Aircraft jacking poll

[Jpravi8tor]

Please answer attached poll and give your opinion on jacking methods

[M20F]

If the internet has taught me anything it is always follow the manufacturers instructions and belittle those who don’t, unless you don’t happen to agree with the manufacturers instructions.  
 
In the absence of engineering data it is always best to conduct a random and unscientific poll to determine best outcomes to get the point over the finish line.  

Personally I really don’t care what folks do.  I find it hilarious though somebody would post I don’t follow the instructions and then scold another individual for not following the instructions.  Internet at its finest!

Thankfully though I have 6-8 pages of humor to read over the next several days. 

[Jpravi8tor]

56 minutes ago, M20F said:

If the internet has taught me anything it is always follow the manufacturers instructions and belittle those who don’t, unless you don’t happen to agree with the manufacturers instructions.  
 
In the absence of engineering data it is always best to conduct a random and unscientific poll to determine best outcomes to get the point over the finish line.  

Personally I really don’t care what folks do.  I find it hilarious though somebody would post I don’t follow the instructions and then scold another individual for not following the instructions.  Internet at its finest!

Thankfully though I have 6-8 pages of humor to read over the next several days. 

Sooo…..what methodology do you use? @M20F or do you rely on a msc or other maintenance facility?

[carusoam]

Jpr,

Mike has hit the major points…

We have seen them all done…

For many, it is an educational exercise…

For some, they learn how to build a nice tail weight to match their needs…

 

1a) There are pages and pages written about not using the engine hoist to hold an airplane up…. Engine case manufactures laugh when we do it…

1b) More pages about putting forces on the prop, and its supporting bearings…. If we can’t pull and push on the prop to move the plane… how are we going to Jack the plane up and support it using the prop?

2a) People fear the strengths of their tail tie downs… when they do, it becomes time to look at what they have back there… the tail has to be strong enough or flight wouldn’t be possible….

2b) Tie down bolt strength? If the tie down bolt strength is a concern…  it isn’t a very good tail tie down then…

3) Following manufacturers guidance, using the MM… rules!

 

4) LBs get a free ride on this discussion… they have a third Jack point on the engine mount itself!   
 

5) For a really good example of damage caused by jack issues…. Invite @donkaye to participate… he has great pics.

6) Jacks and Jack collars are important… proper Jack points are important…

7) Use extreme care in and around planes that are jacked up…

8) Being up on jacks is less of an issue when the gear are down, and close to the ground….  
 

The pole results will probably be skewed by MSers that know the answer….

I couldn’t find the nose Jack point option in the poll…

But, it is a great conversation starter for the new guys that are not as familiar…

Popcorn for breakfast!

Best regards,

-a-

[M20F]

30 minutes ago, Jpravi8tor said:

Sooo…..what methodology do you use? @M20F or do you rely on a msc or other maintenance facility?

I use the rules for me and not for thee methodology in all things aviation.  

[Shadrach]

I know of a guy that attaches the tail with dual ratchet straps to an 8‘ wooden lever made out of 4x4s. Once everything is tightened down, it’s rigid enough to hold the tail in place but flexible enough to prevent much stress to the tail and tail hardware.

[Greg Ellis]

Should have a 4th choice.  I do not jack up my own Mooney or anyone else’s.  I leave that to the pros.  

[Jpravi8tor]

29 minutes ago, Shadrach said:

I know of a guy that attaches the tail with dual ratchet straps to an 8‘ wooden lever made out of 4x4s. Once everything is tightened down, it’s rigid enough to hold the tail in place but flexible enough to prevent much stress to the tail and tail hardware.

I’m trying to imagine such a contraption,

perhaps you could indulge me with a crude drawing?

[Shadrach]

18 minutes ago, Jpravi8tor said:

I’m trying to imagine such a contraption,

perhaps you could indulge me with a crude drawing?

I happened to have a picture and was able to crop an image of the set up. I’m told the weight of the 4x4s helps to dampen any movement.

[M20Doc]

3 hours ago, M20F said:

If the internet has taught me anything it is always follow the manufacturers instructions and belittle those who don’t, unless you don’t happen to agree with the manufacturers instructions.  
 
