Airworthiness Directives; Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A), and 36 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A), and 36 airplanes. This AD requires a one-time inspection of the center ball of the aileron control cable or cables for a defective swage, and corrective actions if necessary. This AD is prompted by a report indicating that an aileron cable failed on one affected airplane when the cable underwent a tension check. We are issuing this AD to prevent severe weakening of the aileron cable, and consequent reduced controllability of the airplane.

DATES:

This AD becomes effective August 9, 2005.

The incorporation by reference of certain publications listed in the AD is approved by the Director of the Federal Register as of August 9, 2005.

ADDRESSES:

For service information identified in this AD, contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942.

Docket: The AD docket contains the proposed AD, comments, and any final disposition. You can examine the AD docket on the Internet at http://dms.dot.gov , or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Washington, DC. This docket number is FAA-2005-20872; the directorate identifier for this docket is 2004-NM-271-AD.

FOR FURTHER INFORMATION CONTACT:

David Hirt, Aerospace Engineer, Systems and Propulsion Branch, ACE-116W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4156; fax (316) 946-4107.

SUPPLEMENTARY INFORMATION:

The FAA proposed to amend 14 CFR part 39 with an AD for certain Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A), and 36 airplanes. That action, published in the Federal Register on April 6, 2005 (70 FR 17349), proposed to require a one-time inspection of the center ball of the aileron control cable or cables for a defective swage, and corrective actions if necessary.

Comments

We provided the public the opportunity to participate in the development of this AD. No comments have been submitted on the proposed AD or on the determination of the cost to the public.

Clarification of Service Bulletin References

All references to “Learjet Alert Service Bulletins” have been changed to refer to “Bombardier Alert Service Bulletins.” This change more accurately reflects the published titles of these documents, and it is necessary to meet the Office of the Federal Register's guidelines for material incorporated by reference.

Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

There are about 1,704 airplanes of the affected design in the worldwide fleet. This AD affects about 1,136 airplanes of U.S. registry. The inspection takes about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $73,840, or $65 per airplane.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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.

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

2005-13-36 Learjet: Amendment 39-14173. Docket No. FAA-2005-20872; Directorate Identifier 2004-NM-271-AD.

Effective Date

(a) This AD becomes effective August 9, 2005.

Affected ADs

(b) None.

Applicability: (c) This AD applies to Learjet Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A), and 36 airplanes; certificated in any category; as identified in the Bombardier alert service bulletins in Table 1 of this AD.

Unsafe Condition

(d) This AD was prompted by a report indicating that an aileron cable failed on one affected airplane when the cable underwent a tension check. We are issuing this AD to prevent severe weakening of the aileron cable, and consequent reduced controllability of the airplane.

Compliance: (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspection and Corrective Action

(f) Within 100 flight hours, or 90 days after the effective date of this AD, whichever occurs first: Do a detailed inspection of the center ball of the aileron control cable or cables for a defective swage, and before further flight, replace any damaged or defective cable with a new cable. Unless otherwise specified in this AD, do all actions in accordance with the Accomplishment Instructions of the applicable service bulletin in Table 1 of this AD.

Note 1:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

Parts Installation

(g) As of the effective date of this AD, no person may install on any airplane an aileron control cable unless it has been inspected in accordance with paragraph (f) of this AD.

No Reporting or Parts Return Requirement

(h) Although the service bulletins in Table 1 of this AD have procedures for submitting a report showing compliance with the applicable service bulletin and for returning any discrepant parts to the manufacturer, this AD does not include those requirements.

Alternative Methods of Compliance (AMOCs)

(i) The Manager, Wichita Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

(j) You must use the service information in Table 2 of this AD to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. To get copies of the service information, contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942. To view the AD docket, go to the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC. To review copies of the service information, go to the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.