SAIB CE-04-62 —

1 SPECIAL AIRWORTHINESS INFORMATION BULLETIN

Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration

CE-04-62 April 12, 2004 www.faa.gov/certification/aircraft This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin alerts you, owners and operators of Pilatus Aircraft Ltd. PC-12 and PC-12/45 airplanes with Manufacturer Serial Numbers (MSN) 101 through 507 with the second (2nd) battery option installed and that don't have the Generator Control Unit P/N 988.21.15.103 installed, that the Federal Office for Civil Aviation (FOCA) of Switzerland has issued a Swiss Airworthiness Directive (AD) No. HB 2004-101, effective April 6, 2004. The Swiss AD requires at the next 100 Hour or Annual Inspection, but no later than 90 days after the effective date, the replacement of the Generator Control Unit (GCU), Part No. 988.21.15.102 with a GCU Part No. 988.21.15.103 in accordance with (IAW) Pilatus PC-12 mandatory Service Bulletin (SB) 24-022, dated June 13, 2003.

Background

The FOCA AD HB 2004-101 was prompted by incidents on Model PC-12 Series airplanes with 2nd battery installation where the 2nd battery was discharged due to loss of the 2nd generator output, without any failure indication on the central advisory and warning system CAWS or overhead panel. Investigations revealed that the Generator Control Unit (GCU) lets the 2nd battery energize the number 2 generator relay until the power output from the battery is not sufficient to hold the relay closed.

This condition, if not corrected, could result in the hidden failure of the second generator while the 2nd battery is discharging. In order to prevent this condition, the Swiss AD requires replacement of GCU P/N 988.21.15.102 with modified GCU P/N 988.21.15.103. Also during accomplishment of the GCU replacement IAW PC-12 SB No. 24-022, the following Pilatus Service Bulletins must be accomplished before or at the same time as SB No. 24-022, as applicable:

• PILATUS PC-12 Service Bulletin 24-010 Revision 1, dated 06 October 2003. - When an Electrosystems generator P/N 978.87.24.121 is installed. • PILATUS PC-12 Service Bulletin 24-019 Revision 1, dated 06 June 2003. - When an Electrodelta voltage regulator P/N 988.21.15.101 is installed.

Note: SB 24-019 Revision 1 changes the P/N of the GCU to 988.21.15.103.

2 Recommendation

We are recommending, but not requiring, that owners and operators of Pilatus PC-12 and PC- 12/45 airplanes with 101 through 507 with the second (2nd) battery option installed and that don't have the Generator Control Unit P/N 988.21.15.103 installed, consider incorporating Pilatus PC-12 SB 24-022 as soon as possible.

For Further Information Contact

Doug Rudolph, Aerospace Engineer, FAA Small Airplane Directorate, ACE 112, 901 Locust, Room 301, Kansas City, MO 64106; phone: (816) 329-4059; fax: (816) 329-4090, email: [email protected]

For copies of Pilatus SB 24-022, contact Pilatus Aircraft Ltd.: Customer Liaison Manager, CH-6371 STANS, Switzerland; phone: 011 41 41 619 6319; fax: 011 41 41 619 6224.