Would this hot start procedure work on a Cessna?

Skid

Skid

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Skid
So with summer in full swing and temperatures at the airport reaching 100 and people flying regularly, the dreaded hot start is becoming common place. While I can make it work and it's not generally a problem, I still always say a quick prayer before attempting. I was doing some reading to boost my confidence and resources some, and it seems like there are as many hot start procedures out there as there are pilots.

One which caught my eye on the jetcareers forums was a procedure described by George Braly. The gist of the article was that one should just sit with the aux fuel pump on for a minimum of 60 seconds to get cool fuel circulated in the lines before attempting a start. Once this is done and the cooler fuel is present, one would just start as they would from a cold engine.

The procedure was discussing TCM engines and not Lycoming, and with my limited knowledge of the actual system, I wasn't sure if the procedure above would work. I remember reading somewhere that there wasn't a fuel return line for the 172, but that may not matter. Then there is also the concern of running down the battery and prematurely wearing out the pump with it running for so long.

Any thoughts?
 
Carb'd or injected?
 
No prime, Throttle 1/4 inch, mixture full lean (full rich when engine fires) always works for me in a hot 172.
 
Biggest concern is flooding.
When I was training in 172s my favorite technique was to leave everything right where it was at shutdown - i.e. Little throttle, mixture cut off, pump initially off but on if not started in a few seconds first try.
 
Try it. I've heard 30 seconds. Maybe you can see what your plane likes, either more or less.

The way I learned: throttle 1/2" for high idle, mixture cutoff, turn key to start, as prop starts turning go full rich, when engine catches, hit boost pump until it smooths out, boost pump off, low idle. The Petersen's Performance Plus website has a 2 minute video on it.
 
Skid said:
The gist of the article was that one should just sit with the aux fuel pump on for a minimum of 60 seconds to get cool fuel circulated in the lines before attempting a start. Once this is done and the cooler fuel is present, one would just start as they would from a cold engine.
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60 seconds with the mixture cut off? Otherwise I would think that would flood the engine.
 
Skid said:
Injected. Lets say a 2005 Cessna 172sp
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No vapor return on a Lyc so no reason to run for 60 sec. Run fuel pump until pressure stabilizes (with mixture in cutoff) then start cranking and increase mixture.
 
There are a lot of procedures and it's good the know a few because what works on one plane/engine won't work on another. I would try a few and settle on the one that gives the best results.:yes:
 
I once listened to @jesse and @Ted DuPuis carry on deep into the night with beers in hand about this very subject. I think they got a good handle on the subject. Perhaps they will shine their light upon this thread.
 
OkieFlyer said:
I once listened to @jesse and @Ted DuPuis carry on deep into the night with beers in hand about this very subject. I think they got a good handle on the subject. Perhaps they will shine their light upon this thread.
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I've posted many times about the ways I recommend hot starting engines. Of course, my ways are not the only ways, but I like mine.

I don't like the method listed of running the boost pump for 60 seconds, and it won't work on a Lycoming. It'll just flood the crap out of the engine, leaving large amounts of fuel on the ground.
 
I always had better luck hot starting fuel injected Continentals than I did with Lycomings. OTOH, one of our customers had it down so pat his Mooney started on the second blade. I should have asked him about his technique. Too soon old, too late smart. :rolleyes:
 
jordane93 said:
No prime, Throttle 1/4 inch, mixture full lean (full rich when engine fires) always works for me in a hot 172.
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This. I flew aerial tours in DFW for about 6 months. We would average about 12-13 flights a night, each about 30 mins. Load, Fly, Unload, Load, Fly, etc all night. Lots of hot starts. This method worked perfect for me each time. Fuel injected 172's...
 
Ted DuPuis said:
I've posted many times about the ways I recommend hot starting engines. Of course, my ways are not the only ways, but I like mine.

I don't like the method listed of running the boost pump for 60 seconds, and it won't work on a Lycoming. It'll just flood the crap out of the engine, leaving large amounts of fuel on the ground.
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Just to clarify this wouldn't be a 60 second prime; the method by Braly described was to keep the mixture in idle cut off and have the fuel recycled so to speak using the return lines. So I wouldn't think anything would escape to pool under the engine. But then again if there's no return line then it's a moot point.
 
Meh, I've had good luck with this

Method 1

Mixture rich, pumps off, crank and slowly advance the throttle.

Failing that.

Method 2

Prime with the pumps,
Mixture ICO, full throttle
Crank, once it catches throttle to idle and mixture in.

That's always got me started in short order.
 
Skid said:
Just to clarify this wouldn't be a 60 second prime; the method by Braly described was to keep the mixture in idle cut off and have the fuel recycled so to speak using the return lines. So I wouldn't think anything would escape to pool under the engine. But then again if there's no return line then it's a moot point.
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Sorry, you are correct. If the mixture is at ICO and the boost pump is on then there shouldn't be any fuel going by. The fuel returns on Continentals are a different beast entirely.

On Navajo Chieftains leaving the boost pumps on even with mixtures at idle cut-off I've found will flood the engines, but it could be just that the Chieftains I flew had fuel systems in poor conditions. I've heard it was repeatable. On a 172 or on my old Aztec so long as the mixtures were at idle cutoff no fuel would get through, boost pump on or off.
 
James331 said:
Meh, I've had good luck with this

Method 1

Mixture rich, pumps off, crank and slowly advance the throttle.

Failing that.

Method 2

Prime with the pumps,
Mixture ICO, full throttle
Crank, once it catches throttle to idle and mixture in.

That's always got me started in short order.
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What kind of aircraft?

Also curious why the normal start procedure calls for the mixture to be ICO. Is full forward delivering too much fuel for normal starts?
 
Skid said:
What kind of aircraft?

Also curious why the normal start procedure calls for the mixture to be ICO. Is full forward delivering too much fuel for normal starts?
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IO520, same deal with the IO550.

Normal the the first method, failing that it's the ICO method.
 
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