Evaluation of Inertial Navigation System in Civil Air Transport Operations. Volume I. Ln-12. Inertial Navigation System. Book I. Discussion and Analysis

摘要

A Litton LN-12 Inertial Navigation System, with a Bendix Corporation Inertial Navigation Steering Computer, was flown in a Pan American World Airways DC-8 aircraft for 55 scheduled transatlantic crossings and 32 other short flights, domestic and foreign. Performance data were collected on inertial accuracy, steering behavior, track holding, maintenance, reliability, in-flight operation, position checks and azimuth drift. Eighty percent of the flights exhibited terminal errors of 10 miles or less in either latitude or longitude coordinates. The LN-12 inertial system operated 424 hours in the navigation mode, during 233 hours of which the aircraft was guided by autopilot controlled by inertial steering commands. Two transatlantic flights are examined in detail for doppler comparison in cross track miles to go, ground speed, and drift angle. These flights are also analyzed for comparison with aircraft compass heading, measured track, drift angle, miles to go, track heading, and waypoint misses, Reliability and maintenance factors were not significant during conduct of the program. Prior to commencement of the data flights, two demonstration flights of dual LN-12 inertial systems were performed. (Author)