Props can and do explode
06-17-2010 | 11:36 PM
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From: Left Coast ,
CA
Props can and do explode
For all of those that like to stand in front or besides your propellers when you do a run up should seriously consider discontinuing that practice.
The other day I was out testing props and a new smoke oil home brew. During this testing the third prop completely exploded, pieces went right, left, up, forward and down. I was standing behind the plane and had just advanced the throttle when the sh$t hit the fan. It was a brand new prop that was balanced and only had a couple of flights on it.
I was using the center retaining nut on this particular 116 cc engine, so no prop bolts or drilling could have lead to this mis-hap. The prop ended up in many little long dagger like pieces.
After the prop let loose that engine sounded like a cox .049 leaned and screaming.
Luckily no one was at the field at that time and I was not in the direction of this flying shrapnel. This only reinforces the reason I never run an engine up in front or besides the propeller.
The other day I was out testing props and a new smoke oil home brew. During this testing the third prop completely exploded, pieces went right, left, up, forward and down. I was standing behind the plane and had just advanced the throttle when the sh$t hit the fan. It was a brand new prop that was balanced and only had a couple of flights on it.
I was using the center retaining nut on this particular 116 cc engine, so no prop bolts or drilling could have lead to this mis-hap. The prop ended up in many little long dagger like pieces.
After the prop let loose that engine sounded like a cox .049 leaned and screaming.
Luckily no one was at the field at that time and I was not in the direction of this flying shrapnel. This only reinforces the reason I never run an engine up in front or besides the propeller.
06-18-2010 | 01:46 AM
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From: Lakewood,
CO
RE: Props can and do explode
I'm glad no one was hurt, these things are inherently dangerous.
I was standing behind one once when a 3 1/2 inch plastic spinner and prop exploded, it was an APC prop and it hit the side of my house very hard, if it would have hit me it would have been a serious injury for sure.
Then another time I was walking from one side of a 60cc plane to the other side, I walked in front of the plane instead of behind it, just when I got to the other side before I got behind it again, the prop stirred up a small rock and the propeller hit it. The rock hit my right thigh so hard it went through my jeans and into the meat of my leg, I pulled it out with a hemostat. Ever been shot by a model airplane? Yep.
I was standing behind one once when a 3 1/2 inch plastic spinner and prop exploded, it was an APC prop and it hit the side of my house very hard, if it would have hit me it would have been a serious injury for sure.
Then another time I was walking from one side of a 60cc plane to the other side, I walked in front of the plane instead of behind it, just when I got to the other side before I got behind it again, the prop stirred up a small rock and the propeller hit it. The rock hit my right thigh so hard it went through my jeans and into the meat of my leg, I pulled it out with a hemostat. Ever been shot by a model airplane? Yep.
06-18-2010 | 09:30 AM
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RE: Props can and do explode
Well GUYS...it is up to you. Get your fellow RC people at your club to start right now & set some rules and enforce them. If one of your friends or Family member gets stuck in the head or eye with a broken prop & die or end up with a perminate injury...it will be with you & haunt you forever.
Take the time to tell the other members about safty...if they are any kind of person or friend...they will listen. .
Best Regards Capt,n
Take the time to tell the other members about safty...if they are any kind of person or friend...they will listen. .
Best Regards Capt,n
06-18-2010 | 10:55 AM
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RE: Props can and do explode
RTK and I talked about this on the phone last night. It was a wood prop in excellent condition. The BME 115/116 uses a center nut to retain the prop, along with the option of using outer prop scres for indexing purposes. The outer screws do not provide propeller clamping force so are a personal option, not a requirement.
There was no evidence of any propeller damage or defect prior to the engine run. I often fly with RTK and know he takes very good care of his equipment and is more than a little fussy with anything concerning the engine.
That his propeller self destructed is a big wake up call for me. I often stand off to the side during a run up but I think that is something I will do no more.
There was no evidence of any propeller damage or defect prior to the engine run. I often fly with RTK and know he takes very good care of his equipment and is more than a little fussy with anything concerning the engine.
