Airplane Jacking Procedures

[PTK]

I was very curious about the appropriateness of weighing the tail down in order to jack the nose.

I just read M20-114. It is NOT recommended to use tail tie-down in order to lift nose wheel off the ground and it's precisely what many shops do! They attach this concrete weight on the tail tie down!

Mooney recommends an A frame with chain hoist from the engine lift point which makes the most sense and doesn't stress the airframe or engine mounts.

[mike_elliott]

I know mooney does not recommend using a tail tie down to support the weight of the engine and lift the nose wheel off the ground, but isn't that exactly what the tail does when it is flying? Help this old Civil Engineer make sense of this static problem....

[Bob_Belville]

This subject was discussed recently when I reported on the $50 I spent building this hanger accessory.   

http://mooneyspace.com/topic/9946-tail-tiedown-weight/

[fantom]

I just read M20-114. It is NOT recommended to use tail tie-down in order to lift nose wheel off the ground and it's precisely what many shops do! They attach this concrete weight on the tail tie down!

Mooney recommends an A frame with chain hoist from the engine lift point which makes the most sense and doesn't stress the airframe or engine mounts.

 

Actually has been discussed at nauseam, and it isn't an issue. Try using the search fuction when you're 'very curious' Peter.

 

It's not Mooney's fucctional recommendation but a liability CYA. Can't wait to see what happens when someone brings a lawsuit after an engine hoist accident.

[KSMooniac]

I know mooney does not recommend using a tail tie down to support the weight of the engine and lift the nose wheel off the ground, but isn't that exactly what the tail does when it is flying? Help this old Civil Engineer make sense of this static problem....

 

The difference is in the point load of the tail weight vs. the distributed load from the horizontal stabilizer reacting through the tailcone monocoque structure.

 

I use the engine lift point.  The IA I used this year used a tail weight but I didn't complain.  Another MSC I know uses a prop sling and I don't complain about that either.

[yvesg]

I am about the build a jackstand to raise the wing enough to replace a tire. Anyone having the height of the tie down ring above ground? This will save me driving to the airport (40 minutes drive) and measure it.

Yves

[thinwing]

Have a long body..?welded fitting take a 7/16 threaded mushroom cap screw...that's an engine mount jackpoint left side of cowling ,next to cowl flap...third jack point that you could stage a disco party on wing!

[yvesg]

Have a short body.

[Bob_Belville]

This jack (26"-43") works perfectly on our vintage Mooneys. The jack point must be about 27" from the floor.

http://www.ebay.com/itm/MODEL-326-3-Ton-Alpha-Aviation-Aircraft-Jack-for-Beech-Mooney-or-Piper-/220568614930?_trksid=p2385738.m2548.l4275

[Mooneymite]

55 minutes ago, yvesg said:

I am about the build a jackstand to raise the wing enough to replace a tire. Anyone having the height of the tie down ring above ground? This will save me driving to the airport (40 minutes drive) and measure it.

Yves

Lots of variables, but roughly 28" at the tie down point to get the main gear off the ground.

[Yetti]

On an F there is only about 160 lbs on the tail tie down ring when jacking. Pretty sure that is not enough to damage anything by using the tail tie down ring. So I added another 160lbs to keep it down.

 

[N201MKTurbo]

The first thing I did when I got my hangar  in '93 was to sink a giant lead anchor in the floor with a hoist bolt. It has a chain to the tail as we speak.

Edited April 20, 2017 by N201MKTurbo

[Yetti]

I could Hilti Gun a plate to the floor, but easier to spend $12 on sacrete

[yvesg]

Thanks folks. I will let you know how things went in about a week....

One last question: How many inches of jack play do you need to rise approximately for the wheel to rise up assuming pucks are in good shape?

 

Yves

[DonMuncy]

10 minutes ago, Yetti said:

I could Hilti Gun a plate to the floor, but easier to spend $12 on sacrete

But not as elegant  

[Yetti]

Seems to be about 4-6 inches per side to get the whole plane up with a tail tie down.  If you are just doing one side at a time, it might be a bit less.

[Yetti]

1 minute ago, DonMuncy said:

But not as elegant  

Ya but when I need to set a post I can just run over and grab a bag :-)

[RLCarter]

43 minutes ago, Yetti said:

Ya but when I need to set a post I can just run over and grab a bag :-)

I would have to check the FAR's, but I seem to remember that once something is used in or around your plane it can no longer be used for its intended use 

[Bob_Belville]

I might have spent $50, probably less.

[Hank]

My last two annuals, I've stacked cases of oil and tool rolls across the stabilizer. Holds it pretty well.

[Shadrach]

On 9/17/2013 at 1:45 PM, KSMooniac said:

 

The difference is in the point load of the tail weight vs. the distributed load from the horizontal stabilizer reacting through the tailcone monocoque structure.

 

I use the engine lift point.  The IA I used this year used a tail weight but I didn't complain.  Another MSC I know uses a prop sling and I don't complain about that either.

The same could be said of the hoist point. It's really only rated for the engine weight. Not designed to carry the airframe, fuel and an A&P in the cockpit for the gear check.

[KSMooniac]

True, but the shear capability of the bolt, the ring, and the engine case greatly exceed the load during jacking. And that load is carried through 4 bolts and the engine mount, and not a single point in the wimpy tail skin area.

I'm a structural analyst and don't sweat any of the common techniques...

Sent from my LG-LS997 using Tapatalk

[47U]

Yves,  You're making me really nervous talking about jacking up one wing far enough to get a tire off the ground.  The jack adapters do not attach solidly to the jack and the chances for upset are too great a risk.  There's a picture somewhere of a Mooney with the jacks sticking up through the wings.

If your brake calipers have not been rotated (per the LASAR STC) then there's plenty of room to jack the gear at the axle on the outboard side.  I use a car scissors jack, about $20 at Harbor Freight.  Using the scissors jack, the gear leg is raised up only an inch or so to get the tire off the ground and the aircraft is much more stable.  In my opinion... 

Tom

[RobertGary1]

1 hour ago, 47U said:

Yves,  You're making me really nervous talking about jacking up one wing far enough to get a tire off the ground.  The jack adapters do not attach solidly to the jack and the chances for upset are too great a risk.  There's a picture somewhere of a Mooney with the jacks sticking up through the wings.

If your brake calipers have not been rotated (per the LASAR STC) then there's plenty of room to jack the gear at the axle on the outboard side.  I use a car scissors jack, about $20 at Harbor Freight.  Using the scissors jack, the gear leg is raised up only an inch or so to get the tire off the ground and the aircraft is much more stable.  In my opinion... 

Tom

Mine sit firming down inside the bowl at the top of the jack. Once the jack mates with the wing there is no way that adapter is going anywhere.

 

-Robert

[DonMuncy]

13 hours ago, Bob_Belville said:

I might have spent $50, probably less.

And semi elegant.