Engine/APU on Fire: Guidance for Controllers
Engine/APU on Fire: Guidance for Controllers
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Description
This article provides guidance for controllers on what to expect and how to act when dealing with the effects of fire during flight on the aircraft engine(s) or Auxiliary Power Unit (APU). This article does not focus on ground fire scenarios. There are no standard rules to be followed universally. As with any unusual or emergency situation, controllers should exercise their best judgment and expertise when dealing with engine fire situations. A generic checklist for handling unusual situations is readily available from EUROCONTROL but it is not intended to be exhaustive and is best used in conjunction with local ATC procedures.
There are some considerations which will enable the controller to provide as much support as possible to the aircraft concerned, and also to maintain the safety of other aircraft in the vicinity and of the ATC service provision in general.
Useful to Know
Fire in the air is one of the most hazardous situations that a flight crew can be faced with. A fire can lead to the catastrophic loss of that aircraft within a very short period of time.
An engine fire is normally detected in a timely fashion and in most cases, contained satisfactorily by the aircraft fire detection and suppression systems. However, in certain circumstances (e.g. an explosive breakup of the turbine), the nature of the fire is such that onboard systems may not be able to contain the fire and it may spread to the wing and/or fuselage. Heat from such fire could cause deformation of wing surfaces, affect the aircraft systems, and ultimately compromise the structural integrity of the aircraft leading to loss of control.
Where an engine fire has been successfully contained, there is still a risk that the fire may reignite and therefore it is still advisable for the crew to land the aircraft as soon as possible and allow fire crews and technical personnel to carry out an inspection of the engine.
Anticipated Impact on Crew
A wide range of practical problems could arise in the cockpit following an engine failure associated with:
- High workload - Such scenarios are associated with intense workload; the crew will carry out the appropriate engine on fire drills.
- Engine shutdown - Normally the fire drills require shutting down the engine and cutting off fuel and electrical supply to the engine. Following this, extinguishant is fired into the engine and a visual inspection of the affected engine is carried out by a member of the cabin or flight crew (if possible). It should be noted that an engine on fire could still produce thrust; it is a critical element to consider when dealing with engine fire emergencies on single engine aircraft. In addition, it should be noted also that historically there have been cases of improper identification of the problematic engine followed by wrong engine shutdown.
- Announcing the problem - the crew will communicate the problem to ATC. Non-standard phraseology should be avoided; an emergency (MAYDAY) or urgency (PAN PAN) call should be made.
- Seeking information and deciding on course of action - the crew will need any information available regarding adjacent aerodromes and weather conditions if they decide to proceed to and land at the nearest suitable aerodrome.
What to Expect
- Rejected Take Off - if the fire is identified prior to V1, the crew might abandon the take-off during the take-off roll; this will normally be communicated to ATC at the same time.
- Emergency landing - if the fire occurs after V1 or during any other airborne phase of the flight, the crew will normally complete the take-off and carry out an emergency landing at the nearest suitable airfield.
- Engine failure - a malfunction, or Uncontained Engine Failure, associated with fire could render the engine inoperative. The emergency procedures followed will depend whether the aircraft is single or multi engined. For a single-engined aircraft, an immediate landing will be unavoidable whether or not a suitable airfield is available.
- Rate of descent - in the event of an enroute engine fire three descent scenarios are possible. If the fire drill is successful and the fire is out, assuming that there is some distance to the diversion airfield, the crew are most likely to initiate a "drift down" profile resulting in a low rate of descent. If the fire is out and the decision has been made to divert to an enroute airfield or continue to planned destination, the descent rate will be more or less normal for the aircraft type. If the fire is uncontrollable, the flight crew are likely to initiate a high speed/maximum rate descent and divert to nearest airfield.
- Smoke in the Cockpit - possible intrusion of smoke into the cockpit or the cabin, due to bleed air system contamination, with the associated communication problems due to sound distortion caused by donning of oxygen masks.
- Pressurisation problems - due to the engine fire/engine shutdown, the aircraft might not be able to stay pressurised. In this scenario, depressurisation is likely to be gradual but depending upon the aircraft type and any collateral damage caused by the fire or uncontained engine failure, the depressurisation could be rapid.
What Help to Provide
Best practice is to follow the following guidelines using the mnemonic ASSIST:
A - Ensure that the reported emergency is well-understood and acknowledged;
S - Establish and maintain separation from other traffic and terrain;
S - Impose silence on your control frequency, if necessary; and do not delay or disturb urgent cockpit action by unnecessary transmissions;
I - Inform your supervisor and other sectors, units and airports as appropriate;
S - Provide maximum support to the flight crew; and,
T - Allow the flight crew sufficient time to manage the emergency.
