Taking out backseat

madpilot · Post by **madpilot** » Mon Sep 03, 2007 1:54 am

I want to take out the backseat or 170B for my vacation. I am sure it isn't that big of a chore, but I thought I would ask for some guidance before trying to learn as you go. Any help?

Larry

Post by **Bruce Fenstermacher** » Mon Sep 03, 2007 2:33 am

I'll assume your seat is not modified to allow the back of the seat to be removed easily fro the bottom to facilitate removal.

This being the case you really need to remove the arm rests and probably ash trays first. Then looking at the center rear support attachment at the floor your wills see the head of a bolt. It's either a 7/16 or 3/8ths. Remove it.

Then look under the bench at the center support near the front You will see or feel another bolt head attaching the support to the floor. I think it's 3/8ths. Remove it.

Then with a flash light look under the seat on each side about in the middle of the bench and you will see another bolt head attaching the seat bench to the side of the fuselage. I'm pretty sure it's 3/8ths. Remove the bolt from each side.

Your seat is know unattached and just sitting in the plane but it is a tight fit. Fold the seat back towards the from disengaging the adjusters from each side. Grab the whole seat assembly and lift up a bit. This will usually dislodge the bench part from between the fuselage sides. Carefully rotate the seat unit up and one side forward and out the door. Another person at this point helps.

Also be careful when removing the seat. it is very easy to catch the seat back adjusting rod ends on the interior and rip or scratch it.

To reinstall reverse the procedure.

My seat back has a simple modification that allows the seat back to come out separately making the removal and installation much easier. If you ask nice I'll tell you about it tomorrow when I have more time. You need to remove your seat the first time anyway.

Oh nearly forgot. Get out your paperwork and record the seat as being removed and adjust your W&B.

dacker · Post by **dacker** » Mon Sep 03, 2007 12:30 pm

Something else that helps to keep from ripping or scratching the interior is to cut two pieces of thin sheetmetal (about 12"x12" or longer should do) and slide these down both sides where the side mounts are, this especially helps when reinstalling. My interior is a fiberglassed STC'ed interior, this is especially critical to prevent from scratching. It was recommended by the manufacturer (Selkirk).
David

mrpibb · Post by **mrpibb** » Mon Sep 03, 2007 2:24 pm

You will probably find the right technique for the seat removal after you remove the bolts. A funny thing is that when my buddy removes the seat he fights with it for about 10 mins, I walk along and pop it out in 5 sec's. My rear seat I fold the seat back down then tilt the whole folded seat backwards to where if you continued a line from seat bottom you would be 45 deg from the floor line. Then I lift, twist, throw some salt over my shoulder

the seat will be out.
Hey, I think that should be a convention contest, the fastest stock backseat removal, winner would get a altee dodge folding seat!!!

Post by **Bruce Fenstermacher** » Mon Sep 03, 2007 6:19 pm

Yea Vic the first time I took out the seat I must have hit the sweet spot cause it came right out. Wondered what all the fuss was about. Then I went to put it back in and realized what a pain it is.

What I did to make it easier was actually started by the previous owner. The back of the seat is held to the bottom by 2 AN3 bolts at the outside corners. The previous owner slit the stitches of the fabric at that location so one could slip a wrench in and hold the end of the AN3 bolt while removing the nut from the other side. Once these are nuts are removed it's an easy task to push the bolts into the seat back and the whole back comes right off.

I replaced the AN3 bolts with drilled AN3 bolts. When reinstalling it's easy to line up the bolt with the hole and with a finger in the slit fabric, push the bolt through. I don't put a nut on the end but instead hold the bolt in place with a pull pin. So all I had to do to remove the back of my seat is pull the pins at each corner. Reach in with a finger and push the bolt into the seat back and out comes the seat back.

With out the seat back it's much easier to deal with the seat bottom and it's not necessary to remove the arm rests or ash trays.

170C · Post by **170C** » Mon Sep 03, 2007 11:26 pm

Has anyone come up with a substitute for the 4 bolts that secure the seat to the airframe? I wonder if there would be some type of pin with the button on the top that could be used to push into the area where the bolts screw in (might require removal of the nutplates) so the pins would hold the seat in place rather than having to unscrew and screw back in each time the seat is removed or reinstalled. Eventually the nut plates wear out and they are a pain to replace not to speak of the effort to remove the bolts themselves & replace each time.

