Winch on rear tire down hook

[r0ckst4r]

I have a slight incline to get my M20R into the hangar.  As you know this is a heavy aircraft.  I have a winch in the back of the hangar and it seems like the obvious point to connect this to is the rear tie down hook.  I would just like to confirm that people have used this and I am not going to cause any damage.

[MB65E]

Some do, I would not. I would set up a fixture to the nose gear and pull it backwards that way. 
 

-Matt

[gsxrpilot]

Since you've got the winch, the airplane, and the slope, I'd give it a test. But I'd put a scale between the winch hook and the plane. That way you can see how much force it takes to move the plane  back into the hangar. You might be surprised how little the force is and be comfortable with it. Or it might be more than expected.

Let us know how it goes.

[whiskytango]

33 minutes ago, MB65E said:

Some do, I would not. I would set up a fixture to the nose gear and pull it backwards that way. 
 

-Matt

This makes sense.  In theory you could use a motorized tug on the nose gear, and apply the bending loads associated with moving the plane up a sloped surface without expecting any damage.  Who knows what the rear tie down hook can withstand.

[ArtVandelay]

I used a 4 line block and tackle, I figure I put about 200 lbs of load on it. But by doing it by hand, there is no jerk like you might get with a winch. I figured if the tie down hook can’t handle 200 lbs, it’s not going to handle a thunderstorm. I tie it on with a nylon 1/4 line, no metal hook.

[MIm20c]

Probably a good time to make or buy a motorized tug...the O is a heavy ____. 

[Guest]

2 hours ago, r0ckst4r said:

I have a slight incline to get my M20R into the hangar.  As you know this is a heavy aircraft.  I have a winch in the back of the hangar and it seems like the obvious point to connect this to is the rear tie down hook.  I would just like to confirm that people have used this and I am not going to cause any damage.

I would not pull it by the tie down ring, I would pull it backwards from the main gear.   Remember that the nose gear retracts aft, there is the possibility of nose gear collapse by pulling aft on it.

Clarence 

[larrynimmo]

I have a J with io360...without a doubt about 200# pull (or a little more) on rear tie down when I put plane on jacks for annual...my AI has full confidence based on experience 

[r0ckst4r]

For the comments on a motorized tug.  I have a Robotow and I am thoroughly disappointed with it.  On flat surface it works well but even the slightest incline and all it does it slip and shred my tire even with downward force on it.  I can line the plane up with the hangar but it will not go in without some additional force such as someone else pushing or a winch.

[PT20J]

I don’t know how strong the tail tie down is. But it is probably designed for a mostly vertical load (it’s a tie down) whereas wenching would be a mostly horizontal load. My mechanic likes to put about 120 lbs of shot bags on the horizontal stabilizer when jacking since Mooney has a service instruction admonishing not to jack by anchoring the tail tie down.
Skip

[Yooper Rocketman]

I couldn’t agree more with Clarence!  The tie down was not designed for that kind load and the nose gear retracts AFT.  The main gear is the most stout and retracts at a right angle to the load you would be placing on it. I’ve seen far too many pictures and videos of “what can go wrong” with scenarios like this.  It’s just not worth the risk. 
 

Tom

[carusoam]

Rock,

You may want to edit your title...  a rear tire down hook? 
 

The upslope change of altitude to put an O in the hangar of a couple of feet over the length of the plane....

Can make pushing the plane up hill singlehandedly a bit of a challenge...

If the tanks are empty I can push the O up the two foot incline into the hangar... solo...

If tanks are half full... it weighs too much...

The amount of force that a human can push on a tow bar is pretty limited... similar to a bench press... while standing...

Expect 100 LBs of force can be exerted....   best to push on the wings... the prop is not a good place... the tow bar has many failure modes of slipping out or breaking...

If there are bumps to go over, these are stress builders to the system...

The smallest 12V electric winch from harbor freight is capable of supplying hundreds of pounds of force...

It is wireless remote... so your eyes can be where the action is...

But like all towing challenges... you don’t want to be anywhere near the towline if it breaks from either end... it is a springy whip...

 

As we can see from the drawing Clarence provided... the bolts are tensile in nature intended to be strong in the vertical direction...

We don’t get to see what they are attached to...

 

There is a towing device that many MSers are using called a sidewinder by redline... it is highly recommended for its ability to go up hills, long distances, and be portable...

rainy days, and ice always add to the challenges...

Serious loads can be accidentally placed on the landing gear... a towing strap around the main legs may make more sense to avoid accidentally collapsing the gear...

From other discussions...

if using the tie-down... get a good look at how the hook you choose will try to ride up and contact the sheet metal...

If collapsing the nose gear is possible... consider it to be about a 70amu option... Oh of engine, prop, nose gear, cowl fix...
 

