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CFR Citation: 14 CFR Part 39

Docket ID: [Docket No. FAA-2008-0644; Directorate Identifier 2007-NM-321-AD]

RIN ID: RIN 2120-AA64

NOTICE: PROPOSED RULES

ACTION: Airworthiness Directives:

DOCUMENT ACTION: Notice of proposed rulemaking (NPRM).

SUBJECT CATEGORY: Airworthiness Directives; BAE Systems (Operations) Limited (Jetstream) Model 4101 Airplanes

DATES: We must receive comments on this proposed AD by July 21, 2008.

DOCUMENT SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes. The existing AD currently requires repetitive tests for free movement of the capsule/bearing of the nose landing gear (NLG), and related investigative and corrective actions. This proposed AD would require a modified test for free movement of the capsule/bearing of the NLG at reduced repeat intervals, and replacement of the NLG assembly with a modified assembly. This proposed AD results from additional reports of the NLG failing to extend fully on an airplane that had been inspected in accordance with AD 20041407. We are proposing this AD to prevent failure of the NLG to extend fully, which could result in reduced controllability of the airplane during landing.

SUMMARY: BAE Systems (Operations) Limited (Jetstream) Model 4101 Airplanes,

SUPPLEMENTAL INFORMATION

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ``Docket No. FAA20080644; Directorate Identifier 2007NM321AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On June 29, 2004, we issued AD 20041407, amendment 3913716 (69 FR 41413, July 9, 2004), for all BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes. That AD requires a test for free movement of the capsule/bearing of the nose landing gear (NLG), and related investigative, significant, and corrective actions. That AD resulted from incidents in which the NLG did not fully extend, necessitating an emergency landing. We issued that AD to prevent failure of the NLG to extend fully, which could result in reduced controllability of the airplane during landing.

Actions Since Existing AD Was Issued

Since we issued AD 20041407, we have received additional reports of the NLG failing to extend fully on an airplane that had been inspected in accordance with AD 20041407. Initial investigations suggest that high levels of friction can develop in the upper and lower sliding bearings, causing the shortening mechanism capsule of the NLG to bind, which prevents the NLG from extending fully. The high friction is caused by dirt contamination of the grease, along with wear in the composite material bearings. The manufacturer of the NLG has developed a NLG assembly that incorporates new aluminum bearings that have improved corrosion protection, and a new lubrication fitting between the bearings that allows clean grease to be applied without the need to remove the capsule exposing it to contamination.

Relevant Service Information

BAE Systems (Operations) Limited has issued Service Bulletin J41 A32082, Revision 3, dated March 30, 2007. (We referred to Revision 1, dated February 20, 2004, of BAE Systems (Operations) Limited Alert Service Bulletin J41A32082 in AD 20041407 as the applicable source of service information for doing the actions required in that AD.) The procedures described in this service bulletin are essentially the same as those described in Revision 1; however, Revision 3 also describes procedures for cleaning and relubricating the NLG shortening mechanism capsule. In addition, Revision 3 also specifies reporting any failures to the manufacturer. BAE Systems (Operations) Limited Service [[Page 35090]]
Bulletin J41A32082, Revision 3, refers to APPH Service Bulletin AIR835863222, Revision 3, dated December 2006, as an additional source of service information for doing the actions specified in BAE Systems (Operations) Limited Service Bulletin J41A32082.

BAE Systems (Operations) Limited has also issued Service Bulletin J4132084, dated November 30, 2005. The service bulletin describes procedures for installing a modified NLG assembly, which has new aluminum bearings with improved corrosion protection, and a new lubrication fitting between the bearings to allow clean grease to be applied without the need to remove the capsule. In addition, the service bulletin specifies inspecting the free movement of the NLG capsule in accordance with BAE Systems (Operations) Limited Service Bulletin J41A32082. BAE Systems (Operations) Limited Service Bulletin J4132084 refers to APPH Service Bulletin AIR835863225, dated October 2005, as an additional source of service information for doing the actions specified in BAE Systems (Operations) Limited Service Bulletin J4132084.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, mandated the service information and issued European airworthiness directive 20060131, dated May 18, 2006, to ensure the continued airworthiness of these airplanes in Europe.

Explanation of British Airworthiness Authority

Paragraph (a)(4) of the existing AD (paragraph (f)(4) of this NPRM) specifies making repairs using a method approved by either the FAA or the Civil Aviation Authority (CAA) (or its delegated agent). The EASA has assumed responsibility for the airplane model subject to this AD. Therefore, we have revised paragraph (f)(4) of this NPRM to specify making repairs using a method approved by the FAA, the CAA (or its delegated agent), or the EASA (or its delegated agent).

