AD 99-25-09

This amendment adopts a new airworthiness directive (AD), applicable to all Dassault Model Mystere-Falcon 50 and 900 series airplanes, Falcon 900EX series airplanes, and Falcon 2000 series airplanes, that requires revising the Airplane Flight Manual to provide the flight crew with certain instructions associated with the onset of stall warning. This amendment also requires repetitive inspections to detect discrepancies of the hinge pin assemblies of the rear horizontal stabilizer, and corrective actions, if necessary. For certain airplanes, this amendment also requires replacement of the hinge pin assemblies with new, improved parts. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent excessive movement and consequent deformation of the hinge pin assemblies of the rear horizontal stabilizer, which could result in flutter and possible failure of the rear horizontal stabilizer.

Final rule

99-25-09 DASSAULT AVIATION: Amendment 39-11452. Docket 98-NM-266-AD.
Applicability: All Model Mystere-Falcon 50 and 900 series airplanes, Falcon 900EX series airplanes, and Falcon 2000 series airplanes; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (g) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent excessive movement and consequent deformation of the hinge pin assemblies of the rear horizontal stabilizer, which could result in flutter and possible failure of the rear horizontal stabilizer, accomplish the following:

Dassault Airplane Flight Manual (AFM) Revision
(a) Within 30 days after the effective date of this AD, revise the Limitations Section of the FAA-approved AFM to include the following statement. This may be accomplished by inserting a copy of this AD into the AFM. "DO NOT INTENTIONALLY FLY THE AIRPLANE SLOWER THAN INITIAL STALL WARNING ONSET"

NOTE 2: The AFM revision required by paragraph (a) of this AD also may be accomplished by inserting a copy of the applicable Temporary Change into the applicable AFM, as specified below. When these Temporary Changes have been incorporated into the general revisions of the AFM, the general revisions may be inserted into the AFM, provided that the information contained in the general revisions is identical to that specified in the Temporary Changes.

For Model Mystere-Falcon 50 series airplanes: Dassault Mystere-Falcon 50 AFM Temporary Change No. 46 (DTM813); and Dassault Mystere-Falcon 50 AFM Temporary Change No. 12 (FM813EX).

For Model Mystere-Falcon 900 series airplanes: Dassault Mystere-Falcon 900 AFM Temporary Change No. 69 (DTM20103).

For Model Falcon 900EX series airplanes: Dassault Falcon 900EX AFM Temporary Change No. 14 (DTM561).

For Model Falcon 2000 series airplanes: Dassault Falcon 2000 AFM Temporary Change No. 44 (DTM537).

Initial and Repetitive Inspections
(b) At the applicable time specified in paragraph (c) of this AD, perform a dimensional inspection to detect discrepancies (damage, deformation, and excessive movement) of the hinge pin assemblies of the rear horizontal stabilizer in accordance with paragraph (b)(1), (b)(2), (b)(3), or (b)(4) of this AD, as applicable. Thereafter, repeat the inspection at intervals not to exceed 3,750 flight cycles or 6 years, whichever occurs first.

(1) For Model Mystere-Falcon 50 series airplanes: Inspect in accordance with Dassault Airplane Maintenance Manual (AMM), Revision 1, dated February 1997, as revised by Temporary Revision (TR) No. 7, work card number 704.0/1, dated November 1997.

(2) For Model Mystere-Falcon 900 series airplanes: Inspect in accordance with Dassault AMM, Revision 2, dated July 1997, as revised by TR No. 17, Procedure 55-501, dated November 1997.

(3) For Model Falcon 900EX series airplanes: Inspect in accordance with Dassault AMM, Revision 1, dated December 1996, as revised by Temporary Revision No. 2, Procedure 55-501, dated November 1997.

(4) For Model Falcon 2000 series airplanes: Inspect in accordance with Dassault AMM, Revision 5, Procedure 55-501, dated November 1997.

NOTE 3: The actions required by paragraph (b) of this AD also may be accomplished in accordance witha general revision of the applicable Dassault AMM, provided that the information contained in the general revision is identical to that specified in the Temporary Revisions cited in that paragraph.

(c) Accomplish the inspection required by paragraph (b) of this AD at the LATER of the times specified in paragraphs (c)(1) and (c)(2) of this AD.

(1) Within 6 years since date of manufacture, or prior to the accumulation of 3,750 total flight cycles, whichever occurs first.

(2) Within 300 flight hours or 6 months after the effective date of this AD, whichever occurs first.