That his propeller self destructed is a big wake up call for me. I often stand off to the side during a run up but I think that is something I will do no more.
06-18-2010 | 11:10 AM
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RE: Props can and do explode
ORIGINAL: captinjohn
Well GUYS...it is up to you. Get your fellow RC people at your club to start right now & set some rules and enforce them. If one of your friends or Family member gets stuck in the head or eye with a broken prop & die or end up with a perminate injury...it will be with you & haunt you forever.
Take the time to tell the other members about safty...if they are any kind of person or friend...they will listen. .[img][/img] Best Regards Capt,n
Well GUYS...it is up to you. Get your fellow RC people at your club to start right now & set some rules and enforce them. If one of your friends or Family member gets stuck in the head or eye with a broken prop & die or end up with a perminate injury...it will be with you & haunt you forever.
Take the time to tell the other members about safty...if they are any kind of person or friend...they will listen. .[img][/img] Best Regards Capt,n
I HAVE spoken up many times but if usually falls on "deaf ears"....
06-18-2010 | 11:59 AM
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From: Left Coast ,
CA
RE: Props can and do explode
ORIGINAL: MetallicaJunkie
did it throw the connecting rod? i once saw that happen to a man and his engine was ruined after that happened
did it throw the connecting rod? i once saw that happen to a man and his engine was ruined after that happened
06-18-2010 | 12:06 PM
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From: Left Coast ,
CA
RE: Props can and do explode
It definitely is a good wake up call. I always try to stand behind the plane before I run up the engine, but at one of my fields the flight line is basically besides the runway so from now on my plane will be pointed a better direction no matter how far I am away from people.
I only recovered about 2/3 of the pieces of the prop. The rest went into an alfalfa field. If any of those pointy sharp pieces would have hit someone they would have been going to the ER room for sure.
I only recovered about 2/3 of the pieces of the prop. The rest went into an alfalfa field. If any of those pointy sharp pieces would have hit someone they would have been going to the ER room for sure.
06-18-2010 | 12:09 PM
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From: Left Coast ,
CA
RE: Props can and do explode
ORIGINAL: loser
I HAVE spoken up many times but if usually falls on ''deaf ears''....
I HAVE spoken up many times but if usually falls on ''deaf ears''....
06-18-2010 | 12:27 PM
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From: Left Coast ,
CA
RE: Props can and do explode
ORIGINAL: thevirginian
Laminated XOAR-props are the answer. They rock and won't splinter. Call Jody at VV
Laminated XOAR-props are the answer. They rock and won't splinter. Call Jody at VV
06-18-2010 | 01:27 PM
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RE: Props can and do explode
No particular prop is the answer. I've been using the laminated PAU/Xoar props for quite some time and although excellent in rigidity and superior due to the number of laminations they can still fail. Over the past 6 months I've had a composite prop shatter while running in a test stand with a prop guard and several more carbon props from various makers delaminate to a dangerous level before discovery. An additional thought here to pass on is that all composite propellers will delaminate over time, so repetitive inspections of carbon props is something that must be performed.
Best not to trust any prop. Even the full scalers do a propeller check before every flight and end any thought of flight if defects are noted. Standing behind a propeller, and pointing the front of the plane away from co-flyers and spectators is the only sensible and relatively safe action regardless of the propeller used.
Thanks for sharing your experience with us Ralph.
Best not to trust any prop. Even the full scalers do a propeller check before every flight and end any thought of flight if defects are noted. Standing behind a propeller, and pointing the front of the plane away from co-flyers and spectators is the only sensible and relatively safe action regardless of the propeller used.
Thanks for sharing your experience with us Ralph.
06-18-2010 | 01:51 PM
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From: Houston, TX
RE: Props can and do explode
Frankly, if someone is dumb enough to stand in the prop arc, it is mother natures duty to clean the gene pool and wack them in the skull. Drafting new rules and laws toprotect the dumbest among us only causes devolution. As the highest order primate and with the keys to the cages, it is our sacred duty to point, laugh our butts off ,and do a back flip each and every time such an accident occurs !!
