Guy hit and killed by prop

jesse said:
The only time I've been whacked by a prop was a kickback during hand propping. Prop leading edge just barely caught my finger nails ripping a couple of them off the fingers. Lesson learned? Pull harder and more through and don't let the damn thing kick back.
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Or turn the left (non-impulse) mag off for starting. Pretty much stops kickback. Don't forget to turn it on aferward...
 
Capt. Geoffrey Thorpe said:
Talking about safety around moving machinery with dangling hoodie drawstrings - What's wrong with this picture... :-(
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I don’t see a problem with it. They can’t be more than 6 inches or so. Not sure what kind of hazard they could create.
 
Stewartb said:
Every pilot should be taught to hand prop during pilot training. When they find out how easily an engine can start by hand they become more careful when handling the prop.
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A guy here has a few champs, and other like types without starters. It’s amazing how he hand props and starts them on the first attempt. Being a long time jet line mechanic props give me the creeps, watching them spin is almost hypnotizing.
 
Tom-D said:
Years ago when I was teaching aircraft safety I'd do this demonstration.

Before the class I'd run the engine so it was warm, As I shut down I'd turn off the key and add a shot of prime as it spun down.
Then with the key off, mixture pull out, I turn the engine by hand until a mag was about to fire.
When the class was assembled, I'd tie the tail down, chock the wheels, and turn the key to the both position.

Then with every one watching I'd simply flip that prop passed the impulse coupling Click. and the engine would start right up spins a few seconds and shut down.

Every time I did this it was an OMG event for every one in the class.
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I imagine the engine ran something like this.
 
True, this guy had to find out the hard way where his impulse coupling was going to fire.
 
flyer770 said:
True, this guy had to find out the hard way where his impulse coupling was going to fire.
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You know it is sad when people get hurt because they don't know what they are doing, specially when training is available.
 
Dan Thomas said:
Or turn the left (non-impulse) mag off for starting. Pretty much stops kickback. Don't forget to turn it on aferward...
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Don't forget all the ADs on mag impulse couplings that can cause this.
 
I think one of the biggest reasons to use vacuum vs positive pressure is that its easier to filter out contaminants being drawn into the system than it would be for a filter to catch trash should the pump **** the bed. Vac pumps do take a dump every now and then, but all the sensitive junk is upstream and is not usually affected.

Sent from my LG-LS997 using Tapatalk
 
Ryanb said:
I don’t see a problem with it. They can’t be more than 6 inches or so. Not sure what kind of hazard they could create.
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Long enough to get caught. Being behind the prop helps, but doing something stupid in what is supposed to be a safety video - well, whole nudder story.

This was a pony tail, not any longer than the drawstrings https://yalealumnimagazine.com/articles/3288-after-a-fatal-accident-new-safety-standards

Not much detail on this one: "A local kid was grinding and the string from his hooded sweatshirt got caught in the wheel and pulled the grinder into his neck. He was dead when his father found him shortly after." https://www.practicalmachinist.com/vb/general/killed-angle-grinder-144821/
 
Tom-D said:
30,000 posts will happen but it is not my goal.
what pushes the vanes? centrifugal force, just like it was being driven in the correct direction. they contact the housing with more force when being driven in the correct direction than they will being driven in the reverse direction.

The warning on your pump is just a CYA for the company.
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One of aviation’s old wives’ tales is that you’ll wreck your vacuum pump if you move the prop backward. Fortunately, that’s not true. While most vacuum pumps are unidirectional—they either turn clockwise or counterclockwise in service based on the direction of rotation of the accessory shaft on the engine (and have CC or CW as a suffice to their model number)—it takes more than a few turns in the wrong direction to cause damage.
 
When washing the airplane and engine, make sure no liquid gets into the vacuum pump—it will turn the graphite dust to paste fairly quickly and destroy the pump. Teflon tape should not be used on pump fittings, pieces break off and get into the pump. The vacuum system filters should be replaced at the annual or at 500 hours (main filter) and 100 hours (other filters) of service, whichever comes first.

p19mb1tau76qivtc8k1bc4rj17.jpg

New stile pumps have a hole to check wear, one of the most common cause of pump failure is FOD from the vacuum system hoses located under the instrument panel.
 
Stewartb said:
Every pilot should be taught to hand prop during pilot training. When they find out how easily an engine can start by hand they become more careful when handling the prop.
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I helped someone by trying to hand-prop their engine. I was terrified because ... it may have started! I was happy it did not. I feel the edges of a prop for damage, any rotation I leave to the starter motor.
 
And there you go. You shouldn’t try it if you don’t know how. If you knew how you wouldn’t be scared.
 
zodiacflyguy said:
I think one of the biggest reasons to use vacuum vs positive pressure is that its easier to filter out contaminants being drawn into the system than it would be for a filter to catch trash should the pump **** the bed. Vac pumps do take a dump every now and then, but all the sensitive junk is upstream and is not usually affected.