In the absence of engineering data it is always best to conduct a random and unscientific poll to determine best outcomes to get the point over the finish line.  

Personally I really don’t care what folks do.  I find it hilarious though somebody would post I don’t follow the instructions and then scold another individual for not following the instructions.  Internet at its finest!

Thankfully though I have 6-8 pages of humor to read over the next several days. 

As a maintenance provider if I pulled the tie down ring off, that Mooney say not to use, or damaged the crankcase when Lycoming says don’t jack the plane with the engine lift ring or use a propeller blade jack or use alternator belts on the blades I’m responsible for the outcome.  

In the event that the tie down ring fails it won’t cause a crash, not sure the same can be said about internal propeller damage.

[M20Doc]

A little more information on airplane jacking via the propeller.  Hartzell’s service docs say to disassemble the propeller for internal inspection if it’s been used as a jack for the airplane.  https://hartzellprop.com/SERVICE-DOCUMENTS/SL/HC-SL-61-231.pdf

Further to all of this, Mooney has yet to amend the maintenance manual to reflect these changes. And as so many here so often say Service bulletins and service instructions are optional for part 91 private airplanes. 

So, damned if you do, damned if you don’t.

[PT20J]

All the folks referencing Mooney SIM20-114 seem to be focusing on one part:

NOTE: It is not recommended to use tail--tie down fitting during jacking process to lift nose wheel off ground. 

This is a NOTE containing a recommendation. But what about the fact that the Service Instruction contains WARNINGS and CAUTIONS one of which is:

WARNING: DO NOT use tie down rings as jack points, DO NOT leave tie down rings on Aircraft during flight.

Now I believe that the phrase WARNING, DO NOT...is much more restrictive than the phrase NOTE, It is not recommended.

So, I assume that all those who cite the SI as the reason for not using a tail weight also remove the tie down rings before every flight, right?

[FlyingDude]

I think the BEST way to Jack up your plane is to install a giant electromagnet on your hangar’s roof, like those at a scrap yard and levitate your plane.

no muss, no fuss 

[PT20J]

It's also not clear what Mooney means by the note in SIM20-114: NOTE: It is not recommended to use tail--tie down fitting during jacking process to lift nose wheel off ground. 

The SI refers to the "tail tie down fitting." I have no idea what that is. The M20J IPC calls out a "tail skid" which is attached using 2 AN4-7A bolts to a "tail skid attach extrusion" and two " tail skid attach strap assys." For all I know Mooney meant not to remove the skid and attach a weight to the attach points.

Skip

 

 

[Raymond J1]

Initially, I proposed to my wife to climb on the fix part of elevator, same the photo of the M20F catalog...

The idea of the baril of metal hanging on the tie down came after, when she had too many ants in her legs to wait, sitting up there and leaning against the vertical plane.
If the ring is a problem, put the lests on the horizontal fixed plane... Since it is its function to lift the front wheel...

Edited November 6, 2022 by Raymond J

[A64Pilot]

I’m still waiting to see what the weight on the nose wheel is compared to engine weight, I suspect as someone has posted the weight of the engine alone exceeds the weight of the weight on the nose wheel, meaning that there is less force applied lifting the nose of the airplane than picking up the engine.

But again the only way I see to lift the nose is with a soft strap on the engine mount, it can easily support the weight as it holds the engine and all gyroscopic forces associated with it at 3.8 G’s.

[Shadrach]

3 minutes ago, A64Pilot said:

I’m still waiting to see what the weight on the nose wheel is compared to engine weight, I suspect as someone has posted the weight of the engine alone exceeds the weight of the weight on the nose wheel, meaning that there is less force applied lifting the nose of the airplane than picking up the engine.

 

Pretty sure @PT20J skip said his nose wheel was supporting >500lbs when his plane was weighed. That number is not surprising to me given the weight of all the accessories, prop, engine mount and gear assembly.

[Raymond J1]

9 minutes ago, A64Pilot said:

I’m still waiting to see what the weight on the nose wheel is compared to engine weight, I suspect as someone has posted the weight of the engine alone exceeds the weight of the weight on the nose wheel, meaning that there is less force applied lifting the nose of the airplane than picking up the engine.

But again the only way I see to lift the nose is with a soft strap on the engine mount, it can easily support the weight as it holds the engine and all gyroscopic forces associated with it at 3.8 G’s.

On the balance table... superior to the engine weight.

Edited November 6, 2022 by Raymond J

[PT20J]

49 minutes ago, A64Pilot said:

I’m still waiting to see what the weight on the nose wheel is compared to engine weight, I suspect as someone has posted the weight of the engine alone exceeds the weight of the weight on the nose wheel, meaning that there is less force applied lifting the nose of the airplane than picking up the engine.

According to the Lycoming Operator’s Manual, the IO-360-A1B6D weighs 330 lbs. When we reweighed my M20J, the weight on the nose wheel was 639 lbs.

[A64Pilot]

41 minutes ago, Shadrach said:

Pretty sure @PT20J skip said his nose wheel was supporting >500lbs when his plane was weighed. That number is not surprising to me given the weight of all the accessories, prop, engine mount and gear assembly.

Sounds plausible.

Just standing beside of the airplane looking at it, there appears to be about 6Ft between the mains and nose gear, and about 12 ft from the mains to the horizontal, just rough guess.

But if there is 500 lbs on the nose wheel, then as the distance to the tail is twice as far it ought to take half the weight to lift the nose, and my 250 lbs draped across the tail boom just in front of the horizontal won’t budge it.

Are the jack points at the same arm as the mains? probably not but should be close.

But this engine mount truss is plenty strong

 

[A64Pilot]

2 minutes ago, PT20J said:

According to the Lycoming Operator’s Manual, the IO-360-A1B6D weighs 330 lbs. When we reweighed my M20J, the weight on the nose wheel was 639 lbs.

OK, more than I thought, so then likely to take 300lbs force on the tail to hold it down.

I have once seen an airplane lifted from the engine, I believe it was a Piper Seneca landed at Falcon Field about 2005 or so and the nose gear collapsed, owner (an A&P) called a crane to pick it up, hooked to the engine lifting point and proceeded to pull a chunk out of the case, but this was a big twin, sitting on its face and attempt from one engine.

That was a memorable day, it went downhill from there

[Shadrach]

2 minutes ago, A64Pilot said:

Sounds plausible.

Just standing beside of the airplane looking at it, there appears to be about 6Ft between the mains and nose gear, and about 12 ft from the mains to the horizontal, just rough guess.

But if there is 500 lbs on the nose wheel, then as the distance to the tail is twice as far it ought to take half the weight to lift the nose, and my 250 lbs draped across the tail boom just in front of the horizontal won’t budge it.

Are the jack points at the same arm as the mains? probably not but should be close.

But this engine mount truss is plenty strong

 

So skip is saying 639lbs on his nose wheel. I have not done it in a long time, but I am pretty sure I was able to lift the nose of my F and I was well under 200 then.  Heavier than lifting the nose of a 172 as I recall but able to lift all the same.

[A64Pilot]

Just now, Shadrach said:

So skip is saying 639lbs on his nose wheel. I have not done it in a long time, but I am pretty sure I was able to lift the nose of my F and I was well under 200 then.  Heavier than lifting the nose of a 172 as I recall but able to lift all the same.

I can’t lift my J, I just tried, but can easily a 172 with an O-360 on the nose

[carusoam]

56 minutes ago, A64Pilot said:

I’m still waiting to see what the weight on the nose wheel is compared to engine weight, I suspect as someone has posted the weight of the engine alone exceeds the weight of the weight on the nose wheel, meaning that there is less force applied lifting the nose of the airplane than picking up the engine.

But again the only way I see to lift the nose is with a soft strap on the engine mount, it can easily support the weight as it holds the engine and all gyroscopic forces associated with it at 3.8 G’s.

 

we know for sure…

Taking the engine off… the tail tries to sit on the ground by itself…

 

So… lifting the entire nose is slightly less than lifting the engine….

 

People typically put a couple of hundred pounds up front to hold things down…

Or use the kid’s sand bags spread across the tail feathers to keep things light up front…

 

-a-

[carusoam]

Lifting the nose of a C172 is an odd Cg comparison…

Their mains are soooo close to the Cg…  we have a huge lever arm to make what looks like a miracle of strength happen…

Best regards,

-a-