Trip to Dugosh

[chrisk]

I took a trip to Dugosh on Friday.  It's always fun to see and learn new things.   Check out the plane in need of SB208 and the old truss. 

 

My plane is the one on jacks.  It's new to me and it was darting a bit.  An adjustment of the nose gear and all is good.

[bumper]

Doesn't look like they are complying with Mooney Service Instruction 20-114 see http://www.mooney.com/servicepdf/2.html which says, "-WARNING- DO NOT use propeller jacks to lift aircraft." (Emphasis thiers). Unless there's something I am missunderstanding. I used to use a cherry picker and nylon slings to lift and support the nose. Even though I'm not aware of any damage done by supporting the prop as shown in your picture, being a chicken, I now use the engine lift eye or straps on the engine mount per the SI.

 

Any thoughts on this?? Slings on the prop or a prop stand is more convenient . . .

 

bumper

[chrisk]

Interesting on the "-WARNING- DO NOT use propeller jacks to lift aircraft.".  I wonder what event generated the SB.

[carusoam]

There is plenty of discussion on how to damage the bearings by pulling or pushing on the prop. Lifting by it wouldn't make any more sense.

Bearings are designed to handle certain types of stress. It's unlikely that lifting the front of the plane would take precedence over pulling the front of the plane in design criteria...

My POH makes statements about what forces are acceptable. Lifting isn't one of them that I know of... Maintenance manual would be a place to look that up...

Overall, they can be damaged, so avoid any undue forces on them. It would be expensive to have to replace them.

Ymmv...

Best regards,

-a-

[chrisk]

With a procedure where the plane is jacked from the wings, and the prop is later lifted, it doesn't really take much force.  It can be lifted by hand and that's from someone who doesn't work out.  I am skeptical that this could possibly cause damage.

 

Now, if someone decided to jack the front of the plane up 3 feet or so, I can see where there would be more stress on the prop. 

[OR75]

With a procedure where the plane is jacked from the wings, and the prop is later lifted, it doesn't really take much force.  It can be lifted by hand and that's from someone who doesn't work out.  I am skeptical that this could possibly cause damage.

 

Now, if someone decided to jack the front of the plane up 3 feet or so, I can see where there would be more stress on the prop.

the jack points are indeed very near the CG line