In-Flight Fire: Guidance for Controllers

In-Flight Fire: Guidance for Controllers


This article provides guidance for controllers on what to expect of an aircraft experiencing an in-flight fire or encountering smoke from an unknown source in either the cockpit or cabin, together with some of the considerations which will enable the controller not only to provide as much support as possible to the aircraft concerned, but also maintain the safety of other aircraft in the vicinity and the ATM system in general.

In-Flight Fire

Fire in the air is one of the most hazardous situations that a flight crew can be faced with. Without aggressive intervention by the flight crew, a fire on board an aircraft can lead to the catastrophic loss of that aircraft within a very short space of time. Once a fire has become established, it is unlikely that the crew will be able to extinguish it. To stand any chance of survival in the face of an uncontrolled fire, the aircraft must land as soon as possible.

The design of any modern airliner features sophisticated fire/smoke detection and suppression systems. System redundancy is achieved in many installations by doubling the number of detectors and separating the detection lines. However, the presence of any fire or smoke alarm, unless confirmed false, will virtually always result in the crew’s decision for an immediate landing.

For more information see the main article Fire in the Air


Flight crews will treat any in-flight fire or fire/smoke alarm with the utmost attention and urgency. The following effects of fire or smoke could be expected, potentially developing from a relatively benign situation to the worst case scenario within minutes:

  • Reduced cockpit visibility;
  • Breathing problems necessitating the donning of oxygen masks and smoke goggles;
  • Communication difficulties due donning of the oxygen masks;
  • Equipment malfunction or isolation;
  • Partial or complete flight control loss;

In an effort to mitigate the smoke/fire risk, crews may conduct a:

What to Expect

If a crew is experiencing smoke/fire in the cockpit, the ATCO should expect:

  • Communication difficulties or even lack of communication at a later stage;
  • Flight crew’s decision to immediately divert to nearest suitable aerodrome;
  • Crew requests for information about the chosen diversion airfield;
  • The flight crew could commence descent without receiving ATC descent instructions;
  • The flight crew might need navigational assistance and request vectors for the nearest suitable aerodrome.


At the first indication, or suspicion, of smoke and fumes, or a fire within the aircraft the flight crew will don smoke goggles and oxygen masks. The wearing of oxygen masks may make the voice messages more difficult to understand.

The fire may well affect aircraft systems and the crew will try to isolate the cause of the fire. As a consequence, data link equipment, transponders, and even radios, may cease to function correctly or be switched off.

After the initial emergency call, and having declared their intentions, the crew will turn their attention to isolating and fighting the fire, and may therefore not respond to calls. The controller will need to be patient and try to anticipate the actions of the flight crew.

If possible, the controller should reduce the amount of RTF traffic on the frequency, clear other traffic to another frequency, or direct aircraft concerned onto a discreet frequency. If possible, it would be advisable to minimise the number of frequency changes given to the aircraft as this increases the chance of loss of communication.

Plan for Immediate Descent and Landing

Many smoke and fire warnings turn out to be spurious. However, if it is a real fire, then a flight crew does not have very long to deal with the situation - time is critical. The crew will commence descent immediately and begin planning for an emergency landing. The crew will not necessarily wait for clearance to descend. If they do ask for clearance for descent and vectors to the closest airfield and if that clearance is not immediately forthcoming, they will likely commence descent without clearance.

Take any measure deemed necessary to ensure unrestricted descent to the flight experiencing an in-flight fire emergency. If an emergency descent is executed, the aircraft must not descend below the lowest published Minimum Safe Altitude (MSA) which will provide a minimum vertical clearance of 300m (1000 ft) or in designated mountainous terrain 600m (2000 ft) above all obstacles located in the area specified.

Putting an aircraft on the ground within 15 minutes of a fire being detected is a challenge for the pilot of a modern passenger jet at cruising altitude, so expect the descent to be rapid.

Give clearance for, and expect, the aircraft to take the shortest most direct route to a runway, regardless of the runway in use at the intended landing airfield, arrival procedures, or traffic.

In certain circumstances, the flight crew may ask for assistance from another aircraft, such as a military interceptor, to confirm signs of fire on the aircraft (for example where the fire relates to a tail mounted engine).

If there is quantifiable evidence of an uncontrolled fire, then there is a real possibility of loss of control in the short term, and therefore the crew may elect to land the aircraft off-field or ditch the aircraft in the sea, on a lake, or shoreline as it may be the only way of surviving the situation.

Seek Help and Warn

Having acknowledged the emergency call, the controller should immediately inform the supervisor and/or colleagues of the situation.

Warn adjacent sectors and airfields:

  • Emergency services at the potential diversion airfields will welcome as much warning as possible.
  • The likelihood is that the runway will be closed when the subject aircraft lands with obvious repercussions for other inbound aircraft.

Best practice embedded in the ASSIST principle could be followed: (A - Acknowledge; S - Separate, S - Silence; I - Inform, S - Support, T - Time)

A - acknowledge the fire/smoke problem, ask for the crews’ intentions when the situation permits, and establish whether the crew is able control the fire/smoke;

S - separate the aircraft from other traffic, provide accurate and optimal vectors, prioritise it for landing (assist with a minimum track mile pattern if requested), keep the active runway clear of departures, arrivals and vehicles;

S - silence the non-urgent calls (as required) and use separate frequency where possible;

I - inform the airport emergency services and all concerned parties according to local procedures;

S - support the flight experiencing fire/smoke problems with any information requested and deemed necessary (e.g. type of approach, runway length and aerodrome details, etc.);

T - provide time for the crew to assess the situation, don’t press with non urgent matters.

The ATCO serves as the focal point for dissemination of information to other agencies, such as the diversion airfield or Rescue and Fire Fighting Services, which have a legitimate need to know. Once the pilot has communicated their intentions, the ATCO should be able to provide concerned agencies with:

  • Aircraft situation, position and intentions;
  • Time to touch down;
  • Post landing intentions (stop on runway for inspection, immediate evacuation, etc);
  • Any critical information that can be obtained from the affected aircraft on a "non-interference" basis such as:
    • Presence of dangerous goods;
    • Number of persons on board;
    • Fuel remaining, etc.

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