AIRWORTHINESS DIRECTIVE

CAA-AD-028/2001

Date of issue: March 29, 2001

AIRCRAFT - HIGH PRESSURE TURBINE DISC - INSPECTION

Applicability: Rolls-Royce Dart 520, 530, 540 and 550 Series engines as detailed in Service Bulletin.

Effective date: May 17, 2001

Compliance: Required as indicated in CAA UK AD 007-02-2001.

Remarks: The compliance of this AD must be recorded in Aircraft Logbook, where applicable the requirements of this AD must be integrated into Aircraft Technical Documentation. Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel: 420 2 33320922, fax: 420 2 20562270.

Ing. Pavel MATOUŠEK
Director of Airworthiness Division
CAA CZ

CAA UK AIRWORTHINESS DIRECTIVE 007-02-2001
APPLICABILITY

Rolls-Royce Dart 520, 530, 540 and 550 Series engines as detailed in Service Bulletin.

SUBJECT - DESCRIPTION

Engine - Turbine wheels and shafts - HP turbine disc - Introduction of seal arm nip and improved corrosion protection.

COMPLIANCE - REQUIMENT (SUMMARY)

Compliance is required with Rolls-Royce Service Bulletin Da72-533 when the engine is next disassembled sufficiently to afford access to the affected engine section but not later than 31 December 2005. The Service Bulletin introduces a revised HPT disc and an improved sacrificial corrosion protective coating to reduce the risk of excitation of the disc and improve corrosion protection. Existing HPT discs may be reworked in accordance with the bulletin. This action is required because since 1972 there have been a number of HPT disc diaphragm failures on in-service engines, two resulted in the HPT disc being released.