Door Stops & Stop latch

How to keep the Cessna 170 flying and airworthy.

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Re: Door Stops & Stop latch

Postby gahorn » Thu Aug 22, 2019 4:31 pm

The first SkyCatch system which was produced re-used the Tinnerman receptacle that Cessna installed at the factory in the door. The SkyCatch only altered the tip of the bracket under the wing. That SkyCatch was later acquired by a fellow in Oklahoma who also produced a nylon/spring-loaded receptacle replacing the Tinnerman part. That second producer stopped production/sales (circa 2003) when an enterprising FAA Inspector convinced him he was in violation of FARs since he had no STC/PMA for his product. (This info was conveyed to me by Johnny Williams, TIC170A member about the seller who had recently sold me one of his last kits.)

My airplane has this SkyCatch system and it has worked flawlessly for me now over 20 years of ownership.

When i bought the 172 last year it had a sorry/failed original Cessna arrangement which I altered into the cabinet-hardware method. The brass “plug” was pinned onto the L-bracket and the double-ball receptacle pop-rivetted onto the top of the door. It works very well and was logged as a minor alteration. (I’m a bit less hard-nosed about such things paperwork-wise since I retired from a professional need to keep my certificates.)
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Re: Door Stops & Stop latch

Postby rnealon1 » Mon Mar 02, 2020 3:05 am

Hi All,

Noticed today that the pilot side door stop bracket tip has broken/rusted off. Is there a replacemnt source for this bracket?

Looks like IPC P/N 0523004-10 Figure 3-109

Thanks,

Bob

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Re: Door Stops & Stop latch

Postby hilltop170 » Mon Mar 02, 2020 4:59 am

rnealon1 wrote:.................. Is there a replacemnt source for this bracket?.................


Door Stewards
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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Re: Door Stops & Stop latch

Postby Bruce Fenstermacher » Mon Mar 02, 2020 12:52 pm

To be more specific than Richard's post. Door Stewards are a very nice addition to the door that illuminates the need for the stop.

FYI since you are looking at that stop and might find a replacement for your rotted stop. The fuel tank is immediately on top of that stop. Should you decide to replace yours you MUST use the same length screws as original (assuming they are original), else you will either immediately or eventually punch a hole in your fuel tank.
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Re: Door Stops & Stop latch

Postby rnealon1 » Mon Mar 02, 2020 5:10 pm

Hi Guys,

Thanks for the tips on both Door Stewards (which are on my upgrade list) and bracket screws/fuel tank issue.

I still need to do something with the existing broken bracket and the simplest solution is to replace it if there is a way to find one.

Thanks,

Bob
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Re: Door Stops & Stop latch

Postby DaveF » Mon Mar 02, 2020 7:52 pm

Here's what happens to the fuel tank when the door stop screws are too long. I found this when I pulled the tanks for reseal.
Edit: Or someone ran a tap up through the nut plates.
DoorStopScrewsTooLong.jpg


Here are the nutplates. Cessna probably should have used closed-end sealed type.
DoorStopScrewNutplates.jpg
Last edited by DaveF on Sat Mar 28, 2020 8:50 pm, edited 1 time in total.
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Re: Door Stops & Stop latch

Postby c170b53 » Mon Mar 02, 2020 8:48 pm

Or...it’s steel I think and since it’s really a non airworthiness item might you just re- contour what you have remaining with a file, then reprotect.
Jim McIntosh..
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Re: Door Stops & Stop latch

Postby rnealon1 » Mon Mar 02, 2020 11:42 pm

Hi Jim and Bruce,

What length screws should be used? If the IPC specifies I can't tell.

I removed the bracket and found 2 screws 1/2" long, 1 5/8" long, and a fourth one missing.

I was also wondering if this bracket is the same on the 170A since there are a few being parted out. The IPC part number is different than the B model but not sure if that means anything.

Thanks,

Bob
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Re: Door Stops & Stop latch

Postby hilltop170 » Tue Mar 03, 2020 12:42 am

c170b53 wrote:Or...it’s steel I think and since it’s really a non airworthiness item might you just re- contour what you have remaining with a file, then reprotect.



Or, you could cut off the ruined area and fab new patch pieces to-spec to go on either side of the remaining bracket with a latch insert between the patches and rivet or screw in place. Then, in the future when the insert wears out just replace it with a new one.
Richard Pulley
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1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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Re: Door Stops & Stop latch

Postby c170b53 » Tue Mar 03, 2020 1:52 am

Not sure what the difference is between the door stops ( wing dihedral vs straight wing = different lengths Wag) Seems panhead screws are optional as I didn’t see them called out either. You could use a hi- lock gauge to determine length or just a piece of Lock wire but definitely go short.
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Re: Door Stops & Stop latch

Postby DaveF » Tue Mar 03, 2020 2:57 am

This is how long the screws are in my right-hand doorstop.
Screenshot 2020-03-02 at 7.49.15 PM.png
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Re: Door Stops & Stop latch

Postby n2582d » Tue Mar 03, 2020 6:19 am

rnealon1 wrote:Hi Jim and Bruce,

What length screws should be used? If the IPC specifies I can't tell.

I removed the bracket and found 2 screws 1/2" long, 1 5/8" long, and a fourth one missing.

I was also wondering if this bracket is the same on the 170A since there are a few being parted out. The IPC part number is different than the B model but not sure if that means anything.

Thanks,

Bob

Bob,
Here's two screen shots from the early C-172 IPC:
Screen Shot 2020-03-02 at 5.29.31 PM.png
Screen Shot 2020-03-02 at 5.29.08 PM.png
I just went out and measured what length screws are on my '52 door stop. The forward ones are 1/2" long AN520-10R8 screws (now superseded to MS35207-263) and the rear ones -- the ones with the critical length -- are 7/16" long AN520-10R7 screws (now superseded to MS35207-262). I hope your too long ones didn't damage your fuel tank. On this entry Kyle uses a 3/8" long AN520-10R6 (MS35207-261) so I'd measure your wing as Jim suggests to determine what screws to use.
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Re: Door Stops & Stop latch

Postby gahorn » Tue Mar 03, 2020 11:01 am

Here’s another solution some find useful:

43BC2BEB-D5EA-49AA-BB49-FEE5B9B70C7A.jpeg
'53 B-model N146YS SN:25713
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An originality nut (mostly) for the right reasons. ;)
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Re: Door Stops & Stop latch

Postby ghostflyer » Tue Mar 03, 2020 10:06 pm

I removed my door stop assy totally. After the 3rd occasion of hitting my head on it [and having had to cancel the flight once ] ,enough was enough. How do I keep my door open ? Well a bungee cord around the window frame and around the wing strut . I have been doing this for the last 10 or more years . All approved ,by me . When not in use it’s stored under the front seats .
Plus my fuel drains under the wing are all flush type drains .
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Re: Door Stops & Stop latch

Postby rnealon1 » Sat Mar 28, 2020 7:01 pm

gahorn wrote:Here’s another solution some find useful:

43BC2BEB-D5EA-49AA-BB49-FEE5B9B70C7A.jpeg


Hi George,

This photo is interesting because the catch fitting on the door is exactly like the one on my aircraft door (and apparently not the original fitting?), but the bracket in the photo looks shortened from the original.

I purchased a "new" bracket from Preferred Airparts, but to match the other side I need to add the male fitting on the tip of the bracket. It sounds like this may be a hardware store part?

Thanks,

Bob
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