Right Door will Not Latch

How to keep the Cessna 170 flying and airworthy.

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MoonlightVFR
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Right Door will Not Latch

Post by MoonlightVFR »

Installing a new strike plate on Right Door C 170B 1954.

Right door will not latch.
Originally thought I had one problem ; broken striker p.n. 0411582.
Now appears that there were Two (2) problems at same time.
Top screw does not want to tighten to secure top of striker in position. bottom screw is O.K.

FIG 24 -20 pg 46 IPC . p.n. 22A17A-82 Nutplate (ESNA) attach striker plate. Broken will not secure.

I am hoping there is a simple way to get locking plate up inside the post without removing any rear seats.

P.N. in question is flush riveted from factory. I cannot replicate.

What is the answer?

I am under official pressure to remove my airplane. NOW
gradyb, '54 B N2890C
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GAHorn
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Re: Right Door will Not Latch

Post by GAHorn »

Look at Fig 36A, Items 27/28 "rear door post fairing". That can be removed using a short screwdriver. After removal, the aft side of the doorpost can be accessed directly.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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MoonlightVFR
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Re: Right Door will Not Latch

Post by MoonlightVFR »

Thank you for post on FIG 36A
Now I know it is accessible.
Made quite a number of inquiries about P.N. 22A17A-82 . Nothing avail.

I am not the first to have this part break. Hoping some one will come advise how they replaced a broken nutplate.

It is a tender part. You can see how in a hamfisted moment TOO much torque the Phillips #2 screw driver breaks the fancy flat screw plate that is so artfully flush riveted to door post. Don't see very many flush rivets on a 170.

I'm coping
gradyb, '54 B N2890C
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n2582d
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Re: Right Door will Not Latch

Post by n2582d »

Grady,
It's accessible enough that you could drill out the nutplate using a #40 drill bit and replace the nutplate with a locknut. Why not do it right though? The question I have is that it calls for using AN526-832R8 screws which are non-structural threaded machine screws. My plane had type B tinnerman or PK screws there. Although a '52 170B the striker plates on mine are mounted as shown in the 170A IPC. The nutplates I have also are the tinnerman type.
170A IPC - Click to enlarge
170A IPC - Click to enlarge
170 B IPC - Click to enlarge
170 B IPC - Click to enlarge
If mine is original it appears to be a A6194-8Z-1 one leg tinnerman anchor nut. If you have AN526-832-8 screws holding the striker in place you should use MK2000-08 anchor nuts.
MK2000m.jpg
MK2000m.jpg (15.57 KiB) Viewed 24993 times
Gary
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MoonlightVFR
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Re: Right Door will Not Latch

Post by MoonlightVFR »

So it appears there are two different fasteners listed to hold same door striker.

Two (2) different nut plates and two different screws.

I located a source for the 22A17A-82 . It was not easy to locate so I want to post their contact info.
They referenced a
Regal Air Inc 2040 Airway Ave, Fort Collins, CO 80524 - tel 970 484-2655
gradyb, '54 B N2890C
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n2582d
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Re: Right Door will Not Latch

Post by n2582d »

Grady,
I'm curious. Is your striker plate fastened with a machine screw or a PK screw?
Gary
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MoonlightVFR
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Re: Right Door will Not Latch

Post by MoonlightVFR »

Looked to me to be a common screw used on the cowling.

It was certainly not the machine screw depicted in the IPC.

I want to have BOTH types with me when I drive 90 miles round trip to effect a repair.

Thank you for sharing your experience on this repair. I am under pressure to vacate hanger.

Claims have been made that runway will be history in 60 days.
gradyb, '54 B N2890C
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MoonlightVFR
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Re: Right Door will Not Latch

Post by MoonlightVFR »

I am ready to get this door closure repair done.

Have purchased two (2) different nut-plates , based on some prior post. Will not know correct one until I remove the rear door post faring.

The original looks so nice w small flush rivets.

I have not ever acquired skill at setting rivets.

Question to the forum. How can removal of damaged nut plate be accomplished and a neat job of riveting in the new part?
gradyb, '54 B N2890C
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c170b53
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Re: Right Door will Not Latch

Post by c170b53 »

Without pontificating on the merits of having a personal mechanic to assist you, I'll just say, Grady sounds like you need some oversight to help you down the road to full time wrenching :D
Even though you door won't latch, it will stay closed with the lock so you can move your plane or is your lock missing as well?
As George suggested have you removed the rear post fairing and if so is the nut plate still there or has it broken off and been replaced with a flat speed nut? If you cannot remove the nut plate you can just run a longer screw through it and attach another nut as long as the cables are not fouled. If you want to remove the nut plate, likely the flush rivet head has been painted over. Lightly scuff off the paint with scotch Brite so you can make out the rivet head. Pinpoint the centre of the rivet and use a 3/32 sharp drill bit to drill the centre of the rivet halfway down the shank of the rivet( I'm assuming it's a 3/32 rivet holding the nut plate) then with a small punch ( I use a straight short o-ring pick) tap it through the door post. Be gentle, the rivet and nut plate will pop off the back of the door post.
I would use again just a common lock nut to secure the screw myself but mmmv.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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MoonlightVFR
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Re: Right Door will Not Latch

Post by MoonlightVFR »

Discovered new problem area with R door not wanting to latch closed.

My paint scheme has a refreshing GREEN paint stripe on side of fuselage front to tail.
Just noticed that stripe on door is 5/16" LOWER than matching portion on fuselage. SAGGING DOOR.
Left door stripes match up beautifully.

Examining the front door hinges and pins they seem O.K.

Thinking that problem in secure latching is that the "CAM" in door lock is hitting the lower portion of Door striker not allowing the
CAM to move into the opening.

My first reaction is to think of fabricating a slippery Wedge to raise the lower portion of door so the locking parts can do their thing .

This can't be an original innovation. What have other owners done?

I am open to any and all mechanical suggestions short of duct tape.
gradyb, '54 B N2890C
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Bruce Fenstermacher
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Re: Right Door will Not Latch

Post by Bruce Fenstermacher »

Only way a door can sage is the hinging changes or the door gets bent. I've tried intentionally to bend a door in a last ditch effort to make it fit the fuselage better and I'm hear to tell you, those are touch doors not easily bent. So, look closer at the hinges more specifically the pin and it's points. This is a common repair issue.

With door in hand, can you pick up on it and see any slop? Look at the hinge half screwed to the fuselage. Have they slid from the position they were in when the plane was painted?

If I could find no issue areas I would loosen the hinge halves on the fuselage and try to reposition them so they align the door correctly. If your hinge screw holes are virgin, and have no wear, you may find there is little play to "adjust" the door. In one of my cases, after much thought, I slotted the hinge holes just a touch in order to adjust the door as required. DON'T do this willy nilly. You can not reattach the material you file out. It also does not take much material removed to adjust the door a lot.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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c170b53
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Re: Right Door will Not Latch

Post by c170b53 »

All what Bruce said. When the door is open can it be lifted on the hinges vertically? All will to a point but if it's too much then it's typical excessive hinge wear of the hinge tabs which will cause the door to sag on an angle. If that's the case you have to add material to the hinge halves or replace them.
Jim Wildharbors had a few top halves he had had some fabricated for his plane. He might still have one left.
I made miniature bushings to take up the gap on another airplane and that worked but that's a short interim fix.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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GAHorn
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Re: Right Door will Not Latch

Post by GAHorn »

Hinge pins are often sourced from Tractor Supply, hardware stores, etc. etc. and their diameter can affect door-hang. Check for looseness and get the correct size pins before doing anything drastic.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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