[ARC5] R-25/ARC-5 Stabilized Receiver

[J Forster]

Gordon White wrote:

>  [snip] Remember,
> temperatures ranged from planes sitting in the African sun to 40,000
> feet over northern Germany in January.
>

Isn't 40,000 feet on the high side for service ceilings for WW II aircraft?
I thought it was more like 30,000.

Best,
-Jhn