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Sliderule identification challenge
11-03-2024, 11:05 PM (This post was last modified: 11-03-2024 11:09 PM by rprosperi.)
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RE: Sliderule identification challenge
(11-03-2024 04:46 PM)Maximilian Hohmann Wrote:  Hello!

(11-03-2024 01:15 PM)rprosperi Wrote:  @Max - you're the flight computer guru, what the heck is this about?

I can only guess that this is a sun compass, probably part of the survival kit that the pilots carried in case they had to eject from the aircraft and needed to find their way home. This one assumes that you know the exact time from your watch.
You can see that it was made for the Dutch airforce, because south is abbreviated "Z" for zuid and when you set the "to Sun" pointer to the "12h" mark, the south-pointer will be a little offset due to the difference in latitude between Greenwich and Amsterdam (or wherever the Dutch reference latitude passes through).
If you happen to carry a watch and a compass then you can use the inner scale to determine how many hours away you are from Greenwich, i.e. you can find out your longitude. What the "Rate 1" and "Rate 1/2" scales are for I have no idea.

Regards
Max

NB: This must be a rare item because the Dutch airforce only had ca. 140 Starfighters.

Thanks for your insights and comments Max, and good catch, pointing out the "Z" is for South in Dutch, I wondered what it was for (clearly South, but why "Z" and why "O" for East...?).

I had not considered a survival kit item, I guess that makes sense, but not sure how comforting it was to know only your latitude in such a situation... (though perhaps tactically, the longitude was easier to guess?)

Thanks!

--Bob Prosperi
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RE: Sliderule identification challenge - rprosperi - 11-03-2024 11:05 PM



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