03-9690. Airworthiness Directives; Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) series airplanes. This action requires a detailed inspection to detect cracks of the vane brackets of the inboard flap actuator beam, and follow-on repetitive detailed inspections or corrective actions, as applicable. This action also provides for two optional terminating actions for the detailed inspection(s). This action is necessary to detect and correct gaps between the flap vane bracket and the adjacent lower skin and between the flap vane bracket and vane actuator beam of the wing flap systems, and premature cracking of the flap vane brackets, which could result in failure of the flap vane bracket(s) when the flaps are extended and the flap vane is aerodynamically loaded. Loss or warping of the flap vane in flight could decrease the lift on one side of the airplane, which could lead to reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Effective May 8, 2003.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 8, 2003.

Comments for inclusion in the Rules Docket must be received on or before May 23, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-317-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via the Internet must contain “Docket No. 2002-NM-317-AD” in the subject line and need not be submitted in triplicate. Comments sent via fax or the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in this AD may be obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT:

Serge Napoleon, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified the FAA that an unsafe condition may exist on certain Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) series airplanes. TCCA advises that several occurrences of gaps were found between the flap vane bracket and the adjacent lower skin and between the flap vane bracket and vane actuator beam. (There are two vane brackets on each of the three vane actuator beams of both the left and right wings.) During a detailed investigation, it was found that an incorrect production process for the installation of the vane bracket resulted in an uneven contact with the adjacent skin and with the vane actuator beam. Such gaps can cause premature cracking of the flap vane brackets of the vane actuator beams, which could lead to the failure of the flap vane bracket(s) when the flaps are extended and the flap vane is aerodynamically loaded. Loss or warping of the flap vane in flight could decrease the lift on one side of the airplane, which could lead to reduced controllability of the airplane.

Canadian Airworthiness Directives

TCCA classified the alert service bulletins specified in Table 2 of this AD and the Time Limits/Maintenance Checks (TLMC) (all described below) as mandatory and issued Canadian airworthiness directives CF-2002-36 and CF-2002-37, effective August 30, 2002, in order to assure the continued airworthiness of these airplanes in Canada.

Explanation of Relevant Service Information

Bombardier has issued the alert service bulletins specified in Table 2 of this AD, which describe procedures for a detailed inspection to detect cracks of the vane brackets of the inboard flap actuator beam, and follow-on repetitive detailed inspections or corrective actions (i.e., Part B or Part C), as applicable.

Part B corrective actions include:

• Doing a detailed inspection to detect gaps at flap stations 60.0, 98.5, and 137.0 between the flap vane bracket(s) and adjacent lower skin and between the flap vane bracket and vane actuator beam, and repair if necessary;
• Measuring the minimum edge distance (MED) for the fastener holes in all flap vane brackets and actuator beams, and replacing any out-of-tolerance bracket and/or actuator beam with a certain new bracket and/or actuator beam; and
• Doing a nondestructive test (NDT) inspection on all vane brackets for cracks, and corrective actions (e.g., remove gaps, ensure that the MED requirements for the replacement brackets meet the allowable values, and replace any cracked vane bracket with a new bracket that meets the MED requirements).

Part C corrective actions include:

• Replacing all 12 vane brackets with new brackets that meet the MED requirements (including removal of any gap between the flap vane brackets and the adjacent lower skin and between the flap vane bracket and actuator beams); and
• Measuring the MED for the fastener holes in all replacement flap vane brackets and actuator beams (including a detailed inspection for gaps); and replacing any out-of-tolerance bracket and/or actuator beam with a certain new bracket and/or actuator beam that meets the MED requirements, and removing any gap, if necessary.

Accomplishment of Part B or Part C corrective actions eliminates the need for the detailed inspection(s) to detect cracks of the vane brackets of the inboard flap actuator beams, described previously.

Explanation of Relevant Time Limits/Maintenance Checks

After doing either Part B or Part C corrective actions, Canadian airworthiness directives CF-2002-36 and CF-2002-37 require compliance with the applicable TLMC threshold and repeat interval of the Airplane Maintenance Manual (AMM) for the flap vane brackets.

