Mod (WD)", and . the manufacturer's - AVR-101 Airborne Voice-Recorder. SyttemjMaintenance Manual # 523- . 0757366-201114 2nd Revision1.5.Feb.' 196.8 and•Baker Electronics Manual # 23-50-08 Rev. .1 InStallation and Operating Instructions. The update complies with FAR 25.1457. . A satisfactory preflight-functional check was