[Milsurplus] Re: APN-1 usage.. was APN-1 vs C-1

[J. Forster]

C Whitaker wrote:

> de WB2CPN
>
> Ol'  8403, the C-47 I bumed around in a lot, had the indicator
> at the navigator's  position.   There was a little telescope that
> looked down at the ground as it went under the airplane.  The
> navigator could measure drift, and ground speed (TAS) if he knew
> how far it was to the ground.  Hence APN-1 and its little
> blip on the circle.

The APN-1 uses a 270 degree meter as a readout. It's marked 0 to 400 or 4000
feet, depending on range.-John

>  Over water an iceberg or waves driven by
> the wind helped.   I don't think APN-1 tied into anything, except
> maybe a minimum altitude gear warning horn.
>
> Of course, I could be lying.
>
> 73  Clete