# Sinn 8 Day Aircraft Clock



## CMSgt Bo

In 1985, as a young Lockheed C-130 Hercules Crew Chief, I was responsible for setting and winding the 8 day mechanical back-up clock mounted on the co-pilots instrument panel before each flight. I took great pride in maintaining my 20 year-old jet in Full Mission Capable (FMC) condition at all times, and winding that clock was a daily ritual for me for the next 13 years. Fast-forward to 2007 while on a WUS Sinn factory tour that Crusader (Martin) organized, I spotted a Sinn aircraft clock built to the same mil-spec as my beloved Herky back-up clocks of old. This one pictured is the currently available Sinn NaBo 56/8 aircraft clock. I just placed an order for one today to go into a custom Land Rover Defender 110 being built for me in the UK.

From Sinns site:

Meets JAA FORM ONE requirements and the military test specification MIL-C-38207A 
Mechanical 8-day movement by Revue Thommen 
Functionally reliable at temperatures between -35 °C and +55 °C 
Especially resistant to vibration and shock 
Minute ring can be rotated in both directions 
Numbers and counters coated with non-persistent fluorescent luminous material 
Crystal with an anti-reflective coating on both sides 
Resistant to low pressure at high flight altitudes










Anyone else into aircraft clocks?


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## Sodiac

Wow, that's a great story! :-! Would like to see pics of the Land Rover and the installed clock when it's finished!

P.S. I'm surprised they're still using mechanical clocks in military planes? I'd have guessed everything was digital, synchronized to a satellite or something?


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## Bleh

CMSgt Bo said:


> Anyone else into aircraft clocks?


I am!! b-)

1943 Waltham 8 day B-17D bomber clock:


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## cavallino33

I bought an NOS mig clock of sort off of ebay. Haven't gotten it yet but I'll post pictures when I do.


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## CMSgt Bo

Sodiac said:


> Wow, that's a great story! :-! Would like to see pics of the Land Rover and the installed clock when it's finished!
> 
> P.S. I'm surprised they're still using mechanical clocks in military planes? I'd have guessed everything was digital, synchronized to a satellite or something?


The clock arrived today and I'm quite delighted with it. I'll post pics tomorrow.

There are electronic timing devises on most modern aircraft. Mechanical clocks are used as back-up instruments in case of power failure or failure of primary instruments. Other basic flight information such as speed, altitude, heading, and aircraft attitude are duplicated on back-up instruments as well.


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## Barnstormer

I bought this Waltham panel clock a long time ago- I'd say it was one of the things that really got me into cool mechanical timepieces.

Anyone know how to date one of these? The serial number is hard to read, but it looks like it is 37193. There is a very small hand engraved date on the back (like a service date scratched into the inside of a caseback on a watch) that says 8/4/54 with a "W" next to it.

It's funny, because as a pilot, I don't think I've ever looked at the mechanical panel clock to see the time- but it is still one of my favorite instruments.

On a side note, you are a CMSgt? Thanks for your service. It's guys like you that make it all work.


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## CMSgt Bo

Barnstormer said:


> I bought this Waltham panel clock a long time ago- I'd say it was one of the things that really got me into cool mechanical timepieces.
> 
> Anyone know how to date one of these? The serial number is hard to read, but it looks like it is 37193. There is a very small hand engraved date on the back (like a service date scratched into the inside of a caseback on a watch) that says 8/4/54 with a "W" next to it.
> 
> It's funny, because as a pilot, I don't think I've ever looked at the mechanical panel clock to see the time- but it is still one of my favorite instruments.


That's a pretty sweet looking Waltham. There's really no way to tell when those clocks were made as the Part Numbers and later National Stock Numbers and Cage Numbers do not denote the date of manufacture. At times Serial Numbers will include a date but that is rare and can actually represent the initial contract date. In this case it's safe to assume your clock easily pre-dates the rebuild/repair date of 8/5/54. Since I've been in the military aircraft clocks are treated as RTF (run til failure) items that are replaced when unservicable. Once replaced they are returned to the Supply System as unservicable/repairable (NRTS = not repairable this station) and go back to Depot for repair.


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## Somewhere else

Want to buy a day 8 wind up mechanical aircraft clock brand new? They're still made. What's more they are made in the USA by the Waltham clock company. The B17 clock shown in the above photo is still in production. If you look on the net, under Waltham clocks or Waltham aircraft clocks you'll find the manufacturer.

when Waltham itself went out of business their 8 day aircraft clcok business was bought by a large distributor of aircraft clocks and they have kept production going to this day.


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## valvestem

Somewhere else said:


> Want to buy a day 8 wind up mechanical aircraft clock brand new? They're still made. What's more they are made in the USA by the Waltham clock company. The B17 clock shown in the above photo is still in production. If you look on the net, under Waltham clocks or Waltham aircraft clocks you'll find the manufacturer.
> 
> when Waltham itself went out of business their 8 day aircraft clcok business was bought by a large distributor of aircraft clocks and they have kept production going to this day.


Here the link, interesting history...

http://www.walthamclocks.com/


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## river rat

Nice clock.Here are a few out of my collection the one in the center is my oldest issued in 1931.I just got two more a russian mig clock and a Waltham A13A that has a chronograph function the second hand reset's and starts with one of the button's on the clock and another hand tell's you when the second hand does a full rotation 60 seconds that one's in a shop for service right now.


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## kiwidj

I'm really starting to want one of these. :-!


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## Beau8

Sweet looking aircraft clock with a sweet movement inside~Congrats! ;-)


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## eltejano

I've always wanted a Sinn watch, but I'm going to put that clock on my wishlist too now - and probably a waltham too. I'm scared to look up the prices though


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## jj30

Anyone have any resources? I bought an elgin online, it doesn't work, I'm trying to fix it. Any links, manuals, PDFs? For 8 day aircraft clocks?
Thanks


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## Mike 777

I haven't tried this fellow yet, but he has an impressive site. He specializes in warbird clock restoration: Historic Timekeepers Restoration Services and Supplies


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## kai-wun

What beautiful pieces! Anyone have a source for these?


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