AD 2004-14-22 Airworthiness Directives; Pratt & Whitney Canada PW206B, PW206C, PW206E, PW207D, and PW207E Turboshaft Engines

This AD applies to Pratt & Whitney Canada (PWC) PW206B engines that have incorporated PWC Service Bulletin (SB) No. 28119, and PW206C, PW206E, PW207D, and PW207E turboshaft engines. These engines are installed on, but not limited to, Augusta 109E, Bell 427, Eurocopter EC135, and MD Explorer helicopters.

You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. Confirmation of Data Collection Unit (DCU) Properly Collecting Engine Low-Cycle-Fatigue (LCF) Data, and Confirmation of Engine LCF Count Values (f) To confirm that the data stored in the DCU is correct and that the data recorded in the engine log books is correct, do a Comparison Check and a Consistency Check as specified in paragraphs (g) and (h) of this AD, within the following compliance requirements: (1) For engines with impeller and or compressor turbine (CT) disks and or power turbine (PT) disks having fewer than 2,000 cycles life limit remaining on the effective date of this AD, do a Comparison Check and a Consistency Check within the next 50 engine flight hours or two months, whichever occurs first, after the effective date of this AD; and (2) For engines with impeller and or CT disks and or PT disks having from 2,000 to 5,000 cycles life limit remaining on the effective date of this AD; do a Comparison Check and a Consistency Check within the next 200 engine flight hours or three months, whichever occurs first, after the effective date of this AD; and (3) For engines with impeller and or CT disks and or PT disks having more than 5,000 cycles life limit remaining on the effective date of this AD; do a Comparison Check and a Consistency Check within the next 500 engine flight hours or four months, whichever occurs first, after the effective date of this AD. Comparison Check (g) Do a Comparison Check of the data stored by the DCU using paragraph 3.C of PWC Alert Service Bulletin (ASB) No. PW200-72-28252, Revision 2, dated March 11, 2004. Interpret the results of the Comparison Check using paragraphs 3.C.9.a. and 3.C.9.b. of PWC ASB No. PW200-72-28252, Revision 2, dated March 11, 2004. If necessary, restore baseline LCF life of components using manual counting using paragraph 3.E of PWC ASB No. PW200-72-28252, Revision 2, dated March 11, 2004. Consistency Check (h) Do a Consistency Check by reviewing the engine log books to confirm the impeller, CT, and PT disks LCF counts are correct using paragraph 3.D. of PWC ASB No. PW200-72-28252, Revision 2, dated March 11, 2004. (1) Interpret the results using paragraphs 3.D.5 and 3.D.6 of PWC ASB No. PW200-72-28252, Revision 2, dated March 11, 2004. (2) If necessary, restore the baseline LCF life of components using manual counting as indicated in paragraph 3.E. of PWC ASB No. PW200-72-28252, Revision 2, dated March 11, 2004. Components Exceeding Published Life Limit (i) Before further flight, replace any impeller, CT, or PT disk that exceeds its published life limit. Validating Proper DCU Automatic LCF Counting Before an Engine Is Installed (j) Before an engine is installed, validate the proper DCU automatic LCF counting using the checks in paragraphs (g) and (h) of this AD and using paragraphs 3A. through 3.A.(21)(a)15 of PWC Service Bulletin (SB) No. PW200-72-28253, dated February 12, 2004. Previous Credit (k) Previous credit is allowed for Comparison Checks and Consistency Checks that were done in accordance with the Original, Revision 1, or Revision 2 of PW ASB No. PW200-72-A28252, before the effective date of this AD. Alternative Methods of

This AD results from two reports of irregular LCF counting observed between engines on the same helicopter, during weekly recording of LCF data in the engine log books. We are issuing this AD to prevent critical rotating parts from exceeding published life limits, which could result in uncontained engine failure and possible loss of the helicopter.