[ARC5] Follow-up, Use of Command Sets

[David Stinson]

If interested in the evolution of the Command/Liaison 
systems, or in Army Aviation pre-WWII in general,
there is an excellent source document available online
(link below).

Aviation in the US. Army,
1919- 1939
Maurer Maurer
United States Air Force 
Historical Research Center

Prior to 1931, the Army's aircraft sets were designated 
by the type of aircraft for which they were intended:  
a "pursuit" set, a "bombing" set etc.
As you might expect, this didn't work so well.  Moreover,
the SCR-13x series of sets had their own set of problems.
Here's a nice passage (parrened notes mine)
from page 231 about the birth of the SCR-183:

   "In 1931 pursuit units assisted the Materiel Division
    in testing experimental radios for command communication. 
   Of five sets submitted by various manufacturers,
   one satisfied weight, space, and performance specifications.
   This radio (the SCR-183) weighed barely 43 pounds, 
    handled both voice and code ( note MCW ), and
    had a fixed antenna ( note- prior sets used antenna reels).     
   With plug-in coils, the receiving component (BC-192)  
   (note- early set that became BC-229)
   covered all required Air Corps frequencies. 
   The set's automatic volume control could be tuned 
   and operated by touch and sound without dependence 
   on sight, a big plus when operated by the pilot. 
   Pleased with the performance in 1932 tests, 
   and believing the SCR-183 and BC-192 
   could serve bombardment and attack as well as pursuit, 
   the Air Corps decided to order as many as funds permitted..."

There's an extensive section on the Airmail story.
Seems human errors, bad weather and aircraft that just hadn't yet
evolved to serve this mission had as much to do 
with the problems as the radios.

The document is in PDF format and is 15 MB:

http://tinyurl.com/35lya2l

Unlike many documents, it has an excellent index
with entries under "Communications" and "Radio."

73 Dave AB5S