Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle - Stab

How to keep the Cessna 170 flying and airworthy.

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cfzxo
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by cfzxo »

I think you might be on to something there Jim, because my 55 26509 has holes and shims at the bulkhead. Slots would make the install simpler as I remember having fun placing the shims and bolts at the bulkhead.
Assuming the slots are fore and aft.
Bill
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gfeher
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by gfeher »

Yes, the slots are fore and aft. I'm also wondering whether the nuts are hiding the slots on some installations. On mine, the length of the slots is less than the width of the nut. So if the bolt were located towards the center of the slot, the nut would completely cover the slot, hiding it, especially if there were a washer under the nut. Also, as I mentioned, paint can hide evidence of the slot, as in the case of the nut that I photographed. I only thought to scrape the paint away at the base of that nut because the adjacent nut had been replaced and you could see the slot where the paint was removed near that nut. Btw, my serial is 20467 ('52).

Interesting issue.
Gene Feher
Argyle (1C3), NY
'52 170B N2315D s/n 20467 C-145-2
Experimental J3 Cub Copy N7GW O-200
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wabuchanan
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by wabuchanan »

IMG_1493.jpg
My plane is in for annual this week. One of the items I noticed was bubbling under the paint on this Angle Bracket, so asked to have it looked at. They have come to the conclusion that is is irreparably corroded and I need a replacement part.

Suggestions from the group? I have a call in to Jason at Wentworth, but have not heard back from him yet. We are removing all tail feathers. Will we need to drill out and remove sheet metal to get to those 10 large rivets during replacement?

The guys are good in this shop, but C-170's are not their Forte', and I am still a new owner so any help and advice is appreciated.

After looking at various threads, I am also noticing that the Vertical fin does not seem to be secured with the proper cap bolts either.......

PS: '50 170 Serial number 19730, and the holes look round. I'll let you know if otherwise.
1950 170A N5776C SN:19730
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n2582d
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by n2582d »

Bill,
If the lead I e-mailed you about doesn't pan out you might try calling Air Repair. Ask them if the L-19 p/n 0612127 (fig. 19-14) matches this 170 part, and if so, do they have one for sale.
Gary
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wabuchanan
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by wabuchanan »

n2582d wrote:Bill,
If the lead I e-mailed you about doesn't pan out you might try calling Air Repair. Ask them if the L-19 p/n 0612127 (fig. 19-14) matches this 170 part, and if so, do they have one for sale.
Thank you! I will check those out. Jason at Wentworth also got back to me this evening and said he has one available as well. I appreciate the leads!

I was taking the tailwheel springs out today to replace the main spring, and it turns out the part that sits on top of the springs ( sorry, have not looked up part number yet ) also has small cracks through the aft end of it. I guess it is my time to need multiple NLA parts this year........

To add to the thread, my holes are circular, not elongated. Seriously corroded however.
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1950 170A N5776C SN:19730
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Showboatsix
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by Showboatsix »

QUOTE:
"Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Postby Bruce Fenstermacher » Thu Mar 17, 2016 12:13 pm

Well huh. Thinking this might have been a late production change to the part I looked at the A model IPC and compared it to the B model. Same part number including the -5. That is not conclusive but generally Cessna changed the dash number when a part changed at all.

Next I looked at the '56 IPC. Started to think ah huh, this was probably a change to accommodate both the old elevator and the new 172 design. But I can't find a figure that shows clearly how the rear elevator attaches in a early 172. What I found looks like this part or anything like it did not exist in a 172. Yet Showboatsix asked specifically about pn 0512108-5 in his '56.

The mystery takes a strange twist. I've now got to find an early 172 and look to see how they were built."




No No No, My 1956 C-172 conversion is NOT like this.

This question is/was for a buddy of mine who has a Cessna 170B with the slotted holes.

He lives in Scottsdale, Az., and the inquiry is about his airplane. Not my C-172.

So have we found other airplanes with slotted holes? I do not remember if I sent in photos during the first inquiry.

Thanks
Dean
UAO, Aurora Oregon
Hanger 26
56' C-172, With Conventional Gear Conversion
S/N 28963
N6863A
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Showboatsix
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by Showboatsix »

Bruce Fenstermacher wrote:So I get a text from Jim Wildharber asking be if I have a good part p/n 0512108-5 Bulkhead Assembly Angle - Stabilizer attachment. I say that's really strange whats wrong with it. He says the holes are worn (slotted or egged out). I say that is really strange cause this is the second time in less than a month I have a member contact me for the same part for the same reason, egged out holes. What are the chances the same wild man with a file attacked the holes in two airplanes, and they be discovered within a month.

I tell Jim there is probably more to the story and that he should have Del figure out why someone would do this.

Well it turns out the Association also owns a part with egged out holes. The mad man with a file is starting to get around. Or maybe, just maybe Cessna made the parts this way.

