AD 2011-07-02 Airworthiness Directives; Pratt & Whitney JT8D-209, -217, -217A, -217C, and -219 Series Turbofan Engines

This AD applies to Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219 series turbofan engines. These engines are installed on, but not limited to, Boeing 727 series and McDonnell Douglas MD-80 series airplanes.

You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. Requirements of AD 2005-02-03 Initial Torque Inspection for JT8D-209, -217, and -217A Engines (f) For JT8D-209, -217, and -217A engines, perform the initial torque inspection of 3rd and 4th stage LPT blades for shroud notch wear. Use the procedures described in Accomplishment Instructions, Part 1, Paragraphs 1 through 3, of PW Alert Service Bulletin (ASB) No. JT8D A6224, Revision 6, dated May 3, 2007, at the applicable threshold in the following Table 1: Table 1—Initial Torque Inspection Threshold for JT8D-209, -217, and -217A Engines Blade type Hours time-in-service (TIS) as of March 3, 2005 (the effective date of AD 2005-02-03) Inspection threshold (1) New pre-Service Bulletin (SB) No. 5867 (small notch) 3rd stage turbine blades Any number Within 6,000 hours TIS. (2) Refurbished pre-SB No. 5867 (small notch) 3rd stage turbine blades (i) Fewer than 3,000 Within 4,000 hours TIS.   (ii) 3,000 or more Within 6,000 hours TIS, or within 1,000 hours TIS from March 3, 2005, whichever occurs first. (3) New post-SB No. 5867 (large notch) 3rd stage turbine blades Any number Within 10,000 hours TIS. (4) Refurbished post-SB No. 5867 (large notch) 3rd stage turbine blades (i) Fewer than 6,000 Within 7,000 hours TIS.   (ii) 6,000 or more Within 8,000 hours TIS, or within 1,000 hours TIS from March 3, 2005, whichever occurs first. (5) New pre-SB No. 6029 (small notch) 4th stage turbine blades Any number Within 6,000 hours TIS. (6) Refurbished pre-SB No. 6029 (small notch) 4th stage turbine blades (i) Fewer than 3,000 Within 4,000 hours TIS.   (ii) 3,000 or more Within 6,000 hours TIS, or within 1,000 hours TIS from March 3, 2005, whichever occurs first. (7) New post-SB No. 6029 or new post-SB No. 6308 (large notch) 4th stage turbine blades Any number Within 10,000 hours TIS. (8) Refurbished post-SB No. 6029 or refurbished post-SB No. 6308 (large notch) 4th stage turbine blades (i) Fewer than 6,000 Within 7,000 hours TIS.   (ii) 6,000 or more Within 8,000 hours TIS, or within 1,000 hours TIS from March 3, 2005, whichever occurs first. Repetitive Torque Inspections for JT8D-209, -217, and -217A Engines (g) For JT8D-209, -217, and -217A engines, perform repetitive torque inspections of 3rd and 4th stage LPT blades for shroud notch wear. Use the procedures described in Accomplishment Instructions, Part 1, Paragraph 1 of PW ASB No. JT8D A6224, Revision 6, dated May 3, 2007, at the applicable intervals in the following Table 2 and Table 3: Table 2—3rd Stage Repetitive Torque Inspection Intervals for JT8D-209, -217, and -217A Engines Inspection torque readings Number of readings Disposition Greater than or equal to 15 LB-IN (1.695 N.m) All Repeat torque inspection within 1,000 hours TIS since last inspection. Less than 15 LB-IN (1.695 N.m) but greater than or equal to 10 LB-IN (1.130 N.m) One or more Repeat torque inspection within 500 hours TIS since last inspection. Less than 10 LB-IN (1.130 N.m) but greater than or equal to 5 LB-IN (0.565 N.m) One to three Repeat torque inspection within 125 hours TIS since last inspection. Less than 10 LB-IN (1.130 N.m) but greater than or equal to 5 LB-IN (0.565 N.m) Four or more Remove engine from service within 20 hours TIS since last inspection. Less than 5 LB-IN (0.565 N.m) One or more Remove engine from service within 20 hours TIS since last inspection. Table 3—4th Stage Repetitive Torque Inspection Intervals for JT8D-209, -217, and -217A Engines Inspection torque readings Number of readings Disposition Greater than or equal to 15 LB-IN (1.695 N.m) All Repeat torque inspection within 1,000 hours TIS since last inspection. Less than 15 LB-IN (1.695 N.m) but greater than or equal to 10 LB-IN (1.130 N.m) One or more Repeat torque inspection within 500 hours TIS since last inspection. Less than 10 LB-IN (1.130 N.m) but greater than or equal to 5 LB-IN (0.565 N.m) One to six Repeat torque inspection within 125 hours TIS since last inspection. Less than 10 LB-IN (1.130 N.m) but greater than or equal to 5 LB-IN (0.565 N.m) Seven or more Remove engine from service within 20 hours TIS since last inspection. Less than 5 LB-IN (0.565 N.m) One or more Remove engine from service within 20 hours TIS since last inspection. (h) Subsequent repeat inspection intervals must not exceed the previous inspection interval. JT8D-209, -217, and -217A Engines Removed From Service (i) JT8D-209, -217, and -217A engines removed from service may be returned to service after a detailed inspection and repair or replacement of all blades of the failed stage, that exceed Engine Manual limits, is done. Information on repairing or replacing turbine blades can be found in Sections 72-53-12 through 72-53-13 of the JT8D-200 Engine Manual, Part No. 773128. Initial Inspection for JT8D-217C and -219 Engines (j) For JT8D-217C and -219 engines, perform the initial torque inspection of 4th stage LPT blades for shroud notch wear. Use the procedures described in Accomplishment Instructions, Part 2, Paragraphs 1 through 3 of PW ASB No. JT8D A6224, Revision 6, dated May 3, 2007, at the applicable threshold in the following Table 4: Table 4—Initial Torque Inspection Threshold for JT8D-217C and -219 Engines Blade type TIS as of March 3, 2005 Inspection threshold (1) New pre-SB No. 6090 (small notch) 4th stage turbine blades Any number Within 5,000 hours TIS. (2) Refurbished pre-SB No. 6090 (small notch) 4th stage turbine blades (i) Fewer than 3,000 Within 4,000 hours TIS.   (ii) 3,000 or more Within 5,000 hours TIS, or within 1,000 hours TIS from March 3, 2005, whichever occurs first. (3) New post-SB No. 6090, new post-SB No. 6402, or new post-SB No. 6412 (large notch) 4th stage turbine blades Any number Within 10,000 hours TIS. (4) Refurbished “As-Cast” post-SB No. 6090, post-SB No. 6402, or post-SB No. 6412 (large notch) 4th stage turbine blades Any number Within 7,000 hours TIS. (5) Refurbished “Modified” post-SB No. 6090, post-SB No. 6402, or post-SB No. 6412 (large notch) 4th stage turbine blades (i) Fewer than 3,000 Within 4,000 hours TIS.   (ii) 3,000 or more Within 7,000 hours TIS, or within 1,000 hours TIS from March 3, 2005, whichever occurs first. Repetitive Torque Inspections for JT8D-217C and -219 Engines (k) For JT8D-217C and -219 engines, perform repetitive torque inspections of 4th stage LPT blades for shroud notch wear. Use the procedures described in Accomplishment Instructions, Part 2, Paragraph 1 of PW ASB No. JT8D A6224, Revision 6, dated May 3, 2007, at the applicable intervals in the following Table 5: Table 5—Repetitive Torque Inspection Intervals for JT8D-217C and -219 Engines Inspection torque readings Number of readings Disposition Greater than or equal to 15 LB-IN (1.695 N.m) All Repeat torque inspection within 1,000 hours TIS since last inspection. Less than 15 LB-IN (1.695 N.m) but greater than or equal to 10 LB-IN (1.130 N.m) One or more Repeat torque inspection within 500 hours TIS since last inspection. Less than 10 LB-IN (1.130 N.m) but greater than or equal to 5 LB-IN (0.565 N.m) One to six Repeat torque inspection within 125 hours TIS since last inspection. Less than 10 LB-IN (1.130 N.m) but greater than or equal to 5 LB-IN (0.565 N.m) Seven or more Remove engine from service within 20 hours TIS since last inspection. Less than 5 LB-IN (0.565 N.m) One or more Remove engine from service within 20 hours TIS since last inspection. (l) Subsequent repeat inspection intervals must not exceed the previous inspection interval. JT8D-217C and -219 Engines Removed From Service (m) JT8D-217C and -219 engines removed from service may be returned to service after a detailed inspection and repair or replacement of all blades of the failed stage, that exceed Engine Manual limits, is done. Information on repairing or replacing turbine blades can be found in Sections 72-53-12 through 72-53-13 of the JT8D-200 Engine Manual, Part No. 773128. Other Criteria for All Engine Models Listed in This AD (n) Whenever a refurbished or used blade is intermixed with new blades in a rotor, use the lowest initial inspection threshold that is applicable. (o) The initial torque inspection or the repetitive inspection intervals for a particular stage may not be reset, unless the blades for that stage are refurbished or replaced. (p) Whenever a used (service run) blade is reinstalled in a rotor, the previous used time should be subtracted from the initial torque inspection threshold. What This AD Changes LPT-to-Exhaust Case Bolts and Nuts Replacement, and Crushable Sleeve Spacer Installation (q) At next accessibility to the LPT-to-Exhaust Case bolts and nuts, do the following: (1) Replace the bolts with part number (P/N) MS9557-26 bolts; and (2) Replace the nuts with P/N 375095 nuts or P/N 490270 nuts; and (3) Install crushable sleeve spacers, P/N 822903, under the head of the bolts. (r) Guidance on replacing the bolts and nuts and installing the crushable sleeve spacers can be found in PW ASB No. JT8D A6494, Revision 1, dated January 26, 2010. Previous Credit (s) Initial inspections performed before the effective date of this AD using PW ASB No. JT8D A6224, Revision 5, dated June 11, 2004, or Revision 6, dated May 3, 2007, satisfy the initial inspection requirements of this AD. Definitions (t) For the purpose of this AD, “refurbished” is defined as restoration of the shrouds and/or blade re-twist per the JT8D-200 Engine Manual, Part No. 773128, or per an operator's approved manual system. (u) For the purpose of this AD, “As-Cast” refers to blades that were machined from new castings, and “Modified” refers to blades that were derived from the pre-SB No. 6090 configuration. (v) For the purpose of this AD, “accessibility to the LPT-to-exhaust case bolts” refers to when the inner turbine fan ducts are removed. Alternative Methods of

This AD results from nine reports of failure of Tinidur material LPT-to-exhaust case bolts, as a result of blade failure, since AD 2005-02-03 became effective. We are issuing this AD to prevent turbine blade failures that could result in uncontained engine debris and damage to the airplane.