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* [http://www.skybrary.aero/bookshelf/books/2696.pdf Safety issues investigation report SII A05-01 Post-impact fires resulting from small-aircraft accidents], TSB Canada, 2006
 
* [http://www.skybrary.aero/bookshelf/books/2696.pdf Safety issues investigation report SII A05-01 Post-impact fires resulting from small-aircraft accidents], TSB Canada, 2006
 
* [http://www.skybrary.aero/bookshelf/books/3786.pdf CAP 699 - Framework for the competence of rescue and fire fighting service (RFFS) personnel], January 2017
 
* [http://www.skybrary.aero/bookshelf/books/3786.pdf CAP 699 - Framework for the competence of rescue and fire fighting service (RFFS) personnel], January 2017
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*[http://www.skybrary.aero/bookshelf/books/4233.pdf Aviation Accident Checklist], by ATSB, 7th edition, June 2017
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*[http://www.skybrary.aero/bookshelf/books/4232.pdf Hazards at Aviation Accident Sites - Guidance for Police and Emergency Personnel], by ATSB, 7th edition, June 2017
  
 
[[Category:Post Crash Fires]]
 
[[Category:Post Crash Fires]]
 
[[Category:Cabin Safety]]
 
[[Category:Cabin Safety]]

Revision as of 10:34, 31 March 2018

Article Information
Category: Fire Smoke and Fumes Fire Smoke and Fumes
Content source: SKYbrary About SKYbrary
Content control: SKYbrary About SKYbrary

POST IMPACT FIRE

Definition

Post Crash Fires are fires which occur after an aircraft has crash landed or has impacted obstacles or other aircraft during ground movement, runway incursion, or runway excursion.

Description

In the event of an impact with the ground or an obstacle, which results in structural damage to an aircraft, a fuel and/or oil fed fire can start if fuel comes into contact with hot surfaces. Equally, if flammable material, being carried as dangerous goods on a Civil aircraft or as cargo by a military aircraft, is damaged or the containment compromised, it may ignite as a consequence of impact, contact with hot surfaces or, in the case of spillage of unstable chemicals, the atmosphere.

Fire can spread quickly to the fuselage and through the cabin generating heat, smoke, and toxic decomposition products. If the temperature of trapped smoke and gasses reaches the auto-ignition temperature, flashover will occur and an aircraft fuselage can be rapidly engulfed by flames.

Effects

Depending upon the severity of the crash, and any resulting fire, the effect on the aircraft can vary from minor damage to total hull loss. Similarly, the potential casualty consequence of a crash/fire event ranges from no injuries to the loss of life of all on board. Collateral damage and casualties are possible dependent upon the location of the crash.

For aircraft with a maximum certified take-off weight of 5700 kilograms or less, post-impact fire contributes significantly to injuries and fatalities in accidents that are otherwise potentially survivable.

Defences

  • Aircraft Design. Aircraft structures and fuel systems can be designed to minimise the quantity of fuel spillage
  • Fuel - Virtually all large passenger aircraft burn jet fuel and not AVGAS. The much higher flashpoint of jet fuel reduces the potential for a post crash fire.

Solutions

  • Preparation of the aircraft - where the crash landing is anticipated, for example if an off-field landing is necessary or the aircraft has a landing gear malfunction, then there are several things that can be done to reduce the probability and severity of a fire:
    • Dump Fuel - if time and aircraft design allow, dump to reduce the amount of fuel and improve the handling of the aircraft. For aircraft not fitted with Fuel Dump capability, the aircraft can loiter in the vicinity of the landing airfield to burn gas. Note that, in the case of an onboard fire, smoke, or fumes, any delay to landing the aircraft, inclusive of dumping fuel, should not be considered.
    • Isolate fuel systems - close crossfeed valves.
    • Cabin - Prepare the cabin for emergency landing.
    • Cargo - Jettison flammable cargo if possible and practical.
  • Aircraft Evacuation - Expeditious emergency evacuation of the aircraft will minimise the loss of life in the event of a post crash fire. Consequently, robust training of the cabin crew in evacuation procedures is essential.
  • Engine Shutdown & Aircraft Systems - To minimize the potential for injury during the evacuation, the flight deck crew will take all necessary actions to shut down and, using fire handles, condition levers, or fire push button (depending on aircraft type) isolate the aircraft engines. Depending upon the degree of damage to the aircraft, this may not always be possible.
  • Rescue and Fire Fighting Services - Rescue and Fire Fighting Services (RFFS) are instrumental in saving lives and minimizing the damage from a post crash fire. If the crash occurs within the airfield boundaries, the initial RFFS response units will be on site within a very short period of time; often less than a minute. Response to an off airfield crash may take considerably longer due to the time it may take to locate the crash and to the accessibility of crash site.

