03-9301. Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This proposal would require identification of the valves installed on the engine struts as hydraulic supply (fire) shutoff valves for the engine-driven pump, corrective action if necessary, and eventual replacement of discrepant valves with serviceable parts. This action is necessary to prevent leakage of hydraulic (flammable) fluid into an engine fire, which could result in an uncontrolled fire. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 2, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-05-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-05-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Kenneth W. Frey, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-05-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-05-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports indicating that various intermittent limit switch functioning problems have caused the failure of certain “Circle Seal” valves installed as the engine-driven pump (EDP) direct-current (DC) motor-operated shutoff valves on certain Boeing Model 747 series airplanes. This particular valve may malfunction if the motor limit switches are not actuated, causing the motor to run at the stop until the clutch fails. If the clutch fails, the valve cannot open and close for the affected hydraulic system. This failure mode was discovered during production testing on Model 747 series airplanes. The subject valve was incorrectly identified by the manufacturer as an acceptable optional part for Model 747 series airplanes. This valve may have been installed during production or normal maintenance. The EDP valve is intended to prevent hydraulic fluid from being supplied to an engine fire, which could result in an uncontrolled fire.

Related Rulemaking

The FAA previously issued similar rulemaking for the same unsafe condition on certain Boeing Model 737, 757, and 767 series airplanes. AD 2001-11-07, amendment 39-12249 (66 FR 31135, June 11, 2001), requires repetitive operational checks to detect malfunctioning of certain motor-operated hydraulic shutoff valves, and their eventual replacement with new valves as terminating action for the repetitive inspections.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 747-29A2102, including an Evaluation Form, dated June 29, 2000, which describes procedures for determining, by a records check or inspection, whether certain Circle Seal valves have been installed on the engine struts as the EDP DC motor-operated shutoff valves. Corrective action for discrepant valves includes repetitive tests of the hydraulic supply (fire) shutoff valves, immediate replacement of failed valves, and eventual replacement of all subject valves with serviceable valves. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously.

Cost Impact

There are approximately 681 airplanes of the affected design in the worldwide fleet. The FAA estimates that 130 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to identify the valve, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $7,800, or $60 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed 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.

Replacing a valve, if required, would take approximately 6 work hours, at an average labor rate of $60 per work hour. Required parts and hydraulic fluid would cost approximately $4,438 per valve. Based on these figures, the cost impact of replacing a valve is estimated to be $4,798.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this 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) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 adding the following new airworthiness directive:

Boeing: Docket 2003-NM-05-AD.

Applicability: Model 747 series airplanes, certificated in any category, as listed in Boeing Alert Service Bulletin 747-29A2102, dated June 29, 2000.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent leakage of hydraulic (flammable) fluid into an engine fire, which could result in an uncontrolled fire, accomplish the following:

Part Identification

(a) Within 6 months after the effective date of this AD, check maintenance records or perform a general visual inspection of each engine strut to determine whether any discrepant valve is installed as a hydraulic supply (fire) shutoff valve for the engine-driven pump. A discrepant valve is a Circle Seal valve part number (P/N) S270T010-3 or a valve that cannot be readily identified. Identify the part in accordance with Boeing Alert Service Bulletin 747-29A2102, excluding the Evaluation Form, dated June 29, 2000. If no discrepant valve is installed, no further work is required by this paragraph.

Note 2:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

Corrective Actions for Discrepant Valves

(b) For any discrepant valve found during the part identification required by paragraph (a) of this AD:

(1) Within 6 months after the effective date of this AD, do a hydraulic supply (fire) shutoff valve test, in accordance with paragraph 3.J. of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-29A2102, dated June 29, 2000.

(i) If the valve passes the test, repeat the test in accordance with paragraph (b)(2) of this AD.

(ii) If the valve does not pass the test: Before further flight, replace the valve and do a hydraulic supply (fire) shutoff valve test, in accordance with paragraph 3.I. of the Accomplishment Instructions of the service bulletin.

(2) Repeat the test specified in paragraph (b)(1) of this AD on each discrepant valve at least every 6 months, until the actions specified by paragraph (b)(3) of this AD have been accomplished.

(3) Within 4 years after identifying the valve as required by paragraph (a) of this AD: Replace each discrepant valve with a serviceable valve and do a hydraulic supply (fire) shutoff valve test, in accordance with paragraph 3.I. of the Accomplishment Instructions of the service bulletin. Replacement of the valve terminates the repetitive tests required by paragraph (b)(2) of this AD for that valve.

Part Installation

(c) As of the effective date of this AD, no person may install a Circle Seal valve P/N S270T010-3 on any airplane unless the requirements of this AD are accomplished for that valve.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(e) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on April 8, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.