SAIB ACE-96-10 —

No. ACE-96-10 December 9, 1996

Published by: FAA, AFS-613, P.O. Box 26460, Oklahoma City, OK 73125 This is issued for informational purposes only and any recommendation for corrective action is not mandatory.

INTRODUCTION: The purpose of this Special Airworthiness Information Bulletin is to provide owners/operators with information pertaining to Airworthiness Directive (AD) 95-12-01. The information contained in this bulletin provides results of the first round of inspections and approved alternative methods of compliances (AMOC’s) granted to date.

BACKGROUND: AD 95-12-01 requires inspection of the wing forward spar fuselage attachment assembly within 12 calendar months after the effective date (July 7, 1995) and thereafter at intervals not to exceed 24 calendar months (except as noted in paragraph (h) of AD 95-12-01). The inspection requires a visual inspection of the wing forward spar fuselage attach cluster for damage, a dye penetrant inspection of the wing forward spar fuselage attachment assembly for cracks, and an ultrasonic inspection of the wing forward spar fuselage attachment assembly for corrosion. Results of the dye penetrant and ultrasonic inspections are required to be sent to the Federal Aviation Administration (FAA), Atlanta Aircraft Certification Office (ACO) within 10 calendar days after completion of the inspections. The Atlanta ACO has conducted a review of the 336 submitted inspection reports where 21 pertain to the Model PA25, 276 pertain to the Model PA25-235 and 39 pertain to the Model PA25-260. The fleet time-in-service (TIS) values range from 466 to 11901 hours TIS. Fifteen reports were received on aircraft operating in Normal Category; 260 reports were received on aircraft operating in Restricted Category; and 61 of the reports did not specify the category of operation. Fifteen aircraft reported failing the ultrasonic inspection requirements of AD 95-12-01 and nine reported failing the dye penetrant inspection requirements of AD 95-12-01. The "INSPECTION PROCEDURES" section in the Appendix to AD 95-12-01 for the ultrasonic inspection requirements specifies minimum thickness values for the wing forward spar fuselage attachment fitting assembly. The wing forward spar fuselage attachment assembly is depicted in Figures 3a, 4a, and 5a of AD 95-12-01 and is comprised of part number (P/N) 61006-0, front spar fitting, and P/N 61005-0, fitting assy-front spar, for the PA25 Model; and P/N 64003-0, front spar fitting, and P/N 64412-0, fitting assy-front spar, for the PA25-235 and PA25-260 Models. The individual fittings are welded integrally to the fuselage tubular cluster to form an attachment fitting assembly. Ultrasonic inspection of the fitting "ears" will determine the presence of internal corrosion in the fitting assembly.

2 ACE-96-10

Readings obtained on the wing forward spar fuselage attachment fittings for the PA25 outside surfaces (most forward and most aft surfaces of the fitting "ears") should range from a minimum of .085-inch and should not exceed .107-inch; and for the PA25 inside surfaces should range from a minimum of .055-inch and should not exceed .070-inch. Similarly, for the PA25-235 and PA25-260 Models the outside surfaces should range from a minimum of .055-inch and should not exceed .070-inch; and the inside surfaces should range from a minimum of .085-inch and should not exceed .107-inch. Several owners/operators have contacted the Atlanta ACO for AMOC’s due to the presence of a modification in the area subject to the AD inspection. For these owners/operators, the ultrasonic inspection procedures were revised and tailored for inspection of the modified area. Similarly, if values exceeding the acceptable values stated above are obtained, the aircraft may have been modified and require an AMOC.

RECOMMENDATIONS: The information contained in this bulletin is being provided in response to numerous inquiries regarding the required ultrasonic inspection, adjustment of the repetitive inspection interval and approvals for terminating action to the inspection requirements. Based on the inspection results, the FAA does not intend to alleviate the requirement for the ultrasonic inspection or adjust the repetitive inspection interval, at this time. The results for the first round of fleet inspections do not provide sufficient justification to warrant relieving the inspection requirements. The FAA will continue to monitor the results and should sufficient data be gathered to warrant an adjustment, additional airworthiness action will be initiated. To date, three Supplemental Type Certificates (STC's) have been issued which provide terminating action to the repetitive inspection requirements of AD 95-12-01. The following information specifies the STC number, eligibility, and holder:

STC Number Model Eligibility STC Holder

1. SA00992AT PA25, PA25-235, and PA25-260 Kosola and Associates, Inc. P.O. Box 3529 Albany, GA 31706 (912) 435-4119

2. SA01073AT PA25-235 and PA25-260 Schweizer Aircraft Corporation P.O. Box 147 Elmira, NY 14902 (607) 739-3821

3. SA01154AT PA25-235 and PA25-260 * The STC Solution, Inc. 12940 S.W. 70th Avenue Miami, FL 33156 (305) 597-4251

ACE-96-10 3

* - STC SA01154AT is eligible on aircraft that meet or exceed the parameters presented in the Appendix to AD 95-12-01. The inspection specified in the Appendix to AD 95-12-01 must be accomplished within 12 calendar months prior to the installation, and a visual inspection for corrosion and a dye penetrant inspection for cracks must be accomplished immediately prior to the reinforcement installation. If any cracks and/or corrosion is discovered, the aircraft is not eligible for the subject reinforcement installation.

NOTE: Modification in accordance with an STC specified above does not alleviate

the routine maintenance requirements (annual/100-hour inspections) in accordance

with FAR Part 43 of the subject area.

FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, Campus Building, 1701 Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; telephone (404) 305-7362; facsimile (404) 305-7348.