Full Details

Name and Model Number Russian Pilot's Circular
Slide Rule NR-1
Country of Origin Soviet Union
Date of Manufacture 1964
Front Scales Various scales for aviation
Back Scales Various scales for aviation
Scale Length Scales of various lengths, diameter of disc 26 cm
Type of Rule Disc
Construction Celluloid disc on a metal disc
Area of Use Aviation
Comment NR-1 was made in Riga, now the capital of Latvia and it was designed to replace the Vetrochet device used from 1927 by pilots to calculate the effects of wind. Vetrochet is robust and handy, but its accuracy is not very good. In addition to features of Vetrochet NR-1 also has at the outer edge a few logarithmic scales similar to the ones in NL slide rules. The diameter of NR-1 is 26 cm and large size may be one of the reasons why the pilots did not like it and it is thus relatively rare. Vetrochet was still widely used until NRK-2 combining the features of Vetrochet and NL slide rules was launched in 1970. Literature
Kumkov I.M.: Navigatsionnyi raschetchik NR-1. Posobie dlya letnogo sostava, 1959, 44 pages
Rarity RRR
Donor Collection of Timo Leipälä
Match Number 399
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In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen
(1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD.
• RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace.
• RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale.
• RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale.