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I've emailed Lycoming to ask their opinion on jacking/ lifting the nose of a Mooney by the lift ring as shown in the S/I. So far no reply from them.

I'll ask during Oshkosh.

Clarence

Clarence, that will be interesting to know. I doubt that Lycoming will be willing to venture any opinion on the record on the Mooney's, or other aircraft's, tail ring. And we might learn that they are not so keen to have more than the engine weight being lifted by their engine hoist point. And while the engine mounts are no doubt strong, it is not intuitively obvious to me that holding up the plane there in better than using the tail ring. 

 

When I jack my plane my biggest worry is knocking the plane off the wing jacks. There is quite a lot of leverage at the wing tips and the tail. A heavy bump there would exert quite a side thrust on the balance points. I make sure the weight that holds down the tail is scotched and cannot be moved without great force. 

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A while back someone posted this picture. Seems appropriate to the discussion.

Yeah, that's a definite "don't like".

 

Hard to tell, but it doesn't look like they had the tail held down so they were holding up the prop or the engine or they were jacking the mains thinking they could change a tire or...

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At least on the mid body Lycoming models I don't believe the engine lift loop is holding up any more weight than the weight of the engine and prop. With the engine off my plane the weight was pretty much nuteral, I had to keep a stool under the tail.

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For a fairly close and simple way to determine the weight at the engine, look at your weight and balance report. The weights from the scales should Tell the weight at the nose and main locations.

Clarence

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The IO550 long bodies get a jacking point on the front left of the engine mount.

Interesting way to minimize W&B issues while jacked off the ground...

Support under the tail still in the event somebody climbs out onto the tail or into the bagge area...

Best regards,

-a-

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  • 2 weeks later...

The IO550 long bodies get a jacking point on the front left of the engine mount.

Interesting way to minimize W&B issues while jacked off the ground...

Support under the tail still in the event somebody climbs out onto the tail or into the bagge area...

Best regards,

-a-

I'd read every post on this so far and was waiting for someone to raise the "Hoist Point" location on the long bodies...beat me to it. ;-)
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The folks at LASAR use the Mooney recommended way of jacking and they lift the nose with straps to the engine mount, not the engine lift loop. That loop was only designed to support the weight of the engine, not the engine plus the weight of a part of the airplane too.

 

It looks like this-

 

Jacking3_zps00e6e56c.jpg

 

They then put a tail stand, not weight under the tail tie down ring. I like this method because it is very stable when you get in and out of the plane.

 

Having said that, Top Gun Aviation, also an MSC, uses the tub of concrete tail weight method as did Accurate Aviation (not an MSC) when they did the annual on my plane before I bought it. I think SWTA also used the weighted tail method when I was there.

 

Because I already owned an engine hoist and not a tub of concrete, it was a no brainer for me in my hangar.

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  • 1 year later...

Good Evening Mooneyspacers

How are you?

Innoviator - flight science (www.innoviator.com) performs gear swings per Service Manual 32-31-06.

We support aircraft at four points (2 wing jacks, tail tiedown weight, engine loop support) during swings, and substantiated by the following: If one considers the M20j is 2740 gross wgt. and most fwd aircraft c.g. is locate at 45", then 90 lbs of horizontal stab down load is applied when flying straight and level. That means if the tail hook structure load path is capable then 90 lbs can be hung as the tail weight mimics flight loading. Next, determining engine loop load is by simply considering the wing jacks as a fulcrum, then solve for the moments. We get 200 lbs and have verified with a load cell. Lastly 200 lbs is less than the weight of the engine statically. 

Hope this is useful information.

Steve

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On 6/27/2015 at 8:56 PM, Bob_Belville said:

I doubt that Lycoming will be willing to venture any opinion on the record on the Mooney's, or other aircraft. 

Going to an airshow to ask a technical question is like trying to go to a Verizon store to get support for your phone.

