Propeller safety

[Guest ozzie]

Just browsing through Face book and a skydiver I know has just done his first solo in a C172 at Cowra this morning. Posted a photo of himself with his instructor both standing within the arc of the propeller and him hanging onto a blade. EEEEK my real pet hate.

 

I have been seeing quite a few photos of this practice being uploaded lately. Caught up in the excitement of achievement it is easy to forget the obvious dangers.

 

I have seen the results of propeller handling gone wrong. One death and several injuries including a severely fractured skull. One other recent example was when a pilot posted a photo of his kids after their first flight. Bright happy little face hanging off the Warriors prop. Point out that hey really don't do this and received the expected response ' switches were off no chance of starting blah blah blah.' Obvious offense was taken. "I'm a pilot don't tell me about 'planes". Well the engine does not have to start to knock you into next Wednesday. Just a flick off compression will do it and really can you guarantee that a mag is not live. Plenty of people out there have had near misses so maybe a time now to bring this subject up and for instructors to think about prop safety and start to reinforce it every time a student does a preflight.

 

 

[turboplanner]

Interesting about the one with the kids Ozzie; the pilot would not accept that he'd put them at risk, and nor did quite a few others, then the post was taken down, so no one learnt a lesson.

 

 

[Happyflyer]

I think it's not only hanging on the prop that's the problem, its being comfortable to be anywhere near the prop arc that's the problem. Drilled into us in the RAAF to avoid the prop arc if at all possible so that one day when it's spinning you don't wander through and do a Jack Newton.

 

 

[Guest ozzie]

I have a T shirt that says,

 

"What doesn't kill you makes you stronger. Except aircraft propellers, they'll just straight up kill you."

 

 

[facthunter]

Treat all props as LIVE or you might end up dead, decapitated and cremated. Nev

 

 

[2tonne]

I was taught to stay away from the prop arc. So when I switched from the J160 to the Tecnam Eaglet, turning the prop to burp the Rotax gave me the heebie-Jeebies. I make sure the technique I use keeps my head and torso away from the prop, but it still makes me nervous.

 

 

[pmccarthy]

A post like this is really helpful. After 5 years with a Rotax I am now back in the Lycoming ranks. And I had become a bit casual about the prop - this has given me reason to review the way I do things.

 

 

[facthunter]

Turn it slow (Rotax Burping) and keep a good grip of it. The compression leaks away and if it fires, (which is fairly unlikely) you can hold it as there is little energy in what's left. Keep out of the arc. Nev

 

 

[PA.]

Treat all props as LIVE or you might end up dead, decapitated and cremated. Nev

All on the same day.

https://www.youtube.com/watch?v=WBGU9AqTimM

 

 

[Guest ozzie]

A post like this is really helpful. After 5 years with a Rotax I am now back in the Lycoming ranks. And I had become a bit casual about the prop - this has given me reason to review the way I do things.

Just one makes it worthwhile

 

 

[nickduncs84]

Just browsing through Face book and a skydiver I know has just done his first solo in a C172 at Cowra this morning. Posted a photo of himself with his instructor both standing within the arc of the propeller and him hanging onto a blade. EEEEK my real pet hate.I have been seeing quite a few photos of this practice being uploaded lately. Caught up in the excitement of achievement it is easy to forget the obvious dangers.

I have seen the results of propeller handling gone wrong. One death and several injuries including a severely fractured skull. One other recent example was when a pilot posted a photo of his kids after their first flight. Bright happy little face hanging off the Warriors prop. Point out that hey really don't do this and received the expected response ' switches were off no chance of starting blah blah blah.' Obvious offense was taken. "I'm a pilot don't tell me about 'planes". Well the engine does not have to start to knock you into next Wednesday. Just a flick off compression will do it and really can you guarantee that a mag is not live. Plenty of people out there have had near misses so maybe a time now to bring this subject up and for instructors to think about prop safety and start to reinforce it every time a student does a preflight.

The point that many of us took issue with wasn't the issue of propeller safety it was the issue of how a well intentioned photo turned into another aviation pi$$ing match. Also the practice of passing judgment based on photo when you can't possibly know all the facts of the scenario. This post is a further example of why some people got annoyed. You say the kids were hanging off the prop? That's not even close to accurate and now people that haven't seen the photo assume it to be true.

 

The point is, if you see something and feel it's a safety issue, then approach things the right way. The way you would approach them if you saw it in person. Pull them aside, ask for clarification and make sure they understand the risk. That doesn't tend to happen on the Internet for some reason.

 

No with that off my chest, thank you for the post. A post on a forum like this about an important safety issue like this is a good thing. On this specific topic, I'm not sure what others have experienced in training, but there sure seems to be some variation. With lycoming engines I was taught about the risk of the engine firing and to assume it will fire if the mag clicks, but it certainly wasn't drilled into me to never touch the prop or stand within its arc.

 

It would also be useful to talk about the variations in engines and engine systems and how it impacts the likelihood of the engine firing.

 

So for example, carb vs fuel injection, hot vs cold, mags off vs on. I guess the key is, many of us would assume that if the mags were off or if there was no fuel in the engine then it wouldn't be possible for it to fire, but maybe there are surprising situations that we should be aware of?

 

Anyway, like I said, a good topic and a valid point. The only thing that annoys many of us is how quickly the conversation can take the tone of an arrogant yelling match rather than a hangar conversation amongst friends.

 

 

[Happyflyer]

The mag switch when off, connects the magneto to earth or ground making the magneto inoperative. If the wire from the mag to the switch and to ground breaks, the mag is live whether or not the mag switch is turned off, so don't trust the switch position too much. It's the reason you do mag checks before shutting down. If you turn off the engine by turning off the mag switch you will know if the earth wire is broken when the engine doesn't turn off!

