How is pulling a prop through safe?

Tom-D said:
How do you know it is at TDC balanced position with out pressure on the cylinder?
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Not difficult at all. Piston moves up, there's a bit of dwell time, piston moves down. Center in the middle of dwell and you're good to go.

You should try it sometime. :D
 
SoCal RV Flyer said:
Not difficult at all. Piston moves up, there's a bit of dwell time, piston moves down. Center in the middle of dwell and you're good to go.

You should try it sometime. :D
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Yep, that's exactly how you time a mag...just look inside the cylinder for TDC. You have a 50% chance of getting it right. ;)
 
RoscoeT said:
Yep, that's exactly how you time a mag...just look inside the cylinder for TDC. You have a 50% chance of getting it right. ;)
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Why not use the timing marks of the engine?
 
SoCal RV Flyer said:
You should come to my hangar sometime. I'll teach you how to properly torque the bolts on a cam gear.
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You should stop by the shop, I show you the proper method of finding the timing marks to go by to find TDC.
 
Tom-D said:
You should stop by the shop, I show you the proper method of finding the timing marks to go by to find TDC.
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I verify with the timing marks too, for extra safety! :D There's just something comforting about actually seeing seeing the piston at TDC. The plugs are already out so you can thread in the extension for the pressure tester.
And guess what...when I use my method for TDC on No. 1, the marks are in exact alignment! No charge if you want to use my technique.
 
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SoCal RV Flyer said:
I verify with the timing marks too, for extra safety! :D There's just something comforting about actually seeing seeing the piston at TDC. The plugs are already out so you can thread in the extension for the pressure tester.
And guess what...when I use my method for TDC on No. 1, the marks are in exact alignment! No charge if you want to use my technique.
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Why didn't you say that to start? rather than say you'd stand in the prop arc. standing in the prop arc was dumb as stated before you went on the attack.?
 
Tom-D said:
He'll call you a troll too, when you ask a question he doesn't like.
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No, I don't think I've ever had an issue with tarheelpilot. He seems like an upstanding guy.

You asked a question, I responded "yes," and then you continued to troll. Which, based on your past behavior, was entirely predictable.
 
SoCal RV Flyer said:
You asked a question, I responded "yes," and then you continued to troll. Which, based on your past behavior, was entirely predictable.
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After reading that, I don't believe you know what trolling is.

You answered "Yes" to a question "would you stand in the prop arc" .. (still dumb). reply should have been " I never stand in the prop arc, Speciality when anyone is working on the aircraft"
 
ifly4fun said:
Can we start a poll for which one of us has sent a customer to the ER on this very topic?

Might want to pick another one to be the authority on.
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He is a prime example of why you shouldn't stand in the prop arc, like you say you can.
OBTW his annual is due again, want to bet who he has do it again?
 
ifly4fun said:
Can we start a poll for which one of us has sent a customer to the ER on this very topic?

Might want to pick another one to be the authority on.
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Sometimes the best person to teach you about an SOP for safety or decision making is the person with experience from bad decisions.

I can teach you some things I learned from negative experiences. Doesn't mean I suck at being a pilot or make me less credible.

Tom might be the perfect guy to learn prop safety and cam torquing procedures from.
 
Tarheelpilot said:
Sometimes the best person to teach you about an SOP for safety or decision making is the person with experience from bad decisions.

I can teach you some things I learned from negative experiences. Doesn't mean I suck at being a pilot or make me less credible.

Tom might be the perfect guy to learn prop safety and cam torquing procedures from.
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problem is, many don't live thru their own mistakes.
I posted these events to demonstrate things people can learn by. then get ragged on by folks like ifly4fun.
but that doesn't bother me, when they do that it simply show their character not mine.
 
Tom-D said:
problem is, many don't live thru their own mistakes.
I posted these events to demonstrate things people can learn by. then get ragged on by folks like ifly4fun.
but that doesn't bother me, when they do that it simply show their character not mine.
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Someone once said, "there is no one as stupid as those who will not learn"
 
neilw2 said:
My 182Q POH states that in cold wx operations you should hand pull the prop a few times to limber the oil.
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How is cold oil "limbered up" by pulling the prop through?

My impression is that dragging metal parts over each in the absence of lubrication is to be avoided. And the quickest way to get oil pressure, to get the oil moving, is to start the engine.

What makes airplane engines fundamentally different from all the other engines such that they need this special handling? Except radials, that is, as explained upthread.
 
