One of the most critical situations any cabin crew member or pilot can encounter is a fire on-board the aircraft. A fire on-board an aircraft can quickly establish itself under the right conditions, it can incapacitate the aircraft occupants due to the level of toxic fumes released as materials combust. It has been documented from accident studies that statistically we have 17 minutes from inception of a fire until it becomes non survivable. (That is from the first circuit breaker pop or arcing of a wire etc. not from the time you find it!).
If faced with a potential inflight fire fighting situation by the time the source of the fire has been located it could already be well established. It goes without saying that aggressive and immediate firefighting action is vital. Sadly historical aviation accidents involving fires have demonstrated the devastating consequences and how quickly the fire accelerated.
Fatal fire accidents Skybrary
What is BCF?
BCF or Bromochlorodifluoromethane, also known as Halon 1211, or Halon 121, is a fire extinguishing agent which is gaseous when discharged in the aircraft. It is an excellent fire extinguishing agent effective on most common types of fires. BCF is however a volatile extinguishing agent that should be used only with a smoked hood in a confined space. There has always been controversy with the use of BCF, at one time it was widely available, however the production of BCF and similar chlorofluorocarbons has been banned in most countries since January 1st 1994 due to the Montreal Protocol on ozone depleting substances. (Recycling of halon 1211/BCF allows its use to continue). Here in Europe and in Australia it is banned – except in critical industries such as aviation, military and the police.
Type II BCF
What’s the issue?
There have been incidents where cabin crew and pilots have been hesitant to use a BCF due its perceived effects. Much aircrew and cabin crew training places emphasis on the effects and level of toxicity. Below is an extract from a study by the NTSB into the use of BCF which makes for interesting reading.
NTSB Extract on the Use of BCF/Halon
Halon Exposure
Generally speaking, halon is not harmful to passengers and crew; however, various publications, including AC 20-42, caution against exposure to “high levels” of halon in confined spaces, citing the possibility of dizziness, impaired coordination, and reduced mental sharpness. AC 20-42 also provides guidelines that describe what is meant by the term “high level” and further states that these levels should not be exceeded in ventilated or non-ventilated passenger compartments on aircraft. However, studies have shown that discharging all of the hand-held halon extinguishers required by regulation in the passenger cabin of an air carrier aircraft will not exceed the maximum concentration levels of halon vapour specified in AC 20-42 or by NFPA 408 guidelines.
NTSB Investigations
NTSB investigations of in-flight fires indicate that crewmembers have been hesitant to use halon extinguishers during flight because of mistaken ideas about adverse effects of halon. In one instance, an F/A went to the flight deck to inform the flight crew of a fire and asked the captain whether to spray halon into a vent where she suspected a fire. The captain instructed her not to use the halon extinguisher, indicating he was concerned about spraying halon in the cabin. In another instance, an off-duty company pilot considered using a halon fire extinguisher, but decided against doing so because he was concerned that the halon “would take away more oxygen.” In each instance, the crewmembers lost critical time and delayed the aggressive pursuit of the fire.
12/22/14 AC 120-80A
NTSB Recommendation
The NTSB has expressed concern that crewmember training programs have overemphasized the risks of exceeding the maximum recommended levels of halon gas outlined in AC 20-42, especially when compared to the risks of an in-flight fire.
The NTSB emphasizes “…that the potential harmful effects on passengers and crew [of Halon] are negligible compared to the safety benefits achieved by fighting in-flight fires aggressively.”
The toxic effects of a typical aircraft seat fire, for example, far outweigh the potential toxic effects of discharging a halon fire extinguisher.
The bottom line is clear, if you think there is a fire or you need to use BCF don’t delay attack it aggressively. It could mean the difference between an incident and an accident example we might find ourselves using in future aircrew and cabin crew safety training courses!
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