Semaphore Trainer, US Navy H-21 all documentation we've seen on

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

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

Journal of Navigation

Has been seen on 1940's DC-3

Semaphore Trainer, US Navy H-21 all documentation we've seen onHere 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