Tom-D said:
problem is, many don't live thru their own mistakes.
I posted these events to demonstrate things people can learn by. then get ragged on by folks like ifly4fun.
but that doesn't bother me, when they do that it simply show their character not mine.
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I appreciate you posting your scenarios so that others can learn. Having done several compression checks of my own, don't think your story doesn't cross my mind every time a cylinder is under pressure.

Your arrogance and insistence to even remotely express any responsibility or remorse shows your true character not mine.
 
Would I stand in the prop arc doing a differential cylinder pressure test, knowing that the particular cylinder being tested was at TDC? Sure. Someone has to hold the prop, and you take necessary precautions of filling the cylinder slowly, wear gloves, etc.

Would I stand in the prop arc while doing maintenance on my aircraft, or cleaning the cowling, or putting the wheel chocks in place? Sure. We've all done it. I sure as hell wouldn't move the prop in this scenario, and I make damn sure that the P-leads are in working order and the key is out, either in my pocket or visible on the glare shield.

Would I stand in the prop arc with fuel in the system, all spark plugs and leads installed and swing the prop through the impulse coupler click? Hell no! I wouldn't move it two mm in this scenario.

You're overthinking this far too much, Tom. You might impart some useful knowledge from time to time, but please check the arrogance at the door.
 
SoCal RV Flyer said:
Would I stand in the prop arc doing a differential cylinder pressure test, knowing that the particular cylinder being tested was at TDC? Sure. Someone has to hold the prop, and you take necessary precautions of filling the cylinder slowly, wear gloves, etc.

Would I stand in the prop arc while doing maintenance on my aircraft, or cleaning the cowling, or putting the wheel chocks in place? Sure. We've all done it. I sure as hell wouldn't move the prop in this scenario, and I make damn sure that the P-leads are in working order and the key is out, either in my pocket or visible on the glare shield.

Would I stand in the prop arc with fuel in the system, all spark plugs and leads installed and swing the prop through the impulse coupler click? Hell no! I wouldn't move it two mm in this scenario.

You're overthinking this far too much, Tom. You might impart some useful knowledge from time to time, but please check the arrogance at the door.
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Arrogance? like your post 48 & 50? when you started calling names and making judgments you know nothing about.

Get real, your posts here show your ability to hide behind your cute little moniker and snipe at those who are out in the open.
 
Pulling the prop through can be same if you make sure the airplane can't move and you treat the engine like it will start every time. I don't "jump out of the way" but I make sure my body trends away from the propeller.

I really enjoy hand propping an airplane. There is a classic, golden age feeling about it for me. Really, I just like yelling, "Contact!"
 
If a pilot has to move the prop, he should turn it backwards unless the POH prohibits it. The old you'll-bust-the-vacuum-pump myth is true only if the pump is worn way beyond its limits, and it's better to bust it on the ground than in the air.

Mechanics turn props backwards all the time and never break anything. The engine will not fire if being turned backward, but we still treat it like a sleeping bear. All you have to do is release that blade when there's a bit of compression in a cylinder, and it can swing and clobber you. Like an axe. It would hurt, bad.
 
FastEddieB said:
How is cold oil "limbered up" by pulling the prop through?

My impression is that dragging metal parts over each in the absence of lubrication is to be avoided. And the quickest way to get oil pressure, to get the oil moving, is to start the engine.

What makes airplane engines fundamentally different from all the other engines such that they need this special handling? Except radials, that is, as explained upthread.
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I hear what you are saying, but I'm going to follow the POH on that.

From the POH:

STARTING

Prior to starting on cold mornings, it is advisable to pull the propeller through several times by hand to "break loose" or "limber" the oil, thus conserving battery energy.
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neilw2 said:
I hear what you are saying, but I'm going to follow the POH on that.

From the POH:
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Got to remember that POH was written long before multi weight oils became the norm.
 
neilw2 said:
I hear what you are saying, but I'm going to follow the POH on that.
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Understood.

I don't doubt that your POH says that. Or even that there might be something to it.

Only that I'd like to know how oil is "limbered" by pulling through the prop. Does it get "thinner"? Flow better? Get "distributed"? What, exactly.

Regarding corrosion, Continental says this: "Turning the propeller by hand is not recommended as this wipes off the residual oil." Maybe not directly applicable, but interesting nonetheless.

BTW, that's from "Continental's Tips On Engine Care" - an excellent read:

http://www.continentalmotors.aero/WorkArea/DownloadAsset.aspx?id=2147483684
 
Limbering the oil... ask 100 mechanics you'll get 100 different answers.
It is an old term left over from the Radial days.
ADRC rank Brown (RIP) way back when, told me it is simply a means of wiping the heavy cold oil from the cylinder walls prior to start so the starter clutch wouldn't slip.
 
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