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 Post subject: Engine Fire EP
PostPosted: Fri Feb 08, 2008 8:00 am 
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Joined: Thu Jan 31, 2008 11:59 pm
Posts: 15
Question concerning the engine fire emergency procedure:
The procedure states to put the flaps at 20-30 degrees and hold airspeed around 80-85 kts.

Can anyone tell me why? I'm thinking to provide positive air pressure in the cabin in hopes to keep smoke out but I'm guessing here.

Thanks


 
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 Post subject: 208B inflight fire EP
PostPosted: Fri Feb 08, 2008 7:01 pm 
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Joined: Fri Oct 29, 2004 3:13 am
Posts: 56
Location: Niagara Falls Area
Nosedown and slower (least oxygen to the fire), .... maybe sucks any smoke / fire to clear lower while getting you down the fastest (sideslip unmentioned), and a safer / steadier operating range when possibly into a difficult / blinded forced approach ......

There could also be a mod for iced speed and attitude .... probably just the usual awareness about the normal speed-increase .... minimum 120kts (no flap), or the max arcspeeds in mind


 
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 Post subject: Re: Engine Fire EP
PostPosted: Thu Feb 14, 2008 3:49 am 
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Joined: Thu Jan 31, 2008 11:59 pm
Posts: 15
I found the answer to my question. By closing the side vents, opening the ventilation system, extending flaps, and slowing down the aircraft is able to maintain approximately .2psi differential pressure above that of the engine compartment. It's not the normal differential of a pressurized cabin but it's enough to make a difference.

Although the EP doesn't specify, this configuration should be maintained until the fire has extinguished and the smoke has dissipated. After the fire is out and the smoke is gone, then the forced landing procedure should be completed.

Just thought I would give a follow up. Thanks pdw for your input, it got me on the right track to find the answer. I appreciate the help.


 
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 Post subject: Re: Engine Fire EP
PostPosted: Thu Feb 14, 2008 7:43 am 
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Joined: Wed Sep 21, 2005 8:39 pm
Posts: 6
I know of PT6's that have caught fire.

But has anyone heard of a turban suburban catching fire *inflight*?


 
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 Post subject: Re: Engine Fire EP
PostPosted: Thu Feb 14, 2008 12:41 pm 
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Joined: Thu Jan 31, 2008 11:59 pm
Posts: 15
In my research on this EP, I found only two engine fires on the Caravan. BOTH were on the ground and BOTH occurred following engine maintenance.

These are the only two that I could find......anyone else know of one because I would be curious too?


 
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 Post subject: Re: Engine Fire EP
PostPosted: Sat Feb 16, 2008 12:44 am 
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Joined: Tue Nov 06, 2007 7:12 pm
Posts: 1
Sometimes it is dificult to find the "real" answer (like the left flap cut-away). I was told recently by a training center instructor that Cessna says that this configuration sets up a "pressure" that keeps the fire away from the firewall...like the burn-can principle.

_________________
...kick the tires, light the fires...first one in the air is the leader...


 
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 Post subject: Re: Engine Fire EP
PostPosted: Sat Feb 16, 2008 2:05 am 
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Joined: Thu Jan 31, 2008 11:59 pm
Posts: 15
I agree that it's hard to find real answers. I would submit that the instructor that told you that was grasping at straws!
The firewall is designed to have fire against it. If the cabin pressure was the only thing "keeping fire away from the firewall", what would happen if there was no pressure in the cabin area? Based on what he said, fire would breech the wall and enter the cockpit. And we know that's not true.

P.S. See my post on the left flap issue. No more rumors on this one.


 
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 Post subject: Re: Engine Fire EP
PostPosted: Thu Jan 21, 2010 7:20 pm 
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Joined: Thu May 05, 2005 3:49 pm
Posts: 12
Location: Central Asia
This is another EP that I think if you strictly follow the checklist, you would be screwed.

If you have an engine failure at say 10,000 feet AGL (Even lower), and you have a real engine fire, why on earth would you slow to 85kts?

I would follow all the procedures for this EP up until the glide part.

Obviously this is a bad situation no matter how you slice it, but with the prop feathered (Since you shut the engine down), you will be coming down at about 700fpm at @85Kts. That means it is going to take you 14 minutes to get that thing on the ground!!

The firewall is rated to withstand 2000 degrees for 20 minutes. I personally would go into an emergency descent with 10 degrees flaps, diving at 160kts, 2000-3000 FPM until I am set up for the landing and decelleration. Getting the aircraft on the ground ASAP before I blow up, or the fire gets even worse. Who knows, maybe that 160kts will also blow out the fire somehow.

Comments?


 
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 Post subject: Re: Engine Fire EP
PostPosted: Sun Jan 24, 2010 8:49 am 
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Joined: Wed Sep 21, 2005 8:39 pm
Posts: 6
Assuming you shut off the fuel, there is not a lot to burn up there.
That's why I ask if anyone has ever heard of one of these going down in flames from the front.
There is plenty to burn in the cabin, but I can not see a prolonged fire in the front.


 
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 Post subject: Re: Engine Fire EP
PostPosted: Sat Feb 13, 2010 6:59 pm 
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Joined: Fri Oct 29, 2004 3:13 am
Posts: 56
Location: Niagara Falls Area
None in the accident statistics (none reported) that I could find.

With tanks switched off to cut supply to the fuel system up front, and power-lever/Fcu off (to eliminate any trickle-in from that small reservoir below), the chances get nil for sustained fire ahead of that firewall mid-flight.


 
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