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One aviation accident that is completely avoidable.


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9 hours ago, triple8s said:

Although I totally agree in principal, the article doesn't tell us how he got hit. Was he hand propping? Did he get out after starting to pull a chock? Did he ....? 

I  am sure still very preventable regardless and sad never the less. 

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10 hours ago, triple8s said:

Part of my first breifing to passengers when driving ith them to the plane clearly states, "if the prop is spinning, do not get out of the aircraft ever". Its usually pretty easy to avoid things like this. I also loved about a month ago, when i was walking to my mechanic, and some guy in a cirrus blasts his plane up with out shouting clear prop or anything. There were 6 people standing around that cirrus when it started. I dont think its to much to ask to state when you start up your aircraft.

Edited by Niko182
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I heard from a friend who was there that he shut down and was out at the front and moved the prop after engine was shut down. The key was not turned off, supposedly he barely moved the prop and it popped once. I have moved the prop after shut down to give clearance with the tug and been fussed at by a few folks for touching the prop. I generally place the key in eye shot of the front of the plane so I know it is indeed out and off, however my mechanic always fusses anytime someone touches the prop on aircraft around his shop he says a broken p-lead is all it could take. 

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1 hour ago, triple8s said:

I heard from a friend who was there that he shut down and was out at the front and moved the prop after engine was shut down. The key was not turned off, supposedly he barely moved the prop and it popped once. I have moved the prop after shut down to give clearance with the tug and been fussed at by a few folks for touching the prop. I generally place the key in eye shot of the front of the plane so I know it is indeed out and off, however my mechanic always fusses anytime someone touches the prop on aircraft around his shop he says a broken p-lead is all it could take. 

Exactly right, but there is a genuine need to move the prop by both mechanics and pilots - you just gave an excellent and very common example of needing to move the prop to hook up the the tug or tow bar. So how do we safely move the prop without getting hurt from it in case the p-leads are not grounded? Mechanics are taught to turn the prop backwards when moving it - this will prevent the impulse coupling from releasing.  

Edited by kortopates
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Like two factor authentication...

Two factor kill the engine and make sure it stays that way...

1) when turning off the engine... drain the fuel from the line with the mixture knob pulled all the way out...

2) To top that off... key out of the ignition... in plain sight..

I have learned with age... pulling the mixture, some times leaves the key in the ‘both’ position...  (add that to the final checklist)

The same age also left the tow bar in position...  201er reminded me of how bad of an idea that is... literally he said ‘you don’t want to leave that there’   :)   Gotta love Mooney fly-ins...

How does ‘two factor kill the engine’ get away?

Things like a failed hot start attempt can leave a lot of fuel in the lines... with all of that cognitive taxing challenge, it is easy to forget how the key has been left...

The broken P-lead is a sure probability, although not very likely... Still, it could happen...

I currently use the two factor method... drain the fuel using the mixture knob, take the key out...

Let me know if this idea is missing something...

PP thoughts only, not a CFI or mechanic...

Best regards,

-a-

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My shutdown checklist includes putting the keys on the glareshield.  It sucks on hot sunny days, though, they get hot real fast :wacko: 

I get paranoid about the best way to move the prop.  Turning it backwards means you're grabbing onto the leading edge, so if it somewhat kicks forwards, it could drag you into the prop.  Turning it forwards means a spark is more likely with a hot mag, but then you're pulling on the face of the blade, so if it kicks forwards it won't pull you in.

I wonder if the safest way would be turning it backwards while standing behind the prop (on the left side).  Then you could pull it by the rear face of the blade, and you wouldn't get pulled in if it turns.  It's kind of an awkward place to stand, though

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31 minutes ago, toto said:

I always turn the ignition to "off" momentarily before switching back to "both" and pulling the mixture. This was taught by my primary instructor, and while it hasn't prevented a catastrophe (yet), I do it by rote.

What does that do?

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Just now, aviatoreb said:

What does that do?

It checks the P lead. If you turn off the ignition, the engine should die (you will flip it back on before the prop quits turning). If the engine doesn't die, the P lead is broken. 

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2 minutes ago, DonMuncy said:

It checks the P lead. If you turn off the ignition, the engine should die (you will flip it back on before the prop quits turning). If the engine doesn't die, the P lead is broken. 

