AD 2003-19-11

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Learjet Model 60 airplanes, that currently requires inspection to detect bends in or damage to the fuel crossflow tube; inspection to determine clearance between the fuel crossflow tube and the flight control cables; and replacement or repair of the tube, if necessary. This amendment requires a review of airplane maintenance records or an inspection to determine if a fuel crossflow tube having a certain part number is installed; and follow-on/corrective actions, as applicable. This amendment also expands the applicability of the existing AD to include additional airplanes. The actions specified by this AD are intended to prevent chafing and consequent failure of the fuel crossflow tube due to inadequate clearance between the tube and the flight control cables, which could result in loss of fuel from one fuel tank during normal operating conditions or loss of fuel from both main fuel tanksduring fuel cross-feeding operations. This action is intended to address the identified unsafe condition.

Final rule.

2003-19-11 Learjet: Amendment 39-13314. Docket 2000-NM-408-AD. Supersedes AD 95-14-09, Amendment 39-9303.

Applicability: Model 60 airplanes, serial numbers 60-001 through 60-145 inclusive, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.
To prevent chafing and consequent failure of the fuel crossflow tube due to inadequate clearance between the tube and the flight control cables, which could result in loss of fuel from one fuel tank during normal operating conditions or loss of fuel from both main fuel tanks during fuel cross-feeding operations, accomplish the following:

Part Identification

(a) Within 25 flight hours after the effective date of this AD, inspect the fuel crossflow tube to determine whether part number (P/ N) 6026020-005 is installed. Instead of inspecting the tube, a review of airplane maintenance records is acceptable if the P/N of the tube can be positively determined from that review.

Clearance Measurement and Corrective Action

(b) For all airplanes: If P/N 6026020-005 is found installed during the review or inspection required by paragraph (a) of this AD, before further flight, measure the clearance between the fuel crossflow tube and the flight control cables to determine if it is at least 0.35 inch, per paragraph 2.B.(8) of the Accomplishment Instructions of Bombardier Alert Service Bulletin A60-28-3, Revision 2, dated October 26, 1998.

(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.

(2) If the clearance is less than 0.35 inch, before further flight, repair per a method approved by the Manager, Wichita Aircraft Certification Office (ACO), FAA.

Part Replacement, Measurement, and Repair

(c) For airplanes having serial numbers 60-001 through 60-055: If P/N 6026020-005 is not found installed during the review or inspection required by paragraph (a) of this AD, within 90 days after accomplishing the review or inspection, replace the existing fuel crossflow tube with a new fuel crossflow tube having P/N 6026020-005, and measure the clearance between the newly installed fuel crossflow tube and the flight control cables, per paragraph 2.A. of the Accomplishment Instructions of Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001.

(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.

(2) If the clearance is less than 0.35 inch, before further flight, repair per a method approved by the Manager, Wichita ACO, FAA.

(d) For airplanes having serial numbers 60-056 through 60-145: If P/N 6026020-005 is not found installed during the review or inspection required by paragraph (a) of this AD, within 90 days after accomplishing the review or inspection, replace the existing fuel crossflow tube with a new fuel crossflow tube having P/N 6026020-005, and measure the clearance between the newly installed fuel crossflow tube and the flight control cables to determine if the clearance is at least 0.35 inch, per paragraph 2.B. of the Accomplishment Instructions of Bombardier Alert Service Bulletin A60-28-3, Revision 2, dated October 26, 1998.

(1) If the clearance is 0.35 inch or more, no further action is required by this paragraph.

(2) If the clearance is less than 0.35 inch, before further flight, repair per a method approved by the Manager, Wichita ACO, FAA.

Note 1: Bombardier Alert Service Bulletin A60-28-3, Revision 2, Figure 1, Detail D, incorrectly identifies the fuel crossflow tube to be installed as P/N 6026020-001. The manufacturer is aware of this error and plans to correct the part number in the next revision of the alert service bulletin.

Part Installation

(e) As of the effective date of this AD, only fuel crossflow tubes having P/N 6026020-005 shall be installed on any airplane.

Alternative Methods of Compliance

(f) In accordance with 14 CFR 39.19, the Manager, Wichita ACO,FAA, is authorized to approve alternative methods of compliance (AMOCs) for this AD.

Incorporation by Reference

(g) Unless otherwise specified by this AD, the actions shall be done in accordance with Bombardier Alert Service Bulletin A60-28-3, Revision 2, dated October 26, 1998; and Bombardier Service Bulletin 60-28-4, Revision 2, dated August 22, 2001; 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 Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(h) This amendment becomes effective on November 3, 2003.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 95-14-09, amendment 39-9303 (60 FR 36984, July 19, 1995), which is applicable to certain Learjet Model 60 airplanes, was published in the Federal Register on June 18, 2003 (68 FR 36502). That action proposed to require inspection to detect bends in or damage to the fuel crossflow tube; inspection to determine clearance between the fuel crossflow tube and the flight control cables; and replacement or repair of the tube, if necessary. That action also proposed to require a review of airplane maintenance records or an inspection to determine if a fuel crossflow tube having a certain part number is installed; and follow-on/ corrective actions, as applicable. That action also proposed to expand the applicability of the existing AD to include additional airplanes.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Explanation of Change to Proposed Rule

In paragraph (a) of the proposed rule, we inadvertently specified an incorrect part number. We have revised this AD to specify the correct part number.

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 previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Change to Labor Rate Estimate

We have reviewed the figures we have used over the past several years to calculate AD costs to operators. To account for various inflationary costs in the airline industry, we find it necessary to increase the labor rate used in these calculations from $60 per work hour to $65 per work hour. The cost impact information, below, reflects this increase in the specified hourly labor rate.

Cost Impact

There are approximately 145 airplanes of the affected design in the worldwide fleet. The FAA estimates that 109 airplanes of U.S. registry will be affected by this AD.

It will take approximately 2 work hours per airplane to accomplish the review of airplane maintenance records/inspection required in this AD action, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the requirements of this AD on U.S. operators is estimated to be $14,170, or $130 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

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.

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 removing amendment 39-9303 (60 FR 36984, July 19, 1995), and by adding a new airworthiness directive (AD), amendment 39-13314, to read as follows: