedures for Non-Alerted Fire/Smoke/Fume Events

Checklists and Procedures for Non-Alerted Fire/Smoke/Fume Events


In 2004, an international initiative, sponsored by the Flight Safety Foundation (FSF), was undertaken with an aim of improving checklist procedures for crews confronted with a non-alerted (not annunciated by an aircraft detection system) fire/smoke/fume event. The group involved was comprised of industry specialists representing aircraft manufacturers including AirbusBoeing and Bombardier, airlines/operators and professional pilot and aviation associations such as IFALPA and IATA. A series of meetings and conference calls culminating in a symposium in early March of 2005 produced a philosophy and a number of definitions specific to fire/smoke/fume events as well as a Checklist Template which, collectively, have been used as the basis for many of the fire/smoke/fume checklists currently in use.


Fire in the Air is one of the most hazardous situations that an aircraft crew can be faced with. Without aggressive intervention, a fire on board an aircraft can lead to the catastrophic loss of that aircraft within a very short period of time. Once a fire has become established, it is unlikely that the crew will be able to extinguish it. With these specifics in mind, the symposium membership identified the following general criteria:

  • The entire crew must be part of the solution
  • For any fire/smoke/fume event, time is critical
  • At the beginning of a fire/smoke/fume event, the crew should consider all of the following:
    • protecting themselves (oxygen masks, smoke goggles)
    • appropriate emergency communications with ATC and crew
    • diversion
    • assessment of the situation and the available resources
  • Fire/smoke/fume checklists should be produced in a large font for legibility in smoke conditions and/or when goggles are worn

As well, they proposed that a fire/smoke/fume checklist should:

  • address non-alerted fire/smoke/fume events (events not annunciated by aircraft detection systems)
  • not replace alerted checklists such as Engine Fire or Cargo Smoke or address multiple events
  • include considerations to support an immediate landing inclusive of overweight, off-airport or ditching
  • systematically identify and eliminate potential fire/smoke/fume sources

Definitions and Checklist Criteria

In developing their checklist template for Fire/Smoke/Fume events, the symposium membership agreed upon a number of definitions and checklist criteria. Definitions included but were not limited to:

  • Land at the nearest suitable airport. Commence diversion to the nearest suitable airport. "Suitable" should include an evaluation of the risk presented by any conditions that may affect safety associated with the approach, landing and post landing.
  • Land immediately. Proceed immediately to the nearest landing site. While this implies an immediate diversion to a landing on a runway, the severity of the scenario may lead to the consideration of an overweight or tailwind landing or an off-airport landing or ditching.
  • Landing imminent. The aircraft is close enough to a landing site that the remaining time must be used to prepare for an approach and landing. To do otherwise (such as continuing with the Fire/Smoke/Fume checklist) would delay the landing.

Agreed criteria for development of the checklist template fell into four categories. These are:

  • Initial steps for Source Elimination
  • Timing for Diversion/Landing
  • Smoke or Fume Removal
  • Additional steps for Source Elimination

Some of the specific recommendations assigned to these categories included:

  • Initial steps for Source Elimination:
    • Assume that pilots may not always be able to accurately identify a smoke source
    • Assume any alerted smoke event checklists have been accomplished but the smoke source may not have been eliminated
    • Manufacturer's initial steps to remove the most probable (based on type/model specific data or analysis) smoke/fume sources must be immediately available to the crew. (Quick Reference Handbook (QRH))
    • These initial steps should:
      • be quick, simple and reversible
      • not make the situation worse or inhibit further assessment
      • not require analysis by the crew
  • Timing for Diversion/Landing:
    • Checklist procedures should not delay diversion
    • Crews should anticipate diversion in response to a fire/smoke/fume event and the checklist should provide a reminder or a directive as appropriate
    • The crew should consider an immediate landing anytime the situation cannot be controlled
  • Smoke or Fume Removal:
    • The smoke removal decision should be made based on the threat presented to the passengers and crew
    • The smoke removal checklist should not be actioned until the fire has been extinguished unless the smoke or fumes present the greater threat. There are two primary reasons for delaying smoke removal until the fire has been extinguished:
      • interrupting the Source Elimination process to action the Smoke or Fume Removal procedure can lead to a delay in actually identifying and eliminating the source of the smoke
      • virtually all smoke removal procedures involve depressurizing and/or opening vents or windows. This will introduce more available oxygen into the aircraft and potentially worsen the fire
  • Additional steps for Source Elimination:
    • Additional steps are subsequent to the manufacturer's initial steps and the diversion decision
    • The crew needs checklist guidance to systematically isolate an unknown Smoke/Fire/Fumes source

For more information see the full text of symposium recommendations produced by the FSF

Using the above definitions, the four step criteria and the associated recommendations, the symposium developed a checklist template for use by industry when developing aircraft type and model specific checklists for non-alerted fire/smoke/fume events.

Accidents and Incidents

On 6 January 2011 an Easyjet Airbus A319 experienced the sudden onset of thick smoke in the cabin as the aircraft cleared the runway after landing. The aircraft was stopped and an evacuation was carried out during which one of the 52 occupants received a minor injury. The subsequent investigation attributed the occurrence to the continued use of reverse idle thrust after clearing the runway onto a little used taxiway where the quantity of de-ice fluid residue was much greater than on the runway.

On 5 June 2015, a DHC8-200 descending towards Bradley experienced an in-flight fire which originated at a windshield terminal block. Attempts to extinguish the fire were unsuccessful with the electrical power still selected to the circuit. However, the fire eventually stopped and only smoke remained. An emergency evacuation was carried out after landing. The Investigation was unable to establish the way in which the malfunction that caused the fire arose but noted the continuing occurrence of similar events on the aircraft type and five Safety Recommendations were made to Bombardier to address the continuing risk.

On 10 January 2009, a Boeing 747-400 being operated by British Airways on a scheduled passenger flight from Phoenix USA to London had been pushed back from the gate in normal daylight visibility and the engines start was continuing when fumes and smoke were observed in the cabin and flight deck. The aircraft commander decided to return to the stand but there was some delay while the tug was reconnected and the movement accomplished. The intensity of the fumes increased and as the aircraft came to a halt on the stand an emergency evacuation was ordered.

On 10 February 2007, smoke was observed coming from an overhead locker on an Airbus A320 which had just departed from New York JFK. It was successfully dealt by cabin crew fire extinguisher use whilst an emergency was declared and a precautionary air turn back made with the aircraft back on the ground six minutes later. The subsequent investigation attributed the fire to a short circuit of unexplained origin in one of a number of spare lithium batteries contained in a passenger's camera case, some packaged an some loose which had led to three of then sustaining fire damage.

On 11 May 1996, the crew of a ValuJet DC9-30 were unable to keep control of their aircraft after fire broke out. The origin of the fire was found to have been live chemical oxygen generators loaded contrary to regulations. The Investigation concluded that, whilst the root cause was poor practices at SabreTech (the maintenance contractor which handed over oxygen generators in an unsafe condition), the context for this was oversight failure at successive levels - Valujet over SabreTech and the FAA over Valujet. Failure of the FAA to require fire suppression in Class 'D' cargo holds was also cited.

Related Articles

Further Reading

Flight Safety Foundation



  • Reflections on the Decision to Ditch a Large Transport Aircraft - an account by the aircraft captain and pilot of a RAF Nimrod which ditched into the North Sea following an engine fire which spread to the wing; edited version of RAF leadership: Able to handle ambiguity by Gp Capt John Jupp, RAF Magazine ‘Spirit of the Air’ Volume 2 No 3, 2007

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