The controller should be prepared to:
- Acknowledge emergency on RTF
- Inform the crew about the nearest suitable aerodrome and provide alternate aerodrome details and weather information as soon as possible
- Ask for number of Persons On Board (POB)
- Ask if there are dangerous goods on board
- Inform the landing aerodrome of the inbound traffic with engine/APU on fire
- Inform the crew if fire/smoke is observed
- Offer the pilot an extended final approach
- Clear the runway according to local instructions
- Keep the safety strip clear
- Ensure that a go-around is not necessary due to ATC reasons
- Anticipate the potential for overheated brakes and burst tire
- Expect a blocked runway
- Expect positioning of the aircraft with the burning engine downwind on the runway and immediate evacuation
- Ensure that towing equipment is on stand-by as appropriate
- In case of forced landing, record last known position and time
Defences
- Personal Awareness - ATCOs should always monitor the course and altitude of traffic in their sector. Being constantly aware of any ongoing deviations should provide precious time for vectoring of nearby traffic. If there are any uncertainties - verify until there is no doubt.
- Adequate Reaction - Some of the possible actions: transfer all other aircraft to another frequency (possible broadcast to all stations to increase awareness); leave the emergency traffic on the current frequency; increase the volume of the receiver; have a colleague (a separate pair of ears) to also listen to all transmissions from the aircraft.
- Technological Limitations - Try to keep aircraft within radar cover. Have in mind the features of the existing radar system.
- Organisational Awareness - The fast provision of ATCOs during emergency situations should be an objective at administrative level. Periodic training and drills are likely to improve intra-organisational coordination.
Accidents and Incidents
The following events involved engine fire:
On 2 October 2021, an Airbus A320neo PW1100G right engine ingested a large bird during takeoff at Atlantic City and a high speed rejected takeoff followed. When leaked fuel pooling within the engine cowling subsequently ignited, an on-runway emergency evacuation was completed with the fire service in attendance. The Investigation identified the ingested bird as a Bald Eagle with a mass above the applicable certification standard and the fuel leak a secondary consequence of a fan blade broken by bird impact. Engine component design improvements to address the fire risk following large bird ingestion are being developed.
On 18 April 2018, an engine fire warning was annunciated on an Airbus 330-300 which had just taken off from Atlanta. The warning remained after engine shutdown but was eventually replaced by a fire detection caution. Although not visible to the crew, a continued/reignited engine fire was subsequently seen by ATC on final approach and extinguished after landing. The Investigation concluded that the avoidable delay in the return to land had considerably increased the engine and pylon damage and noted that continuation of the fire had been facilitated by hydraulic fluid passing through a valve held partly open by debris.
On 2 July 2015, the left engine of a Bombarier CRJ 700A exiting the runway after landing at Denver caught fire and continued burning after the aircraft had been stopped on the taxiway and the engine shut down. The Investigation found that the fuel supply to the fuel-operated engine performance valve had failed and the quantity of fuel which then leaked had overwhelmed the engine cowl drain capacity and ignited. A history of similar failures was found and this one resulted in the introduction of additional mandatory in-serviced checks pending the replacement of the valve concerned with an improved design.
On 20 February 2021, a PW4077-powered Boeing 777-200 was climbing through 12,500 feet after takeoff from Denver when there was a sudden uncontained failure of the right engine. The associated fire did not fully extinguish in response to the prescribed non-normal procedure and on completion of a return to land, it was fully extinguished before the aircraft could be towed in for passenger disembarkation. The Investigation has already established that the failure originated in a single fan blade within which internal fatigue cracking had been initiated. All operators of 777s powered by PW4000 series engines have grounded their fleets indefinitely.
On 24 January 2005, an Atlas Air Boeing 747-200F overran the end of the landing runway at Düsseldorf after runway braking action notified just prior to landing as medium due to snowfall unexpectedly deteriorated after the snowfall intensified. The overrun led to collision with ground obstacles and engines 2 and 3 caught fire. Escape slide malfunction at the forward left hand door led to an alternative non standard crew evacuation route being used. Significant damage to the aircraft resulted in it being declared a hull loss. The Investigation took almost 8 years to complete and publish.
On 25 March 2008, an Air Atlanta Icelandic Boeing 747-300 was decelerating after landing at Dhaka when a fuel leak in the vicinity of the No 3 engine led to a fire which could not be extinguished. An emergency evacuation was accomplished with only a few minor injuries. The cause of the fuel leak was traced to mis-assembly of a fuel feed line coupling during a C Check some six months previously. The failure to follow clear AMM instructions for this task in two specific respects was of concern to the Investigating Agency.
On 24 May 2013 the fan cowl doors on both engines of an Airbus A319 detached as it took off from London Heathrow. Their un-latched status after a routine maintenance input had gone undetected. Extensive structural and system damage resulted and a fire which could not be extinguished until the aircraft was back on the ground began in one engine. Many previously-recorded cases of fan cowl door loss were noted but none involving such significant collateral damage. Safety Recommendations were made on aircraft type certification in general, A320-family aircraft modification, maintenance fatigue risk management and aircrew procedures and training.
On 10 June 2008, a Sudan Airways Airbus A310 made a late night touchdown at Khartoum and the actions of the experienced crew were subsequently unable to stop the aircraft, which was in service with one thrust reverser inoperative and locked out, on the wet runway. The aircraft stopped essentially intact some 215 metres beyond the runway end after overrunning on smooth ground but a fuel-fed fire then took hold which impeded evacuation and eventually destroyed the aircraft.