FAA's Conclusions

These airplane models are manufactured in Canada and are 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 the FAA informed of the situation described above. The FAA has 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 United States.

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 is being issued to detect and correct gaps between the flap vane bracket and the adjacent lower skin and between the flap vane bracket and vane actuator beam of the wing flap systems, which can cause premature cracking in this area, and consequent failure of the flap vane bracket(s) when the flaps are extended and the flap vane is aerodynamically loaded. Loss or warping of the flap vane in flight could decrease the lift on one side of the airplane, which could lead to reduced controllability of the airplane. This AD requires a detailed inspection to detect cracks of the vane brackets of the inboard flap actuator beam, and follow-on repetitive detailed inspections or corrective actions, as applicable. This AD also provides for two optional terminating actions for the detailed inspection(s). The actions, if accomplished, are required to be accomplished in accordance with the applicable alert service bulletin described previously, except as discussed below.

Differences Between the Alert Service Bulletins and This AD

Although the alert service bulletins describe procedures for identifying and returning all cracked vane brackets to Bombardier, neither the Canadian airworthiness directives nor this AD require such actions.

In addition, although the alert service bulletins specify that the manufacturer may be contacted for disposition of certain repair conditions, this AD requires the repair of those conditions to be accomplished per a method approved by either the FAA, or TCCA (or its delegated agent). In light of the type of repair that is required to address the identified unsafe condition, and in consonance with existing bilateral airworthiness agreements, the FAA has determined that, for this AD, a repair approved by either the FAA or TCCA will be acceptable for compliance with this AD.

Clarification Between the AD and Canadian Airworthiness Directives/Referenced Alert Service Bulletins

Operators should note that, although the parallel Canadian airworthiness directives require compliance with the applicable TLMC threshold and repeat interval of the AMM for the flap vane brackets, this AD first requires a revision of the Airworthiness Limitation Section (ALS) of the Instructions for Continued Airworthiness to incorporate those new threshold and repeat inspection intervals. Revising the ALS, rather than requiring individual repetitive inspections, is advantageous for operators because it allows them to record AD compliance status only at the time that they make the revision, rather than after every inspection. It also has the advantage of keeping all airworthiness limitations, whether imposed by original certification or by AD, in one place with the operator's maintenance program, thereby reducing the risk of non-compliance because of oversight or confusion.

Interim Action

This is considered to be interim action. The FAA is currently considering requiring Part B or Part C corrective actions (described previously), which will constitute terminating action for the detailed inspection(s) to detect cracks of the vane brackets of the inboard flap actuator beam required by this AD action. However, the planned compliance time for the Part B or Part C corrective actions is sufficiently long so that notice and opportunity for prior public comment will be practicable.

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 30 days.

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 alert 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 the FAA 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 2002-NM-317-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.

The FAA has 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 adding the following new airworthiness directive:

2003-08-12 Bombardier, Inc. (Formerly Canadair): Amendment 39-13125. Docket 2002-NM-317-AD.

Applicability: This AD applies to the airplanes listed in Table 1 of this AD, certificated in any category. Table 1 is as follows:

Table 1.—Applicability

Model	Serial Nos.
CL-600-1A11 (CL-600) series airplanes	1004 through 1085 inclusive.
CL-600-2A12 (CL-601) series airplanes	3001 through 3066 inclusive.
CL-600-2B16 (CL-601-3A and CL-601-3R) series airplanes	5001 through 5194 inclusive.
CL-600-2B16 (CL-604) series airplanes	5301 through 5499 inclusive.

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 (i) 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 detect and correct gaps between the flap vane bracket and the adjacent lower skin and between the flap vane bracket and vane actuator beam of the wing flap systems, and premature cracking of the flap vane brackets, which could result in failure of the flap vane bracket(s) when the flaps are extended and the flap vane is aerodynamically loaded, and consequent reduced controllability of the airplane, accomplish the following:

Note 2:

Where there are differences between the applicable Bombardier alert service bulletin specified in Table 2 of this AD and this AD, the AD prevails.

