05-6249. Airworthiness Directives; BAE Systems (Operations) Limited Model BAe 146 Series Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain BAE Systems (Operations) Limited Model BAe 146 series airplanes. This proposed AD would require repetitive inspections for cracks of the fuselage pressure skin above the left and right main landing gear (MLG) bay. This proposed AD also would require corrective action, including related investigative actions, if leaks are found. This proposed AD is prompted by reports of cracks in the fuselage pressure skin above the left and right MLG bay. We are proposing this AD to detect and correct fatigue cracking in the fuselage pressure skin above the left and right MLG bay; such fatigue cracking could adversely affect the structural integrity of the fuselage and its ability to maintain pressure differential.

DATES:

We must receive comments on this proposed AD by April 29, 2005.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, Nassif Building, room PL-401, Washington, DC 20590.
• By fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW, Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact British Aerospace Regional Aircraft American Support, 13850 Mclearen Road, Herndon, Virginia 20171.

You can examine the contents of this AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2005-20724; the directorate identifier for this docket is 2004-NM-233-AD.

FOR FURTHER INFORMATION CONTACT:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2005-20724; Directorate Identifier 2004-NM-233-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments submitted by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of our docket website, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You can review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

Examining the Docket

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 [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified us that an unsafe condition may exist on certain BAE Systems (Operations) Limited Model BAe 146 series airplanes. The CAA advises that significant cracking in the fuselage pressure skin above the main landing gear (MLG) bay has been reported following unrelated maintenance. The published inspection technique does not guarantee that any damage will be detected. This condition, if not corrected, could adversely affect the structural integrity of the fuselage and its ability to maintain pressure differential.

Relevant Service Information

BAE Systems (Operations) Limited has issued Inspection Service Bulletin 53-170, dated August 8, 2003. The service bulletin describes procedures for repetitive inspections for cracks of the fuselage pressure skin above the left and right main landing gear (MLG) bay; and for corrective action, including related investigative actions, if necessary. The inspections for cracks include listening for air leaks and doing a visual check for air leaks. The corrective action includes repairing any crack found during the inspections for air leaks and contacting the manufacturer if the crack exceeds the limit specified in the service bulletin. The related investigative actions include doing a detailed visual and fluorescent dye penetrant or eddy current inspection for cracking on the fuselage pressure skin. If any cracking is found during the related investigative actions, the service bulletin specifies to report the findings to BAe Systems. The service bulletin also specifies that accomplishing BAe Modification HCM00972C ends the inspections.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. The CAA mandated the service information and issued British airworthiness directive G-2004-0004, dated February 26, 2004, to ensure the continued airworthiness of these airplanes in the United Kingdom.

FAA's Determination and Requirements of the Proposed AD

This airplane model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of § 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. We have examined the CAA's findings, evaluated all pertinent information, and determined that we need to issue an AD for products of this type design that are certificated for operation in the United States.

Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the Service Bulletin.”

Differences Between the Proposed AD and the Service Bulletin

The service bulletin specifies that you may contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require you to repair those conditions using a method that we or the Civil Aviation Authority (or its delegated agent) approve. In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair we or the Civil Aviation Authority (or its delegated agent) approve would be acceptable for compliance with this proposed AD.

Operators should note that, although the Accomplishment Instructions of the service bulletin describe procedures for submitting findings to the manufacturer, this proposed AD would not require that action.

Although the service bulletin specifies that accomplishing BAe Modification HCM00972C ends the inspections, we have not included a terminating modification in the proposed AD. We have determined that the modification does not contain substantive information about the modification and will vary among operators. Operators may request an alternative method of compliance (AMOC) according to the provisions of paragraph (j) of the proposed AD, if sufficient data are included to justify that the AMOC would provide an acceptable level of safety.

Costs of Compliance

The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Parts	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
Inspection, per inspection cycle	7	$65	$0	$455	18	1 8,190
1 Per inspection cycle.

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;

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

BAE Systems (Operations) Limited (Formerly British Aerospace Regional Aircraft): Docket No. FAA-2005-20724; Directorate Identifier 2004-NM-233-AD.

Comments Due Date

(a) The Federal Aviation Administration must receive comments on this AD action by April 29, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to BAE Systems (Operations) Limited Model BAe 146 series airplanes, certificated in any category; except those on which BAe Modification HCM00972A or HCM00972C has been accomplished.

Unsafe Condition

(d) This AD was prompted by reports of cracks in the fuselage pressure skin above the left and right main landing gear (MLG) bay. We are issuing this AD to detect and correct fatigue cracking in the fuselage pressure skin above the left and right MLG bay; such fatigue cracking could adversely affect the structural integrity of the fuselage and its ability to maintain pressure differential.

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.

Initial and Repetitive Inspections

(f) At the times specified in Table 1 of this AD, inspect the fuselage pressure skin above the left and right MLG bay for cracks in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin 53-170, dated August 8, 2003.

Table 1.—Compliance Times

For airplanes listed in paragraph (c) of this AD—	Do initial inspections—	And do repetitive inspections thereafter—
On which neither BAe modification HCM00744M nor HCM00850A has been accomplished	Prior to the accumulation of 15,000 total flight cycles or within 500 flight cycles after the effective date of this AD, whichever occurs later	At intervals not to exceed 1,000 flight cycles.
On which neither BAe modification HCM00744M nor HCM00850A has been accomplished	Prior to the accumulation of 15,000 total flight cycles or within 1,000 flight cycles after the effective date of this AD, whichever occurs later	At intervals not to exceed 3,000 flight cycles.
On which both BAe modification HCM00744M nor HCM00850A has been accomplished

Corrective Action

(g) If any crack is found during any inspection required by paragraph (f) of this AD, do the corrective action and any related investigative actions, in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin 53-170, dated August 8, 2003, except as required by paragraph (h) of this AD.

(h) If any cracking is found during any inspection or related investigative action required by this AD, and the service bulletin recommends contacting BAe Systems for appropriate action: Before further flight, repair the cracks according to a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, or the Civil Aviation Authority (or its delegated agent).

No Reporting

(i) Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(j) The Manager, International Branch, ANM-116, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Related Information

(k) British airworthiness directive G-2004-0004, dated February 26, 2004, also addresses the subject of this AD.

Issued in Renton, Washington, on March 17, 2005.

Jeffery E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.