Engine fire on startup

[moxiepilot]

What a way to start the day on the last day of work before the move to my new survey pilot job.

Oh yeah, and the fire extinguisher which was checked in the green arc before startup, hardly discharged after pulling the pin. Useless.

[Nick]

Was it daytime or night? I had an engine catch on fire once while we were starting it. It was night and I saw the orange glow on the ground before it got big. If that had been daytime it would not have been so easy to see and could've been worse.

What kind of plane?

[JaceTheAce]

Too much primer?

Re: the fire extinguisher, that's why I always bring a spare mini fire extinguisher in my flight bag.

[moxiepilot]

yeah, too much primer for the sub freezing temp. it was this morning, so the black smoke was the first indication

it was a 150 that needs to be put to rest anyway.

[averyrm]

The small fire extinguishers don't spray that long, you have maybe 1 sec of trigger pull and it's done, and that's at full charge.

[ananoman]

One thing you might want to think about is priming when you are cranking the engine. Just give it a few squirts, then crank the engine and give it some more. I never liked pumping the primer that much, or pumping the throttle unless the engine was turning. Less chance of all that fuel running down into the airbox and causing an induction fire that way.

[moxiepilot]

ONLY if you have a horizontally opposed carbureatour, not a vertically opposed one. because then the fuel does not come back down into the box. A number of fires start that way, like you said.

Originally Posted by ananoman

One thing you might want to think about is priming when you are cranking the engine. Just give it a few squirts, then crank the engine and give it some more. I never liked pumping the primer that much, or pumping the throttle unless the engine was turning. Less chance of all that fuel running down into the airbox and causing an induction fire that way.

[EDUC8-or]

I was doing a walk around the other day and I saw a plane that was starting their APU. It sort of hung for a while and all of a sudden a big flame shot out of the APU exhaust area. About 10-15' worth of flame. I walked over and let the crew know (it wasn't my airline) and they were pretty surprised, but could smell lots of smoke when they turned on the packs. I don't know much about the systems on the airplane, but they let it run for about 2 minutes to burn off the fuel and then shut it down. They walked over and thanked me later, I guess there was a big pool of fuel somewhere in the APU area which really shouldn't happen. Kind of stinks when you can't just pull the mixture to idle or dry motor the engines to put the fuego caliente out.

Crazy site nonetheless!

[ananoman]

Originally Posted by moxiepilot

ONLY if you have a horizontally opposed carbureatour, not a vertically opposed one. because then the fuel does not come back down into the box. A number of fires start that way, like you said.

When you talk about carburators, they are called updraft, side draft and down draft. The side drafts mounted on the back of some of the lycomings (like in the Seminole) are more resistant to induction fires, because they have a valve in the bottom of the induction manifold that will drain the fuel onto the ground under the engine. This is still not the greatest scenario though. If someone goes overboard you will get quite a puddle under the engine. If the valve doesn't work, you can still get a fire. Sometimes the valve will stick open and the engine will run lean (had this happen once). The engine ran very rough and was backfiring on the ramp.