85-14-51 R2 BOEING OF CANADA, LTD., DE HAVILLAND DIVISION: Amendment 39- 5185 as amended by Amendment 39-5440, is further amended by Amendment 39-6207.
Applicability: Model DHC-8-100 series airplanes, serial numbers up to and including 93, certificated in any category.
Compliance: Required as indicated, unless previously accomplished.
To minimize the danger of lightning transient-induced damage to the electronic engine control units, accomplish the following:
A. Prior to further flight, incorporate the following limitations into the Limitations Section of the Airplane Flight Manual (AFM). This may be accomplished by including a copy of this AD in the AFM:
1. To preclude unacceptable loss of power during critical phases of flight, takeoff is prohibited when lightning or thunderstorms are observed or reported within 5 nautical miles of the takeoff climb path of the airplane, or when existing weather conditions may reasonably be expected to result in a lightning strike.
2. Operating with engine ignition selected to manual is required when operating below 1500 feet AGL with 5 nautical miles of any observed or reported lightning or thunderstorms, of any weather condition that may reasonably be expected to result in a lightning strike.
B. Within 12 months after the effective date of this amendment, install the following modifications. Installation of all four of these modifications constitutes terminating action for this AD, and the operating limitations required by paragraph A., above, may then be removed from the AFM.
1. Modification No. 8/0597, installation of left and right shielded harnesses incorporating electronic control unit (ECU) and signal conditioning unit (SCU) wiring, in accordance with de Havilland DHC-8 Service Bulletin 8-73-7, Revision E, dated October 14, 1988.
2. Modification No. 8/0598, installation of improved engine grounding jumpers, in accordance with de Havilland DHC-8 Service Bulletin 8-71-10, Revision B, dated October 14, 1988.
3. Modification 8/0964, replacement of the electrical wiring harness assembly, in accordance with de Havilland DHC-8 Service Bulletin 8-72-2, Revision A, dated October 14, 1988.
4. Modification 8/0813, installation of an SCU grounding strap on Pratt & Whitney PW120A engines, in accordance with de Havilland DHC-8 Service Bulletin 8-72-4, Revision A, dated October 14, 1988.
C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, New York Aircraft Certification Office (ANE-170), FAA, Engine and Propeller Directorate, Aircraft Certification Service.
NOTE: If appropriate, the request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, New York Aircraft Certification Office.
D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.
All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing of Canada Ltd., de Havilland Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or at the FAA, New York Aircraft Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, 181 South Franklin Avenue, Room 202, Valley Stream, New York.
Amendment 39-5185, AD 85-14-51 became effective December 26, 1985, as to all persons, except those persons to whom it was made immediately effective by telegraphic AD T85- 14-51 issued July 12, 1985.
Amendment (39-5440, AD 85-14-51 R1) became effective on October 27, 1986.
This amendment (39-6207, AD 85-14-51 R2) becomes effective on June 9, 1989.