Sent from my LG-LS997 using Tapatalk
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The vacuum pump manufacturer will tell you to clean all the vacuum lines out if the pump craters. That's because the instruments act as small vacuum tanks, and when the pump suddenly stops, those little tanks suck pump debris back up the lines, where it will sit until you install the new pump, which will then suck those bits in and destroy itself.
 
Dan Thomas said:
Or turn the left (non-impulse) mag off for starting. Pretty much stops kickback. Don't forget to turn it on aferward...
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Wouldn’t help. This was a Continental a75 with very old magnetos. No impulse couplers at all. As a result, it really liked to kickback, but wasn’t an issue as long as you pulled hard enough and through far enough.
 
jesse said:
Wouldn’t help. This was a Continental a75 with very old magnetos. No impulse couplers at all. As a result, it really liked to kickback, but wasn’t an issue as long as you pulled hard enough and through far enough.
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Ah. Those old Bendix mags. Hot spark.
 
Try kickstarting an old Harley Sportster. You’ll learn all you need to know about kickback.
 
Capt. Geoffrey Thorpe said:
Long enough to get caught. Being behind the prop helps, but doing something stupid in what is supposed to be a safety video - well, whole nudder story.

This was a pony tail, not any longer than the drawstrings https://yalealumnimagazine.com/articles/3288-after-a-fatal-accident-new-safety-standards

Not much detail on this one: "A local kid was grinding and the string from his hooded sweatshirt got caught in the wheel and pulled the grinder into his neck. He was dead when his father found him shortly after." https://www.practicalmachinist.com/vb/general/killed-angle-grinder-144821/
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I agree with your premise and he should have just tucked them in. Comparing using hand tools up close to hand propping isn’t quite apples to apples. I don’t see how you would catch a draw string that is less than half the length of your arms anywhere on the prop. That said, it’s not good practice.

It does remind me of an article I read on the all time great hurdler, Edwin Moses. During one race his shoelace came untied. After the race a reporter asked if he was worried that he would trip on it. He just laughed sand said, “I have an 11 foot stride, unless my shoelace is 12 feet long, it’s never going to happen.”
 
In addition to everything all y'all are saying, my number one absolute most important rule was to teach my kids to stay outside a large circle around all props on all planes, even walking past parked and "unoccupied" planes.
 
Dan Thomas said:
The vacuum pump manufacturer will tell you to clean all the vacuum lines out if the pump craters. That's because the instruments act as small vacuum tanks, and when the pump suddenly stops, those little tanks suck pump debris back up the lines, where it will sit until you install the new pump, which will then suck those bits in and destroy itself.
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That too, I was thinking of more immediate effects, where a positive pressure air pump were to fail and send trash into the instruments at time of failure. So then you would be potentially replacing not just the pump and filters, but a couple intruments as well.

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zodiacflyguy said:
That too, I was thinking of more immediate effects, where a positive pressure air pump were to fail and send trash into the instruments at time of failure. So then you would be potentially replacing not just the pump and filters, but a couple intruments as well.

Sent from my LG-LS997 using Tapatalk
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There's a filter between the pump and instruments in a pressure system. It will catch the garbage.
 
Dan Thomas said:
There's a filter between the pump and instruments in a pressure system. It will catch the garbage.
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I know that too, but the original conversation was why vacuum vs pressure. Complexity and weight was one issue and nearly direct conversion from venturi driven system was as well.

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Rushie said:
In addition to everything all y'all are saying, my number one absolute most important rule was to teach my kids to stay outside a large circle around all props on all planes, even walking past parked and "unoccupied" planes.
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Good habits are always good. I make it a habit to look at the prop and ask myself. Can it move?

I work around props most every day, we A&Ps must go into the prop arc to do our jobs, all you can do is, be certain it can not or will not move. On occasion I've even removed a battery cable.
 
Capt. Geoffrey Thorpe said:
That. Don't forget that the crank is spinning faster than the prop.
A 912UL is not that hard - I doubt that the 100 hp is that much harder, but no one has brought one by for me to try.
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I have hand propped a Tecnam P-92 with the 100hp engine. Also a Remos-GX.
It wasn't any harder than some of the Lycs, and Continentals engines I've propped, and it cost the local know-it-all $100.00 when he was dumb enough to bet against me.
In fact, it was a YouTube video by our very own Captain Thorpe that inspired me to try it one morning, just to see if.
 