FAA's Determination and Requirements of the Proposed AD

These airplanes are manufactured in the United Kingdom 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, EASA has kept the FAA informed of the situation described above. We have examined EASA's findings, evaluated all pertinent information, and determined that AD action is necessary for airplanes of this type design that are certificated for operation in the United States.

This proposed AD would supersede AD 20041407 and would retain the requirements of the existing AD. This proposed AD would also require accomplishing the actions specified in the service information described previously.

Change to Existing AD

This proposed AD would retain the requirements of AD 20041407. Since AD 20041407 was issued, the AD format has been revised, and certain paragraphs have been rearranged. As a result, the corresponding paragraph identifiers have changed in this proposed AD, as listed in the following table:
Revised Paragraph Identifiers
Corresponding requirement Requirement in AD 20041407 in this proposed AD paragraph (a)............................. paragraph (f).
paragraph (b)............................. paragraph (g).
paragraph (c)............................. paragraph (h).
paragraph (d)............................. paragraph (l)

Costs of Compliance

The following table provides the estimated costs for U.S. operators to comply with this proposed AD.
Estimated Costs Average Number of U.S. Action Work labor rate Parts Cost per registered Fleet cost hours per hour airplane airplanes Testing for free movement of 6 $80 $0 $480, per 7 $3,360, per the NLG capsule/bearing cleaning, cleaning, (required by AD 20041407). lubrication, lubrication, and inspection and inspection cycle. cycle. Cleaning, lubrication, and 6 80 10 $490, per 7 $3,430, per inspecting for free movement cleaning, cleaning, of the NLG capsule/bearing lubrication, lubrication, (new proposed action). and inspection and inspection cycle. cycle NLG assembly replacement..... 6 80 3,100 $3,580......... 7 $25,060. 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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 the proposed regulation:

1. Is not a ``significant regulatory action'' under Executive Order 12866;

[[Page 35091]]

2. Is not a ``significant rule'' under the 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 proposed AD and placed it in the AD docket. 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, Safety. The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39AIRWORTHINESS 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by removing amendment 3913716 (69 FR 41413, July 9, 2004) and adding the following new airworthiness directive (AD):
BAE Systems (Operations) Limited (Formerly British Aerospace Regional Aircraft): Docket No. FAA20080644; Directorate Identifier 2007NM321AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by July 21, 2008.
Affected ADs
(b) This AD supersedes AD 20041407.
Applicability
(c) This AD applies to all BAE Systems (Operations) Limited Model Jetstream 4101 airplanes, certificated in any category. Unsafe Condition
(d) This AD results from additional reports of the NLG failing to extend fully on an airplane that had been inspected in accordance with AD 20041407. We are issuing this AD to prevent failure of the NLG to extend fully, which could result in reduced controllability of the airplane during landing.
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.
Restatement of the Requirements of AD 20041407
Service Bulletin Reference and Clarifications
(f) The term ``service bulletin,'' as used in this AD, means BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 1, dated February 20, 2004; and the Accomplishment Instructions and the flow chart provided in paragraph 1.N. of BAE Systems (Operations) Limited Service Bulletin J41A32082, Revision 3, dated March 30, 2007. After the effective date of this AD, only Revision 3 of the service bulletin may be used.
(1) The term ``flow chart,'' as used in this AD, means the flow chart following paragraph 1.M. of BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 1; or following paragraph 1.N. of BAE Systems (Operations) Limited Service Bulletin J41A32082, Revision 3.
(2) BAE Systems (Operations) Limited Alert Service Bulletin J41 A32082, Revision 1, refers to APPH Service Bulletin AIR835863222, Revision 1, dated February 2004, as an additional source of service information for accomplishing the actions in the BAE Systems (Operations) Limited service bulletin. BAE Systems (Operations) Limited Alert Service Bulletin J41J32082, Revision 3, refers to APPH Service Bulletin AIR835863222, Revision 3, dated December 2006, as an additional source of service information for
accomplishing the actions in the BAE Systems (Operations) Limited service bulletin.
(3) Actions accomplished before the effective date of this AD per the Accomplishment Instructions of BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, dated February 11, 2004; Revision 1, dated February 20, 2004; or Revision 2, dated November 25, 2005; are considered acceptable for the corresponding actions required by this AD. (The original issue of BAE Systems (Operations) Limited Alert Service Bulletin J41A32082 refers to the original issue of APPH Service Bulletin AIR835863222, dated February 2004, as an additional source of service information for accomplishing the actions in the BAE Systems (Operations) Limited service bulletin.) (4) Where BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 1; BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 3; and APPH Service Bulletin AIR835863222, Revision 1; specify to contact BAE Systems or APPH for repair instructions: Before further flight, repair per a method approved by the Manager, International Branch, ANM116, FAA, Transport Airplane Directorate; the Civil Aviation Authority (CAA) (or its delegated agent); or EASA (or its delegated agent). (5) Where the flow chart in BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 1; or BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 3; specifies ``flying hours,'' for the purposes of this AD, this means ``flight hours.''
(6) Where BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 1; or BAE Systems (Operations) Limited Alert Service Bulletin J41A32082, Revision 3; specifies to complete a reporting form and return it to the manufacturer, this AD does not require that action.
(7) BAE Systems (Operations) Limited Alert Service Bulletin J41 A32084, dated November 30, 2005, refers to APPH Service Bulletin AIR835863225, dated October 2005, as an additional source of service information for accomplishing the actions in the BAE Systems (Operations) Limited service bulletin.
Initial Test
(g) Within 300 flight cycles or 30 days after August 13, 2004 (the effective date of AD 20041407), whichever occurs first: Perform a test for free movement of the NLG capsule/bearing, as specified in the flow chart of the service bulletin. Do all of the actions per the Accomplishment Instructions of the service bulletin.