(d) If any discrepancy is detected during any inspection required by this AD, prior to further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM- 116, FAA, Transport Airplane Directorate; or the Direction G n rale de l'Aviation Civile (DGAC) (or its delegated agent).

NOTE 4: Accomplishment of repair of the hinge pin assemblies in accordance with Falcon Repair Solution F2000-R3 (For Model Falcon 2000 series airplanes), F50-R52 (for Model Mystere-Falcon 50 series airplanes), or F900-R71 (for Model Mystere-Falcon 900 and Falcon 900EX series airplanes); as applicable; is acceptable for compliance with the repairs required by paragraph (d) of this AD.

Replacement
(e) For airplanes listed in Dassault Service Bulletins F50-274, F900-203, F900EX-37, and F2000-118, all dated December 17, 1997: Replace the hinge pin assemblies of the rear horizontal stabilizer with new, improved parts in accordance with Part 2, paragraph B.(2) of the Accomplishment Instructions of the applicable service bulletin at the LATER of the times specified in paragraphs (e)(1) and (e)(2) of this AD.

(1) Accomplish the replacement within 6 years since date of manufacture, or prior to the accumulation of 3,750 total flight cycles, whichever occurs first.

(2) Accomplish the replacement within 300 flight hours or 6 months after the effective date of this AD, whichever occurs first.

Spares
(f) As of the effective date of this AD, no person shall install a rear horizontal stabilizer hinge pin having part number MY2033175 on any airplane.

Alternative Methods of Compliance
(g) 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, International Branch, ANM-116, FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

NOTE 5: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

Special Flight Permits
(h) 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.

Incorporation by Reference
(i) The replacements shall be done in accordance with Dassault Service Bulletin F50-274, dated December 17, 1997; Dassault Service Bulletin F900-203, dated December 17, 1997; Dassault Service Bulletin F900EX-37, dated December 17, 1997; and Dassault Service Bulletin F2000-118, dated December 17, 1997; as applicable. 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 Dassault Falcon Jet, P.O. Box 2000, South Hackensack, New Jersey 07606. 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.

NOTE 6: The subject of this AD is addressed in French airworthiness directives 1997-370- 020(B)R2, dated June 2, 1999; and 1997-369-004(B) R1, dated June 2, 1999, as revised by Erratum, dated June 30, 1999.

(j) This amendment becomes effective on January 12, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all Dassault Model Mystere-Falcon 50 and 900 series airplanes, Falcon 900EX series airplanes, and Falcon 2000 series airplanes was published in the Federal Register on June 4, 1999 (64 FR 29966). That action proposed to require revising the Airplane Flight Manual (AFM) to provide the flight crew with certain instructions associated with the onset of stall warning. That action also proposed to require repetitive inspections to detect discrepancies of the hinge pin assemblies of the rear horizontal stabilizer, and corrective actions, if necessary. For certain airplanes, that action also proposed to require replacement of the hinge pin assemblies with new, improved parts.

Comments Received
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due considerationhas been given to the comments received.

Request to Extend Compliance Time for Initial Inspection
Two commenters request that the compliance time be revised for the initial inspection required by paragraph (b) of this AD. One commenter states that such a short compliance time (within 300 flight hours or 6 months after the effective date of this AD) would constitute a considerable hardship on operators, due to the time and resources available to accomplish the task in this short period of time. The commenter notes that related airplane flight and maintenance manuals have already been revised by the manufacturer to specify additional time. Another commenter, the manufacturer, suggests that the requirement for an early initial dimensional inspection should be removed. This commenter states that the review of dimensional controls completed on a large portion of affected airplanes has resulted in its conclusion that such early inspection is not necessary to ensure the safety of the flying public, and creates an unnecessary burden on operators. This conclusion is based on the fact that, of all airplanes inspected to date, only a few airplanes have exceeded the criteria, and none were found to exceed by greater than 14 microns (0.0006 in).

Additionally, tests and analyses have demonstrated that the fitting deformations do not increase during a 3,750 flight cycle interval in which normal loads have been experienced. The commenter concludes from this data that extending the initial inspection threshold to 3,750 total flight cycles is acceptable.

The FAA concurs. The Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, the Joint Aviation Authorities (JAA), and the manufacturer have advised the FAA that results of early inspections have shown no indication of significant fitting deformations. Based on inspections conducted to date, the FAA has concluded that the requirement for an early initial inspection is nolonger necessary. Accordingly, paragraph (b) of the AD has been revised [and a new paragraph (c) has been added] to extend the compliance time for the initial inspection. Additionally, to simplify the requirements of the AD, the repetitive inspection requirements contained in paragraphs (d) and (e) of the proposed AD are now included in paragraph (b) of the final rule.

