Document ID: chunk:federal_register_of_legislation:F2006B06368:body:0:p1
Version: federal_register_of_legislation:F2006B06368
Segment Type: other
Provision Reference: 
Character Range: 20–2996

AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

 Pratt and Whitney Canada Turbine Engines - PT6A Series

AD/PT6A/32 Exhaust Duct Cracking 3/2003

 Applicability: All PT6A-6, -6A, -6B, -11, -11AG, -15AG, -20, -20A, -20B, -21, -25, -25A, -25C, -
            27, -28, -34, -34AG, -34B, -36, -110, -112, -135, and –135A series turboprop engines fitted with turbine exhaust ducts that are not in compliance with Pratt and Whitney Canada (P&WC) Service Bulletins (SB) 1610, 1610R1, 1610R2 or 12173R1.

              Requirement: 1. Inspect the turbine exhaust duct for low-quality welds, created during repair, on the turbine exhaust duct near flange "A", in accordance with Paragraphs 3B through 3E of:

                  1. P&WC SB PT6A-72-1610 Revision 2 for models PT6A-6, -6A, -6B, -20, - 20A, -20B, -21, -25, -25A, -25C, -27, -28, -34, -34AG, -34B, -36, -135, and - 135A engines; or

b.        P&WC SB PT6A-72-12173 Revision 1 for models PT6A-11, -11AG, - 15AG, -110, and -112 engines.

              2.        If it is determined that the welds meet acceptable criteria as detailed in Requirement 1a or 1b of this Directive:

                  1. Return the duct to service.

b.        Carry out an internal inspection of the exhaust duct for cracking in accordance with the applicable P&WC Engine Overhaul Manual.

              3.        If it is determined that the welds do not meet acceptable criteria as detailed in Requirement 1a or 1b of this Directive:

                  1. Replace the duct with a serviceable part; or

b.        Carry out an inspection as detailed in Requirement 4 of this Directive.

              4.        Use a 5x magnification to visually inspect the circumference of the forward area of the exhaust duct from the propeller reduction gearbox mounting flange to 2 inches aft of the flange for any crack indication:

                  1. If no cracks are found, return the duct to service and repeat the initial inspection as detailed in Requirement 4 at the detailed interval.

Pratt and Whitney Canada Turbine Engines - PT6A Series

 AD/PT6A/32 (Continued)

b.        If cracks are found exceeding the limits below, replace the duct with a serviceable part;

                    1. If 3 or less cracks are found, and the total cumulative length of the cracks exceeds 2 inches; or

                    ii.        If any