On 27 July 2010, a Boeing MD11F being operated by Lufthansa Cargo on a scheduled flight from Frankfurt to Riyadh bounced twice prior to a third hard touchdown whilst attempting to land on 4205 metre-long Runway 33L at destination in normal day visibility. The fuselage was ruptured and, as the aircraft left the side of the runway, the nose landing gear collapsed and a fire began to take hold. A ‘MAYDAY’ call was made as the aircraft slid following the final touchdown. Once the aircraft had come to a stop, the two pilots evacuated before it was largely destroyed by fire. One pilot received minor injuries, the other injuries described as major.
On 28 February 2018, an Airbus A320 would not rotate for a touch-and-go takeoff and flightpath control remained temporarily problematic and the aircraft briefly settled back onto the runway with the gear in transit damaging both engines. A very steep climb was then followed by an equally steep descent to 600 feet agl with an EGPWS ‘PULL UP’ activation before recovery. Pitch control was regained using manual stabiliser trim but after both engines stopped during a MAYDAY turnback, an undershoot touchdown followed. The root cause of loss of primary pitch control was determined as unapproved oil in the stabiliser actuator.
The following events involved failure of the APU and/or APU fire:
On 15 December 2019, an Airbus A330-200 turned back to Sydney shortly after departure when a major hydraulic system leak was annunciated. The return was uneventful until engine shutdown after clearing the runway following which APU use for air conditioning was followed by a gradual build up of hydraulic haze and fumes which eventually prompted an emergency evacuation. The Investigation found that fluid leaking from ruptured rudder servo hose had entered the APU air intake. The resulting evacuation was found to have been somewhat disorganised with this being attributed mainly to a combination of inadequate cabin crew procedures and training.
On 20 January 2015, The APU of a Fokker 100 being routinely de-iced prior to departing Nuremburg oversped as a result of the ignition of ingested de-icing fluid in the APU. This led to its explosive uncontained failure as the result of which ejected debris entered the aft cabin and smoke occurred. No occupants were injured and all were promptly disembarked. The Investigation found that the de-icing contractor involved had not followed manufacturer-issued aircraft-specific de-icing procedures and in the continued absence of any applicable safety regulatory oversight of ground de-icing activity, corresponding Safety Recommendations were made.
On 26 June 2016, thick white smoke suddenly appeared in the cabin of a fully loaded Airbus A330-300 prior to engine start with the door used for boarding still connected to the air bridge. An emergency evacuation initiated by cabin crew was accomplished without injury although amidst some confusion due to a brief conflict between flight crew and cabin crew instructions. The Investigation found that the smoke had been caused when an APU seal failed and hot oil entered the bleed air supply and pyrolysed. Safety Recommendations in respect of both crew communication and procedures and APU auto-shutdown were made.
On 25 September 2001, an Embraer 145 in descent to Manchester sustained a low power lightning strike which was followed, within a few seconds, by the left engine stopping without failure annunciation. A successful single engine landing followed. The Investigation concluded that the cause of failure of the FADEC-controlled AE3007 engine (which has no surge recovery logic) was the aero-thermal effects of the strike to which all aircraft with relatively small diameter fuselages and close mounted engines are vulnerable. It was considered that there was a risk of simultaneous double engine flameout in such circumstances which was impossible to quantify.
On 28 July 2013, with passengers still boarding an Air France Boeing 777-300, an abnormal 'burnt' smell was detected by the crew and then thin smoke appeared in the cabin. A MAYDAY was declared and the Captain made a PA telling the cabin crew to evacuate the passengers via the doors, only via the doors. The resulting evacuation process was confused but eventually completed. The Investigation attributed the confused evacuation to the way it had been ordered and established that a fault in the APU had caused the smoke and fumes which had the potential to be toxic.
On 11 December 2008 an EMB 145 being operated by Finnish Commuter Airlines on a scheduled passenger flight caught fire during the taxi in after a night landing after the APU failed to start and a major electrical power failure occurred simultaneously. The fire was not detected until after the aircraft arrived on stand when, with the passengers still on board, a member of the ground crew saw signs of fire at the back of the aircraft. The aircraft s own fire suppression system was successfully used to extinguish the fire, the passengers left the aircraft and there were no injuries and only minor damage to the aircraft.
Related Articles
- In Flight Fire
- Wing Fire
- In-Flight Fire: Guidance for Flight Crews
- In-Flight Fire: Guidance for Controllers
- Engine Fire Protection
- Aircraft Fire Extinguishing Systems
- Uncontained Engine Failure
- Engine Failure: Guidance for Controllers
- Unexpected Events Training (OGHFA BN)
- Pressurisation Problems: Guidance for Controllers
- Auxiliary Power Unit (APU)
Further Reading
EUROCONTROL
- Guidelines for Controller Training in the Handling of Unusual/Emergency Situations
- ATC Refresher Training Manual, ed.1.0, March 2015
UK CAA
FAA
Others
