Interesting piece of Pilot navigator equipment from the 1960’s is this Airfare / Navi Supersonic type MB-9 by Jeppesen Company from the USA . This Air Navigation slide rule is made of plastic and comes with the original manual and in the original signed sleeve. It is two side and in hardly used condition, as is the case (unsigned) and the original manual. Mach setting goes up to mach 3.5. This circular slide rule measures ca. 12,5 cm or 5 inches in diameter. Check the attached video on how to work your vintage man tool: aviation slide rule operation instructions!
