AD 2017-10-20 Airworthiness Directives; Piper Aircraft, Inc. Airplanes

Makes named: piper. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Piper Aircraft, Inc. Navajo Models PA-31, PA-31-300, and PA-31-325, serial numbers 31-2 through 31-900, and 31-7300901 through 31-8312019; and Chieftain/T-1020 Models PA-31-350, serial numbers 31-5001 through 31-5004, and 31-7305005 through 31-8553002, certificated in any category. Note 1 to paragraph (c) of this AD: The Model PA-31 may also be identified as a PA-31-310 even though the PA-31-310 is not a model recognized by the Federal Aviation Administration (FAA) on the type certificate data sheet.

Comply with paragraphs (g)(1) through (3) of this AD within the compliance times specified, unless already done.

(1) For airplanes with 3,000 hours time-in-service (TIS) or less as of June 29, 2017 (the effective date of this AD): Initially within 500 hours TIS after reaching 3,000 hours TIS and repetitively thereafter every 200 hours TIS, inspect the fuselage station (FS) 332.00 bulkhead assembly for cracks following the instructions in Part I of Piper Aircraft, Inc. Service Bulletin (SB) No. 1289A, dated October 26, 2016. (2) For airplanes with over 3,000 hours TIS as of June 29, 2017 (the effective date of this AD): Initially within the next 500 hours TIS after June 29, 2017 (the effective date of this AD) and repetitively thereafter every 200 hours TIS, inspect the FS 332.00 bulkhead assembly for cracks, following the instructions in Part I of Piper Aircraft, Inc. SB No. 1289A, dated October 26, 2016. (3) If cracks are found during any of the inspections required in paragraphs (g)(1) or (2) of this AD, before further flight, repair the cracks following the modification instructions in Part II of Piper Aircraft, Inc. SB No. 1289A, dated October 26, 2016, and one of the following as applicable: (i) If the crack does not extend beyond the inspection/template area of figure 2 of Piper Aircraft, Inc. SB No. 1289A, dated October 26, 2016, and meets the minimum acceptable distance in figure 3 and table 2 of Part II of Piper Aircraft, Inc. SB No. 1289A, dated October 26, 2016, then the installation of Piper Kit 88578-001 Revision B, dated June 23, 2016, is acceptable as a repair and is considered terminating action for the repetitive inspection requirement in paragraphs (g)(1) and (2) of this AD. (ii) If the crack extends beyond the inspection/template area of figure 2 of Piper Aircraft, Inc. SB No. 1289A, dated October 26, 2016, or does not meet the minimum acceptable distance in figure 3 and table 2 of Part II of Piper Aircraft, Inc. SB No. 1289A, dated October 26, 2016, then the installation of Piper Kit 88578-001 Revision B, dated June 23, 2016, is not an acceptable repair. You must obtain an alternative method of compliance (AMOC) for any repair or modification in this area. You may contact Piper Aircraft, Inc. for repair instruction development specific to this condition. For contact information refer to paragraph (j) of this AD. (4) If no cracks are found, you may install Piper Kit 88578-001 Revision B, dated June 23, 2016, on an uncracked bulkhead following the Modification instructions in Part II of Piper Aircraft, Inc. SB No. 1289A, dated October 26, 2016. Installation of Piper Kit 88578-001 Revision B, dated June 23, 2016, on an uncracked bulkhead is considered terminating action for the repetitive inspection requirement in paragraphs (g)(1) and (2) of this AD.

This AD was prompted by fatigue cracking in the fuselage station (FS) 332.00 bulkhead common to the horizontal stabilizer front spar attachment. This AD requires repetitive inspections to detect cracks in the bulkhead and any necessary repairs. This AD also provides an optional modification if no cracks are found that will greatly reduce the likelihood of the specified cracks. Cracks in the bulkhead could compromise the structural components capability to carry flight loads, increasing the potential to overload and fail adjacent structure and lead to loss of control.

None.