Request to Remove Inspection After Stall Event
One commenter, the manufacturer, requests that the proposed AD be revised to remove the requirement for additional inspection after any stall event, as required by paragraph (c) of the proposed AD. The commenter states that the AFM has already been revised to preclude intentional stalls. Additionally, the likelihood for an unintentional stall is sufficiently low that inspection at intervals of 3,750 flight cycles is deemed adequate to determine if discrepancies of the hinge pin assemblies exist.

The FAA concurs. The DGAC has advised the FAA that it has approved the findings of the manufacturer, and has revised the parallel French airworthiness directives to delete the inspection following a stall event. Based on the manufacturer's information, and in consonance with the DGAC, the FAA has determined that the additional inspection after a stall event is not required. Accordingly, paragraph (c) of the proposed AD has been removed from the final rule.

Request to Revise Replacement Compliance Time
One commenter requests that paragraph (f)(2) of the proposed AD be deleted, as the replacement required at the time specified in that paragraph can be delayed until the thresholds required by paragraph (f)(1) of the AD. The FAA does not concur, but finds that clarification of the compliance times required in paragraph (f) of the proposal [now paragraph (e)] is necessary. Paragraph (e) of the final rule requires accomplishment of certain actions at the LATER of the times indicated in paragraphs (e)(1) and (e)(2). The compliance times in paragraph (e)(2) are "within 300 flight hours or 6 months after the effective date of this AD, whichever occurs first." These times provide a "grace period" for airplanes that have exceeded the thresholds of "within 6 years since date of manufacture, or prior to the accumulation of 3,750 total flight cycles, whichever occurs first," as required by paragraph (e)(1) of the AD. The FAA considers such a "grace period" to be beneficial to operators in order to avoid unnecessary grounding of the fleet. No change is necessary in this regard.

Text Revisions Requested
One commenter, the manufacturer, requests various changes to the text of the proposed AD. The commenter requests that the latest revisions to the related French airworthiness directives be referenced, since the previous revisions have been cancelled. The commenter also notes that Dassault Aviation has developed repair solutions for discrepancies of the hinge pin assemblies of the rear horizontal stabilizer, and these repair solutions have been approved by the DGAC. The commenter requests that these repair solutions be referenced in the proposed AD. Additionally, the commenter notes an incorrect reference in paragraph (a) of the proposed AD to Dassault Mystere-Falcon 50 AFM Temporary Change No. 12 as M813EX, which should be listed as FM813EX. Lastly, the commenter requests that the proposed AD be revised to refer to the applicable revision of Chapter 5-40 of each airplane maintenance manual, since that chapter provides the information necessary to accomplish the repetitive inspections required by the AD.

The FAA partially concurs with the various requests. The FAA has revised "NOTE 6" of the AD to refer to the latest French airworthiness directives. The FAA concurs that the referenced approved repair solutions provide an acceptable method of compliance for the repairs required by paragraph (d) of the AD, and has included this information in new "NOTE 4" to the final rule. The FAA also acknowledges the typographical error in regard to AFM Temporary Change No. 12, and has corrected the reference in the AD. The FAA has also clarified other temporary revision references contained in paragraph (b) of the AD.

The FAA does not concur that references to the applicable revisions of Chapter 5-40 of the maintenance manuals should be included. This information is redundant to the temporary procedures already cited as the appropriate sources of service information, and the required intervals for repetitive inspections are directly specified in this AD. However, the FAA has added a new "NOTE 3" to the AD to inform operators that a general revision to the maintenance manual may be used in lieu of the temporary revisions cited in this AD, provided that the information contained in the general revision is identical to that contained in the temporary revisions.

Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 269 airplanes of U.S. registry will be affected by this AD.

For all airplanes, it will take approximately 1 work hour per airplane to accomplish the required Airplane Flight Manual (AFM) revision, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AFM revision required by this AD on U.S. operators is estimated to be $16,140, or $60 per airplane.

Additionally, for all airplanes, it will take approximately 8 work hours per airplane to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $129,120, or $480 per airplane, per inspection cycle.

For 49 airplanes of U.S. registry it will take approximately 10 work hours per airplane to accomplish the required replacement, at an average labor rate of $60 per work hour. Required parts will cost approximately $6,000 per airplane. Based on these figures, the cost impact of the replacement required by this AD on U.S. operators is estimated to be $323,400, or $6,600 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined thatthis final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.

39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: