Brady Jet Ruler
Advo,
I went through training with Rog Brady at Cranwell in the late 70s. There were primitive'jet rulers' available in Flight Planning but non that really fit the bill. We used to cut down Nav Rulers to pocket size and customize them as required. Rog saw the gap in the market. I think he went on to the Buccaneer Force after that, then Cathay??
HVD