This is a special purpose slide rule, which was used by pilots to determine true airspeed, based on indicated air speed, altitude, and other instrument readings. It is typical of the many specialized slide rules used for air navigation and flight management, before the advent of electronic calculators and satellite-based navigation systems.
The slide rule was found with a collection of paper archives that were donated to the Smithsonian in 1957.
Display Status
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Country of Origin
United States of America
Type
INSTRUMENTS-Computers, General Purpose
Manufacturer
G. Felsenthal & Sons Inc.
Dimensions
3-D (Diameter x Depth): 0.6 × 20.3cm (1/4 × 8 in.)
Storage: 25.4 × 5.7 × 25.4cm (10 in. × 2 1/4 in. × 10 in.)
Materials
Plastic
Ink
Steel
Non-Magnetic Metal Alloy
Paint
Inventory Number
A19970199000
Credit Line
Bequest of the Estate of E.L. Jones.
Data Source
National Air and Space Museum
Restrictions & Rights
Usage conditions apply
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