Semaphore Trainer, US Navy H-21 Doing so rotates the circular

Doing so rotates the circular inset card displaying the BHP

and can be seen behind the cockpit of many allied fighters and mid spine on multi engine aircraft

all documentation we've seen on these aircraft illustrate the type B-5 ignition switch

Has been seen on 1940's DC-3

Journal of Navigation

Semaphore Trainer, US Navy H-21 Doing so rotates the circularHere is a very interesting device, a Semaphore, or Flag Signaling, Trainer, made for the US Navy Special Devices Center by the advertising promotional firm Einson Freeman, Inc. The device is a rotating training card within a card. The "Sender" view is on one side and the "Receiver" view on the reverse side. When rotated to the desired letter by the Sender, he see's which flag arm position must be taken to communicate that letter. The Receiver, upon