Customer got hit by a prop today.

KFD said:
Tom if I were you I'd edit your first post to accurately reflect what happened that he was deliberately grabbing the prop not accidentally. That changes things a lot.
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No it doesn't. It's called responsibility. Guy could have been killed.
 
Tom-D said:
And he did it so quickly I could not react in time to have prevented this. To say I caused this by holding the gauges in a certain way, doesn't consider he did not do this on the other 3 cylinders. I could have prevented this had he told me what he was about to do. But when he diverted from the norm unexpectedly ?
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I put that gun to my head and pulled the trigger a hundred times and nothing happened. How was I to know he loaded it the last time? This thread has run its course. Tom will never admit that HE should have ensured that anyone standing near his compression check never should have been in a position to grab, intentionally or unintentionally, the propeller. He will go to his grave refusing to change his modus operandi to preclude clueless bystanders from killing themselves while he is performing dangerous procedures. If the owner had killed himself, does anyone believe that Tom would not have had to answer for his stubborn refusal to admit even a tiny bit of responsibility?
 
Witmo said:
I put that gun to my head and pulled the trigger a hundred times and nothing happened. How was I to know he loaded it the last time? This thread has run its course. Tom will never admit that HE should have ensured that anyone standing near his compression check never should have been in a position to grab, intentionally or unintentionally, the propeller. He will go to his grave refusing to change his modus operandi to preclude clueless bystanders from killing themselves while he is performing dangerous procedures. If the owner had killed himself, does anyone believe that Tom would not have had to answer for his stubborn refusal to admit even a tiny bit of responsibility?
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Yeah right he was an innocent bystander.

When he deviated from the normal routine(standard procedures), he caused this incident. Had he informed me of his intentions this would not have happened no matter what you believe.
And you'll never admit you are wrong.
 
I learned I don't
Lachlan said:
I have no idea, but after reading this thread I *know* that it wasn't Glenn's fault.
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you owe me a new car. I just spit coffee all over mine.
That was funny
 
Tom-D said:
Jesse, I'd not try the one handed trick on a 0-540 or a R-985. best to place at TDC and not get in the arc, because if bumped it will bite.
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I've never seen anyone compression check a O-540 without holding it.

I mean from a pure force perspective...A O-540 would be just as much force on the prop you'd have to resist as a O-360 would be. The 540 would be about twice as hard as my Continental A75 to secure which is super easy.
 
Luigi said:
Why was GlennAB-1 banned?
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SkyDog58 said:
Good question.
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According to the Rules of Conduct:

  • Bans and warnings, actual or suspected, shall not be discussed on the forums. Any inquiries or comments regarding bans are to be sent in private messages or via email. A moderator may choose to publicly inform the participants of a forum about bans and warnings if this is in the interest of the forum.
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jesse said:
I've never seen anyone compression check a O-540 without holding it.

I mean from a pure force perspective...A O-540 would be just as much force on the prop you'd have to resist as a O-360 would be. The 540 would be about twice as hard as my Continental A75 to secure which is super easy.
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There is nothing wrong with having some one to hold the prop on any engine as long as that is the norman procedure and that is what every one is expecting. But what happens when some one unexpectedly breaks from the normal procedure? can you blame any one but then?
 
The game called circle, we all win.
 
Witmo said:
I put that gun to my head and pulled the trigger a hundred times and nothing happened. How was I to know he loaded it the last time?
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Answer your own question, who deviated from the normal? the guy who loaded the gun, or the guy who put it to his head?
Now you must decide who in my case deviated from the normal, me? when it is perfectly normal to show the gauge to some one to record the readings, or the guy who grabs the prop unexpectedly?
 
mscard88 said:
No it doesn't. It's called responsibility. Guy could have been killed.
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Who's responsibility ? mine or the guy who deviated from the normal safe procedure? Remember it is very normal for one to do the test and the other to record readings. it is not normal to move the prop when the cylinder is under pressure.
 
Tom-D said:
Who's responsibility ? mine or the guy who deviated from the normal safe procedure? Remember it is very normal for one to do the test and the other to record readings. it is not normal to move the prop when the cylinder is under pressure.
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You keep talking about a customer deviating from safe procedure.....

