Starting round engines

jsstevens

jsstevens

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jsstevens
I recently flew a Beech 18 while getting my AMES rating. It’s equipped with P&W R-985 engines.

In this plane, the starting sequence was:
1) engage boost pump
2) verify fuel pressure
3) pump off
4) engage starter (after verifying prop clear)
5) count three blades to ensure no hydraulic lock
6) mags on
7) pump throttle around 11 times, fast enough but not too fast (primers not working correctly I was told)
8) at some magic point throttle to idle and engine catches.

My question to you round engine types is: What are you seeing, hearing or sensing that tells you it’s ready to start and you can stop pumping the throttle?

I didn’t observe anything that I could put my finger on. It didn’t puff, cough, stumble or anything I noticed. I told my wife after successfully completing my Checkride that while I can fly it I’m not at all confident I could start it unaided.

John
 
jsstevens said:
7) pump throttle around 11 times, fast enough but not too fast (primers not working correctly I was told)
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FWIW: It was always pounded in my head by my old mentors to fix the primer systems on round engines whenever possible. Helps keep the risk of a carb fire on the low side which can create its own interesting issues. And just to add, in my experience, every round engine has its own personality when it comes to starting.
 
For the record, the primers were enroute but had not arrived. They fully intend to fix them. But it’s not a grounding issue.

And that misses the whole point of my question: what tells you the engine is ready to start?
 
Dear heavens! No wonder jets have taken over…

To wit, A-4 Skyhawk:

Hold up 1 finger
Hold up 2 fingers
Push throttle from off to idle
Hold up 3 fingers
Hold up 4 fingers

Prolly designed that way for us Navy folk…

DUDE, so want to do THAT ASES. Very cool.

I about guarantee that’s just what they’ve found that works. I got a bud who has that engine on a Agcat, I’ll ask him…
 
Tools said:
Dear heavens! No wonder jets have taken over…

To wit, A-4 Skyhawk:

Hold up 1 finger
Hold up 2 fingers
Push throttle from off to idle
Hold up 3 fingers
Hold up 4 fingers

Prolly designed that way for us Navy folk…

DUDE, so want to do THAT ASES. Very cool.
Click to expand...
It was very cool! Sweet airplane.
 
Thats significantly different than my start in the beaver. 10 (IIRC) pumps of the primer and a couple pumps of the throttle. Always started on the second or third blade. I did the same thing for the 1340 in the Norseman and it seemed to like that too.
 
The first thing on the list for us is pulling them through two full revolutions by hand. We have discovered liquid lock a few times. I sure wouldn’t want to discover it with the starter even without fuel or ignition.

It’s a tough job with the bombers, but it seems to be a worthwhile precaution.
 
jsstevens said:
And that misses the whole point of my question: what tells you the engine is ready to start?
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Umm, when the cylinders start to light off, that's your signal.

I will say that in flying a few different Beech 18s, the R-985 seems (for me) the most cantankerous to get started. The R-1340s in various T-6s have been pretty easy, while the bigger radials I've flown are even easier yet. The R-1300, 1820, 1830 and 2600s have different priming systems with a solenoid valve that squirts fuel below the carb into the blower; seems to provide a more reliable and repeatable start.
 
jbDC9 said:
Umm, when the cylinders start to light off, that's your signal.

I will say that in flying a few different Beech 18s, the R-985 seems (for me) the most cantankerous to get started. The R-1340s in various T-6s have been pretty easy, while the bigger radials I've flown are even easier yet. The R-1300, 1820, 1830 and 2600s have different priming systems with a solenoid valve that squirts fuel below the carb into the blower; seems to provide a more reliable and repeatable start.
Click to expand...
The cylinders didn't light off until I pulled the throttle back (that I noticed anyway- no smoke, no sounds). That was the puzzle to me: how didi he know when to pull it back? It wasn't the same number of pumps each time. That's what confused me.
 
MauleSkinner said:
Based on what?

What tells you when to stop priming when the primer works?
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Based on the FAA examiner (not a DPE) having examined the logs with me, then standing behind us while we did the check ride? Sure, FAA folks are human and make mistakes, but he seem very thorough and had no issue with it.

I have no idea how it works with the primer-I never flew it that way.
 
jsstevens said:
Based on the FAA examiner (not a DPE) having examined the logs with me, then standing behind us while we did the check ride? Sure, FAA folks are human and make mistakes, but he seem very thorough and had no issue with it.
Click to expand...
was “both primers inop” or the equivalent in the logs? Did you tell him they were inop?
jsstevens said:
I have no idea how it works with the primer-I never flew it that way.
Click to expand...
so you didn’t read the POH, either?
 
MauleSkinner said:
was “both primers inop” or the equivalent in the logs? Did you tell him they were inop?

so you didn’t read the POH, either?
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Yes he was fully aware and we discussed it while starting.

Well, I did. But it's a 1954 CAR 3 plane so there isn't a POH in the newer sense. It's, um, sparse.
 
jsstevens said:
The cylinders didn't light off until I pulled the throttle back
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FYI: In start mode, after pumping the throttle, when you pull the throttle back it makes the mixture "richer" plus directs the mixture into the cylinders. Boom. Its also the same process that can lead to a backfire and subsequent carb fire if you're loaded up with too much fuel.
 
jsstevens said:
Yes he was fully aware and we discussed it while starting.

Well, I did. But it's a 1954 CAR 3 plane so there isn't a POH in the newer sense. It's, um, sparse.
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your examiner knew how to game the inspector and you both, didn’t he?
 
