Standard Cirrus C-Hook

As the "other poster" the main thing I was saying was to comply with the
design Tech Note which would mean not going to a non-standard bearing size
or specification. As for "used parts" it depends on whether you can be
sure that they were the correct parts in the first place and what has
happened to them since new.

John Galloway



At 12:37 23 September 2008, JJ Sinclair wrote:
Hmmmm,
All 3 of the birds I have in the barn are 19mm, you may have a problem
in getting SH to come up with what was an early change to the design.
I'll take a look at the elevator side to see how much of a hassle it
would be to change both sides of the hook-up.

Another poster said you shouldn't consider "used parts". My response
would be; What do you think a 39 year old sailplane is, if not a
collection of used parts flying in close formation?
JJ

Randy wrote:
The bearing size for my original C-Hook is approximately 14.15mm.
The newer/larger bearing size is 19.00mm

Randy


On Sep 20, 7:42=EF=BF=BDam, JJ Sinclair wrote:
Chris,
What size do you need in mm ?
JJ

Randy,
It will take some glass work to swap out both sides of your elevator
drive, ie change early SH 14.15mm connections to later SH 19mm drive
mechanisms. As with any "used parts", they must be inspected by a
qualified person to determine damage, wear and corrosion. These parts
have been stored in my barn for about 20 years, ever sence their
rather spectacular 'last flight'. You could change to a "used"
elevator with 19mm drive, but that would be over-kill to solve a
rather simple problem. The C-hook is nothing more than a 10mm bolt
with the "C" fitting welded on top of it. Recommend you take both new
and old fittings to a good machine shop and have them cut the C
portion off both and then weld the new 10mm bolt section onto the old
14.15 C-hook. Before removing the C-hook from your Cirrus, be sure to
measure the exact distance from the top of the push-rod to the bottom
of the C in the C-hook. When installing the new part, screw it in
until the distance is exactly the same. Then tighten the jam-nut and
check the elevator throw against the FM/MM.
Have fun,
JJ

Randy wrote:
The bearing size for my original C-Hook is approximately 14.15mm.
The newer/larger bearing size is 19.00mm

Randy


On Sep 20, 7:42�am, JJ Sinclair wrote:
Chris,
What size do you need in mm ?
JJ

At 20:17 22 September 2008, Randy wrote:
Gavin,
The Serial number for this glider is #9. This is what is in the
cockpit, aircraft log books,
original Bill of Sale and on the Airworthiness Certificate. It was
built in 1969.



Randy,

I am impressed. I thought the chances of you having a single digit serial
number was so low that I didn't mention it.

Notwithstanding the other advice you have been given I am sure
Schempp-Hirth will support/come up with a suitable way ahead. When I
visited the factory in the summer some of the most interesting work was
being done by some of the retired workers. They are allowed to use all
teh factory's facilities and work on projects that are not financially
viable for good causes (local clubs etc). I saw a Std Cirrus that had
gone through a hedge and had its wings ripped off. The central metal
'cage' in teh fuselage had been completely rebuilt. Another set of
wings was being offered up. Also in the crash the tail boom had broken
and the tail written off. The team were grafting on a Nimbus 2 tail (if
recall correctly).

So a sorting out an early C hook to match the early size tail plane
bearing should be straight forward.

Good luck.

I am just wrestling with the question as to whether to fit a transponder
or not this winter... crowded skies in this part of Europe.




Gavin
Std Cirrus, CNN now G-SCNN, #173
LSV Viersen, Keiheuvel, Belgium

Mines a collection of ABused spare parts flying in generally tight formation.
For what it is worth my 1970 Std Cirrus has the smaller (14.15mm?) "C" hook, and I replaced it via the agent with no
problem last year. The reason for replacement was wear - abrasion of the hook from all the dust over 38 years.

Serial number #57 - I think they changed the size when they went to the "B" fuselage on serial number 158.

Bruce

JJ Sinclair wrote:
Hmmmm,
All 3 of the birds I have in the barn are 19mm, you may have a problem
in getting SH to come up with what was an early change to the design.
I'll take a look at the elevator side to see how much of a hassle it
would be to change both sides of the hook-up.

Another poster said you shouldn't consider "used parts". My response
would be; What do you think a 39 year old sailplane is, if not a
collection of used parts flying in close formation?
JJ

Randy wrote:
The bearing size for my original C-Hook is approximately 14.15mm.
The newer/larger bearing size is 19.00mm

Randy


On Sep 20, 7:42�am, JJ Sinclair wrote:
Chris,
What size do you need in mm ?
JJ

I am having a new C-Hook made by the Factory Engineers.
This way I will sleep better after I sell this glider.

Randy

Here is a note I received today the from factory engineer.

"The bigger C-Hook for the Standard Cirrus elevator is for the
Standard Cirri without the TN 278-25...these Standard Cirri
have still the original bearing in the elevator.
But in Germany the Technical ote 278-25 was mandatory....
so maybe this was the same in the US. With the TN 278-25
the bearing will be replaced by messing hubs....and then the
C-Hook has to be smaller. So i think, that you will need the
smaller one.

Please let me know, if Carsten should send you the smaller one...
or talk with Carsten by yourself.

Best regards and greetings to everybody,"

Christoph

S/N 36 also has the smaller hook.

On Sep 22, 4:17*pm, Randy wrote:
Gavin,
The Serial number for this glider is #9. This is what is in the
cockpit, aircraft log books,
original Bill of Sale and on the Airworthiness Certificate. It was
built in 1969.

Randy,

Does nothing to help you with your issue, but, did you know that you
have the Standard Cirrus from the famous Polars of 8 article by Paul
Bikle? I was just sitting down to some "meditation" time in the
reading room when I glanced at one of the tables and saw serial #9
(N184N). It in the June 1971 issue of Soaring

Erik Mann
LS8-18 P3