The bulletin
Text extracted from the PDF.
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-98-16 December 10, 1997
Published by: FAA, AFS-610, P.O. Box 26460, Oklahoma City, OK 73125 This is issued for informational purposes only and any recommendation for corrective action is not mandatory.
The purpose of this Special Airworthiness Inform ation Bulletin (SAIB) is to remind registered owners of deHavilland DH C1 Chipmunk airpla nes of a modification described in British Aerospace Technical News Sheet CT(C1) No. 201. That Technical News Sheet introduces an Isolation Switch in the starter system of certain configurations of the airplane to further eliminate the possibility of inadvertent starter engagement when auxiliary ground power is connected to the aircraft.
BACKGROUND In March, 1997, British Aerospace issued Technical Ne ws Sheet CT(C1) No. 201 for aircraft fitted with BAe Mod H 303 electric start and for aircraft fitted with similar electric start installations. The Technical News Sheet states that on such installati ons there is a remote po ssibility that even with the aircraft electrically safe, an undetected fau lt within the starter sw itch, or an inadvertent operation of the starter switch, could render the engine start circuit live. The subsequent connection of a ground power unit to the aircraft could then result in an uncommanded rotation of the propeller that could possibly endanger personnel in the close proximity of the aircraft.
RECOMMENDATION The FAA is recommending, but not requiring, that owners/operators of deHavilland Chipmunk airplanes review the configuration of their airc raft to determine if the condition described by Technical News Sheet CT(C1) No. 201 is applicable, and if so, consider modifying the electric start system by installing the Isolation Switch as described in the Technical News Sheet.
Copies of Technical News Sheet CT(C1) N o. 201 can be obtained from British Areospace Aerostructures, Ltd., Chadderton Site, Greengate, Middleton, Manchester, M24 1SA, England.
FOR FURTHER INFORMATION CONTACT FAA, Small Airplane Directorate, Atten tion: Mr. Roger P. Chudy, ACE-112, 1201 Walnut, Suite 900, Kansas City, MO 64106, telephone (816) 426-6934, fax (816) 426-2169.