They are salesmen only and are there to make money. If you have a problem or need to ask a technical question, they get a deer in the headlights look or tell you to call a 1-800 number to India. I don't know how many times I've heard: "well I can e-mail my head engineer and get back to you" or "you'll have to call our support staff to answer that question". :rolleyes:

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After the purchase of my "E" I built 2 wing jacks that can be pinned (in fact the bottle jack can even be removed and replaced should it fail while still holding up the aircraft) , a tail stand with both a coarse and fine adjustment and an "A" frame with a chain hoist. I sleep well at night knowing that nothing can bleed down and possibly damage the aircraft, it is also very stable supported this way (4 points) and does not move at all when climbing in and out and all over the aircraft. The reason I use the method that Mooney recommends is, should anything go wrong a savy insurance adjuster could deny the claim. 

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5 hours ago, Raptor05121 said:

Going to an airshow to ask a technical question is like trying to go to a Verizon store to get support for your phone.

They are salesmen only and are there to make money. If you have a problem or need to ask a technical question, they get a deer in the headlights look or tell you to call a 1-800 number to India. I don't know how many times I've heard: "well I can e-mail my head engineer and get back to you" or "you'll have to call our support staff to answer that question". :rolleyes:

I did ask the Lycoming tech help guys at Oshkosh about lifting the airplane with the engine lift ring. They said the ring is designed to lift the engine only, not the plane.  The guys at Mooney must have had different info when they wrote the S/I.

Clarence

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Taking into account what everyone is saying...

1) lifting the engine up by it's support will have the airplane follow the engine...

2) Lycoming wouldn't cover all the installations without undue effort.

3) Some people at KOSH are very technical, Some are sales people, And some are really technical sales people.  It helps when you can tell the difference.  Not all sales people are the equivalent of kids in a Verizon store.... (Sorry Alex:), your spot on.  It takes a really good sales guy to first overcome the low expectation that has been set.)

4) proving the theory that lifting the engine takes no more effort with the plane attached, see what is required to remove the engine from the plane.  If a stand is required to support the tail, this is a good sign...

5) A good sales guy really knows what he is talking about, an excellent sales guy delivers what he knows in a way everyone can understand.   Steve has done a nice job of explaining what happens and how he does it with a fair amount of why he does it.  Compare this style to the one used by the Fuel level indicator guy....

6) anyone see a Mooney sitting on it's tail, because it's engine is separated on a pallet?

7) the ordinary forces of weight and balance are a few hundred pounds moved around a dozen or so inches.  Getting a feeling for how gentle the balance part is...is an eye opener for people considering having a friend sit in baggage compartment...

8) the challenge of lifting an engine that is attached to the plane is...  You never know how much force you are actually using.  If you don't do a fair amount of pre-work to make sure you aren't accidently lifting more than is expected.  Or using a load sensor in the lifting device. 

This is a Summary of what I am seeing here.  I am only a PP not a mechanic. I was once a technical sales guy...

Best regards,

-a-

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I would have a hard time explaining a cracked crankcase to a customer after we lifted the airplane and engine from the engine lift ring. Some time back ther was a thread about a Brave with a cracked case, coincidentally at the forward lift ring.

I have jacked short body Mooneys using a 500 pound concrete and steel tail weight and 2 wing jacks, long body Mooneys have 3 jack points, additionally we add a support stand at the tail tie down ring. 

Pin 30 plus years we've never dropped one or hurt one.  I suspect that the Mooney SI maya have resulted from a broken or damaged tail tie down failing while the plane was on jacks.

Clarence 

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12 hours ago, M20Doc said:

I did ask the Lycoming tech help guys at Oshkosh about lifting the airplane with the engine lift ring. They said the ring is designed to lift the engine only, not the plane.  The guys at Mooney must have had different info when they wrote the S/I.

Clarence

So we can't hold the tail down with cement, we can't lift the front with a prop jack or the engine lifting eye.  

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Just now, RLCarter said:

We all seem to agree on the mains and are split on how to raise the nose wheel. Maybe something like this would be an option

AirplaneMech.jpg

I was thinking something along the same lines.  Not sure which of my guys will volunteer for it.  Or we just convert everything back to fixed gear.

Clarence

Clarence

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