MauleSkinner said:
your examiner knew how to game the inspector and you both, didn’t he?
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I really don’t get all your condescension. The examiner was the FAA guy who was fully aware of the situation and had done at least two prior tests to mine in the same airplane.

Do you have documentation showing the primers are required for airworthiness?
 
jsstevens said:
I really don’t get all your condescension. The examiner was the FAA guy who was fully aware of the situation and had done at least two prior tests to mine in the same airplane.

Do you have documentation showing the primers are required for airworthiness?
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How about a BE-18 Manual that says, “Do not pump the throttle in an attempt to prime the engine….”

It might not be so bad if you indicated you had the slightest knowledge of priming a piston engine and/or deferring inop equipment.
 
I don’t remember reading that in the one I read but it was a few weeks ago and I no longer have it. It would still not indicate the primers are required equipment.

I did not attempt to write out all I know about operating piston engines as I was asking a question to which it’s not relevant.

I operated the airplane in accordance with the instruction I was given and with which the FAA examiner had no issues.
 
jsstevens said:
I don’t remember reading that in the one I read but it was a few weeks ago and I no longer have it. It would still not indicate the primers are required equipment.
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Maybe not, but you’ve presented absolutely no evidence that they were (or can be) properly deferred. Or even that anyone thought properly deferring them was worthwhile.
jsstevens said:
I did not attempt to write out all I know about operating piston engines as I was asking a question to which it’s not relevant.
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You also indicated that someone determining how to put adequate fuel into the engine (post #2) as the goal of priming doesn’t answer the question of how to know when you’ve put enough fuel in the engine to prime it.
jsstevens said:
I operated the airplane in accordance with the instruction I was given and with which the FAA examiner had no issues.
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Like I said, you and the examiner were both gamed. It’s actually fairly easy to do.
 
Jeezul peezul simma down nah and let’s get back to what is your favorite radial engine plane and why is it the Beaver?
 
Tools said:
Dear heavens! No wonder jets have taken over…

To wit, A-4 Skyhawk:

Hold up 1 finger
Hold up 2 fingers
Push throttle from off to idle
Hold up 3 fingers
Hold up 4 fingers

Prolly designed that way for us Navy folk…
Click to expand...
Watch out for that wet start…
 
Tools said:
Dear heavens! No wonder jets have taken over…

To wit, A-4 Skyhawk:

Hold up 1 finger
Hold up 2 fingers
Push throttle from off to idle
Hold up 3 fingers
Hold up 4 fingers

Prolly designed that way for us Navy folk…

DUDE, so want to do THAT ASES. Very cool.

I about guarantee that’s just what they’ve found that works. I got a bud who has that engine on a Agcat, I’ll ask him…
Click to expand...
Overly complicated.

For the A-10 (same engines as the Hoover):

APU to Start
Once APU is stable.
Throttle 1 to Idle
Once Engine 1 is stable
Throttle 2 to Idle
Done

Versus the T-37 finger dance.t-37 start sequence
 

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  • T-37 Engine Start.png
    T-37 Engine Start.png
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So hand propping a plane with a dead battery is flying a non airworthy aircraft now. Sorry, but if you are concerned that people are flying planes even though the primer isn’t working you need a life.
 
Salty said:
So hand propping a plane with a dead battery is flying a non airworthy aircraft now. Sorry, but if you are concerned that people are flying planes even though the primer isn’t working you need a life.
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regularly operating in a way that the manufacturer recommends against due to the possibility of setting the airplane on fire seems like it might be worthy of concern.

But the bigger concerns are the OP wanting to be better at improperly operating the airplane, not caring about being able to properly operate the airplane, and not caring about properly deferring inoperative equipment, and believing this is all appropriate for real life or a checkride simply because his instructor told him to do it that way.
 
Sierra_Hotel said:
Sure are reading a lot into what has been posted.
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How else should these be read?
jsstevens said:
My question to you round engine types is: What are you seeing, hearing or sensing that tells you it’s ready to start and you can stop pumping the throttle?
Click to expand...
jsstevens said:
I have no idea how it works with the primer-I never flew it that way.
Click to expand...
jsstevens said:
I operated the airplane in accordance with the instruction I was given.
Click to expand...
 
You keep saying OP doesn't care about any of those things, and yet here they are asking how to do it better and correctly, so your entire premise is wrong. Maybe take it up with the flight school or instructor that allowed the plane to be flown with INOP primers if you really care that much.
 
Sierra_Hotel said:
You keep saying OP doesn't care about any of those things, and yet here they are asking how to do it better and correctly, so your entire premise is wrong.
Click to expand...
No…he’s not asking how to do it correctly. He’s asking how to do it wrong.
 
Last edited:
Pinecone said:
Overly complicated.

For the A-10 (same engines as the Hoover):

APU to Start
Once APU is stable.
Throttle 1 to Idle
Once Engine 1 is stable
Throttle 2 to Idle
Done

Versus the T-37 finger dance.t-37 start sequence
Click to expand...

Wow… love the A-10! The old War Hoove was more like the T-37…
 
My 800 or so hours flying twin Beech's with R985's. I don't think I ever used the primers. About 6 pumps on the wobble pump, 2 throttle burst, hit starter, three more throttle burst, and idle. Normally fires right off. If hot, only 3 while cranking. I never operated it in very cold weather where the primers were needed.
 
Get ready to be told how wrong you are.
 
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