AD 94-14-15

94-14-15 DASSAULT AVIATION: Amendment 39-8963. Docket 93-NM-159-AD. Applicability: Model Mystere-Falcon 50 series airplanes, serial numbers 2 through 216, inclusive; equipped with exhaust duct attachment clamps, part number (P/N) NH1002299-10 or P/N NH1007763- 10; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of attachment clamps installed on the engine exhaust ducts, which could cause exhaust gas to leak and, subsequently, could trigger a false engine fire alarm, accomplish the following:

(a) For airplanes equipped with exhaust duct attachment clamps having P/N NH1002299-10: Within 300 flight hours after the effective date of this AD, or within 6 months after the effective date of this AD, whichever occurs first, replace attachment clamps having P/N NH1002299-10 with attachment clamps having P/N NH1007763-10, in accordance with Dassault Aviation Service Bulletin F50-229 (F50- 54-13), Revision 1, dated July 21, 1993.

(b) For airplanes equipped with exhaust duct attachment clamps having P/N NH1007763-10: Within 1,400 flight hours after the effective date of this AD, inspect the attachment clamps installed on the engine exhaust ducts to verify if the clamp screw is straight (not bent), in accordance with Dassault Aviation Service Bulletin F50-229 (F50-54-13), Revision 1, dated July 21, 1993.

(1) If the clamp screw is straight, prior to further flight, verify if the tightening torque value of the screw is marked on the attachment clamp as follows: "NORMAL NET TORQUE 100-120 IN-LBS."

(i) If the marking is as specified in paragraph (b)(1) of this AD, no further action is required.

(ii) If the marking is not as specified in paragraph (b)(1) of this AD, prior to further flight, erase the incorrect marking and replace it with the correct tightening torque value.

(iii) After correcting the marking, prior to further flight, ensure that the clamp screw is secured to the tightening torque value specified in paragraph (b)(1) of this AD.

(2) If the clamp screw is bent, prior to further flight, replace the discrepant attachment clamp with a new attachment clamp having the same part number, in accordance with the Accomplishment Instructions of Dassault Aviation Service Bulletin F50-229 (F50-54-13), Revision 1, dated July 21, 1993.

(c) As of the effective date of this AD, no person shall install an exhaust duct attachment clamp having P/N NH1007763-10 on any airplane, unless that attachment clamp is marked "NORMAL NET TORQUE 100-120 IN-LBS."

(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, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

(e) Special flight permits may be issued in accordance with sections 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 Dassault Aviation Service Bulletin F50-229 (F50-54-13), Revision 1, dated July 21, 1993. 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, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on August 5, 1994.