Note 1: As specified in the flow chart in the service bulletin, only the actions in paragraph 2.A. (Part 1) of the Accomplishment Instructions of APPH Service Bulletin AIR835863222, Revision 1, dated February 2004, are required by paragraph (f) of this AD. Related Investigative, Significant, and Corrective Actions
(h) Perform related investigative, significant, and corrective actions as specified in the flow chart of the service bulletin, at the compliance times specified in the flow chart of the service bulletin. Do all of the actions per the Accomplishment Instructions of the service bulletin, except as provided by paragraph (f)(4) of this AD. During any test, if the movement of the capsule/bearing is restricted, the applicable corrective actions must be accomplished before further flight.
Parts Installation
(i) As of August 13, 2004, no person may install a NLG on any airplane unless it has been inspected in accordance with the requirements of paragraphs (g) and (h) of this AD.
New Requirements of This AD
Repetitive Cleanings, Lubrications, and Inspections for Free Movement of the NLG Capsule
(j) Within 400 flight hours after the effective date of this AD, or within 800 flight hours after the last test done in accordance with paragraph (g) of this AD, whichever is later, but not exceeding 3,000 flight hours after the last test done in accordance with paragraph (g) of this AD; and before further flight after each scheduled or unscheduled NLG replacement: Clean, lubricate, and inspect for free movement of the NLG capsule/bearing in accordance with the service bulletin.
(1) For NLG capsules that have adequate free movement: At the applicable interval specified in paragraphs (j)(1)(i) and (j)(1)(ii) of this AD, repeat the cleaning, lubrication, and inspection for free movement of the NLG capsule/bearing in accordance with the service bulletin.
[[Page 35092]]
(i) For airplanes on which the modification specified in BAe Systems (Operations) Limited Service Bulletin J41A32084
(Modification JM41670), dated November 30, 2005, has not been accomplished, repeat the actions specified in paragraph (j)(1) of this AD at intervals not to exceed 800 flight hours after the last inspection done in accordance with paragraph (j) of this AD. (ii) For airplanes on which the modification specified in BAe Systems (Operations) Limited Service Bulletin J41A32084
(Modification JM41670), dated November 30, 2005, has been
accomplished, repeat the actions specified in paragraph (j)(1) of this AD at intervals not to exceed 3,000 flight hours after the last inspection done in accordance with paragraph (j) of this AD. (2) For NLG capsules that do not have adequate free movement: Before further flight, replace the NLG assembly with a serviceable assembly in accordance with the service bulletin. Thereafter, repeat the actions specified in paragraph (j) of this AD at the applicable interval specified in paragraph (j)(1) of this AD.
Replace the NLG Assembly With a Modified NLG Assembly
(k) Within 48 months after the effective date of this AD: Replace the NLG assembly with a modified assembly, in accordance with BAE Systems (Operations) Limited Service Bulletin J4132084, dated November 30, 2005. Thereafter, repeat the actions specified in paragraph (j) of this AD at the applicable interval specified in paragraph (j)(1) of this AD.
Parts Installation
(l) As of the effective date of this AD, no person may install a NLG on any airplane unless it has been inspected in accordance with paragraph (j) of this AD.
Alternative Methods of Compliance (AMOCs)
(m)(1) The Manager, International Branch, ANM116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.
(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.
Related Information
(n) European Aviation Safety Agency airworthiness directive 20060131, dated May 18, 2006, also addresses the subject of this AD.

Issued in Renton, Washington, on June 9, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. E813919 Filed 61908; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT Todd Thompson, Aerospace Engineer, International Branch, ANM116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 980573356; telephone (425) 2271175; fax (425) 2271149.