STC SE04136AT

FAA Aviation Safety

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN SUBJ: Fuselage – Pilatus PC-9 Frame 11 Fittings – Inspection SAIB: CE-16-17 Date: May 17, 2016 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin is to alert owners, operators, maintenance technicians, and inspectors of an airworthiness concern on Pilatus Aircraft (Pilatus) Models PC-9, PC-9/A, PC-9/B, and PC-9/F airplanes with manufacturer’s serial numbers (MSN) 101 through MSN 248 and MSN 501 through MSN 567. Specifically, the concern is the possibility of stress corrosion cracking (SCC) on the main frame on the Frame (FR) 11 left fitting part number (P/N)

112.35.07.489 and right fitting P/N 112.35.07.490. This condition, if left uncorrected, could lead to potential loss of the horizontal stabilizer.

These airplanes are not type certificated in the United States and, therefore, the condition is not addressed by FAA Airworthiness Directive (AD) action. However, these airplanes could be operating in the United States with an experimental airworthiness certificate or other means.

Background

The Swiss Federal Office of Civil Aviation (FOCA) has issue FOCA AD HB-2016-002 dated May 3, 2016, on Pilatus Models PC-9, PC-9/A, PC-9/B, and PC-9/F airplanes to mandate a one-time check to identify the material specification and then require inspections of the affected areas of the airframe that are made of aluminum alloy AA2024-T351. Any structural parts of the airplane structure found to be cracked should be reported to Pilatus prior to further flight.

The required actions and compliance times for the FOCA AD are as follows:

(1) Within the next 120 days after the effective date of this AD, perform a test to identify the material specification of the left and right fittings P/N 112.35.07.489 and P/N 112.35.07.490 as required by paragraph (§) 3.B. of PILATUS PC-9 Service Bulletin No. 53-021.

(2) If during the inspection required by § (1) of this AD, fittings made of aluminum alloy AA2124-T851 are found, report the inspection results as required by § 3.D. of PILATUS PC- 9 Service Bulletin No. 53-021.

(3) If during the inspection required by § (1) of this AD, fittings made of aluminum alloy AA2024-T351 are found, before next flight after the effective date of this AD, perform an inspection for cracks as required by § 3.C. of PILATUS PC-9 Service Bulletin No. 53-021 for cracks. No cracks are allowed.

Note 1: A scheduled maintenance interval of 12 months to check for cracks at the FR 11 fittings made of aluminum alloy AA2024-T351 will be added to Chapter 5 of the Aircraft Maintenance Manual (AMM).

(4) If during the inspection required by § (3) of this AD, cracks are found, prior further flight, replace the fittings in accordance with the instructions given in PILATUS PC-9 Service Bulletin No. 53-022.

Recommendations

For Pilatus Models PC-9, PC-9/A, PC-9/B, and PC-9/F airplanes, we recommend adherence to the inspections and corrections per the FOCA AD HB-2016-002 and the corresponding Pilatus PC-9 Service Bulletin No. 53-021 and PC-9 Service Bulletin No. 53-022.

For Further Information Contact

Doug Rudolph, Aerospace Engineer Federal Aviation Administration, Small Airplane Directorate, ACE-112, 901 Locust Street, Room 301, Kansas City, MO; phone: (816) 329-4059; fax: (816) 329- 4090; e-mail: doug.rudolph@faa.gov.

For Related Service Information Contact

The applicable manufacturer’s documentation may be obtained directly from:

PILATUS AIRCRAFT LTD.

Customer Technical Support (MCC) P.O. Box 992 CH-6371 Stans, Switzerland

Tel.: +41 (0)41 619 67 74 Fax: +41 (0)41 619 67 73 E-mail: Techsupport@pilatus-aircraft.com

For further information on the FOCA AD contact:

FEDERAL OFFICE OF CIVIL AVIATION (FOCA) Design and Production (STEH) CH-3003 Bern, Switzerland

E-mail: airdir@bazl.admin.ch