Tue Sep 04, 2007 12:45 am

One thing you have to keep in mind is that the seat belts are attached to the seat frame and so the seat frame needs to be securely attached to the airframe.

blueldr · Post by **blueldr** » Tue Sep 04, 2007 3:04 am

If you're following Bruces instructions, be advised his measurements are wrench sizes, not bolt sizes.

A small ratcheting cargo strap is helpful in compressing the seat back down against the seat during removal.

Tue Sep 04, 2007 12:28 pm

Thanks BL, when I write answers sometimes we think we are writing the obvious. I don't think in terms of the actual bolt size I'm removing but the size of wrench I need to turn the bolt.

BTW I use a 1/4" ratchet and appropriate socket with an extension of at least 3" for all the bolts. When I reinstall the seat I place it in position then use a punch pushed through the holes in the seat bottom sides and into the nut plates to line them up. If they are lined up the bolts go in easily and stripping of the nut plate won't happen.

Kyle · Post by **Kyle** » Tue Sep 04, 2007 2:18 pm

I think it may have been mentioned here before but I'm considering this

for the upcoming winter. It would be pulling the seat out and making a modification. That being to make a metal jig that duplicates the mounting hole positions for the seat. I would strip the seat to the bare frame and shorten it by 1 1/2" total width using the jig to maintain mounting positions. Then the two side bolts would each receive a 3/4" phenolic bearing spacer when the seat was re-installed. Just that smaller width would make a world of difference in swaping the seat in and out.

That's a bit easier to do considering I have a welding shop at my disposal. The issue of course is the paperwork. Even though I would consider it a minor modification I'm not sure how the FAA would view it.

As Bruse mentioned it's re-attachment is a critical issue as the seat belt integrity is directly related. This is just a topic of conversation and before I jump - I'll get a read from them on the approval.....

Currently I have the vertical cable run covers off of my aft door posts and am fabricating a small thin stainless dubbler that will protect the area that is alwways hit when the seat back catches come forward and hit that piece. Remember I have two boys who despite my best efforts are not always as gentle as I might hope for

Post by **Bruce Fenstermacher** » Tue Sep 04, 2007 2:35 pm

Kyle that is a lot of work. I'd look at the mod I suggested as a first step. I doubt you would do any more after that. It is that much easier.

mrpibb · Post by **mrpibb** » Tue Sep 04, 2007 4:56 pm

If I was a rich man, or at least a middle class worker paid for what he was worth

, I would really consider the Altee Dodge fold up seats. It's just that my current social class status and wage prohibits the $1,800 plus upholstery for the seats and stc

. But thats what I would like to do.

N2255D · Post by **N2255D** » Tue Sep 04, 2007 6:07 pm

I did the same thing that Doug did, except I used pip pins instead of bolts I don't have a basis for approval but it is sooooooooo much easier to get the seat out without the back attached it's unbelievable. The bottom is maneuverable enough I can take the seat out without removing armrests and ash trays. The guy who did the annual before I got the airplane knocked the "D" window out trying to get the seat in with the back cushion attached..

Harold Holiman · Post by **Harold Holiman** » Tue Sep 04, 2007 9:41 pm

I also installed pull pins, I think they were either 1/4 or 5/16 with the little expanding ball in one end and a pull ring in the other. They made removing or replacing the back a snap and likewise made the seat bottom easily removable.

Harold

170C · Post by **170C** » Tue Sep 04, 2007 10:11 pm

The "pull pins" that Harold referred to was what I was referring to in my earlier post, I just couldn't think of the correct term. Would using those pins be legal? Harold, when you used those pins, did you use them for all 4 attachment locations? Did you leave the nutplates intact? Doing so would reduce the diameter of the pin that would go into the attachment area. Just wondering. Later model Cessna's have a much superior rear seat (split backs on some) and much easier/quicker to remove. Eliminating that long back attachment rod is really better. Of course installing a baggage door was a superior improvement too.

The International Cessna 170 Association

Taking out backseat

Taking out backseat

rEMOVAL OF BACK SEAT

Seat Removal