182P seat rail replacement

Who is signing off the installation? I would think it's their decision to make.
 
Paulie said:
Who is signing off the installation? I would think it's their decision to make.
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If both methods of fastening are OK, I would think it's up to the aircraft owner.
 
Kenny Phillips said:
If both methods of fastening are OK, I would think it's up to the aircraft owner.
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The owner can select which brand seat rail to use however it falls to the installer how it gets installed under Part 43. But by all means, if there is an option a discussion should take place if there are differing preferences. Personally, I prefer screws when possible. I believe there is a FAA bulletin on this somewhere that addresses using screws.
 
If they use screws, and the screws have phillips heads, and the repairmen just use a phillips driver to tighten them, make sure they also tighten the nuts from the back side really guttentite. The screws are soft and can't be adequately tightened with just the phillips head design.

DAMHIK
 
write-stuff said:
In my opinion, rivets are the preferred method.
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Yes my opinion too, but there are a few that can't be hit with a bucking bar so a bolt or screw is used.
there is a service bulletin on this subject By McFarlane
 
Where I can't drive a solid rivet I set a cherry max of the correct size.
 
I would opt to keep the airplane as original as possible and opt for rivets.
 
Bell206 said:
The owner can select which brand seat rail to use however it falls to the installer how it gets installed under Part 43. But by all means, if there is an option a discussion should take place if there are differing preferences. Personally, I prefer screws when possible. I believe there is a FAA bulletin on this somewhere that addresses using screws.
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I plan on using the McFarlane rails and thanks to this forum, we have a solid plan on how they should be installed correctly.
 
Mark B Schick said:
I plan on using the McFarlane rails and thanks to this forum, we have a solid plan on how they should be installed correctly.
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Your plan should be like this.
1 remove the heads of the rivets, to remove old tracks. do not over size the holes in the old track.
2 clean up the floors removing all buck tails from the holes in the floor, and corrosion if any then prime the floors area.
3 clamp the old track to an aluminum strap, (1/4" X 2" X 36" long). being certain the the old track is aligned with the edge of the strap.
4 using a squared up drill press, duplicate the track's holes in the strap.
5 replace the old track with the new one, placing it exactly where the old track was on the strap, then back drill the new strap.
This way the new track will fit the floor hole pattern exactly. and be in the correct place for the sear to operate smoothly.
It is important that the strap be thick enough that it can act as a drill guide. and not elongate any hole.
 
Tom-D said:
Your plan should be like this.
1 remove the heads of the rivets, to remove old tracks. do not over size the holes in the old track.
2 clean up the floors removing all buck tails from the holes in the floor, and corrosion if any then prime the floors area.
3 clamp the old track to an aluminum strap, (1/4" X 2" X 36" long). being certain the the old track is aligned with the edge of the strap.
4 using a squared up drill press, duplicate the track's holes in the strap.
5 replace the old track with the new one, placing it exactly where the old track was on the strap, then back drill the new strap.
This way the new track will fit the floor hole pattern exactly. and be in the correct place for the sear to operate smoothly.
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Thanks Tom for the detailed reply. Very helpful. I can also avoid buying the templates from McFarlane now that I know the size they should be. I will plan to buy the rivet set from McFarlane and just four screws as indicated above.
 
Mark B Schick said:
Thanks Tom for the detailed reply. Very helpful. I can also avoid buying the templates from McFarlane now that I know the size they should be. I will plan to buy the rivet set from McFarlane and just four screws as indicated above.
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Simply buy a 1/8th pound of each size from Aircraft Spruce.
The dimension I gave you of the strap is too large, so it can be used several times by simply moving track to a different place on the track.
 
Just remember,,,, :) your old track is your best hole pattern, don't mess it up.
 
W
nrpetersen said:
If they use screws, and the screws have phillips heads, and the repairmen just use a phillips driver to tighten them, make sure they also tighten the nuts from the back side really guttentite. The screws are soft and can't be adequately tightened with just the phillips head design.

DAMHIK
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What? There are several types of screws that are significantly stronger than a AD rivet.
 
It's up to the guy signing it off, unless you're a A&P this is not a job for the unqualified. If I was signing it off and installing it it would be my way or find another mechanic. Actually I'd install it either ay but the cost would be adjusted accordanly.
 
Paulie said:
W

What? There are several types of screws that are significantly stronger than a AD rivet.
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Yes, but can they be wrenched to full strength from the head end only? A phillips driver (used on some) is a pretty wimpy tightening system.
 
Paulie said:
It's up to the guy signing it off, unless you're a A&P this is not a job for the unqualified. If I was signing it off and installing it it would be my way or find another mechanic. Actually I'd install it either ay but the cost would be adjusted accordanly.
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Every rivet in the seat track installation of a 182 can be driven by the proper bucking bar, and rivet gun.
The best bucking bar for the job is a 1.5" X 1.5" X 6" bar.
The most difficult are the last 5 rear of the right hand seat outboard track.
I'm usually tired by then, and shoot 5 cherrymax.
 
