AD/PT6A/16 - Improved Strength P.T. Shaft Housing and Reduction Gearbox Condition Monitoring (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Pratt and Whitney Canada Turbine Engines - PT6A Series

AD/PT6A/16 Improved Strength P.T. Shaft Housing and Reduction Gearbox Condition Monitoring

10/85

Applicability: All PT6A-6, -6A, -6B, -6/C20, -20, -20A, 20B, -21. PT6B-9, PT6A-27, -28, -34.

Requirement: 1. Modify affected engine fitted with the P.N 3010548 welded power turbine shaft housing by incorporation of UACL SB No. 1138, Rev. 3.

Note: Information regarding affected engine model S/Nos., etc. will be found in UACL SBs No. 1138, Rev. 3 and 1217, Rev. 4.

2. Modify all affected engines by installation of a magnetic chip detector in accordance with paragraphs 2.A.1. and 2.A.2 of UACL SB No. 1217, Rev. 4.

3. For engines modified in accordance with paragraph 2 above, check the magnetic chip detector pins for electrical continuity using any utility volt ohmmeter. If continuity is detected, remove the detector and inspect the magnetic pole pieces for contaminants and also perform the oil filter inspection described in paragraph 4 below. Determine subsequent action in accordance with the guidance provided in the paragraphs relating to oil filter element inspections in Part 3, Section 3 of the latest issue of the applicable engine Maintenance Manual.

4. For all engines, remove the main engine oil filter element and inspect visually for signs of metallic contamination. If no visible contamination is present, use a ten power magnifying glass and magnet (minimum lift 225 grammes (8 oz)) to further inspect the element for magnetic and non-magnetic particles. Determine subsequent action in accordance with the guidance provided in the paragraphs relating to oil filter element inspections in Part 3 Section 3 of the latest issue of the applicable engine maintenance manual.