Commonwealth legislation

AD/HU 269/73 - Main Gearbox Ring Gear - Inspection and Increase of Bolt Torque

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

The directive requires operators of Schweizer (Hughes) 269A/B/C-series helicopters with specified main gearbox part numbers (except gearboxes marked “W”) to inspect the main‑gearbox ring‑gear attachment bolts and increase bolt torque as needed, following Hughes SIN N‑181, within 100 hours after 30 September 1982. CASA issued it to reduce reported bolt looseness that can cause ring‑gear/carrier failure; owners/operators bear the inspection, maintenance and downtime costs.

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AD/HU 269/73 - Main Gearbox Ring Gear - Inspection and Increase of Bolt Torque

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Schweizer (Hughes) 269 Series Helicopters

AD/HU 269/73 Main Gearbox Ring Gear - Inspection

and Increase of Bolt Torque

9/82

Applicability: All models 269A, 269A-1, 269B, 269C fitted with main gear box assembly P/N 269A5175-7, -9, -11, -13, -15 or -17, except those gearboxes identified with a letter “W” adjacent to the serial number on the identification plate.

Document: Hughes SIN N-181.

FAA AD 82-15-01 refers.

Compliance: Within 100 hours time in service after 30 September 1982.

Background: We are advised that there have been several reports of looseness to the main gearbox ring gear attach bolts. The possible resulting fatigue failure to bolts or ring gear carrier could cause loss of rotor drive, or jamming of the main gearbox.

Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

1 AD/HU 269/73 - Main Gearbox Ring Gear - Inspection and Increase of Bolt Torque