Hit by prop

[skydvrboy]

When parking outside, especially in the winter, I'll rotate my prop vertical.  If not, water will pool in the spinner.  In the summer, it just throws water all over the place, but in the winter, turns to ice and makes for one really out of balance prop.  I used to rotate it counter clockwise (facing the prop) because I didn't want to damage anything turning it backwards.  An old A&P saw me and asked what I was doing (using more colorful language).  Informed me that I wouldn't hurt anything turning it backwards, so now that is my SOP when parking outside with rain in the forecast.

[RobertGary1]

The reason for not turning it backwards is for the vacuum pump. It should be ok but after years of wearing a certain way some worry that moving the veins backward could accelerate problems. I don’t have any research to confirm that though. 

-Robert 

[Oldguy]

The other thing I have observed from some of the Taylorcraft and Cessna guys who do not have an electrical system is they stand behind the prop to hand prop it. As one pilot responded when I asked him why they did it that way, he said getting hit in the head by a wing was preferable to being hit by a prop if something went wrong while propping it. Makes sense to me.

[RobertGary1]

In the sea planes we had to prop from behind but I always propped from in front for land planes. 

-Robert 

[jaylw314]

56 minutes ago, Oldguy said:

The other thing I have observed from some of the Taylorcraft and Cessna guys who do not have an electrical system is they stand behind the prop to hand prop it. As one pilot responded when I asked him why they did it that way, he said getting hit in the head by a wing was preferable to being hit by a prop if something went wrong while propping it. Makes sense to me.

This was discussed in another thread, but propping from behind requires having your fingers pulling on the trailing edge of the prop blade, since you can't push on the face from that side.  I'd hate to think of the effect a kickback could have.

Somewhere, I recall Mike Busch commenting that the oil pump requires a minimum speed to move oil, and turning the prop by hand is simply not fast enough, so there is zero chance of getting additional oil anywhere.

[Niko182]

1 hour ago, Oldguy said:

The other thing I have observed from some of the Taylorcraft and Cessna guys who do not have an electrical system is they stand behind the prop to hand prop it. As one pilot responded when I asked him why they did it that way, he said getting hit in the head by a wing was preferable to being hit by a prop if something went wrong while propping it. Makes sense to me.

In the J-3 i learned to fly in, I also hand started it from behind the prop.

[bradp]

13 hours ago, jetdriven said:

Ever since I was a student we always did a magneto grounding check before pulling the mixture on every flight. Do this every flight and it greatly mitigates the likelihood of a broken P lead. But does not eliminate it  entirely

Found a broken P lead this exact way - mag check prior to shutdown. We put a big sign on the prop for the FBO to the effect of loaded gun don't touch.  How many times have you found your plane towed by some unsuspecting line boy and the prop horizontal instead of near vertical (for two bladers).  They may or may not have a clue.

Perhaps for a cam shaft that sits low in the oil pan you could dip it by rotating through but absolutely no chance of getting oil anywhere important for prevention of wear in a cam-north lycoming.

[Browncbr1]

Why would the engine oil care if it is turned over by hand vs the starter?    If the point is to move oil on the cam lobe, can this not be achieved by turning it over with the key?  Isn’t that what         ?compression viscosity? is for as mike Busch explains?  Maybe he called it compression librication?   This was one of the reason I chose to run Exxon elite..  

Edited October 2, 2018 by Browncbr1

[Guest]

9 hours ago, bob865 said:

Is your mooney different?  I thought all Mooney's had a SOS system?

Without an impulse coupling and SOS not operational even with broken p-leads etc., the possibility of getting a spark while hand propping is basically nil.

I beg to differ, broken P leads means live magnetos, a healthy mag can make sparks at even slow speeds.  The risk isn’t worth it in my opinion.

Clarence

[201er]

My flight to and experience at the Mooney Summit.

 

 

[Guest]

7 hours ago, Marauder said:

 

Surely you are not referring to my nose, belly and nipple rings as well!


Sent from my iPad using Tapatalk Pro

 

Only if you have the interconnecting gold chain, without the chain you’re safe.

Clarence

 

[LANCECASPER]

55 minutes ago, M20Doc said:

Only if you have the interconnecting gold chain, without the chain you’re safe.

Clarence

 

Of course he has the chain.

[EricJ]

9 hours ago, Mooneymite said:

I've owned and hand-propped several different 65 HP tail-draggers.  I really enjoyed hand propping them until one of them kicked back and caught my wedding ring.  Ouch!

Were you propping it from the front or back?

[jaylw314]

35 minutes ago, LANCECASPER said:

Of course he has the chain.

