SPECIAL AIRWORTHINESS INFORMATION BULLETIN
Aircraft Certification Service
Washington, DC
U.S. Department of Transportation
Federal Aviation Administration
AIR-21-02

January 6, 2021

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 all manufacturer’s serial numbers (MSN). Specifically, the concern is that there is an urgent need to inspect the Harley-type buckle assemblies on the seat harnesses of the front and rear ejection seats on all PC-9 airplanes. There has been a reported incident where the adjustable shoulder strap of a seat harness was found to be unattached to the main harness. Subsequent investigation concluded that one of the two release bar retaining screws located on Harley-type buckle assemblies was missing and the other one was loose and could be unscrewed by hand.

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 issued FOCA Emergency Airworthiness Directive (AD) HB-2020-013 dated December 10, 2020 on Pilatus Models PC-9, PC-9/A, PC-9/B, and PC-9/F airplanes to inspect the Harley-type buckle assemblies on the seat harnesses of the front and rear ejection seats per Pilatus PC-9 SB 25-009 dated November 27, 2020, IrvinGQ SB IGQSB033 Issue 2 dated December 2020, and Martin-Baker Aircraft Company Special Information Leaflet (SIL) No. 864A dated December 9, 2020 and prohibits (re-)installation of the affected parts.

The required actions and compliance times for the FOCA AD HB-2020-013-E are as follows:

Inspection of FOCA AD:


(1) Before the next flight after the effective date of the FOCA AD, inspect the Harley-type buckle assemblies on the seat harnesses of the front and rear ejection seats in accordance with the instructions of section 3.B. of the Pilatus SB, the Martin-Baker Special Information Leaflet
and section 2 of the IrvinGQ SB.

Corrective action(s) of FOCA AD:


(2) If, during the inspection as required by paragraph (1) of the FOCA AD, discrepancies are detected, as identified in the applicable SBs and the Special Information Leaflet, before next flight, accomplish the applicable corrective action(s) in accordance with the instructions of the applicable SBs and the Special Information Leaflet.

Parts Installation per FOCA AD:


(3) From the effective date of the FOCA AD, it is allowed to install a Harley-type buckle assembly on the seat harnesses of the front and rear ejection seats, provided it is a serviceable part, as defined in the FOCA AD.

Recommendations


For Pilatus Models PC-9, PC-9/A, PC-9/B, and PC-9/F airplanes, we recommend accomplishing the inspections and corrective actions per the FOCA AD HB-2020-013-E before next flight.

For Further Information Contact


Doug Rudolph, Aerospace Engineer Federal Aviation Administration, General Aviation &
Rotorcraft Section, International Validation Branch, 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

Note: an electronic copy of the service documents along with a copy of the actual FOCA AD HB-2020-013-E can be found on the FOCA website at:

https://www.bazl.admin.ch/bazl/en/home/specialists/aircraft/airworthiness-directives--ad-/lta-schweizer-produkte/pc-9.html

For further information on the FOCA AD contact:

FEDERAL OFFICE OF CIVIL AVIATION (FOCA)
Airworthiness Engineering (STIL)
CH-3003 Bern, Switzerland

E-mail: airdir@bazl.admin.ch