Tie Down Fuel Tank Question

[Echo]

I have extended tanks that apparently compromise the Tie down (as it enters the extended tank).  Anyone else experience this?  I have purchased Laser jack/tiedown and want to install them, but I don't want massive tank leaks.  I appreciate suggested methods to safely and properly install the Laser tie down/jack points.

[Shadrach]

20 minutes ago, Echo said:

I have extended tanks that apparently compromise the Tie down (as it enters the extended tank).  Anyone else experience this?  I have purchased Laser jack/tiedown and want to install them, but I don't want massive tank leaks.  I appreciate suggested methods to safely and properly install the Laser tie down/jack points.

 

 

 

I am not familiar with the extended wet wing tanks. What document suggests that the tie down enters the expanded tank? I’m pretty sure the tie down/Jack point bracket is on the back side of the spar. What kind of tie downs does it currently use?

[Echo]

I am unfamiliar as well Ross.  Only info I had on this was the previous owner telling me.  Maybe he did not have tie downs?  

[hammdo]

Since Maxwells has the STC for the tanks extension - maybe a call to them? Also, Wet wing or Houston Tank can chime in too… I’d like to know how it’s jacked up for annual if you can’t use those locations. 
 

I have the Laser tie downs - really nice to have on for tie downs/jacking…
 

-Don

[Echo]

1 minute ago, hammdo said:

Since Maxwells has the STC for the tanks extension - maybe a call to them? Also, Wet wing or Houston Tank can chime in too… I’d like to know how it’s jacked up for annual if you can’t use those locations. 
 

-Don

Right.  The jackpoint and threads are there, so jackpoints appear functional.  This was Monroy STC completed a longtime ago.

[Echo]

On my first plane jackpoints were not threaded like theLaser combo.  They just had short pins.  Last plane was J with Monroy conversion and jack points worked (Laser).  This is a head scratcher.

[Shadrach]

Just now, Echo said:

On my first plane jackpoints were not threaded like theLaser combo.  They just had short pins.  Last plane was J with Monroy conversion and jack points worked (Laser).  This is a head scratcher.

My 67F was threaded for tie downs. I upgraded to the LASAR jack points. I needed to cut new threads to make them work. This perplexed Paul Lowen who said he’d never encountered that issue.

[Echo]

14 minutes ago, Shadrach said:

My 67F was threaded for tie downs. I upgraded to the LASAR jack points. I needed to cut new threads to make them work. This perplexed Paul Lowen who said he’d never encountered that issue.

See in the Laser add above it talks about "helicoiling". (for "larger" bolts)?  Anyone know what they are talking about?

Edited January 1 by Echo

[Fly Boomer]

2 minutes ago, Echo said:

See in the Laser add above it talks about "helicoiling". (for "larger" bolts)?  Anyone know what they are talking about?

Sounds like some have been drilled and tapped for larger threads and, if so, need to be returned to original size with a helicoil.

[Shadrach]

7 minutes ago, Echo said:

See n the Laser add it talks about "helicoating". (for "larger" bolts)?  Anyone know what they are talking about?

So apparently there were others after me. Now that I think about it (this was 15 years ago), the LASAR bolts were too small.  We had to drill out the old threads and install helicoils sized to the LASAR Jack point/tie down bolts. The only difference is that at the time they had not come across the issue and now they are recommending the solution we used as a workaround. Not that we pioneered it. It is the logical solution. I remember disliking the possibility of steel fragments floating around in an aluminum wing. We used grease to hold the shavings and vacuumed the area thoroughly.

[Shadrach]

1 minute ago, Fly Boomer said:

Sounds like some have been drilled and tapped for larger threads and, if so, need to be returned to original size with a helicoil.

Close. They need to be drilled and helicoiled for smaller threads

[Fly Boomer]

1 minute ago, Shadrach said:

Close. They need to be drilled and helicoiled for smaller threads

Smaller=original.

[Shadrach]

1 minute ago, Fly Boomer said:

Smaller=original.

Not in my case. The LASAR bolts would slide right into the tie down boss without gripping. We drilled the old threads out and threaded in a helicoil insert that reduced the thread size to match the LASAR hardwear.

[Echo]

So did size of tie downs vary over the years or what is going on here?

[Shadrach]

15 minutes ago, Echo said:

So did size of tie downs vary over the years or what is going on here?

The answer must be yes. To what degree is anyones guess. Do you have the factory removable tie down rings? Will be easy to compare your existing tie down to the LASAR tie downs. You’ll know right away if a helicoil is in your future.

[Echo]

6 minutes ago, Shadrach said:

The answer must be yes. To what degree is anyones guess. Do you have the factory removable tie down rings? Will be easy to compare your existing tie down to the LASAR tie downs. You’ll know right away if a helicoil is in your future.

Laser parts coming tomorrow.  Plane did NOT have OEM tie down rings when I purchased.  I am curius to see if they thread.

[Shadrach]

2 minutes ago, Echo said:

Laser parts coming tomorrow.  Plane did NOT have OEM tie down rings when I purchased.  I am curius to see if they thread.

Did it have any tie down rings?

[Echo]

If my memory is right I removed Laser'and reinstalled OEM when we sold our '66 M20E.  They fit fine on our 1980 J/Missile.  I think I have J OEM tie downs somewhere...

[Echo]

Just now, Shadrach said:

Did it have any tie down rings?

Nope

[Shadrach]

3 minutes ago, Echo said:

Nope

Look forward to learning how this shakes out.

[Echo]

I have a photo showing interior on another plane.  Just a piece of angle for support with threads in hole terminating in open bay that now holds fuel.  Any reason not to put plumbers tape on threads and insert?  That is going to be my plan unless others have better method.

[Joshua Blackh4t]

My E had ring tie downs that were bent from people trying to use them for jacking points.

The thread was finer than the Lasar ones, so I bought new stainless steel bolts and machined the heads to fit into the lasar jacking collars.

 

[Shadrach]

17 minutes ago, Echo said:

I have a photo showing interior on another plane.  Just a piece of angle for support with threads in hole terminating in open bay that now holds fuel.  Any reason not to put plumbers tape on threads and insert?  That is going to be my plan unless others have better method.

Perhaps you should call Monroe for a consultation.

https://www.monroyaero.com

[Echo]

2 hours ago, Shadrach said:

Perhaps you should call Monroe for a consultation.

https://www.monroyaero.com

I reached out to Paul Beck in MN.  I am sure he has dealt with this before.

[Kelpro999]

6 hours ago, Echo said:

I have a photo showing interior on another plane.  Just a piece of angle for support with threads in hole terminating in open bay that now holds fuel.  Any reason not to put plumbers tape on threads and insert?  That is going to be my plan unless others have better method.

Plumbers tape (Teflon) doesn’t fair well with straight threads as it won’t capture and compress the tape. The oe threads are 5/16-18, then after they get worn or damaged, the holes get re-threaded to 3/8-16 and larger tie down rings go in. If yours are 3/8, Heli-coil back to 5/15” (Lasar bolt size) kind of works but not perfect then use fuel tank access panel sealant on the lasar bolt threads, between the jack points ,tie eyes and wing skin.

 All this seems kind of strange having fuel above the tie down eye since the poh says to remove tie down eyes before flight.