AD 94-22-10 Airworthiness Directives; De Havilland Model DHC-8-100 and DHC-8- 300 Series Airplanes

Models named: DHC-8-102, -103, -301, -311 series. Read the applicability below — it usually turns on serial or part numbers too.

Model DHC-8-102, -103, -301, and -311 series airplanes, having serial numbers 003 through 214, inclusive; on which Modification 8/1273 (as described in De Havilland Service Bulletin S/B No. 8-33-19, Revision `A', dated May 31, 1993) has not been accomplished; certificated in any category.

Required as indicated, unless accomplished previously. To ensure correct operation of the proximity switch electronics unit (PSEU) and its associated systems, accomplish the following: (a) Within the applicable time specified in paragraph (a)(1) or (a)(2) of this AD, revise the Limitations Section of the FAA- approved Airplane Flight Manual (AFM) to include the following statement. The revision of the AFM may be accomplished by inserting a copy of this AD into the AFM. ``The electrical power supplies for the white anti-collision lights may fail and cause the following abnormalities: --Flashing of the landing gear green locked down advisory lights during cruise; --Fluctuation of cabin pressurization rate needle during cruise; and --Retraction and extension of roll and ground spoilers during ground operation. The failure may also result in loss of nose landing gear steering subsequent to landing, and loss of wheel brakes below 35-40 knots. If any of these abnormal indications are observed, select A/COL light switch--RED. Leave the switch in this position for the remainder of the flight.'' (1) For Model DHC-8-102, -103, and -311 series airplanes: Accomplish the revision of the AFM within 30 days after December 15, 1994 (the effective date of AD 94-22-01, amendment 39-9060), (2) For Model DHC-8-301 series airplanes: Accomplish the revision of the AFM within 30 days after the effective date of this amendment. (b) If the flight crew reports the occurrence of any of the cockpit indications stated in paragraph (a) of this AD: Prior to the next flight, perform the maintenance procedures to confirm and isolate the faulty power supply unit, in accordance with paragraph III., Part B, Accomplishment Instructions of de Havilland Alert Service Bulletin S.B. A8-33-33, dated May 31, 1993. (1) If any power supply unit is determined to be faulty, prior to further flight, replace the unit with a new or serviceable ``Grimes'' unit or a new ``Whelen'' system in accordance with the alert service bulletin. (2) If the specific unit causing the faults cannot be determined, prior to further flight, replace all three units with new or serviceable ``Grimes'' units or a new ``Whelen'' system in accordance with the alert service bulletin. Installation of a new ``Whelen'' system at all three locations constitutes terminating action for the requirements of this AD and, following installation, the AFM revision required by paragraph (a) of this AD may be removed. (c) Within 6 months after the effective date of this AD, install Modification 8/1273 (which entails replacement of the existing anti- collision strobe lights, brackets, and power supplies with the ```Whelen' Anti-Collision Strobe Light System'') at all three locations, in accordance with de Havilland Service Bulletin S/B No. 8-33-19, Revision `A', dated May 31, 1993. Following installation, the AFM revision required by paragraph (a) of this AD may be removed. (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, New York Aircraft Certification Office (ACO), ANE-170, FAA, Engine and Propeller Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO. Note: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO. (e) Special flight permits may be issued in accordance with Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. (f) The actions shall be done in accordance with de Havilland Alert Service Bulletin S.B. A8-33-33, dated May 31, 1993; and de Havilland Service Bulletin S/B No. 8-33-19, Revision `A', dated May 31, 1993; as applicable. This incorporation by reference was approved previously by the Director of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of December 15, 1994 (59 FR 58765, November 15, 1994). Copies may be obtained from de Havilland, Inc., Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller Directorate, New York Aircraft Certification Office, 181 South Franklin Avenue, Room 202, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (g) This amendment becomes effective on February 3, 1995. Issued in Renton, Washington, on January 11, 1995. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 95-1127 Filed 1-18-95; 8:45 am] BILLING CODE 4910-13-M