Stamped from the Synthetic Training Section, AAFNS, Hondo, Texas. G-103 on the front.
AAFNS was the Army Air Force Navigational School at Hondo Air Base during WW2. They trained bomber and transport navigators.
A classroom setting of what I am guessing to be some type of radio communications training.
A very rare and unique photo. The history of the Hondo Air Base is extensive and online, check it out on Wikia.
Be sure to check out the other photos I have listed from this grouping.
Measures 8 x 10