Commonwealth legislation

AD/HU 369/37 - Tail Rotor Swashplate Bearing Locknut - Inspection and Increase in Torque

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This airworthiness directive requires operators of specified McDonnell Douglas (Hughes)/Kawasaki 369D helicopters (S/N 0003D–0409D not modified per Hughes SIN DN-37) to inspect the tail rotor swashplate bearing locknut at each preflight until the swashplate is modified, and to complete that modification (Hughes SIN DN-37) within 100 hours after 10 May 1979. If the locknut or tang washer is loose, the tail rotor pitch control assembly must be replaced with a serviceable unit marked with a white dot before further flight.

Pilots may perform the preflight inspection without certification; otherwise a licensed Aircraft Maintenance Engineer or appropriate maintenance release must record and certify the inspection or modification. Operators bear the inspection and modification costs and must schedule the corrective work.

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AD/HU 369/37 - Tail Rotor Swashplate Bearing Locknut - Inspection and Increase in Torque

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters

AD/HU 369/37 Tail Rotor Swashplate Bearing Locknut - Inspection and Increase in Torque

6/79

Applicability: All model 369D with S/Nos. from 0003D to 0409D, not modified in accordance with Hughes SIN DN-37.

Requirement: 1. Visually inspect the tail rotor swashplate bearing as follows;

(a) Pull back the non-rotating boot P/N 369D21806 from the tail rotor pitch control assembly P/N 369D21800 and check the locknut and tang washer by hand for looseness.

(b) If the locknut or tang washer is loose, remove and replace the tail rotor pitch control assembly with a serviceable assembly with a white dot on the locknut, before further flight.

2. Modify the tail rotor swashplate in accordance with Hughes SIN DN-37. For aircraft maintained in accordance with ANO 100.5.1, Part 1 of this Directive shall be entered on the maintenance release as maintenance required. The inspection may be performed by the pilot in command, in which case certification is not required. In all other cases certification may be made on the maintenance release. This inspection may also be performed and certified by any Licensed Aircraft Maintenance Engineer.

Compliance: For Part 1 - At each preflight inspection, until modified in accordance with Part 2.

For Part 2 - Within 100 hours time in service after 10 May 1979.

Background: To prevent loosening of the tail rotor swashplate bearing locknut and possible loss of tail rotor control, the tightening torque of the locknut is increased. Until this is accomplished, the locknut is to be inspected prior to each flight.

Source text

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

1 AD/HU 369/37 - Tail Rotor Swashplate Bearing Locknut - Inspection and Increase in Torque