 

 

[SDQDI]

I was always taught to treat the prop with respect, I guess learning on a plane that required hand propping has its benifits!

 

Talk of mag switches and differences between carb/efi and hot or cold engines IMO is irrelevant. I think it is a bit like gun safety, no matter how sure you are that it is unloaded you don't step in front of one or point it at anything you don't want to shoot and then you develope good safe habits and then on the off chance that something is missed no one gets hurt. Same for props, stay out of the arc no matter how safe it is and that will eventually become a habit that could save you one day.

 

 

[Guest ozzie]

Actually it was the poster of the photo that turned it into a pissing match. If they had acknowledged the fact that it was a poor judgement call to put the kids in that position the topic would have stopped there but they offered a bunch of lame retorts that invited responses from several people. End result they came away looking bad and pulled the photo to save face.

 

 

[Icarus]

 

For those that have not seen this video yet.

 

Before the comments about Darwin almost gets another etc.

 

Think about how easily this can happen .

 

you cant see the prop from the side. your mind is pre -occupied with everything else going on.

 

your exited about the impending flight, whats that noise? in the background now??

 

oh yeah the engine sound a bit off , hows the fuel!!!, oops forgot about the prop.

 

Should there be some sort of cage around the prop?

 

 

[Guest Howard Hughes]

Lighten up man, it's possible to have respect for propellers and still have a photo taken with your hand on one. Also people put their hands through propellor arcs everyday to put bungs in etc...

 

 

[Pearo]

As a relative noob to flying, I needed no intro to prop danger. As a boatie, I just stay away from them. As a pilot, the prop is bigger and more deadly, so even more reason not to trust it.

 

I always do a mag check before shut down, and I wont go near the prop arc unless I confirm that the master is off and the mags are off. And I dont trust what anyone else says. I am a sparky by trade and I have been bitten before by trusting others.

 

Further more, I was also taught how to handle a prop when I have to touch it. I hate spinning the things even when I know everything is dead.

 

 

[kgwilson]

Being distracted when a prop is spinning probably has caused more accidents/deaths than the engine firing while turning the engine over. I was close by when a co-pilot of a twin walked straight into a spinning prop & was killed instantly. I didn't see it thankfully but it scared the sh!t out of me for a long time.

 

I know that the Jab engine has to be turning at 300rpm before a spark is produced. This is good but not good if you have a poor battery as you can't hand prop the engine to start it. Maybe this is why Lycoming etc have not introduce the same system.

 

 

[Old Koreelah]

True, but a Jabiru engine fitted with a cold start kit starts at quite low revs; the starter solenoid must be activated for it to spark.

 

 

[dutchroll]

The guy who taught me to fly my Pitts was seriously injured a few years back when he pulled the prop through (for the hydraulic lock check) on one, and had accidentally left the mags on.

 

One lousy attention lapse in an otherwise quintessentially professional guy - the most experienced Pitts Model 12 pilot and A&P on the planet. I'm always healthily nervous and obsessive ("Did I check the switches? Yeah I'm pretty certain I did but I'll check them again anyway") when pulling it through.

 

 

[facthunter]

Switches that earth an armature out aren't reliable enough for me, even if checked on shutdown. It used to be commonplace to run the fuel out of the carb when taxiing in, but even that gives no guarantee someone hasn't even for a short while turned the fuel on. Nev

 

 

[pmccarthy]

Even if you have shut down with lean mixture and left the mixture control at lean, the engine will fire up for a second or two if you hit the starter. Enough to kill someone.

 

 

[Guest ozzie]

Mixture at idle cutoff and switches off help to prevent inadvertent starts but most injuries come from unexpected blade movement. More common with engines with a high number of cylinders like radials but it can happen with any engine. The more cylinders the higher the chance of one cylinder stopping on top of compression. The danger is when it unexpectedly flicks off compression and it does not need any help to do it. Have seen a Beaver that had been parked for a couple of hours have the prop move a little then it moved a bit more and several seconds later flicked off compression with a fair bit of force. It only moved a short distance but it did so with enough force that would have rattled a few teeth if it hit someones head. If conditions were right with a bit of fuel in the induction system a mag live, it may fire on one, again no need to start. If it does not hit you it will give you a huge scare.

 

When working around running engines i used to have nightmares of messing up and getting hit. Grabbed more than one skydiver that almost got away from me during a hot load. And a competition director that walked thru a Twin Otter prop as it was spooling up and lit off. If you walk into the back of a running prop it will chop you but spit you back out, walk into the front of a prop it will drag you in and dice you, it's how they work. That was why Jack Newton survived he walked into the rear of the prop it chopped him a few times then spat him out.

 

If you are around a hanger and someone is doing a leakage test ask to hold the prop when they put 100psi into the cylinder. You will be surprised at how hard it is to hold it on top. Be careful more than one person has been whacked doing the job.

 

Couple tips. Need to touch the prop? Take the keys out and put them on top of the dash so they can be seen from outside or put them in your pocket. Move the prop from one compression to another first at arms reach standing out side the arc before moving close to put bungs in etc. And never put people in harms way. Let them hang off the strut or sit on the wing for a photo.

 

An old saying

 

There are Hartzell props and McCauley Props. Is there a prop with your name on it?

 

and i have a T shirt with,

 

"Things that don't kill you make you stronger, except aircraft propellers, they will just straight up kill you"

 

 

[Roundsounds]

http://www.faa.gov/documentLibrary/media/Advisory_Circular/91-42d.pdf

[frank marriott]

Had the metal band of my watch short across the solenoid - only turned one blade but could have had a different result.