Paulie said:
What? There are several types of screws that are significantly stronger than a AD rivet.
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In fact they all are... steel vs. aluminum. :)

Beside their clamping ability is much better.
 
Tom-D said:
In fact they all are... steel vs. aluminum. :)

Beside their clamping ability is much better.
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AD rivets are made of 2117T4 and have a tensile strength of 38KSI. MS 35207 screws are made of a low-alloy steel that has a tensile of only 60KSI. The thread depth of the screw reduces that well below the apparent tensile, and the ability to overtighten a nut (real easy to do on small hardware) stretches that screw so it might be cracking or otherwise near failure. And if the rail isn't spot-milled for the screw head, you bend the screw just under the head and start the cracking sooner.

If you're going to use screws they need to be of the 120KSI stuff, like the MS27039, so that tightening the nut doesn't compromise it. I have found the softer screws in plenty of places they don't belong, including seat rails. They're a non-structural screw.

It's almost easier to just buck rivets than to try to get tiny nuts and washers on screws under the floor.
 
Dan Thomas said:
AD rivets are made of 2117T4 and have a tensile strength of 38KSI. MS 35207 screws are made of a low-alloy steel that has a tensile of only 60KSI. The thread depth of the screw reduces that well below the apparent tensile, and the ability to overtighten a nut (real easy to do on small hardware) stretches that screw so it might be cracking or otherwise near failure. And if the rail isn't spot-milled for the screw head, you bend the screw just under the head and start the cracking sooner.

If you're going to use screws they need to be of the 120KSI stuff, like the MS27039, so that tightening the nut doesn't compromise it. I have found the softer screws in plenty of places they don't belong, including seat rails. They're a non-structural screw.

It's almost easier to just buck rivets than to try to get tiny nuts and washers on screws under the floor.
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If you had read the SB from McFarlane you know what screws to use.

secondly, If you can get a bucking bar in place to buck a rivet, why couldn't you get a tiny nut/washer
 
Dan Thomas said:
AD rivets are made of 2117T4 and have a tensile strength of 38KSI. MS 35207 screws are made of a low-alloy steel that has a tensile of only 60KSI. .
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don't forget that number is for 1 square inch of material. not the cross section of screws.
 
Tom-D said:
I'm usually tired by then, and shoot 5 cherr
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Wouldn't want to miss nap time!

If I ever saw CR rivets in a seat rail, I would skip nap time and fix it right.
 
JAWS said:
Wouldn't want to miss nap time!

If I ever saw CR rivets in a seat rail, I would skip nap time and fix it right.
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Can I watch you buck the last 2 #6 rivets to the rear on each track?
 
Tom-D said:
Can I watch you buck the last 2 #6 rivets to the rear on each track?
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Specially the last rivet in the right track on the right seat, it is a # 6 X 5/8' long. It can't be touched by a bucking bar, or a wrench. I've yet to see a track that has been replaced that doesn't have a Cherry max in it.
 
Tom-D said:
don't forget that number is for 1 square inch of material. not the cross section of screws.
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It applies to the screw as well as the rivet. It's easy enough to calculate the cross-sectional area of the shank and multiply it by the strength. It's done all the time by engineers, and not just for fasteners. Sheet, bar, whatever.
 
Dan Thomas said:
It applies to the screw as well as the rivet. It's easy enough to calculate the cross-sectional area of the shank and multiply it by the strength. It's done all the time by engineers, and not just for fasteners. Sheet, bar, whatever.
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Give it up, and simply use the P/Ns that are given.

You remind me of the guy that measures with a micrometer, and cuts with a chain saw.
 
JAWS said:
CR rivets are part of the McFarlane kit?



Oh, well then, that makes it right then! :rolleyes:
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Right? no, acceptable. IAW with McFarlane.
 
Tom-D said:
Right? no, acceptable. IAW with McFarlane.
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Seat Rails for Cessna Aircraft

  • Carefully engineered with many improvements
  • Added strength and longer life
  • Anodized for corrosion and wear resistance
  • Easier installation
  • Full interchangeability with the original Cessna parts

Question
Can use blind rivets (e.g., CherryMAX or CherryLOCK) when replacing my seat rails?
We do not recommend using blind rivets for seat rail installation.
Can I replace rivets with screws when replacing my seat rails?
What is the standard hole depth for drilling additional holes in seat rails?
 
JAWS said:
Can use blind rivets (e.g., CherryMAX or CherryLOCK) when replacing my seat rails?
We do not recommend using blind rivets for seat rail installation.
Can I replace rivets with screws when replacing my seat rails?
What is the standard hole depth for drilling additional holes in seat rails?
Click to expand...
Doesn't say you can't.
Cessna's structural repair manual says they can be use in structure repairs.
 
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