AD 2003-11-11

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 series airplanes, that currently requires repetitive eddy current inspections for cracking of the main landing gear (MLG) main fittings, and replacement with new or serviceable MLG main fittings if necessary. That AD also requires servicing the MLG shock struts; inspecting the MLG shock struts for nitrogen pressure, visible chrome dimension, and oil leakage; and performing corrective actions, if necessary. This amendment clarifies the applicability, adds certain repetitive inspections, reduces an initial inspection threshold, and removes a provision to extend the repetitive interval for the eddy current inspection.

This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent failure of the MLG main fittings, which could result incollapse of the MLG upon landing.

Final rule; request for comments.

2003-11-11 Bombardier, Inc.: Amendment 39-13170. Docket 2003-NM-03-AD. Supersedes AD 2001-22-09, Amendment 39-12488.

Applicability: Model CL-600-2B19 series airplanes, certificated in any category, having serial numbers 7003 and subsequent, equipped with main landing gear (MLG) main fittings having part numbers (P/N) 601R85001-3 and 601R85001-4 (Messier Dowty, Inc. P/Ns 17064-101, 17064-102, 17064-103, and 17064-104).

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 (m)(1) of this AD. The request should include an assessment of the effect of the modification, alteration, or repairon 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.

Note 2: Where there are differences between the referenced service bulletin and the AD, the AD prevails.

To prevent failure of the MLG main fittings, which could result in collapse of the MLG upon landing, accomplish the following:

Service Bulletin References

(a) Accomplishment of the inspections and servicing, as applicable, specified in paragraphs (c), (g), (h), and (i) of this AD, per Bombardier Alert Service Bulletin A601R-32-079, dated December 3, 1999; Revision "A," dated January 7, 2000; Revision "B," dated June 1, 2000; Revision "C," dated October 26, 2000; or Revision "D," dated December 1, 2000; prior to the effective date of this AD, is considered acceptable for compliance with the requirements of paragraphs (c), (g), (h), and (i) of this AD.

(b) The term "service bulletin," as used in this AD, means the Accomplishment Instructions of Bombardier Alert Service Bulletin A601R-32-079, Revision "E," dated September 12, 2002; including Appendix 1, Revision D, dated September 12, 2002; including Appendices 2 and 3, dated September 12, 2002.

Initial Eddy Current Inspection

(c) Perform an eddy current inspection to detect cracking of the MLG main fittings, per PART B of the service bulletin, at the earlier of the times specified in paragraph (c)(1) or (c)(2) of this AD.

(1) Prior to the accumulation of 1,500 total flight cycles on the MLG, or within 150 flight cycles after December 4, 2001 (the effective date of AD 2001-22-09, amendment 39-12488), whichever occurs later.

(2) Prior to the accumulation of 1,000 total flight cycles on the MLG, or within 150 flight cycles after the effective date of this AD, whichever occurs later.

Repetitive Eddy Current Inspections

(d) Repeat the eddy current inspection specified in paragraph (c) of this AD at the time specified in paragraph (d)(1), (d)(2), or (d)(3), as applicable, except as provided by paragraph (d)(4) of this AD, per PART B of the service bulletin.

(1) For airplanes on which the eddy current inspection required by paragraph (c) of this AD is accomplished after the effective date of this AD: Repeat the inspection at intervals not to exceed 500 flight cycles.

(2) For airplanes on which the repetitive eddy current inspection required by AD 2001-22-09, amendment 39-12488, has been accomplished, and on which the repetitive intervals have been increased per paragraph (e) of AD 2001-22-09 before the effective date of this AD: Repeat the inspection within 500 flight cycles after the effective date of this AD, or within 1,000 flight cycles since the last eddy current inspection, whichever occurs first, and thereafter at intervals not to exceed 500 flight cycles.

(3) For airplanes on which the repetitive eddy current inspection required by AD 2001-22-09 has been accomplished, and on which the repetitive intervals have not been increased per paragraph (e) of AD 2001-22-09 before the effective date of this AD: Repeat the eddy current inspection at intervals not to exceed 500 flight cycles.

(4) For airplanes on which an eddy current inspection has been accomplished to confirm the detailed inspection required by paragraph (j) of this AD: The next eddy current inspection must be done within 500 flight cycles following the last detailed inspection required by paragraph (j) of this AD, and thereafter at intervals not to exceed 500 flight cycles.

Corrective Actions

(e) If no cracking of the MLG main fittings is suspected during the next eddy current inspection required by paragraph (c) or (d) of this AD, but the paint has been removed: Prior to further flight, apply a new finish and install the harness clamp on the brake line with the bolt, washers, nut, and cotter pin; per PART B of the service bulletin.

(f) If any cracking of the MLG main fittings is found during any eddy current inspection required by paragraph (c) or (d) of this AD: Prior to further flight, replace any cracked MLG main fitting with a new or serviceable part per the service bulletin.

