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Using prop to jack up airplane?


DustinNwind

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You can, you just don’t want to...

There are devices made and people use them... so it looks like an official way to lift the nose of a plane...

The crank shaft of the engine was designed to provide power....

Expecting it to work as a 20amu jack point... is a bit beyond expectation...

You will also read a few plane owners use the hoist loop on the top of the engine to lift the front of the plane...

It’s design function was to lift the engine into position on the engine mount...

It is too easy to damage expensive things by not following the procedures for lifting the plane...

And the procedures have been updated over time... get the modern version...

Most Mooney use a pair of jack points under the wing... and a tail tie down 

Long bodies use a pair of jack points and a third jack point on the engine mount...

PP thoughts only, not a mechanic...

Best regards,

-a-

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Seems odd that you could do this and it wouldn't have any negative effects on crankshaft given that if your plane falls off the front jacks and the propeller touches the ground it calls for a tear down inspection.  Yes, in one case you have a sudden impact but in both the prop and engine components are supporting hundreds of pounds of pressure that wasn't intended in their design...

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Mooney doesn't want you to hold down the tail or lift from the prop  (SIM 20-114). Someone posted that Lycoming doesn't want you to lift more than the engine weight from the engine lift point. So may the Force be with you.

Many shops attach a weighted tail stand to the tail tiedown with some shot bags on the horizontal stabilizer. Last time we swung the gear, we lifted at the engine. I know Don Maxwell puts a fan belt around each blade shank. Over all the years of using various techniques, has anyone heard of a problem attributed to the lifting technique?

Skip

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At least one of the big shops uses a lift strap attached to an engine hoist/cherry picker wrapped around the engine mount top bar.  No strain whatsoever on the prop/crankshaft and no chance of it slipping off.

Doesn't help the guy trying to replace his flat tire on the ramp, though.

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I’ve had two MSC’s raise my plane. DUGOSH will lift the plane up by a prop stand and Advance weighs the tail down. Between the two I would rather have the tail weighted down but ideally I would rather the nose be raised by lifting on the engine mount with an engine hoist.


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9 hours ago, TTaylor said:

... use a jack that fits the 1" tube in the front gear.

 

47 minutes ago, EricJ said:

A pipe through the gear where the tow bar goes can be lifted with an ordinary jack.   Have something to keep the pipe on the jack and something under the tail.

These two responses answer the "how" portion of raising the plane to change the front tire the best, in my limited experience.

3 minutes ago, PT20J said:

Over all the years of using various techniques, has anyone heard of a problem attributed to the lifting technique?

Not sure if Don Kaye has the answer to Skips question, but he has exceptional experience on what happens when the front end slips off the jack and bounces the prop on the floor.

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So... out on the tie-down area...

1) Bags of sand on the tail can lessen the load... A couple of hundred pounds of tail tie-down force

2) The pipe through the tow bar hole has been discussed around here a few times...

3) moving the plane can be done by putting the nose wheel on a dolly... some dollys are easier to get under the wheel than others...

4) safely leave the plane on wood blocks... in the event a helicopter taxis by...

 

PP thoughts I have read around MS... not a mechanic...

Best regards,

-a-

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5 minutes ago, Oldguy said:

Not sure if Don Kaye has the answer to Skips question, but he has exceptional experience on what happens when the front end slips off the jack and bounces the prop on the floor.

I don't think Don's Bravo "slipped" off the jack. I think I recall someone retracted the gear while they thought it was securely on the jacks. I could be wrong, but that's what I recall.

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i decided not to pull the tail on my old bird. Built my own Jack and used an engine hoist with a nylon strap around the nose of the engine case.

The hoist loop was just sheet metal on the engine case, barely strong enough for engine, but not lifting the plane also. 

I bought the 3' long strap at farm and fleet.  Very little  room for the right g to fish it through, could always cut ring off, fish nylon through and put a proper removable hoist ring on it

 

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I do not follow Mooney’s jacking advise in the SI.  I have raised all short to mid body models with 2 wing jacks and a heavy but very stable tail weight as long as the tail tie down ring is not worn thin by ground contact.  I don’t trust that the plane is stable enough when supported by a strap and a hoist.

All long body models are raised on 3 jacks and then a support stand is placed under the tail tie down ring for added stability.

Here’s an Airbus that fell off the jacks, I don’t know the details, but I would not want to be responsible for that one.

Clarence

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6 hours ago, DustinNwind said:

@carusoam

 

Scenario is, flat tire out at my tie down and this is the way my mechanic wants to change the tire.

 

 

If you change a main you don't need to do anything to raise the nose or tail. If you change the nose you can't support it by the nose gear tube without being in the way. So I'm not sure this would work out.

 

-Robert

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3 hours ago, Hradec said:

i decided not to pull the tail on my old bird. Built my own Jack and used an engine hoist with a nylon strap around the nose of the engine case.

The hoist loop was just sheet metal on the engine case, barely strong enough for engine, but not lifting the plane also. 

 

In my experience the weight required to raise the nose when the plane is on jacks isn't really anything more than the weight of the engine. The bulk of the weight is on the mains and I can push the nose up and down by hand. I certainly can't pick up a Lycoming off the floor by hand.

-Robert

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Changing the nose tire is easy and safe by getting a guy, preferably 2, to push down the rear of the fuselage long enough for the mechanic to slip off the wheel and place a block under the nose wheel axle. (Chock the mains, and/or set parking brakes first.)

Once the new tire has been mounted reverse process.

FWIW, I’m with Clarence for securely jacking the whole plane.


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Not saying it's the right way to do it, but I watched a few guys lift the nose by pushing down on the stabilizer while the owner removed the nose wheel and put some wooden blocks under it.  Changed the tire and put it back on the same way, no jacks, no hoists, no problems (that I'm aware of).

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56 minutes ago, skydvrboy said:

Not saying it's the right way to do it, but I watched a few guys lift the nose by pushing down on the stabilizer while the owner removed the nose wheel and put some wooden blocks under it.  Changed the tire and put it back on the same way, no jacks, no hoists, no problems (that I'm aware of).

I've done it this way. It was surprising to me how little pressure it takes on the tail, to lift the nose gear.

But putting a pipe through the knuckle where you normally attach a tow bar just above the tire and then jacking it up with a floor jack is super easy as well. Just don't put the jack on the same side as the wheel comes off.

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1 hour ago, skydvrboy said:

Not saying it's the right way to do it, but I watched a few guys lift the nose by pushing down on the stabilizer while the owner removed the nose wheel and put some wooden blocks under it.  Changed the tire and put it back on the same way, no jacks, no hoists, no problems (that I'm aware of).

I would be concerned with this method as guys could push on a H-stab skin, off the spar and bend it. IIRC there was an issues with lifting C172 (possible damage to the Stabilizer) like that and those have much less weight on NG then Mooney. YMMV.

As a student I was thought to lift and rotated C172 by pushing on the aft fuselage, not the stab. Wouldn't try on my Mooney (to heavy)  and I use DIY tail stand (concrete in a tub). 

YMMV.

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3 hours ago, M20Doc said:

I do not follow Mooney’s jacking advise in the SI.  I have raised all short to mid body models with 2 wing jacks and a heavy but very stable tail weight as long as the tail tie down ring is not worn thin by ground contact.  I don’t trust that the plane is stable enough when supported by a strap and a hoist.

All long body models are raised on 3 jacks and then a support stand is placed under the tail tie down ring for added stability.

Here’s an Airbus that fell off the jacks, I don’t know the details, but I would not want to be responsible for that one.

Clarence

9D90B4EF-11F0-4821-BA5B-F3129A36D65E.jpeg

Merde. 

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