Makes sense.  

But will it backfire when you flip it back on?

how ironic it is so hard to hot start a fuel injected engine but it may well hit start by just touching the prop - not that I doubt it.

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Just now, aviatoreb said:

 

But will it backfire when you flip it back on?

 

Not if you do it quickly. Don't try this with the engine running very fast; but at idle, I have never had it happen, and I do it at every shut- down.

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3 hours ago, carusoam said:

currently use the two factor method... drain the fuel using the mixture knob, take the key out...

This, combined with a mag grounding check before shutdown is about all we can do.  In terms of securing the airplane.

But it only takes one combustion event to kill. Just a half turn of the prop. Even with mixture at IC there could be some residual fuel vapors that could ignite if a mag was hot. Moving the prop backwards prevents the impulse coupling from snapping and is probably the safest way to move the prop. 

There have been people killed doing compression checks too, 80psi can put fatal kinetic energy into the prop. Years ago my dad lost a friend this way.

Be carful out there!

Dan

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So...

1) We have two factor methods of avoiding most simple accidental start issues... mixture and keys.

2) a procedure for checking the P-leads are still grounding before shut down... ignition position sweep

3) a method to move the prop without inducing the impulse coupling... reverse rotation

4) Notes on moving props backwards always gets questions related to vac pump vane brakeage... OWT it is most often claimed... if the vanes get damaged, they were so worn out already... time to go all electric! We just got a great reason to support our spending needs...

5) does anyone not wrap their hands around the prop to move it, just pressure on the blade’s face? Is this even possible or worthy?

PP summary only, no original ideas from me...

Best regards,

-a-

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It checks the P lead. If you turn off the ignition, the engine should die (you will flip it back on before the prop quits turning). If the engine doesn't die, the P lead is broken. 

Doesn’t the runup sequence accomplish the same thing, instead of turning off both, you turn 1 off at a time. If P lead was broken and mag was not turning off, you would not get RPM drop, etc

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Has anyone hand propped a Mooney? We've tried it once on my 3-blade, and it never got even close. When starting my plane normally with the high-speed SkyTec, she turns over about 4-5 blades before it lights off. When my starter died away from home, my CFI tried for about 15 minutes to get it. Even with me holding the SoS, it would go one compression and stop. Never got even close to popping off. It seems to me that the SoS is superior in starting and superior in ground safety (given my experience).

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2 hours ago, teejayevans said:

Doesn’t the runup sequence accomplish the same thing, instead of turning off both, you turn 1 off at a time. If P lead was broken and mag was not turning off, you would not get RPM drop, etc

It does ck the P leads, turning the switch to off monetarily after a flight verifies the P leads are still intact after the flight and is somewhat safe when the engine is off

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2 hours ago, Raptor05121 said:

Has anyone hand propped a Mooney? We've tried it once on my 3-blade, and it never got even close. When starting my plane normally with the high-speed SkyTec, she turns over about 4-5 blades before it lights off. When my starter died away from home, my CFI tried for about 15 minutes to get it. Even with me holding the SoS, it would go one compression and stop. Never got even close to popping off. It seems to me that the SoS is superior in starting and superior in ground safety (given my experience).

I did it once and was able to get it running.   The trick is to turn it over some to get it primed.   My very experienced A&p did it, and he is anal about anyone touching the prop.  He disconnects all plugs when doing any kind of work on a plane. 

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What does that do?

It’s testing that the P-lead is not grounded before shutdown. Everyone SHOULD have been taught this by their instructor - preferably primary!

 

Doing the run up test it too but after any flight you need to re-test that the p-leads are STILL not grounded before getting out and grabbing the prop!

Sent from my iPhone using Tapatalk

 

 

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Has anyone hand propped a Mooney? We've tried it once on my 3-blade, and it never got even close. When starting my plane normally with the high-speed SkyTec, she turns over about 4-5 blades before it lights off. When my starter died away from home, my CFI tried for about 15 minutes to get it. Even with me holding the SoS, it would go one compression and stop. Never got even close to popping off. It seems to me that the SoS is superior in starting and superior in ground safety (given my experience).

I’ve done it multiple times including BIG radial engines. It’s not that hard once you have had training. But no one has any business trying without prior training on how to do it safely- the stats speak for themselves.


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