Servicing the Shock Struts

(g) Prior to the accumulation of 1,500 total flight cycles on the MLG shock struts, or within 500 flight cycles after December 4, 2001, whichever occurs later: Service (Oil and Nitrogen) the left and right MLG shock struts per PART C (for airplanes on the ground) or PART D (for airplanes on jacks) of the service bulletin.

Other Inspections

(h) Within 500 flight cycles after completing the actions required by paragraph (g) of this AD: Inspect the MLG left and right shock struts for nitrogen pressure, visible chrome dimension, and oil leakage, in accordance with PART E of the service bulletin. Thereafter, repeat the inspection at intervals not to exceed 500 flight cycles.

Corrective Actions for Certain Inspections

(i) If the chrome extension dimension of the shock strut pressure reading is outside the limits specified in the Airplane Maintenance Manual, Task 32-11-05-220-801, or any oil leakage is found during any inspection required by paragraph (h) of this AD: Prior to further flight, service the MLG shock strut in accordance with PART C (for airplanes on the ground) or PART D (for airplanes on jacks) of the service bulletin.

Detailed and Follow-on Inspections, and Corrective Action

(j) Prior to the accumulation of 1,000 total flight cycles on the MLG, or within 250 flight cycles after the effective date of this AD, whichever occurs later: Accomplish a detailed inspection of the MLG main fittings to detect signs of cracking (including linear paint cracks along the circumference of the main fitting tube, lack of paint (paint peeling) or other paint damage, lack of adhesion or paint bulging, and signs of corrosion), per PART A of the service bulletin. Repeat the inspection thereafter at intervals not to exceed 100 flight cycles.

Note 3: For the purposes of this AD, a detailed inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required."

(k) If any linear paint crack along the circumference of the main fitting tube, lack of paint (paint peeling) or other paint damage, evidence of paint bulging due to lack of adhesion, or evidence of corrosion is found during any inspection required by paragraph (j) of this AD: Prior to further flight, accomplish either an eddy current inspection to detect cracking, per PART B of the service bulletin; or a fluorescent penetrant inspection to detect cracking, per PART F of the service bulletin.

(1) If no cracking of the MLG main fittings is found during any inspection required by paragraph (k) of this AD: Prior to further flight, repaint and/or repair/rework any paint damage per PART B of the service bulletin.

(2) If any cracking of the MLG main fittings is found during any inspection required by paragraph (k) of this AD: Prior to further flight, replace any cracked MLG main fitting with a new or serviceable part per the service bulletin.

Reporting Requirement

(l) Within 30 days after each inspection and servicing required by paragraphs (c), (d), (g), (h), (j), and (k) of this AD, report all findings, positive or negative, to: Bombardier Aerospace, In-Service Engineering, fax number 514-855-8501. Although the service bulletin references completion of a "Service Bulletin Comment Sheet-Facsimile Reply Sheet," this AD does not require that action. Informationcollection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

Alternative Methods of Compliance

(m)(1) 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), FAA. 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.

(2) Alternative methods of compliance issued to allow escalation of the repetitive intervals for the eddy current inspections from 500 to 1,000 flight cycles, per paragraph (e) of AD 2001-22-09, are not approved as alternative methods of compliance with this AD.

Note 4: Information concerning the existence ofapproved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO.

Special Flight Permits

(n) 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

(o) Unless otherwise specified by this AD, the actions shall be done per Bombardier Alert Service Bulletin A601R-32-079, Revision "E," dated September 12, 2002; including Appendix 1, Revision D, dated September 12, 2002; including Appendices 2 and 3, dated September 12, 2002; which includes the following effective pages:

Page Number
Revision Level Shown on Page
Date Shown on Page
1-30
E
September 12, 2002.

Appendix 1
A1-A10
D
September 12, 2002.

Appendix 2
A1-A2
Original
September 12, 2002.

Appendix 3
A1-A8
Original
September 12, 2002.This incorporation by reference is 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 Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 5: The subject of this AD is addressed in Canadian airworthiness directive CF-1999-32R2, dated September 19, 2002.

Effective Date

(p) This amendment becomes effective on June 13, 2003.

On October 22, 2001, the FAA issued airworthiness directive (AD) 2001-22-09, amendment 39-12488 (66 FR 54658, October 30, 2001). (A correction of that AD was published in the Federal Register on November 26, 2001 (66 FR 58931), and a second correction of that AD was published in the Federal Register on December 14, 2001 (66 FR 64739).) That AD is applicable to certain Bombardier Model CL-600-2B19 series airplanes and currently requires repetitive eddy current inspections for cracking of the main landing gear (MLG) main fittings, and replacement with new or serviceable MLG main fittings if necessary. That AD also requires servicing the MLG shock struts; inspecting the MLG shock struts for nitrogen pressure, visible chrome dimension, and oil leakage; and performing corrective actions, if necessary. The actions required by that AD are intended to prevent failure of the MLG main fittings, which could result in collapse of the MLG upon landing.

