E9-23190. Airworthiness Directives; Boeing Model 747-100, 747-200B, 747-300, and 747SR Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

We are revising an earlier proposed airworthiness directive (AD) for certain Boeing Model 747-100, 747-200B, 747-300, and 747SR series airplanes. The original NPRM proposed to require installation of a closeout panel and moisture curtains for the main equipment center. The original NPRM also proposed to require changing the drain tubes for the power drive units (PDU) and the pitot static tubes and installing larger moisture shrouds. The original NPRM resulted from a report of water contamination in the electrical and electronic units in the main equipment center. This action revises the original NPRM by adding airplanes to the applicability and removing certain others, and removing certain requirements. We are proposing this supplemental NPRM to prevent the malfunction of one or more electrical and electronic units in the main equipment center, which could adversely affect the airplane's continued safe flight.

DATES:

We must receive comments on this supplemental NPRM by October 20, 2009.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com. You may review copies of the referenced 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 or 425-227-1152.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Marcia Smith, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

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. FAA-2008-0376; Directorate Identifier 2007-NM-322-AD” 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

We issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 747-100, 747-200B, 747-300, and 747SR series airplanes. That original NPRM was published in the Federal Register on April 1, 2008 (73 FR 17258). The original NPRM proposed to require installation of a closeout panel and moisture curtains for the main equipment center. The original NPRM also proposed to require changing the drain tubes for the power drive units and the pitot static tubes and installing larger moisture shrouds.

Actions Since Original NPRM Was Issued

Since we issued the original NPRM, we have reviewed a new revision of Boeing Alert Service Bulletin 747-25A3368. The original NPRM referred to Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007, as the appropriate source of service information for installing a closeout panel and moisture curtains. We have reviewed Boeing Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008. Revision 2 adds instructions to fabricate parts. In addition, the effectivity of the service bulletin changed, adding 14 airplanes and removing 3 airplanes.

We have revised paragraph (f) of the original NPRM (which is now paragraph (g) of this supplemental NPRM) to refer to Boeing Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008. We have also revised paragraph (h) of this supplemental NPRM to clarify the additional work that must be done if actions have been accomplished in accordance with the original issue of the service bulletin. We have also added a new paragraph (i) to this supplemental NPRM to allow credit for actions accomplished in accordance with Revision 1 of the service bulletin. We have reidentified the subsequent paragraphs accordingly.

Removal of Requirement To Install Larger Moisture Shrouds and Additional Drain Lines

The original NPRM referred to Boeing Alert Service Bulletin 747-25A3346, dated September 13, 2007, as the source of information for changing the PDU drain tubes and pitot static tubes, and installing larger moisture shrouds. We have deleted all reference to Boeing Alert Service Bulletin 747-25A3346 because Boeing is currently revising that service bulletin, and waiting for the revision would prevent mandating the interim solution in a timely manner. Boeing Alert Service Bulletin 747-25A3346 currently provides instructions that do not work for installing some of the drain lines because the airplanes do not have the configuration that Boeing expected. Therefore, we deleted reference to Boeing Alert Service Bulletin 747-25A3346, dated September 13, 2007, from the applicability statement of the original NPRM. We also deleted the requirement to install the larger moisture shrouds and additional drain lines in paragraph (g) of the original NPRM, and we deleted Note 2 of the original NPRM. As a result, this proposed AD action is interim, and we may require a final action when we approve the revised service information.

Explanation of Additional Paragraph in the Supplemental NPRM

We have added a new paragraph (d) to this supplemental NPRM to provide Air Transport Association (ATA) of America subject code 25: Equipment/furnishings. This code is added to make the format of this supplemental NPRM parallel with other new AD actions. We have reidentified subsequent paragraphs accordingly.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

We are proposing this supplemental NPRM because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. Certain changes described above expand the scope of the original NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.

Interim Action

We consider this supplemental NPRM interim action. The manufacturer is currently developing a modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, we might consider additional rulemaking.

Costs of Compliance

We estimate that this proposed AD would affect 47 airplanes of U.S. registry. The following table provides the estimated costs, at an average labor rate of $80 per work hour, for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Parts	Cost per product	Number of U.S.-registered airplanes	Fleet cost
Installation	Up to 10	Up to $11,672	Up to $12,472	47	Up to $586,184.

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 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 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. 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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• 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 AD:

Boeing: Docket No. FAA-2008-0376; Directorate Identifier 2007-NM-322-AD.

Comments Due Date

(a) We must receive comments by October 20, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 747-100, 747-200B, 747-300, and 747SR series airplanes, certificated in any category; as identified in Boeing Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008.

Note 1:

The affected airplanes are those that have been converted by Boeing to the Boeing Special Freighter configuration.

Subject

(d) Air Transport Association (ATA) of America Code 25: Equipment/furnishings.

Unsafe Condition

(e) This AD results from a report of water contamination in the electrical and electronic units in the main equipment center. We are issuing this AD to prevent the malfunction of one or more electrical and electronic units in the main equipment center, which could adversely affect the airplane's continued safe flight.

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.

Install the Closeout Panel and Moisture Curtains

(g) Within 24 months after the effective date of this AD, install the closeout panel and moisture curtains for the main equipment center, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008.

Credit for Actions Done According to Previous Issue of the Service Bulletin

(h) Actions done before the effective date of this AD in accordance with the Accomplishment Instructions in Boeing Alert Service Bulletin 747-25A3368, dated August 25, 2005, are acceptable for compliance with the corresponding actions required by paragraph (g) of this AD, provided that the additional work specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007; or Revision 2, dated June 12, 2008; is accomplished. The additional work required is to cap seal all rivets fastening the mounting base assembly to the moisture shroud as given in Figure 10 in Boeing Alert Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008, and to fill any unused pilot holes in the mounting base assembly in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3368, Revision 2, dated June 12, 2008; or cap seal all rivets fastening the mounting base assembly to the moisture shroud as given in Figure 10 of Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007, and to fill any unused pilot holes in the mounting base assembly in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007.

(i) Actions done before the effective date of this AD in accordance with Boeing Alert Service Bulletin 747-25A3368, Revision 1, dated June 25, 2007, are acceptable for compliance with the corresponding actions required by paragraph (g) of this AD.

Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Marcia Smith, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Or, e-mail information to [e-mail].

(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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

Issued in Renton, Washington, on September 16, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.