Show us where the proper procedures were discussed? You can't. Because you didn't.

This was owner assisted, if he was a professional like you, he wouldn't need you.

My 8 year old can cut the Holiday ham if I let him, but that doesn't mean I'm going to. You're giving your customers WAY too much benefit of the doubt.

Who signs the log book... him or you?
 
jesse said:
I mean from a pure force perspective...A O-540 would be just as much force on the prop you'd have to resist as a O-360 would be.
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Nope, do the math, figure the square inch area of both pistons, multiply that number by 80PSI. to get force on the piston. then divide the stroke by 2 to get the arm of the crank, multiply that by the force to get the rotational torque given to the prop. you will find that the 0-540's bigger piston and its longer stroke will generate much more torque, and remember the prop blade length are about the same as a lever to resist the torque.
When you allow the 0-540 to get very far off TDCit will get away from very quickly.
When a piston is at TDC there is no lever, it can't develop any torque, at 90 degrees to crankshaft travel it is at maximum torque for the given 80psi standard pressure.
 
SmashTime said:
You keep talking about a customer deviating from safe procedure.....

Show us where the proper procedures were discussed? You can't. Because you didn't.

This was owner assisted, if he was a professional like you, he wouldn't need you.

My 8 year old can cut the Holiday ham if I let him, but that doesn't mean I'm going to. You're giving your customers WAY too much benefit of the doubt.

Who signs the log book... him or you?
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Part of determining the health of any engine is a compression test that is a portion of the required Annual inspection requirements set under 43-D. those are not allowed to be completed by any other but the inspector (me), and that is what gets signed off.

What you are saying is I did not follow the standard test procedure, How do you rationalize that? how can you say that an unsuspected action by others is my fault. specially when it occurs out of the normal procedures they know very well?

Under your theory, if we were having a normal conversation and I suddenly slap you, that's your fault. you should have known I was capable.
And many owners are very good at maintaining their aircraft and do high quality work, as noted prior this owner has built this 150 from the ground up. he just is not inclined to do the required training to get his A&P or the required 3 years of maintaining other's aircraft to qualify for his IA. So Yes he needs me, because I did. that does not mean he is not a professional.

you are now way off your knowledge base, because your postings show you do not know what goes on during an owner assisted annual.
 
Tom-D said:
Nope, do the math, figure the square inch area of both pistons, multiply that number by 80PSI. to get force on the piston. then divide the stroke by 2 to get the arm of the crank, multiply that by the force to get the rotational torque given to the prop. you will find that the 0-540's bigger piston and its longer stroke will generate much more torque, and remember the prop blade length are about the same as a lever to resist the torque.
When you allow the 0-540 to get very far off TDCit will get away from very quickly.
When a piston is at TDC there is no lever, it can't develop any torque, at 90 degrees to crankshaft travel it is at maximum torque for the given 80psi standard pressure.
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Tom....I ain't the strongest fat guy in the world....buy I have no problem holding a short three bladed prop on a 540 while performing a compression check. It ain't all that difficult. :frown2:

btw....if there is any leakage....there isn't 80 psi acting on the piston. It's less...
 
Simple solution, customer is kept far enough from the prop that they can't touch it during the test and instructed not to touch the AC or prop.
 
Checkout_my_Six said:
Tom....I always hold the prop in one hand and the gauge in the other. It will never move....cause I'm securing it. If I have a helper....they use their ears to locate the noise while I'm securing the prop.

The prop leaves my hands....when pressure is released.:stirpot:
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Many A&P's do it your way.
Years ago I was watching a A&P-IA doing a compression check on a piper Dakota 0-540, he like you had a hold of the prop blade and the cylinder was pressurized, while he was looking at the gauges, the owner walked by an pushed the prop out of his way to get by. The engine yanked the I off his feet and broke his arm as he fell.
Nope I'll simply place it on perfect TDC and get out of the prop arc. while checking the gauges, then shut off the air, disconnect the hose remove the adaptor and move on.
 
PaulS said:
Simple solution, customer is kept far enough from the prop that they can't touch it during the test and instructed not to touch the AC or prop.
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he certainly was, he knows the danger, this was not his first rodeo.
 
