[Milsurplus] non-louvered BC-375

[David Stinson]

----- Original Message ----- 
From: "Schreiber, Patrick" <Patrick.Schreiber at arrowsheds.com>

> I saw a BC-375
>on the "E" place with non louvered panels for the tube access
>compartment and the panel on the back side.  ???  I think every
>BC-375/191 that I have seen has louvered panels.  What is the
>significance of the solid panels?

I have both variants.  The non-louvered panels are on the later contracts,
IIRC.  I don't have any documentation as to why they switched to an
unvented panel, but I do have a lot of experience running the BC-375.
I think they did it to aid stability.
If properly allowed to warm-up, a 375 in good condition is a remarkably
stable machine for a 1928 design.  They were typically well-warmed before
a combat mission.  However,  the temperature in the radio room would undergo
a steep and rapid decrease as the bomber climbed to cruising altitude.
The vents let the heat out and the transmitter would therefore drift off
frequency.  A non-vented panel would add a lot of thermal inertia,
better retaining the heat and, thereby, increasing stability.
73 Dave S.