The Aviation DataBase: Service Information: Aircraft Radio & Control (ARC)
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DataBases updated: Jul 16th, 2025
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Field Service Bulletins
NameRevisionLangSubjectDate
en Squelch Failure in RT-131A (Mod 3)2/23/1971
en Replacement Oscillator Cavity for RT-106A and RT-506A4/29/1971
en RT-131 Intermittent RF Output5/6/1971
en Addition of Ventilated Covers on RT-131 & Synthesizer ARC# 384626/4/1971
en 400A Autopilot Actuator Follow-Up Pot8/21/1972
en Inspection of Internal Screw, to Avoid Any Possible Binding of Autopilot Servo Actuator, Types PA-500A/520A/520B2/22/1974
en Ensure Adequate Inspection of or to Permit Override of Autopilot Servo Actuator, Type PA-500A12/1/1975
en Authorization to Use Relay ARC P/N 38381-1006 in Mod 1 PA-495A-2 Actuators3/23/1978
A en Authorization to Use Relay ARC P/N 38381-1006 in Mod 1 PA-495A-2 Actuators7/24/1978
Service Advisory Bulletins
NameRevisionLangSubjectDate
en Improved Contact for the R-542 - RT-522/5322/10/1970
B en Prevent the Remote Possibility of Moisture Collecting in PA-500 Actuator
en To Prevent Possible Jamming of the Follow Up Potentiometer Drive Gear by Large Objects in the PA-500 Actuator4/8/1971
en To Prevent Accidental Engagement of the AF-530 Autopilot5/5/1971
Service Letters
NameRevisionLangSubjectDate
en Sigma Tek Control Panel - 760 Channel Comm Modification11/13/1989
Miscellaneous
NameRevisionLangSubjectDate
en Tech Aids: Error in Service/Parts Manual D4550-13, 200A/300A Series Autopilot Test Set (Type 42A)10/10/1975