SAIB ACE-96-10

SPECIAL

AIRWORTHINESS

INFORMATION

BULLETIN

AIRCRAFT CERTIFICATION SERVICE 800 INDEPENDENCE AVENUE, S.W.

WASHINGTON, DC 20591

U.S. Department of Transportation Federal Aviation Administration

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 Informati on Bulletin is to provide owners/operators with information pertaining to Airworthiness Directiv e (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 th e 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 paragra ph (h) of AD 95-12-01). The inspection requires a visual inspection of the wing forward spar fusela ge attach cluster for damage, a dye penetrant inspection of the wing forward spar fuselage att achment assembly for cracks, and an ultrasonic inspection of the wing forward spar fuselage attach ment 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 calenda r 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 fr om 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 di d not specify the categor y of operation. Fifteen aircraft reported failing the ultrasonic inspecti on 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 th e Appendix to AD 95-12-01 for the ultrasonic inspection requirements specifies minimum thickne ss 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 co mprised 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 fuse lage 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.

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Readings obtained on the wing forward spar fuse lage attachment fittings for the PA25 outside surfaces (most forward and most af t 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 A tlanta ACO for AMOC’s due to the presence of a modification in the area subject to the AD inspec tion. 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 a bove 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, adjust ment 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 re sults for the first round of fleet inspections do not provide sufficient justification to warrant relie ving the inspection requirements. The FAA will continue to monitor the results and should sufficien t 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 requirement s 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

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* - STC SA01154AT is eligible on aircraft that m eet or exceed the parameters presented in the Appendix to AD 95-12-01. The inspection specifi ed 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 corro sion 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, Atla nta Aircraft Certification Office, Campus Building, 1701 Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; telephone

(404) 305-7362; facsimile (404) 305-7348.