BA 777 on fire in Las Vegas
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I guess this debate centers on how you define and apply the word "must".
My company's FAA approved QRH for the 777 does not include the WARNING that your QRH has.
My company's FAA approved QRH for the 777 does not include the WARNING that your QRH has.
Horses for courses I suppose.
At the end of the day as long as the donks are switched off before we disgorge passengers onto the tarmac then the job is done.
You are correct but it is important to differentiate what these controls do.
The cutoff switches close ONLY the fuel valves whereas the fire handles cut off the spar valves and fuel valves, trip the engine generators, closes the bleed valves, isolate the hydraulics, depressurizes the associated engine driven pump and removes power to the thrust reverser isolation valve.
The cutoff switches close ONLY the fuel valves whereas the fire handles cut off the spar valves and fuel valves, trip the engine generators, closes the bleed valves, isolate the hydraulics, depressurizes the associated engine driven pump and removes power to the thrust reverser isolation valve.
The primary reason that the pilot is instructed to set the fuel switch to Cutoff before pulling the fire handle is redundancy - when the Fire handle is pulled, it removes power from the fuel switch circuit. If there has been damage to the fire handle wire routing but not the fuel switch wires and you pull the fire handle first, you've lost the ability shutoff the fuel. Fuel switch first maximizes the ability to shutoff the fuel after a major failure.
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Fuel Control Switches vs Engine Fire Switches
Originally Posted by tdracer
The primary reason that the pilot is instructed to set the fuel switch to Cutoff before pulling the fire handle is redundancy - when the Fire handle is pulled, it removes power from the fuel switch circuit. If there has been damage to the fire handle wire routing but not the fuel switch wires and you pull the fire handle first, you've lost the ability shutoff the fuel. Fuel switch first maximizes the ability to shutoff the fuel after a major failure.
Our B-777 Operations Manual, Vol 2, should have included this information.
Maybe it's buried somewhere in there and I missed it.
BTW, it doesn't hurt anything to shutdown via the fire handle - we regularly do that during functional testing to make sure the circuit works. However it is important to then place the fuel switch in cutoff as well.
There was a case back in the early days of the 747-400 - at the end of a customer acceptance flight, the customer pilot reached up and shut down all four engines via the fire handle - then pushed them back in without setting the fuel switches to cutoff. That re-introduced fuel into the still spinning engines resulting in massive tailpipe fires and ended up overtemping all four turbines
There was a case back in the early days of the 747-400 - at the end of a customer acceptance flight, the customer pilot reached up and shut down all four engines via the fire handle - then pushed them back in without setting the fuel switches to cutoff. That re-introduced fuel into the still spinning engines resulting in massive tailpipe fires and ended up overtemping all four turbines
Referring back to why the Engine Fuel Switches are placed to OFF before the Fire Switches are pulled, on the 737 CFM (300/400) the Engine Start Levers shut both spar and main engine fuel valves, whereas the Fire Switches only shut the spar valves. I remember a crew I was training forgetting to move the Start Levers to Cutoff following an RTO and Evac scenario and wondering why the engines continued to run for about 12 seconds........
Good to see that on the newer Boeings the Fire Switches shut both valves.
Good to see that on the newer Boeings the Fire Switches shut both valves.
Cessnapete is correct - Boeing ate it. Although it occurred on a customer acceptance flight, the airplane still technically belonged to Boeing.
And here I'd intentionally not specified who the guilty operator was
Eckhard, 12 seconds is fast - on most of our current aircraft it takes about a minute before the engine shuts down if only the spar valve closes (been there, done that)
And here I'd intentionally not specified who the guilty operator was
Eckhard, 12 seconds is fast - on most of our current aircraft it takes about a minute before the engine shuts down if only the spar valve closes (been there, done that)
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I may tell you an old trick from a composites repairman...
I may tell you an old trick from a composites repairman...
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Kindly read AAIB final report concerning Ethiopian Airlines ELT fire at LHR and hopefully you will withdraw you contention which is totally incorrect. Also read final USAF report fe B2A crash in Guam and kindly stop making specious claims, thank you.
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Determined to be what was expected, 8th compressor disk crack took out the 9th and 10th as well severing a fuel line.
Accident: British Airways B772 at Las Vegas on Sep 8th 2015, rejected takeoff due to engine fire, engine failure uncontained
Accident: British Airways B772 at Las Vegas on Sep 8th 2015, rejected takeoff due to engine fire, engine failure uncontained
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I agree 100% with Spooky! My experience matches his description to a T. Post #598, a few pages back.
Since I was on scene within a minute or so and witnessed the fireball, smoke plume, slides deployed and gathered some of the evidence after................
Since I was on scene within a minute or so and witnessed the fireball, smoke plume, slides deployed and gathered some of the evidence after................