Felsenthal Instrument Company (Chicago, Illinois, USA) Aeronautical Navigation Computer 'Supersonic Computer' - 1960-1970 - Felsenthal Instrument 70s

"Supersonic Computer – Pilot’s Dead Reckoning" aircraft navigation computer, model PTC, manufactured by E. Felsenthal Instrument Co. in October 1970.

This instrument is an advanced circular slide rule, used by military pilots and navigators during the supersonic age to calculate:
• true airspeed (TAS)
• Mach
• altitude and offsets
• fuel consumption
• wind, drift and cruising angles
• course corrections
• time, distance and high-speed navigation

Includes:
• Original PTC aircraft computer in excellent condition
• Protective bag for the season
• Complete instruction manual (1970) with diagrams and all original tables

The set is complete and is an excellent example of the instruments used before onboard electronic calculators.

• Very good overall condition
• Clean and fully legible signs and scales
• Bag with normal signs of use.
• Complete manual, no loose pages

• Bag: approx. 16 × 12 cm
• Computer: approx. 11.5 cm in diameter