A little hot under the cowling!

There are a few words in aviation that will strike fear into ones heart. For a new instrument pilot it may be the dreaded call from ATC advising of a reroute, advise when ready to copy.

A little further up the scale might be hearing ATC to ask if your ready to copy a phone number is another.

At the top of the list however is one single word, FIRE!

In all my years of flying I have not had an engine fire. This all changed recently.

I have had my share of hair raising moments and one emergency, but fire was never involved.

I know we’ve all read the staring checklist that includes the section if an engine fire occurs to keep cranking until the engine starts and run it for a minute or so and then shutdown to inspect.

The other line that makes me chuckle is to “Have ground attendants obtain a fire extinguisher” I always wondered exactly how I would get a ground attendant to do that in the time constrained event of a fire and the fact we don’t have ground personnel around during GA activities.

What was that sound?

So on a recent lesson starting the Cessna 152 we went thru the starting checklist as usual, turned the key to start and after a few turns of the prop it didn’t  start. Hmm, okay, waited a second, turn it again and pumped the throttle once as we cranked and on the 2nd or 3rd revolution we heard a “POP”

I wonder what that was? This is when it got interesting. Thankfully another club instructor had just returned and was parking the plane immediately to our right. I heard a voice yell something and he’s pointing at my plane. Did he just yell FIRE? Yup, he did and he repeated it “FIRE!”  and added “Keep cranking!”

Getting ready to run

Granted, me and the student almost bailed on the plane and had the doors open, but the training kicked in and I reached over and turned the key and kept cranking until it started up. All the while the other CFI is looking all around the cowling and the front of the plane very intently.

After a minute I get the kill signal and shutdown to inspect and talk about it. He said a flame shot out of the bottom about a foot long and then when it started it got sucked back up, so we gather it was coming out of the carburetor and not the exhaust pipe.

Whew, averted something serious and we locked the plane up and went inside to report it to the chief pilot to get it looked at to make sure nothing was damaged that caused it and to inspect for any damage before returning it to service.

All is well

I got the call the next day that nothing was damaged and the consensus was we over primed it and fuel had run down back through the carburetor and when it did start or backfired, it ignited the fuel in the induction system and blew out the bottom as it’s an updraft carburetor.

My lesson learned is to listen for that “pop” during the start, it didn’t sound like an explosion and we never saw smoke or fire. So had we not had that second set of eyes on us the outcome may have been different. Knowing the normal sounds of startup is important as it is in the abnormal sounds that we need to really pay attention to.

Fly safe and keep learning!

Ron Klutts CFI

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