Inspection

(a) Do a detailed inspection to detect cracks of the vane brackets of the inboard flap actuator beam, per Part A of the Accomplishment Instructions of the applicable Bombardier alert service bulletin specified in Table 2 of this AD; at the applicable time indicated in Table 3 of this AD. Table 2 is as follows:

Table 2.—Alert Service Bulletins

For model—	Bombardier alert service bulletin	Excluding
CL-600-1A11 (CL-600) series airplanes	A600-0699, Revision 01, dated July 8, 2002	Service Bulletin Incorporation Sheet, Flap Vane Bracket Inspection Program page, and Minimum Edge Distance Inspection pages.
CL-600-2A12 (CL-601) series airplanes, and CL-600-2B16 (CL-601-3A and CL-601-3R) series airplanes	A601-0532, Revision 01, dated July 8, 2002	Service Bulletin Incorporation Sheet, Flap Vane Bracket Inspection Program page, and Minimum Edge Distance Inspection pages.
CL-600-2B16 (CL-604) series airplanes	A604-27-007, Revision 01, dated July 8, 2002	Service Bulletin Incorporation Sheet, Flap Vane Bracket Inspection Program page, and Minimum Edge Distance Inspection pages.

Table 3 is as follows:

 Table 3.—Compliance Time

For airplanes that have accumulated—	Compliance time
1,200 total landings or less as of the effective date of this AD	Before the accumulation of 1,300 total landings.
More than 1,200 total landings, but less than 3,000 total landings as of the effective date of this Ad	Within 100 landings after the effective date of this AD.
3,000 total landings or more as of the effective date of this AD	Within 50 landings after the effective date of this AD.

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.”

No Crack Findings: Repetitive Inspections

(b) If no crack is detected during the detailed inspection required by paragraph (a) of this AD, repeat that inspection thereafter at intervals not to exceed 100 landings.

Crack Findings: Corrective Actions

(c) If any crack is detected during the detailed inspection required by paragraph (a) of this AD, before further flight, do the actions specified in paragraph (d) or (e) of this AD.

Optional Terminating Actions

(d) Do the actions specified in paragraphs (d)(1), (d)(2), and (d)(3) of this AD per Part B of the Accomplishment Instructions of the applicable alert service bulletin identified in Table 2 of this AD, unless otherwise specified in this AD. Accomplishment of these actions constitutes compliance with the requirements of paragraphs (a), (b), and (c) of this AD.

(1) Do a detailed inspection to detect gaps at flap stations 60.0, 98.5, and 137.0 between the vane bracket(s) and adjacent lower skin and vane actuator beam. If any gap is in excess of the limits specified in the applicable alert service bulletin, before further flight, repair per a method approved by either the Manager, New York Aircraft Certification Office (ACO), FAA; or Transport Canada Civil Aviation (TCCA) (or its delegated agent).

(2) Measure the minimum edge distance (MED) for the fastener holes in all flap vane brackets and actuator beams. If the MED requirements for any bracket or actuator beam do not meet the allowable values specified in Figure 2 of the applicable alert service bulletin, before further flight, replace the out-of-tolerance bracket and/or actuator beam with a new bracket and/or actuator beam that meet the MED requirements specified in Figure 2 of the applicable alert service bulletin.

(3) Do a nondestructive test (NDT) inspection on all vane brackets for cracks. If any crack is found, before further flight, accomplish the corrective actions (e.g., remove gaps, ensure that the MED requirements for the replacement brackets meet the allowable values specified in Figure 2 of the applicable alert service bulletin, and replace any cracked vane bracket with a new bracket that meets the MED requirements specified in Figure 2 of the applicable alert service bulletin). Although the applicable alert service bulletin describes procedures for identifying and returning all cracked vane brackets to Bombardier, this AD does not require such actions.

(e) In lieu of the actions specified in paragraph (d) of this AD, do the actions specified in paragraphs (e)(1) and (e)(2) of this AD per Part C of the Accomplishment Instructions of the applicable alert service bulletin identified in Table 2 of this AD. Accomplishment of these actions constitutes compliance with the requirements of paragraphs (a), (b), and (c) of this AD.

(1) Replace all 12 vane brackets with new brackets that meet the MED requirements specified in Figure 2 of the applicable alert service bulletin (including removal of any gap between the vane brackets and the adjacent lower skin and actuator beams).

