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Dorsal Fin Attachment

Posted: Fri Dec 07, 2012 6:39 pm
by n2582d
N2255D wrote:
runerider wrote: Your 170 stab is held in place by one sheet metal screw on each side and two brackets at the rear of the vertical Stab. I have never heard of a vertical stab departing the airframe of a100 series cessna, so wiggle away.
The front of my vertical stab is held by 2 AN-4 bolts and the dorsal fin by 1 10-32 screw and a bolt. If yours is really only held by one sheet metal screw on each side I don't think I'd be flying it
Walt, The directory shows that you have a 1952 B model yet your vertical fin description matches that of an A model. I'd never noticed this before but the two models attach the dorsal slightly differently. The A has an AN 3-4A bolt mounted upside down to secure the dorsal where the B has two AN 526 screws which hold down "L" brackets on either side of the dorsal fin. Is your dorsal mounted on your B model like Cessna mounted it on the A models? It's interesting too that Cessna chose to use AN 526 non-structural screws rather than AN 525 structural screws. Loads must not be that great on the dorsal.
C-170A Vertical.jpg
C-170B Vertical.jpg

Re: Dorsal Fin Attachment

Posted: Mon Dec 10, 2012 3:34 am
by N2255D
Yes I have a 52 B and it is held by the 3 screws shown in the "B" parts manual. I used the parts manual to describe how the dorsal was put on and grabbed the "A" instead of the "B" manual. I was trying to point out that our vertical fin front was held by more than sheet metal screws and that even the dorsal fin was held on by more than sheet metal screws. Thanks for keeping me honest.