COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Supplementary Equipment
AD/SUPP/5
Amdt 1
Air Equipment Hoists - "Up Limit" Micro Switches - Inspection and Modification
3/85
Applicability: All Air Equipment hoists P/No. 76370, 76370-010, -011, -020 and -030 fitted to helicopters.
Requirement: 1. Model 76370-010 hoist : Gain access to "Up Limit" micro switches by removing cover from micro switch enclosure. Inspect micro switches and interior of enclosure for evidence of moisture ingress and/or corrosion. If either is detected replace micro switches before further use of the hoist
2. Model 76370, 76370-010, -011, -020 and -030 hoists: Modify the hoist according to the instructions contained in Air Equipment Service Information Letter No. 25.62.0E.
Compliance: For Para 1: Before further use of the hoist after 5 July 1984 and thereafter at periods not exceeding 3 months. The inspection requirements are terminated after the hoist has been modified.
For Para 2: Before further use of the hoist after 31 August 1985.
Background: A dual "up limit" micro switch failure attributed to water ingress has occurred. The hoist cable and hook assembly continued past the normal up limit position until cable failure occurred approximately 200mm from the hook.
This Directive is raised in issue to reflect the manufacturers maintenance requirements.