Contributing Factors

Large amounts of fuel can be carried by modern aircraft and an aircraft crash has the potential to rupture the fuel tanks. Should the spilling fuel be exposed to a spark or open flame a fire may occur. This is particularly true of fuels with low flashpoints such as AVGAS. While jet fuels have a higher flashpoint and are less susceptible to sparks, exposing them to operating engines or to hot engine components may raise the temperature of the fuel to its auto-ignition point and a fire will result.

Accidents and Incidents

A selection of incidents from the SKYbrary database related to Post Crash Fire:

  • B742 / B741, Tenerife Canary Islands Spain, 1977 (On 27 March 1977, a KLM Boeing 747-200 began its low visibility take-off at Tenerife without requesting or receiving take-off clearance and a collision with a Boeing 747-100 backtracking the same runway subsequently occurred. Both aircraft were destroyed by the impact and consequential fire and 583 people died. The Investigation attributed the crash primarily to the actions and inactions of the KLM Captain, who was the Operator's Chief Flying Instructor. Safety Recommendations made emphasised the importance of standard phraseology in all normal radio communications and avoidance of the phrase "take-off" in ATC Departure Clearances.)
  • B190 / BE9L, Quincy IL USA, 1996 (On 19 November 1996, a Beech 1900C which had just landed and a Beech King Air A90 which was taking off collided at the intersection of two runways at the non-Towered Quincy Municipal Airport. Both aircraft were destroyed by impact forces and fire and all occupants of both aircraft were killed. The Investigation found that the King Air pilots had failed to monitor the CTAF or properly scan visually for traffic. The loss of life of the Beech 1900 occupants, who had probably survived the impact, was attributed largely to inability to open the main door of the aircraft.)
  • H25B, vicinity Akron OH USA, 2015 (On 10 November 2015, the crew of an HS 125 lost control of their aircraft during an unstabilised non-precision approach to Akron when descent was continued below Minimum Descent Altitude without the prescribed visual reference. The airspeed decayed significantly below minimum safe so that a low level aerodynamic stall resulted from which recovery was not achieved. All nine occupants died when it hit an apartment block but nobody on the ground was injured. The Investigation faulted crew flight management and its context - a dysfunctional Operator and inadequate FAA oversight of both its pilot training programme and flight operations.)
  • AT45, en-route, north of Islamabad Pakistan, 2016 (On 7 December 2016, the crew of an ATR 42-500 lost control after airworthiness-related complications followed shutdown of the left engine whilst in the cruise and high speed terrain impact followed. The Investigation concluded that three pre-existing faults with the left engine and its propeller control mechanism had led to a loss of power which had necessitated its shutdown but that these faults had then caused much higher left side drag than would normally result from an engine shutdown and made it progressively more difficult to maintain control. Recovery from a first loss of control was followed by another without recovery.)
  • B738 / B738, Toronto Canada, 2018 (On 5 January 2018, an out of service Boeing 737-800 was pushed back at night into collision with an in-service Boeing 737-800 waiting on the taxiway for a marshaller to arrive and direct it onto the adjacent terminal gate. The first aircraft’s tail collided with the second aircraft’s right wing and a fire started. The evacuation of the second aircraft was delayed by non-availability of cabin emergency lighting. The Investigation attributed the collision to failure of the apron controller and pushback crew to follow documented procedures or take reasonable care to ensure that it was safe to begin the pushback.)

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