engine start

[gas_man]

some years ago , when i was a military doctor, i used to notice a guy pushing a rather large fire extinguisher to each turbo prop engine as each was started . what was the use, don,t aircraft have their own engine fire suppression ?. .The aircraft in question was the Y 8 ...a chinese version of the antonov 22?. .. .prasanna

[Hot 'n' High]

gas_man - I too have often seen this happening. Indeed, for some years, I pushed out those extinguishers myself and prayed the bl**dy things started OK. Why did I do it? Well, common sense and cheap manpower - and the charge of being "cheap" has often been aimed at H 'n' H - by his ex-mates!!! <img border="0" title="" alt="[Eek!]" src="eek.gif" /> . .. .Seriously, often, if you have a "wet start" or another problem, the fire is in the engine core itself and the extinguishers don't work in the engine but around the engine. The quicker you put it out the better - as most Pilots would agree. The only way to put out an internal engine fire is to spray the stuff into the intake with one hand and indicate to the Marshaller/Pilot with the other that all is not well. <img border="0" title="" alt="[Razz]" src="tongue.gif" /> . .. .Why don't they do that at LHR with your 747-400 these days? Well, in the main because the things start more reliably these days and also H 'n' H has withdrawn his cheap labour as unofficial firefighter! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> . .. .Hope this explains another mystery of life!. .. .Regards, H 'n' H <img border="0" title="" alt="[Cool]" src="cool.gif" />

[gas_man]

thanks a lot.. .. .How would you know if there was a fire or not? would you see a fire that happens in the core?. .in fact once i saw a bad start. the thing just spat and sputtered. the pilot then taxied the aircraft with the balance engines and steered the thing into the wind (i guess) and the engine fired properly.....

[Hot 'n' High]

gas_man - Trust me, you can tell!!!!!!! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> . .. .It is sometimes a bit difficult to differentiate between a "wet start", where unburnt fuel pools in the jet-pipe during the start cycle and then flares off safely when the engine starts, and the start of a real fire. A "wet start" flares off in a few seconds. A real fire........... <img border="0" title="" alt="[Eek!]" src="eek.gif" /> . .. .As far as visibility goes, all the flames in the core get blasted back out the jetpipe by the air flowing through the core so it looks very obviously "interesting"! The seat of the fire is in the core - probably being fed by HP fuel - which is why you wave at the Pilot to cut the fuel off - otherwise you are using one very small extiguisher to try put out a fire being fed by 1000s of litres of fuel fed to the fire under pressure. . .. .I did say I prayed it all went according to plan - every single time I stood there - waiting! . .. .Hope this helps. Cheers, H 'n' H. .. .PS As an aside, the very early 747's sometimes had problems starting when pointing out of wind and so they had to turn them into wind and have another go. I am not too sure why this was but it was clearly something to do with airflow through the engine at very low RPMs/poor Starter Motors. That may explain your observation but I can't comment.

[Al Weaver]

If the reason for the tailpipe fire is overfueling (no ignition and lots of fuel being pumped into the engine) than you want to shutoff the fuel but to motor the engine to ensure that the tailpipe fire stays behind the pylon/wing area. I have seen cases where evacuations took place and the crew was forced to stop the motoring and then the fire turned upward and severely damaged the wing (747-400)

[411A]

...and i'll just bet that the reason for the evac was over enthusiastic cabin crew.. .Lessons are learned the hard way.

[Al Weaver]

&gt;...and i'll just bet that the reason for the evac was over enthusiastic cabin crew. Lessons are learned the hard way. &lt;. .. .Nope... overenthusiastic passengers! The cabin crew couldn't stop them all.

[Hot 'n' High]

Best stuff for causing mayhem goes back some years and was known as AVPIN. It was a Monofuel which was used, rather like solid Cartridge Starters, to start piston engines. . .. .As a Monofuel, AVPIN did not need air to burn as the O2 is part of the fuel. So, once alight, that is it. You wait until it burns itself out. Was used in (I think) the 50's and 60's. Apparently, you could always tell an AVPIN fire, even when you were quite a way off. . .. .That was the one where you saw the Pilot overtaking the fire crew - as they ALL legged it away from the burning aircraft! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />