AD 92-04-02

92-04-02 DASSAULT AVIATION (FORMERLY AVIONS MARCEL DASSAULT- BREGUET AVIATION): Amendment 39-8171. Docket 91-NM-31-AD. Applicability: Model Mystere Falcon 900 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent stiffness of the center engine power control and/or flight controls (elevator and rudder), and reduced controllability of the airplane, accomplish the following:

(a) Within 30 days after the effective date of this AD, and thereafter at intervals not to exceed 7 days, accomplish paragraphs (a)(1) and (a)(2) of this AD:

(1) Verify proper operation of the drain stub heating, in accordance with the manufacturer's Maintenance Manual (reference Procedure 30-700).

(2) Verify freedom from clogging of the system by pressurizing the fuselage on the ground to a cabin pressure altitude of Z = -1,500 feet using the engines or APU, and by checking with the hand that air flows out of the drain stub, in accordance with the manufacturer's Maintenance Manual (reference Procedure 21-311).

(b) Within 90 days after the effective date of this AD, perform the modifications and inspections specified by paragraphs (b)(1), (b)(2), and (b)(3) of this AD, which constitute terminating action for the requirements of paragraph (a) of this AD.

(1) On drain stub Part Number C49RD0033, eliminate the 3 mm. diameter restrictor and enlarge the outlet cross-section, in accordance with Dassault Aviation Service Bulletin F900-38-1 (F900-82), dated October 4, 1990.

(2) On the drainage system, add protective screens to the drainage holes of the water collector under the washbasin, in accordance with Dassault Aviation Service Bulletin F900-38-1 (F900- 82), dated October 4, 1990; and install a protective screen to the drainage holes on each side of the center beam, in accordance with Dassault Aviation Service Bulletin F900-53-5 (F900-57), dated October 4, 1990.

(3) Following the installation of the modifications required by paragraphs (b)(1) and (b)(2) of this AD, prior to further flight, check the stub heating for proper operations, in accordance with Procedure 30-701 in the manufacturer's Maintenance Manual, and inspect and clean the modified drain holes.

(c) Within 300 hours time-in-service after the effective date of this AD, or within 6 months after accomplishing the modifications required by paragraph (b) of this AD, whichever occurs first; and thereafter at intervals not to exceed 300 hours time-in-service or 6 months, whichever occurs first; accomplish paragraphs (c)(1), (c)(2), and (c)(3) of this AD, in accordance with Dassault Aviation Service Bulletins F900-38-1 (F900-82) or F900-53-5 (F900-57), both dated October 4, 1990, as applicable:

(1) Check the stub heating for proper operation.

(2) Inspect and clean the drain hole protective screens.

(3) Verify correct water drainage via the frame 25 and washbasin collector drains.

(d) Within 12 months after the effective date of this AD, modify the collector drains, in accordance with Dassault Aviation Falcon 900 Service Bulletin F900-38-2 (F900-83), dated April 25, 1991. Installation of this modification constitutes terminating action for the repetitive inspections required by paragraph (c) of this AD.

(e) An alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM- 113, FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113.

(f) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(g) The modifications and inspections shall be done in accordance with the Dassault Aviation Service Bulletin F900-38-1 (F900-82), dated October 4, 1990; Dassault Aviation Falcon 900 Service Bulletin F900-38-2 (F900-83), dated April 25, 1991; and Dassault Aviation Service Bulletin F900-53-5 (F900-57), dated October 4, 1990. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Falcon Jet Corporation, Customer Support Department, Teterboro Airport, Teterboro, New Jersey 07608. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, DC.

(h) This amendment (39-8171, AD 92-04-02) becomes effective on March 16, 1992.