(2) Measure the MED for the fastener holes in all replacement flap vane brackets and actuator beams (including a detailed inspection for gaps).

(i) If the MED requirements for any bracket or actuator beam do not meet the allowable values specified in Figure 2 of the applicable alert service bulletin, before further flight, replace the out-of-tolerance bracket and/or actuator beam with a new bracket and/or actuator beam that meets the MED requirements specified in Figure 2 of the applicable alert service bulletin.

(ii) If any gap is detected, before further flight, repair the gap.

Other Means of Acceptable Compliance With Paragraph (e) of This AD

(f) Accomplishment of the inspections and modifications per Part B or Part C of the applicable alert service bulletin listed in Table 4 of this AD; and the MED dimension checks for the flap brackets and the actuator beams as specified in drawing K600-14251, including any required rework; is considered acceptable for compliance with the requirements of paragraph (e) of this AD. Table 4 of this AD is as follows:

Table 4.—Acceptable Basic Issue Alert Service Bulletins

For model—	Bombardier alert service bulletin—
CL-600-1A11 (CL-600) series airplanes	A600-0699, Basic Issue, dated November 29, 2001.
CL-600-2A12 (CL-601) series airplanes, and CL-600-2B16 (CL-601-3A and CL-601-3R) series airplanes	A601-0532, Basic Issue, dated November 29, 2001.
CL-600-2B16 (CL-604) series airplanes	A604-27-007, Basic Issue, dated November 29, 2001.

Time Limits/Maintenance Checks

(g) After doing the actions specified in paragraph (d) or (e) of this AD, revise the Airworthiness Limitation Section (ALS) of the Instructions for Continued Airworthiness to state the following (this may be accomplished by inserting a copy of this AD in the ALS):

“Do the applicable Time Limits/Maintenance Checks (TLMC) inspection task for the flap vane brackets at the times specified in the following table:

Table 5.—Compliance Time for TLMCs

Condition of brackets and gaps	Compliance time
No gap or crack in any flap vane bracket	Continue using existing TLMC bracket schedule as published in the applicable ALS.
No crack in any flap vane bracket, but shims added	For Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) series airplanes:
	Repeat inspections remain at 600 landings from rework.
	For Model CL-600-2B16 (CL-604) series airplanes:
	Repeat inspections remain at 1,800 landings from rework.
All 12 flap vane brackets have been replaced	For Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) series airplanes:
	New threshold of 7,000 landings from installation of new flap vane brackets. Repeat inspections remain at 600 landings.
	For Model CL-600-2B16 (CL-604) series airplanes:
	New threshold of 7,200 landings from installation of new flap vane brackets. Repeat inspections remain at 1,800 landings.”

(h) After doing the requirements of paragraph (g) of this AD, except as provided in paragraph (i) of this AD, no alternative inspection times may be approved for these flap vane brackets.

Alternative Methods of Compliance

(i) 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 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.

Note 4:

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

Special Flight Permits

(j) 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 (IBR)

(k) Unless otherwise specified in this AD, the actions shall be done in accordance with the Bombardier alert service bulletin specified in Table 5 of this AD, as applicable.

Table 5 is as follows:

Table 6.—IBR Alert Service Bulletins

Alert service bulletin	Excluding
Bombardier Alert Service Bulletin A600-0699, Revision 01, dated July 8, 2002	Service Bulletin Incorporation Sheet, Flap Vane Bracket Inspection Program page, and Minimum Edge Distance Inspection pages.
Bombardier Alert Service Bulletin A601-0532, Revision 01, dated July 8, 2002	Service Bulletin Incorporation Sheet, Flap Vane Bracket Inspection Program page, and Minimum Edge Distance Inspection pages.
Bombardier Alert Service Bulletin A604-27-007, Revision 01, dated July 8, 2002	Service Bulletin Incorporation Sheet, Flap Vane Bracket Inspection Program page, and Minimum Edge Distance Inspection pages.

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 Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station A, 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 directives CF-2002-36 and CF-2002-37, effective August 30, 2002.

Effective Date

(l) This amendment becomes effective on May 8, 2003.

Issued in Renton, Washington, on April 14, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.