PP thoughts of what I have read around here....

Best regards,

-a-

 

[ArtVandelay]

I would not pull it by the tie down ring...

The tie down ring is secured with AN4 series bolt, the same type of bolt used to secure the engine frame to the firewall. Seems like heavy duty bolt for hardware not designed for a 200lb lateral load.

BTW, FAR requires
“© Tie-down. If tie-down points are provided, the main tie-down points and local structure must withstand the limit loads resulting from a 65-knot horizontal wind from any direction.”



Tom

[Yetti]

Easy enough to rig two lines to the main gear.  The holes in the main gear accept a 3/4 " pipe.  3/4" pipe with end caps won't slip out.  3/4" pipe is not structural.   Some people have made tow bars out of it.  There are proper angles for rigging lines.   I would have to look them up.

Edited March 23, 2020 by Yetti

[Mooneymuscle56m]

2 hours ago, r0ckst4r said:

For the comments on a motorized tug.  I have a Robotow and I am thoroughly disappointed with it.  On flat surface it works well but even the slightest incline and all it does it slip and shred my tire even with downward force on it.  I can line the plane up with the hangar but it will not go in without some additional force such as someone else pushing or a winch.

Sidewinder is the same problem, if the tire is wet, forget it. 

[MIm20c]

The winch to the main gear is a good backup if there is an ice dam or similar. However, attaching that every time you go flying will get old quick. We’ve used 5hp units that attach to the nose wheel (where the towbar slides in) for decades on 210’s, long bodies, and short. We chain them up in the winter and push through snow and over ice. Find an old snowblower and weld on an attachment or buy a ez40. 

[r0ckst4r]

I have started using a rope tied through the hollow tubes on the main gear and using the winch hook on that.  It works but I have to admit I'm a little nervous about my knots when I see how much tension is on that rope.  Probably too much for the rear tie down ring.

[DanM20C]

A friend of mine made a bracket that attaches to the nose gear knee joint (Tow attach point)for his O. He winches it backwards from there. I don’t see how this would be any more stress on the nose gear than using a traditional tug. He uses it when it’s icy, normally he uses a sidewinder. 

Cheers,

Dan

[McMooney]

On 3/22/2020 at 4:46 PM, r0ckst4r said:

I have a slight incline to get my M20R into the hangar.  As you know this is a heavy aircraft.  I have a winch in the back of the hangar and it seems like the obvious point to connect this to is the rear tie down hook.  I would just like to confirm that people have used this and I am not going to cause any damage.

M20E here so not AS heavy, but def feels like it when pushing it about by hand.

Def Not saying it's right, but I use a Harbor Freight winch to pull Birdy into the hangar.  3years and so far so good.

Added a few bungess to blunt the jerking motion  

I've tried attaching at the nose gear, but this seems to be much harder on the winch  -- difference in angle ?

 

 

 

 

 

 

Edited March 28, 2020 by McMooney

[ArtVandelay]

A friend of mine made a bracket that attaches to the nose gear knee joint (Tow attach point)for his O. He winches it backwards from there. I don’t see how this would be any more stress on the nose gear than using a traditional tug. He uses it when it’s icy, normally he uses a sidewinder. 
Cheers,
Dan

Usually our planes are not towed backwards under any kind of stress, just used to back into a space. If pulling it backwards over a sizable hump, especially if the plane is jerked, I can see that “might” be a problem.

[HRM]

On 3/22/2020 at 5:46 PM, r0ckst4r said:

I have a slight incline to get my M20R into the hangar.  As you know this is a heavy aircraft.  I have a winch in the back of the hangar and it seems like the obvious point to connect this to is the rear tie down hook.  I would just like to confirm that people have used this and I am not going to cause any damage.

Pay no attention to any of those guys behind the curtain, I've had this arrangement for a couple of years.

I recommend, though, that you install LASAR's SS tail tiedown.

Photo shows tail just across hngr threshold, cable runs back to winch secured (by SS cable straps) to rear D-beam of hngr. This pulls on the cage, not the skin.

[kmyfm20s]

I used to use a winch all the time. No problem at all!

[HRM]

8 hours ago, McMooney said:

Harbor Freight winch

This one regularly goes on sale. I like the remote pendant. After a flight I can sit at the back and control the pull-in.

[McMooney]

2 minutes ago, HRM said:

This one regularly goes on sale. I like the remote pendant. After a flight I can sit at the back and control the pull-in.

this is the one i have : https://www.harborfreight.com/2000-lb-marine-electric-winch-61237.html, cost me $10

 

[r0ckst4r]

On 3/28/2020 at 9:17 AM, kmyfm20s said:

I used to use a winch all the time. No problem at all!

On the rear tie down ring?