vert stab/fin fasteners

How to keep the Cessna 170 flying and airworthy.

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simatos
Posts: 108
Joined: Tue Sep 07, 2004 9:31 pm

vert stab/fin fasteners

Post by simatos »

Wondering about bolts to fasten aft vert stab to empenage. In the IPC figure 13 shows attachment of "Fitting rear spar lower " with bolt NAS145-14s and NAS145-18. These are like big allen key bolts with hex socket in heads. Are these special and/or could regular AN bolts also be used? Thanks G
jon s blocker
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Joined: Tue Apr 23, 2002 1:56 pm

special bolts

Post by jon s blocker »

I replaced those bolts on my plane while rebuilding it. If memory serves me correctly you couldn't get an external wrench on a standard bolt at that location. The fit is too tight. Those bolts aren't hard to order and are the only bolts I know of to fit there, as well as being the only "correct" bolts to use. Also I think they have special washers you have to use with them, that are chamfered in the opening, because the bolt is radiused at the shoulder. Good luck, Jon
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jlwild
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Post by jlwild »

The NAS145-14 & -18 bolts are special high shear and have been replaced 8) by MS 20005-6 & -11 bolts and high shear chamfered washers P/N MS 20002-5. :D I ordered my replacement bolts/washers from Genuine Aircraft Hardware. Check them out on the web: http://www.gen-aircraft-hardware.com Also belive the minimum order for the washers was 25; so, make sure they are the high shear / chamfered ones. 8O If I remember correcly, I ordered the wrong ones the first time. :oops:
Jim Wildharber, Kennesaw, GA
Past President TIC170A (2010-12) and Georgia Area Representative
'55 170B, N3415D, SN:26958, O-300D; People's Choice '06 Kelowna, B.C., Best Modified '07 Galveston, TX, Best Modified '08 Branson, MO.
N170BP
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Post by N170BP »

I concur with jlwild. The MS20005 bolts are equivalent replacements.
I also concur with where to get them! (Genuine Aircraft Hardware).

Here are my notes when I ordered from them:

(2) MS20005-6 bolts @ $7.88 each = $15.76
(5) MS20005-9 bolts @ $8.58 each = $42.88 (sold in packages of 5 only)
(25) MS20002C5 counter-relieved washers @ $0.26 each = $6.50 (sold in packages of 25)
(25) MS20002-5 hardened washers @ $0.13 each = $3.18 (sold in packages of 25)

Total = $68.32 (+ shipping)

For what it's worth, buying the "original" NAS145 bolts from Cessna
would have cost $116.45 each (ouch....).
Bela P. Havasreti
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'54 C-180
simatos
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Post by simatos »

Guys thanks That answers all my questions Cheers Gary
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GAHorn
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Post by GAHorn »

Additionally,...using ordinary AN hardware in that location places unusual stress on the fitting because the chamfer/profile does not match. I've seen a few aircraft with ordinary AN bolts there. I wouldn't fly in them. IMHO. (And I wouldn't want to have to try finding replacement angles/attachment fittings when they eventually develop cracks.)
'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. ;)
simatos
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Post by simatos »

I am just reviewing notes from Bel and Jim . You note the dash numbers are different . two bolts with dash 6 but Jim I think you list dash 9and Bella, dash 11. Also You list 5 (five of the longer ones) I see spots for only 2 so where do the other 3 go?? Gonna order these up if you might be able to clarify these points. Thanks G
N170BP
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Post by N170BP »

If I remember right, when I called them for the order,
they didn't have the exact dash-numbers on-hand (hence
the longer ones I reference).

The additional number of bolts stems from the fact that
(at least when I called them), you could only purchase
said bolts in lots/bags of five.

Maybe give them a call, and see if they have exactly what
you're looking for in the quantities you're after.
Bela P. Havasreti
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'54 C-180
simatos
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Joined: Tue Sep 07, 2004 9:31 pm

Post by simatos »

just had the conversation with the General Aviation Hardware folks. Same as you guys so have lots of extra washers if anyone needs. Thanks again for your help Gary
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