AD 2010-21-19

We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires replacing aluminum fire extinguisher discharge tubes with new, improved tubes; checking the fire extinguisher container for certain serial numbers; replacing fire extinguisher containers that have affected serial numbers; inspecting the pressure indicator on certain fire extinguisher containers for discrepancies; and performing corrective action if necessary. This AD was prompted by a report of accidental discharge of a fire extinguisher container and damage to an aluminum discharge tube. Investigation revealed that following the discharge an inaccurate pressure indication, due to the indicator dial being incorrectly staked, showed that the container was fully charged. We are issuing this AD to prevent inaccurate pressure readings and subsequent damage to the discharge tubes during operation, which could result in failure of the fire extinguisher system and an uncontained fire inan emergency situation.

Final rule.

2010-21-19 Learjet Inc: Amendment 39-16479; Docket No. FAA-2010- 0676; Directorate Identifier 2010-NM-095-AD.

Effective Date

(a) This AD is effective November 18, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Learjet Inc. Model 45 airplanes, certificated in any category; as identified in Bombardier Service Bulletins 40-26-05 and 45-26-9, both Revision 2, both dated May 4, 2009.

Subject

(d) Air Transport Association (ATA) of America Code 26: Fire protection.

Unsafe Condition

(e) This AD results from a report of accidental discharge of a fire extinguisher container and damage to an aluminum discharge tube. Investigation revealed that following the discharge an inaccurate pressure indication, due to the indicator dial being incorrectly staked, showed that the container was fully charged. The Federal Aviation Administration is issuing this AD to prevent inaccurate pressure readings and subsequent damage to the discharge tubes during operation, which could result in failure of the fire extinguisher system and an uncontained fire in an emergency situation.

Compliance

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

Replacement, Check, Inspection, Corrective Action

(g) Within 12 months after the effective date of this AD: Replace the aluminum fire extinguisher discharge tubes with new, improved stainless steel tubes; check the fire extinguisher container for any serial number specified in Table 1 of Bombardier Service Bulletin 40-26-05 or 45-26-9, both Revision 2, both dated May 4, 2009, as applicable; replace any containers that have affected serial numbers, do a weight check of all containers, including the replacement container, if applicable; and inspect the pressure indicator on the containers for discrepancies; by doing all applicable actions in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 40-26-05 or 45-26-9, both Revision 2, both dated May 4, 2009; as applicable. If any discrepancy is found, replace the container before further flight in accordance with the Accomplishment Instructions of Bombardier Service Bulletin 40-26-05 or 45-26-9, both Revision 2, both dated May 4, 2009; as applicable.
(h) Actions done before the effective date of this AD in accordance with the applicable service information listed in Table 1 of this AD are acceptable for compliance with the corresponding requirements in paragraph (g) of this AD.

Table 1--Credit for Actions Accomplished in Accordance With Previous Service Information

Affected Serial Numbers
Bombardier Service Bulletin
Revision
Dated
For Model 45 airplanes having serial numbers 2001 through 2114, inclusive
40-26-05
Basic Issue
November 24, 2008
For Model 45 airplanes having serial numbers 2001 through 2114, inclusive
40-26-05
1
December 22, 2008For Model 45 airplanes having serial numbers 006 through 383, inclusive
45-26-9
Basic Issue
November 24, 2008
For Model 45 airplanes having serial numbers 006 through 383, inclusive
45-26-9
1
December 22, 2008

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Wichita Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD.
(2) Before using any approved AMOC, notify your Principal Maintenance Inspector or Principal Avionics Inspector, as appropriate, or lacking a principal inspector, your local Flight Standards District Office.

Related Information

(j) For more information about this AD, contact James Galstad, 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- 4135; fax (316) 946-4107; e-mail james.galstad@faa.gov.

Material Incorporated by Reference

(k) You must use the service information contained in Table 2 of this AD, as applicable, to do the actions required by this AD, unless the AD specifies otherwise.

Table 2--Material Incorporated by Reference

Document
Revision
Date
Bombardier Service Bulletin 40-26-05
2
May 4, 2009
Bombardier Service Bulletin 45-26-9
2
May 4, 2009

(1) The Director of the Federal Register approved the incorporation by reference of the service information contained in Table 2 of this AD under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) For service information identified in this AD, contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942;telephone 316-946-2000; fax 316-946-2220; e-mail ac.ict@aero.bombardier.com; Internet http://www.bombardier.com.
(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.
(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call 202-741-6030, or go to http:// www.archives.gov/federal_register/code_of_federal_regulations/ ibr_locations.html.

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to the specified products. That NPRM was published in the Federal Register on July 7, 2010 (75 FR 38941). That NPRM proposed to require replacing aluminum fire extinguisher discharge tubes with new, improved tubes; checking the fire extinguisher container for certain serial numbers; replacing fire extinguisher containers that have affected serial numbers; inspecting the pressure indicator on certain fire extinguisher containers for discrepancies; and performing corrective action if necessary.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and the public interest require adopting the AD as proposed.Costs of Compliance

We estimate that this AD affects 322 airplanes of U.S. registry. We also estimate that it will take 5 work-hours per product to comply with this AD. The average labor rate is $85 per work-hour. Required parts cost is minimal. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these costs. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $136,850, or $425 per product.

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 authoritydescribed 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

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 "significantrule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.

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.

Sec. 39.13 [Amended]

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