Shepherd said:
I have hand propped a Tecnam P-92 with the 100hp engine. Also a Remos-GX.
It wasn't any harder than some of the Lycs, and Continentals engines I've propped, and it cost the local know-it-all $100.00 when he was dumb enough to bet against me.
In fact, it was a YouTube video by our very own Captain Thorpe that inspired me to try it one morning, just to see if.
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I wonder how many times people have hand propped a GO-300-D
 
Shepherd said:
I have hand propped a Tecnam P-92 with the 100hp engine. Also a Remos-GX.
It wasn't any harder than some of the Lycs, and Continentals engines I've propped, and it cost the local know-it-all $100.00 when he was dumb enough to bet against me.
In fact, it was a YouTube video by our very own Captain Thorpe that inspired me to try it one morning, just to see if.
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Well, if there was anyone dumb enough there it was you, trying to prop the engine against very explicit manufacturer recommendations..
 
Warmi said:
Well, if there was anyone dumb enough there it was you, trying to prop the engine against very explicit manufacturer recommendations..
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I'd love to see those myself.
I know Tecnam will tell you it can't be done, and you really have to pull hard and fast, but I have done it.
 
I don’t have any written specs at the moment, just remember being told that during official Rotax training ( for owners) last year.
 
There might be a good technical reason. Or it might just be cover-your butt stuff. I can imagine that hand-propping a geared engine involves enough effort that falling into the prop is more likely.
 
FWIW, iper the PoH, n cold weather you turn the Skycatcher's prop backward 2 or 3 turns to get oil moved around. If I need to move the prop to look at the engine during preflight, I rotate backward. So far, my head remains attached.
 
Doug F said:
FWIW, iper the PoH, n cold weather you turn the Skycatcher's prop backward 2 or 3 turns to get oil moved around. If I need to move the prop to look at the engine during preflight, I rotate backward. So far, my head remains attached.
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I hope you realize that when you turn a prop backwards you are taking oil out of the oil gallies and putting it back into the sump.
 
Tom-D said:
I hope you realize that when you turn a prop backwards you are taking oil out of the oil gallies and putting it back into the sump.
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That may be, but here is the text direct from the POH

Prior to starting on cold mornings, it is advisable to turn the propeller
manually through several engine compression cycles by hand to loosen
the oil, so the engine cranks (motors) more easily and uses less battery
power. When the propeller is turned manually, turn it in the opposite
direction to normal engine rotation for greater safety. Opposite rotation
disengages the magneto impulse couplings and prevents possible
unwanted ignition.

As sayeth The Manual, so shall thou doest. It's not my plane so I'll follow the directions unless and until the flight center says otherwise (and my CFI told me to do the same thing and he worked for the center).
 
Doug F said:
That may be, but here is the text direct from the POH

Prior to starting on cold mornings, it is advisable to turn the propeller
manually through several engine compression cycles by hand to loosen
the oil, so the engine cranks (motors) more easily and uses less battery
power. When the propeller is turned manually, turn it in the opposite
direction to normal engine rotation for greater safety. Opposite rotation
disengages the magneto impulse couplings and prevents possible
unwanted ignition.

As sayeth The Manual, so shall thou doest. It's not my plane so I'll follow the directions unless and until the flight center says otherwise (and my CFI told me to do the same thing and he worked for the center).
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I think I'd rather pre-heat.
 
Tom-D said:
I hope you realize that when you turn a prop backwards you are taking oil out of the oil gallies and putting it back into the sump.
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Two or three turns isn't going to empty the galleries. The pump runs off the camshaft, half crankshaft speed, and one or two rotations of the pump will move a few tablespoons of oil. It's all back in there before the engine even fires.
 
Dan Thomas said:
Two or three turns isn't going to empty the galleries. The pump runs off the camshaft, half crankshaft speed, and one or two rotations of the pump will move a few tablespoons of oil. It's all back in there before the engine even fires.
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then you do not deny that the theory is true, turn the oil pump backwards and it works backwards. how much oil is moved, who knows?
 
Who moves the prop backwards more than 1/6th of a rotation?? The only reason I move a prop is if it is in the way of a towbar. Can't get rid of that much oil.

Also 2nd request for an explanation of the OWT's in the 2nd post @Tom-D
 
Tom-D said:
then you do not deny that the theory is true, turn the oil pump backwards and it works backwards. how much oil is moved, who knows?
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Fer Pete's sake, Tom. If you are starting an engine and you let go of the starter just as it fires but doesn't quite catch, and then it fires before TDC on the non-impulse mag, it spins backward quite a few turns. I don't know how many times I've seen this, and it didn't break vacuum pumps nor did it run all the oil out of the galleries and end up in the engine exploding after starting. Even if it did clear the galleries it will run long enough to refill the system without any damage. It's not running at high bearing pressures at start. Even the OEM's POHs will tell you to shut the engine down if there's no oil pressure within 30 seconds; at a 700 RPM idle that's 350 revolutions of the prop.
 
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