Tom-D said:
Answer your own question, who deviated from the normal? the guy who loaded the gun, or the guy who put it to his head?
Now you must decide who in my case deviated from the normal, me? when it is perfectly normal to show the gauge to some one to record the readings, or the guy who grabs the prop unexpectedly?
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Tom,

I'm trying to understand something with your description of the events:
In the first post you state that the prop hit him in the head, which I understand, but later you say that he grabbed the prop to move it.
I can't understand how he grabbed the prop to wiggle it while standing in the prop arc. Can you explain that, cause I can't picture it?
 
hockeyrcks9901 said:
Tom,

I'm trying to understand something with your description of the events:
In the first post you state that the prop hit him in the head, which I understand, but later you say that he grabbed the prop to move it.
I can't understand how he grabbed the prop to wiggle it while standing in the prop arc. Can you explain that, cause I can't picture it?
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He simply wasn't ready for the yank the prop gave him. they will pull you in almost every time.
My standard procedure is to stay out of the prop arc, if you are going to do some thing let others know so they can be prepared.
Had he said "" I want o pump the prop back and forth" I'd have dropped the pressure made certain he had a good hold on the blade, then added the pressure again.
 
Tom-D said:
He simply wasn't ready for the yank the prop gave him. they will pull you in almost every time.
My standard procedure is to stay out of the prop arc, if you are going to do some thing let others know so they can be prepared.
Had he said "" I want o pump the prop back and forth" I'd have dropped the pressure made certain he had a good hold on the blade, then added the pressure again.
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Makes sense. I just couldn't picture it. Thanks.
 
Tom-D said:
Nope, do the math, figure the square inch area of both pistons, multiply that number by 80PSI. to get force on the piston. then divide the stroke by 2 to get the arm of the crank, multiply that by the force to get the rotational torque given to the prop. you will find that the 0-540's bigger piston and its longer stroke will generate much more torque, and remember the prop blade length are about the same as a lever to resist the torque.
When you allow the 0-540 to get very far off TDCit will get away from very quickly.
When a piston is at TDC there is no lever, it can't develop any torque, at 90 degrees to crankshaft travel it is at maximum torque for the given 80psi standard pressure.
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I don't understand. An O-360 is a 4 cylinder, and an O-540 is a 6 cylinder. That means each cylinder has 90 CID, for both engines. Since CID for one cylinder is pi/4*bore^2*stroke, how can the O-540 have bigger pistons AND a bigger stroke? I presume you only air up one cylinder at a time, since there can only be only one at TDC on the compression stroke at a time.
 
Lachlan said:
Methinks you are more opinionated than those you criticize for stating their opinions. Let me know when you're ready for your beating with a stout length of dimensional lumber. ;)
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Yeah, I have a few hot buttons.

Read this from the beginning, Mr. Buttinski threw his weight around a lot, telling Tom it was all his fault for letting the customer into his shop, not having a signed risk agreement, etc., etc. Meanwhile, Tom was working on the customer's plane in the customer's hangar, and the customer reached forward faster than Tom could stop him.

Apparently that's not good enough for Dipstick, he kept telling Tom it was all his fault, along with the superior methods his own hindsight showed could have prevented it. Apparently customers are never responsible for their own actions, nor for whatever those actions lead to, it's always the fault of the working man who they surprise.

To me, there's more than enough blame to share. Beat me with a piece of lumber if you must, but I'll be swinging back with my own. ;)
 
PaulS said:
Simple solution, customer is kept far enough from the prop that they can't touch it during the test and instructed not to touch the AC or prop.
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Too simple. It's every owner's right to have his own prop strike him in the head. It would be unAmerican to do anything whatsoever to protect him from himself.
 