06-18-2010 | 02:46 PM
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RE: Props can and do explode
ORIGINAL: FrankHawks
Frankly, if someone is dumb enough to stand in the prop arc, it is mother natures duty to clean the gene pool and wack them in the skull. Drafting new rules and laws to protect the dumbest among us only causes devolution. As the highest order primate and with the keys to the cages, it is our sacred duty to point, laugh our butts off ,and do a back flip each and every time such an accident occurs !!
Frankly, if someone is dumb enough to stand in the prop arc, it is mother natures duty to clean the gene pool and wack them in the skull. Drafting new rules and laws to protect the dumbest among us only causes devolution. As the highest order primate and with the keys to the cages, it is our sacred duty to point, laugh our butts off ,and do a back flip each and every time such an accident occurs !!
If it was your plane and your engine that spat a prop and a person was seriously injured or died, regardless of the chestbeating here, it would haunt you forever.
Each modeler must take responsibility for their own equipment and any safety issues it may present.
06-18-2010 | 05:02 PM
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RE: Props can and do explode
Bad enough someone gets hurt. Ever have to clean a lot of blood out of your car after a mad dash to a hospital? I have. It's not fun and not the easiest thing on the stomach. Yes there are times we all wish for a clearing of the gene pool but the prop won't care who it hits. Owner or spectator someone gets hurt, perhaps badly, with the results possibly lasting forever. If it's a spectator the later legal action would likely end your flying days, and any future disposable income. The flying field goes away, as does the prop manufacturer.
People need to think beyond the immediate in everything they do. They also need to reflect on how their actions or inaction might impact others.
People need to think beyond the immediate in everything they do. They also need to reflect on how their actions or inaction might impact others.
06-18-2010 | 07:01 PM
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From: Summerfield,
NC
RE: Props can and do explode
ORIGINAL: apalsson
Sorry mate, wrong, wrong, wrong and not a tad funny either!!
If it was your plane and your engine that spat a prop and a person was seriously injured or died, regardless of the chestbeating here, it would haunt you forever.
Each modeler must take responsibility for their own equipment and any safety issues it may present.
ORIGINAL: FrankHawks
Frankly, if someone is dumb enough to stand in the prop arc, it is mother natures duty to clean the gene pool and wack them in the skull. Drafting new rules and laws to protect the dumbest among us only causes devolution. As the highest order primate and with the keys to the cages, it is our sacred duty to point, laugh our butts off ,and do a back flip each and every time such an accident occurs !!
Frankly, if someone is dumb enough to stand in the prop arc, it is mother natures duty to clean the gene pool and wack them in the skull. Drafting new rules and laws to protect the dumbest among us only causes devolution. As the highest order primate and with the keys to the cages, it is our sacred duty to point, laugh our butts off ,and do a back flip each and every time such an accident occurs !!
If it was your plane and your engine that spat a prop and a person was seriously injured or died, regardless of the chestbeating here, it would haunt you forever.
Each modeler must take responsibility for their own equipment and any safety issues it may present.
06-18-2010 | 07:11 PM
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From: California City,
CA
RE: Props can and do explode
The most expensive model airplane prop is cheaper than the least expensive ER visit.
I've only ever had one prop incident, had one come loose when my Saito .80 4s kicked back. Didn't come off, but that was enough for me. After I get the motor started Iget ot from in front ASAP and do all my work from behind. Hey, I'm already blind in one eye, don't need to play Russian Roulette with the other one!
I've only ever had one prop incident, had one come loose when my Saito .80 4s kicked back. Didn't come off, but that was enough for me. After I get the motor started Iget ot from in front ASAP and do all my work from behind. Hey, I'm already blind in one eye, don't need to play Russian Roulette with the other one!
06-18-2010 | 09:31 PM
#22
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RE: Props can and do explode
ORIGINAL: Tired Old Man
RTK and I talked about this on the phone last night. It was a wood prop in excellent condition. The BME 115/116 uses a center nut to retain the prop, along with the option of using outer prop scres for indexing purposes. The outer screws do not provide propeller clamping force so are a personal option, not a requirement.
There was no evidence of any propeller damage or defect prior to the engine run. I often fly with RTK and know he takes very good care of his equipment and is more than a little fussy with anything concerning the engine.
That his propeller self destructed is a big wake up call for me. I often stand off to the side during a run up but I think that is something I will do no more.
RTK and I talked about this on the phone last night. It was a wood prop in excellent condition. The BME 115/116 uses a center nut to retain the prop, along with the option of using outer prop scres for indexing purposes. The outer screws do not provide propeller clamping force so are a personal option, not a requirement.
There was no evidence of any propeller damage or defect prior to the engine run. I often fly with RTK and know he takes very good care of his equipment and is more than a little fussy with anything concerning the engine.
That his propeller self destructed is a big wake up call for me. I often stand off to the side during a run up but I think that is something I will do no more.
On high-torque YS engines, the use of a lock prop nut is a must.
Regardless, standing in front of or close to a spinning prop is a bad idea. Sometimes, fellow club members or speculators fall in the danger zone of a spinning prop, without knowing it. The pilot should never point the airplane to people without have it constrained.
06-18-2010 | 10:01 PM
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From: Left Coast ,
CA
RE: Props can and do explode
Since I was testing many props I did not use any other outer bolts. I doubt this was a contributing factor because on my 110 I never used any other bolts (only center nut and prop washer) for many years without any problems, the front prop hub washer is very thick and distributes the load very well.
06-18-2010 | 10:22 PM
#24
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RE: Props can and do explode
The outer bolts on a BME do not carry a load. If you try to torque them down to do so (there are 6 to choose from) you'll likely break the prop clamp waher. If you try to use the outer screws to retain the prop without the center nut the results are eventually disastrous.
The center nut works just fine on many engines, some much larger that a 115/116. The 289 Herbranson is one of them. The nut washer provides a clamping force similar to a vise.
The center nut works just fine on many engines, some much larger that a 115/116. The 289 Herbranson is one of them. The nut washer provides a clamping force similar to a vise.
06-18-2010 | 10:39 PM
#25
Senior Member
RE: Props can and do explode
ORIGINAL: Tired Old Man
No particular prop is the answer. I've been using the laminated PAU/Xoar props for quite some time and although excellent in rigidity and superior due to the number of laminations they can still fail. Over the past 6 months I've had a composite prop shatter while running in a test stand with a prop guard and several more carbon props from various makers delaminate to a dangerous level before discovery. An additional thought here to pass on is that all composite propellers will delaminate over time, so repetitive inspections of carbon props is something that must be performed.
Best not to trust any prop. Even the full scalers do a propeller check before every flight and end any thought of flight if defects are noted. Standing behind a propeller, and pointing the front of the plane away from co-flyers and spectators is the only sensible and relatively safe action regardless of the propeller used.
Thanks for sharing your experience with us Ralph.
No particular prop is the answer. I've been using the laminated PAU/Xoar props for quite some time and although excellent in rigidity and superior due to the number of laminations they can still fail. Over the past 6 months I've had a composite prop shatter while running in a test stand with a prop guard and several more carbon props from various makers delaminate to a dangerous level before discovery. An additional thought here to pass on is that all composite propellers will delaminate over time, so repetitive inspections of carbon props is something that must be performed.
Best not to trust any prop. Even the full scalers do a propeller check before every flight and end any thought of flight if defects are noted. Standing behind a propeller, and pointing the front of the plane away from co-flyers and spectators is the only sensible and relatively safe action regardless of the propeller used.
Thanks for sharing your experience with us Ralph.
Most recently, just this past Feb, I was testing my then new SAP180 in the garage, dialing in the pipe. I was using an experimental prop of my design so it may not count, however, the result definitely does.... one chucked blade from the hub and 2 of 3 broken mounting bolts. The engine stopped dead instantly and the violent stop sheared the bolts clean off. Luckily, none of the grandchildren like engine noise so they don't enter the inner sanctum
