Hat Shelf Question

[Bruce Fenstermacher]

After 7 years without a headliner installed I'm thinking of having one made and reinstalled. (I know your asking yourself "Bruce why would you want to do that )

While considering the installation I got to thinking I'd like to remove the hat shelf. That is when I looked closely at my hat shelf or more specifically under the front forward edge at each side. Located there on both sides is what looks like some kind of bracket or hinge or at least half of a hinge.

Each of these bracket things is made of two identical sides stamped from sheet meet that is riveted to the under side of the shelf and extend about an inch and a half below the shelf. The sides are about an inch and a half apart and have a pin suspended at the end between each side of the bracket.

These pieces can not be seen in the parts manuals nor are they listed that I can see.

Anybody else have them and what the heck are they for?

[bsdunek]

My 170A doesn't have anything like that. Could your's have been some sort of modification?

[lowNslow]

I'm having a hard time picturing your shelf, but it sounds like it might be a shade tree mod to allow the hat shelf to be quickly removed when needed. Maybe you should apply for an STC and donate it to the IC170A.

[Bruce Fenstermacher]

Yes a picture would be better but I never have a camera handy for these things.

These are mass manufactured parts, it's no shade tree modification.

The hat shelf itself can not move. If these are hinges something would swing below the hat shelf from them like for example a screen or barrier of some kind to secure stuff in the baggage area if the rear seat was removed.

They also look like they could be some part of a latching system for a seat back but of course in our 170s the set back attachés to the fuselage sides.

BTW this hat shelf could easily have come from another model/year of Cessna but there doesn't seem to be any other modification to the hat shelf to make it fit and it does fit very well.

[Indopilot]

Those are the seat back adjustments. They are riveted to the shelf and screwed/bolted to the fuselage sides on the 172's anyway. I removed the shelf and had to drill the rivets off so I could mount the brackets and still use the rear seat w/o the passengers flopping backwards like carp on the river bank.

[Bruce Fenstermacher]

OK since you have both a 52 and a 56 does the 52 have them?

These brackets do nothing with regard to my rear seat back adjustment. That is all done with sloted pieces riveted to the fuselage side.

If your 172 has them and the seat back does use them then my hat shelf must have come from a later 172 which doesn't surprise me in the least.

[doug8082a]

Does it look like this?

I got this from the "Pre 1963" C172 manual on http://www.micro-tools.com/pdf/cessna/ Page 128.

[flying]

I am replacing the headliner & rear seat side panels. Came across this posting from 5 years ago. My 170B is a 1956 model. My seat back has approximately 3" long channels with adjustment notches that slide thru above the pin on each side, then drop into the pins. By so doing the angle of the seat back is adjustable with the handle in the center to raise the channels to move seat to next notch.
Sioux Lookout 170B

[Bruce Fenstermacher]

The answer to my original question years ago was that those brackets, which can be seen on the forward outside edge in the drawing doug posted of the later 172 IPC, are part of the back seat adjustment.

As you point out Bill, seats on 170 after 26996 have channels which slide inside the brackets and the channel has slots the bracket bar sits in and adjusts the back seat. This is a completely different system than found on earlier 170s which is why I was not, at the time, familier with them. It is also why a person with this system could not remove the rear hat shelf.

This is one of those small details that one can use to win bar bets when guessing a model year or serial number range of a particular 170.