I believe the consensus of Del and George Horn, who has the Associations part in hand, is yes, Cessna slotted the parts.

So how about we get everyone to go look at their parts and lets see how many slotted parts are in the field. Here are some pictures of slotted and unslotted brackets.
IMAG0147.jpg
IMG_2759.jpg
IMG_2753.jpg
A follow up to this post, I contacted my Cessna buddy at Wichita and asked him about this issue.
This is his response is below.

"Dean,
This does look familiar to me however I don’t see anything in the drawings or our additional documentation that specifically defines the elongation of the hole. My drawings confirm (qty 4) .257” holes (clean and round). I tried to look through past service bulletins to see if we had anything to support the elongation and found no such note to elongate.

If I come across anything else I’ll let you know, but as it stands at this point I believe the holes should be clean and round per design. If fit issues are a concern you might consider working with the parts department to see about getting the part undrilled which may or may not help."

Thanks,
Brandon Judson
Customer Service Engineer-Structures
Textron Aviation
UAO, Aurora Oregon
Hanger 26
56' C-172, With Conventional Gear Conversion
S/N 28963
N6863A
bagarre
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by bagarre »

I checked mine on 95D (1952 170B) and they are slotted.
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ghostflyer
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by ghostflyer »

So does anybody know what sort of aluminium it is ? Maybe 7075 ??
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wingnut
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by wingnut »

The rudder has 3 hinge points. 2 are on the vertical stab, the lower point is on the fuselage aft bulkhead. These slotted holes allow the entire stabilizer assembly (vertical and horizontal) to be moved fore/aft so that all 3 rudder hinges points can be aligned perfectly. Then the forward spar of the horizontal to bulkhead attachment is shimmed as required.
I do know I have worked on several planes that had an obvious rudder hinge points misalignment when taking it apart; some so bad to cause cracked spars and hinge brackets, and is likely a contributing factor for the lower hinge bushing wearing so quickly, or often missing.
It is possible that adding the slots was an easy corrective action for a problem Cessna realized late in production. Possibly some Gomer didn't set up a jig correctly and a lot of rudders were built a bit out of whack.
No matter the reason, I like the slots.
Del Lehmann
Mena, Arkansas
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Showboatsix
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by Showboatsix »

Did you read my post with the Cessna Structures Engineers comments about the only drawing in Cessna's possession which describes the part as only having 4 round holes?

Also stated that no S/B was found to slot the holes!
UAO, Aurora Oregon
Hanger 26
56' C-172, With Conventional Gear Conversion
S/N 28963
N6863A
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Bruce Fenstermacher
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by Bruce Fenstermacher »

Showboatsix wrote:Did you read my post with the Cessna Structures Engineers comments about the only drawing in Cessna's possession which describes the part as only having 4 round holes?

Also stated that no S/B was found to slot the holes!
Might be the case but not definitive on the question whether Cessna ever slotted the holes, which we have mounting evidence they did.

Cessna has lost their drawings. This is why from time to time they called us and asked how they did something.
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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Showboatsix
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by Showboatsix »

It's still goes back to the issue of what approve documentation do you have for the slotted holes in the rear bracket?
That is the question we have with this current airplane down in Scottsdale Arizona , documentation from Cessna says they did not do it so what field approval data can we rely on that says slotted holes are acceptable in a structural component of the aircraft ?
UAO, Aurora Oregon
Hanger 26
56' C-172, With Conventional Gear Conversion
S/N 28963
N6863A
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canav8
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by canav8 »

My bracket is slotted as well. The frequency of this slotting leads me to believe that the Cessna Engineers were not talking to the assembly line guys in Assembly. There is to many examples with broad serial numbers to isolate an assembly line fauxpaux. My guess is Cessna Assembly line was under deadline pressure to get these out and this was the solution. I would also be curious to see any log book documentation of replacement of this bracket. I bet there will be very few examples. D
52' C-170B N2713D Ser #25255
Doug
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c170b53
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Re: Need Fig.25-24, p/n 0512108-5 Bulkhead Assembly Angle -

Post by c170b53 »

What makes the slotted holes unairworthy? That should always be the question. Is there insufficient edge distance? A close eyeball would easily tell whether the holes were milled. Hand drilling would not produce identical smooth holes with straight walls.
Totally different world today...I mean totally... :D A jump stick likely can hold every Cessna engineering drawing produced in the fifty's for their single line if Cessna still had them.
Today, every hull that Boeing produces come with its unique build variance log, no two planes are the same.
Back in a simpler time post WW II where get- er - done was done without saying, a simple practical fix wouldn't need a weeks worth of teleconferences. Thinking the documentation should be the same back then as it is today.....sorry just piling on again :oops:
Don't get me wrong. I'm relying on those that insist on total documentation or finding such documentation because really,.... I want a 170B maintenance manual. :D I know it secretly exists :D
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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