BackgroundAs described in the notice of proposed rulemaking (NPRM) for AD 2001-22-09, three cases of premature failure of the MLG main fittings had been reported. The reports indicated that a circumferential crack was found on the MLG main fittings at the radius between the fitting cylinder area and the upper attachment lug for the shock strut. Further investigation indicated that, under certain conditions, an incorrectly serviced shock strut could lead to premature failure of the MLG main fittings.

Actions Since Issuance of Previous Rule

Since the issuance of AD 2001-22-09, Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, has advised us of reports of another premature failure of the MLG main fittings. Subsequent laboratory examination has confirmed that the failure was at the identical location of the previously reported failures, except that this new incident resulted from a different failure mode.

Since the findings of this latest premature failure of the MLG main fittings, the following new service information has been issued:

The manufacturer issued Bombardier Alert Service Bulletin A601R-32-079, Revision "E," dated September 12, 2002; including Appendix 1, Revision D, dated September 12, 2002; including Appendices 2 and 3, dated September 12, 2002. The revised service bulletin describes procedures for performing repetitive visual, eddy current, and fluorescent penetrant inspections of the MLG fittings, and replacement if necessary; servicing and inspecting the MLG shock struts; and performing corrective actions if necessary. The major changes to Bombardier Alert Service Bulletin A601R-32-079, Revision D, dated December 1, 2000, which is cited as the appropriate source of service information for accomplishment of AD 2001-22-09, include revising certain compliance times, adding repetitive fluorescent penetrant inspections, and removing the escalation of eddy current repetitive inspections. TCCA classified this service bulletin as mandatory.

TCCA has issued Canadian airworthiness directive CF-1999-32R2, dated September 19, 2002, to ensure the continued airworthiness of these airplanes in Canada. The Canadian airworthiness directive removes the procedure for escalation of the eddy current inspection interval and adds a detailed visual inspection of the MLG main fittings to supplement the eddy current inspection.

FAA's Conclusions

This airplane model is manufactured in Canada and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, TCCA has kept us informed of the situation described above. We have examined the findings of TCCA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the UnitedStates.

Explanation of Requirements of Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD supersedes AD 2001-22-09 to continue to require certain requirements. Those requirements include performing repetitive eddy current inspections for cracking of the MLG main fittings; replacing with new or serviceable MLG main fittings if necessary; servicing the MLG shock struts; inspecting the MLG shock struts for nitrogen pressure, visible chrome dimension, and oil leakage; and performing corrective actions if necessary.

This AD clarifies the applicability, adds certain repetitive inspections, reduces an initial inspection threshold, and removes a provision to extend the repetitive interval for the eddy current inspection. The actions required by this AD must be accomplished per the referenced service bulletin, as described previously.

Clarification of Compliance Time Related to the Components

The compliance times specified in AD 2001-22-09 did not specify that the total flight cycles in paragraphs (a) and (b) of that AD are related to the MLG or shock struts, as applicable. To clarify this, we have revised certain paragraphs in this AD to specify that the compliance time is related to the components referenced in those paragraphs rather than to the airplane.

Clarification of Applicability

The Canadian airworthiness directive and Bombardier service bulletin both include Messier Dowty part numbers (P/Ns) for the MLG main fittings, which are comparable to the Bombardier P/Ns. For this reason, we have determined that it is necessary to clarify the applicability of this AD by referencing both Messier Dowty and Bombardier P/Ns.

Clarification of Replacement Requirement

AD 2001-22-09 requires replacement of any cracked MLG main fitting with a new or serviceable MLG, and the Bombardier service bulletin specifies such replacement with either an MLG or MLG fitting. However, in consonance with the Canadian airworthiness directive, this AD requires replacing any cracked MLG main fitting with a new or serviceable main fitting instead of replacing the entire MLG.

Explanation of Change to Existing AD

We have added paragraph (m)(2) of this AD to prohibit the use of alternative methods of compliance issued per paragraph (e) of AD 2001-22-09 that would have allowed escalation of the repetitive intervals for the eddy current inspections from 500 to 1,000 flight cycles.

Interim Action

This is considered to be interim action until final action is identified, at which time we may consider further rulemaking.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Submit comments using the following format:

Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.

For each issue, state what specific change to the AD is being requested.

Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing us to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2003-NM-03-AD." The postcard will be date stamped and returned to the commenter.Regulatory Impact

The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

We have determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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 removing amendment 39-12488 (66 FR 54658, October 30, 2001), corrected at 66 FR 58931, November 26, 2001; and corrected at 66 FR 64739, December 14, 2001; and by adding a new airworthiness directive (AD), amendment 39-13170, to read as follows: