Pilot Dies From Hand-Propping Propeller Accident

i saw pics of guys turning over b-17-b-29 4 eng planes by hand ,but i dought trying to start

 

Those guys were turning the prop blades to push out oil that had collected in the lower cylinders while the engine was sitting for a lengthy period of time. The clearances between the pistons and cylinder walls are great enough to allow oil to drain from the case down into the cylinder heads of the bottom cylinders. If this incompressible oil remained in the cylinders when the combustion took place it would blow the cylinders off or bend the master rod. Most usually it was the latter, however I have seen both. So, it is wise to push the 60 weight oil out before starting the engine. The remaining oil is the cause of the dense blue smoke when the engine starts, then as the aluminum pistons get hot and expand to close the clearances between them and the cylinder barrel, the smoke stops. It is now standard procedure to crank the props around several blades instead of pushing them because the starters will not apply as much pressure on the cylinders. Sounds like I just made all that up.

 

I should have said pressure on the connecting rods, not cylinders.

 

...and if one looks closely...whenever the props are pushed through it always is backwards...another safety measure at work

 

You can tell it's been more than 20 years since I propped an airplane... I had completely forgotten that rule, but I strictly adheared to it back then... Some things stick in your mind and others don't...

 

Is there some sort of external starter that could be used?

Maybe a large version of a r/c plane electric starter. It could be on wheels and pushed up to the plane and spin the prop.

 

Probably has been designed, but seems like a lot of extra cost when it can be done by hand for no cost (just the risk for those not as experienced ). Or if you have an SR-71 Blackbird, you can lend your 454 engines to start a friend's.

 

I always like your wry little comments at the end of some of your posts... you crack me up!



Jedi

 

They had this device in the 20's and 30's that was mounted on a Model T or equivalent. Set at an angle to match the crankshaft of the engine and prop shaft, the truck drove up to the airplane until the starter cog on the end of the shaft engaged the mating cog on the prop shaft and cranked it over. It was called the Hucks Starter. You Tube has video footage of this being used on the 1934 Hawker Hind and Hawker Demond or Nimrod. Worked great.

 

Of course there had to be one everywhere you landed, or you were back to hand propping it.

 

Those Hawkers were also equipped with " stem winders", cranks inserted into the right side of the bonnet that permitted the mechanic to wind up the inertia starter or, in a few cases, crank the engine until the impulse mag kicked in.

 

Hucks Starter, with a pic:

https://en.wikipedia.org/wiki/Hucks_starter

 

Sad to hear about this in the original post. Did you guys see this other thread, apparently on the same topic? http://www.ferrarichat.com/forum/showthread.php?t=354944

 

That is really interesting, I'm going to look for those videos.

 

thanks,