Wikipedia has some details.
It was used in Imperial Airways advertising from the early 30's and appeared on their aircraft around 1938.
The original Speedird before the above examples was simpler and I think more elegant.
https://www.britairliners.org/airlin...-of-boac&id=24
Last edited by renfrew; 17th Apr 2024 at 11:53.
Reason: more