MAKG1 said:
I don't understand. An O-360 is a 4 cylinder, and an O-540 is a 6 cylinder. That means each cylinder has 90 CID, for both engines. Since CID for one cylinder is pi/4*bore^2*stroke, how can the O-540 have bigger pistons AND a bigger stroke? I presume you only air up one cylinder at a time, since there can only be only one at TDC on the compression stroke at a time.
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Cubic inch displacements have nothing to do with it, the formula is force area pressure area of the piston, times the pressure gives you the push, the arm gives you the torque.
and yes the 4 banger lycomings have large piston area. and they are more difficult to hold when pushed off TDC

There is another factor, you are not going to be hit by the blade you are holding, you are going to be hit by the blade coming over the top, or other wise the opposite blade, or the next blade as in a 3 or 4 blade prop. By the time the blade comes over the top, the pressure in the cylinder has been dumped by the valve opening, So in this case the blade will not have the same force as one that fires. So are you going to be killed by it, possibility ... but most likely not. hurt by it? OH HELL YES.
 
Witmo said:
Too simple. It's every owner's right to have his own prop strike him in the head. It would be unAmerican to do anything whatsoever to protect him from himself.
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Your sarcasm is showing your ignorance. You can't make your point so now you make fun of it. this proves you have lost the argument.
 
jesse said:
I've never seen anyone compression check a O-540 without holding it.

I mean from a pure force perspective...A O-540 would be just as much force on the prop you'd have to resist as a O-360 would be. The 540 would be about twice as hard as my Continental A75 to secure which is super easy.
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IAW my math, the 0-200 with a bore of 4,0625" pushed by 80 PSI will develop 690.9 inch pounds or 57.5 foot pounds of torque 90 degrees after TDC.

The Lycoming 0-360 with a bore of 5.125 will develop 3607.4 inch pounds or 300 foot pounds of torque 90 degrees after TDC.

are we really sure we want a hold of these props when doing the compression check? because the farther off center they get the harder they pull.

granted you are not going to have exactly 80 PSI on them at 90 degrees after TDC because of the metering orifice in the tester but it will have you off balance by then, so?
 
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Tom-D said:
Your sarcasm is showing your ignorance. You can't make your point so now you make fun of it. this proves you have lost the argument.
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I've made my point time and again. It's you who is in denial. I'm being sarcastic because you refuse to accept the reality that you could have prevented someone getting hurt by stupidly simple procedures. Your defense to a charge of inadequate control while performing a dangerous operation is blatant rationalization. You're lucky the owner didn't get killed and yet you blame him totally. Yes, he made a mistake, several, the first was hiring someone who purports to be a professional but refuses to take the simplest precautions to prevent observers from getting injured during hazardous procedures he is performing. I don't like lawyers as such as the next guy but I don't doubt even a crummy one could have had a field day if the owner had sued you. Your story changed as people pointed out what you should have done to prevent the accident but it doesn't change the fact that you failed to make any attempt whatsoever to control the immediate area around the propeller which was poised to do exactly what it did when nudged by someone you allowed to be near enough to do the nudging. Deny away but the consensus is you need to grow a pair, put on some big boy pants, and take responsibility for your failure to supervise someone you allowed to observe in close proximity, a compression test.
 
Tom-D said:
Cubic inch displacements have nothing to do with it, the formula is force area pressure area of the piston, times the pressure gives you the push, the arm gives you the torque.
and yes the 4 banger lycomings have large piston area. and they are more difficult to hold when pushed off TDC

There is another factor, you are not going to be hit by the blade you are holding, you are going to be hit by the blade coming over the top, or other wise the opposite blade, or the next blade as in a 3 or 4 blade prop. By the time the blade comes over the top, the pressure in the cylinder has been dumped by the valve opening, So in this case the blade will not have the same force as one that fires. So are you going to be killed by it, possibility ... but most likely not. hurt by it? OH HELL YES.
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Umm, write your formulas down, and you'll find the one you're using is torque = CID/ncyl * pressure/2. That means there can't be a difference between O-540 and O-360 like you asserted. Maybe between 2 and 3 bladed props, but the torque applied by the engine will be the same.
 
MAKG1 said:
Umm, write your formulas down, and you'll find the one you're using is torque = CID/ncyl * pressure/2. That means there can't be a difference between O-540 and O-360 like you asserted. Maybe between 2 and 3 bladed props, but the torque applied by the engine will be the same.
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Not CID, it is the area of the piston. because torque is what rotates the prop.
 
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