Halon  1211  or  CO₂   are  the  extinguishing  agents used on these fires.  However, when a fire in an aircraft cannot  be  extinguished  with  Halon  1211  or  CO₂,  the use of AFFF to prevent further damage outweighs the disadvantages. Internal Engine Fires Internal  engine  fires  usually  result  when  residual fuel  is  dumped  into  the  engine  on  shutdown.  When starting equipment and qualified starting personnel are immediately available, these fires may be controlled by windmilling the engine.  If this procedure fails or if the equipment     and     personnel     are     not     available,     an extinguishing  agent  must  be  directed  into  the  engine. Halon  1211  or  CO₂  is  the  primary  agent  for  internal fires.   Application   of   Halon   1211   or   CO₂    must   be accomplished at a distance so that the Halon 1211 or CO₂  enters the fire area in gaseous form. CAUTION When    CO₂ or    Halon    1211    is    expelled directly   into   an   engine,   thermal   shock   may result,   causing   engine   damage.   High   bypass turbofan  engines  require  unique  techniques  to extinguish engine core fires. Aircraft Engine Fires Use   the   following   procedures   for   extinguishing fires in high bypass turbofan engines: 1. Engine accessory section fire. a. Halon 1211 or CO₂ may be introduced into the  engine  accessory  section  area  through  the  access doors located on the aircraft engine cowling. b. When  the  fire  is  under  control,  one  fire fighter in full protective clothing (hot suit) will open the engine cowling. An AFFF hand line should be used to provide fire protection to the fire fighter. NOTE:  A screwdriver may be required to open the engine  cowling  due  to  the  restrictions  of  proximity gloves. 2. Engine fire turbine section engine core. When the engine is shutdown, apply Halon 1211 or CO₂, and if required AFFF, into the aircraft exhaust section only until the fire is extinguished. 3. Engine fire in compressor section engine core. CAUTION The   source   of   this   fire   will   probably   be burning  titanium,  and  can  be  identified  by  the sparking    effect    of    this    material    when    it    is burning.   This fire is potentially destructive and may possibly burn through the engine casing if immediate   fire   suppression   measures   are   not taken. a. Halon 1211 or CO₂ may be introduced into the engine intake, exhaust, or accessory section. b. When  the  fire  is  under  control,  one  fire fighter in full protective clothing (hot suit) will open the engine cowling. An AFFF hand line should be used to provide fire protection to the fire fighter. c. When  the  engine  cowling  is  open,  apply AFFF  to  both  sides  of  the  engine  casing  to  complete extinguishing and provide additional cooling. Electrical and Electronic Equipment Fires In combating electrical fires, you must secure the source of electrical power.  For combating class C fires, Halon  1211  or  CO₂  is  the  primary  agent,  and  should have   no   adverse   effect   on   electrical   or   electronic components. WARNING Halon    1211    may    be    used    in    a    small electronics compartment to make the atmosphere  inert,  provided  fire  fighters  do  not enter    the    compartment,    or    enter    it    with    a self-contained breathing apparatus. Do NOT use CO₂  to  make  the  atmosphere  in  an  electronics compartment inert, as it may produce a spark. TAILPIPE FIRES When  a  fire  occurs  in  the  tailpipe  of  an  aircraft during shutdown, the aircraft engine should be started by authorized personnel in order to attempt extinguishing     through     exhaust     pressures.     If     this operation  does  not  extinguish  the  fire,  the  following should be performed by the crash crew. 1. Direct fire-extinguishing agents Halon 1211 or CO₂  into the tailpipe. 2. If    fire    is    not    extinguished    by    the    above methods,  direct  the  stream  of  extinguisher  agent  into the intake duct. 12-19