Ewwww, I won't be able to get the image of @Marauder out of my head now

[Mooneymite]

1 hour ago, EricJ said:

Were you propping it from the front or back?

Front.

Most small engines can be propped either way.  Front seems to be preferred.  I saw my neighbor's T-6 hand propped.  That has to be done from the front.  

The Mooneymite was almost always propped from the back while perched against the leading edge of the right wing.

[Gone]

19 hours ago, jetdriven said:

Ever since I was a student we always did a magneto grounding check before pulling the mixture on every flight. Do this every flight and it greatly mitigates the likelihood of a broken P lead. But does not eliminate it  entirely

+ 1 for this check.  We call it the dead mag check.  End every flight with it. 

[Htwjr]

Does this count as a prop strike?  I thought the reason for turning the prop was to check the relative compression between the cylinders. Hard to turn means good compression,. easier means problem with one cylinder. 

[Shiny moose]

IMHO In aviations horizontally opposed engines there is absolutely no reason to rotate or pull a prop through before flight to check engine. What are you checking? How many flights have you cancelled cause you found a problem while hand rotating the prop? What your going to check is mag and p lead operation, and when you find the p-lead broken (common)and a strong mag (common) you might not be able to tell anyone due to injuries or worse 

can you imagine your brother in law who lives in your spare bedroom and owns a 1967 VW beetle, and EVERY morning when he leaves  for the so called job that he may or may not have , he gets his sister (your wife) to help him. He puts the VW in gear and has your wife push the bug down the driveway, and when you ask why he does such a foolish thing , he would explain how he is ensuring that the engine has compression, lubes the cam, doesn’t want to overwork the starter, and will rotate through all 4 cylinders before he starts and drives off. Your wife agrees with HIM

 

 

[Stephen]

14 hours ago, Mooneymite said:

.  I saw my neighbor's T-6 hand propped.  That has to be done from the front.  

Ive hand propped a beech D18 and cherokee. I think I would rather do th 18 again versus a smaller plane. Seems like there is more time to get out of the way in your built-in escape manuver. Probably similar to doing a T6

[RobertGary1]

55 minutes ago, Stephen said:

Ive hand propped a beech D18 and cherokee. I think I would rather do th 18 again versus a smaller plane. Seems like there is more time to get out of the way in your built-in escape manuver. Probably similar to doing a T6

Hand proping anything over 100 HP worries me. The extra compression really changing it. Its also super hard to get enough grip without wrapping your fingers around the prop (a dangerous rookie mistake). 

-Robert

[RobertGary1]

6 hours ago, Htwjr said:

Does this count as a prop strike?  I thought the reason for turning the prop was to check the relative compression between the cylinders. Hard to turn means good compression,. easier means problem with one cylinder. 

Safer to get an EDM if you're worried about a cylinder missing compression 

-Robert

[jaylw314]

6 hours ago, Htwjr said:

Does this count as a prop strike?  I thought the reason for turning the prop was to check the relative compression between the cylinders. Hard to turn means good compression,. easier means problem with one cylinder. 

The difference between good and bad compression caused by cylinder wear will probably be imperceptible while turning the a prop by hand, nor would it tell you all that much (compressions are supposed to be checked while the engine is warm, not cold).

On the other hand, NO compression due to a stuck valve might be noticeable while turning the prop by hand.  You'd also notice it pretty damned quick once you start the engine and before taxiing, so finding out before starting the engine doesn't really seem to give you any safety advantage--you'd still find out while safely on the ground.  THEN you might go back and turn the prop by hand as part of your troubleshooting (hopefully after disconnecting the spark plug leads), but there's a difference between doing that for a specific reason and doing it routinely before every flight.

[Andy95W]

17 minutes ago, jaylw314 said:

 

 You'd also notice it pretty damned quick once you start the engine and before taxiing, so finding out before starting the engine doesn't really seem to give you any safety advantage--you'd still find out while safely on the ground.  

I'll second what Jay said, and throw in that checking the impulse couplings (for aircraft so equipped) would also be quickly noticed because the engine wouldn't start.  

So in addition to safety reasons and Lycoming service bulletins that say not to pull the prop through by hand, we can add that there really aren't any good reasons to do it for our horizontally opposed engines.

This seems like an OWT that some instructors continue to perpetuate simply because that's how they were taught by an instructor that learned on radial engines.  Maybe it's time to put this one to bed along with over square, LOP, etc.

[bradp]

Pulling the prop through can be used for a diagnosis after a failed start but you don’t need a diagnosis if there is no symptom.  Confuscious says.  

[201er]

Here's a 360 video of the first of two formation demos during the Mooney Summit.