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Proposed Rule

Airworthiness Directives; Boeing Model 737-300, -400, -500, -600, -700, -700C, -800 and -900 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

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 Boeing Model 737-300, -400, -500, -600, -700, -700C, -800 and -900 series airplanes. This proposed AD would require installing an updated version of the operational program software (OPS) in the flight management computers (FMCs), and doing other specified actions. This proposed AD would also require reinstalling software, if necessary. This proposed AD is prompted by one operator reporting FMC map shifts on several Model 737-400 series airplanes with dual FMCs, using OPS version U10.4A. We are proposing this AD to prevent the FMC from displaying the incorrect actual navigation performance value to the flightcrew, which could prevent adequate alerting of a potential navigation error. This condition could result in a near miss with other airplanes or terrain, or collision if other warning systems also fail.

DATES:

We must receive comments on this proposed AD by April 1, 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: (202) 493-2251.
  • Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9:00 a.m. and 5:00 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, PO Box 3707, Seattle, Washington 98124-2207.

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-2005-20347; the directorate identifier for this docket is 2004-NM-226-AD.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Sam Slentz, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6483; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

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-2005-20347; Directorate Identifier 2004-NM-226-AD” in the subject line 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 that 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 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 (800) 647-5227) 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

We have received from one operator a report of flight management computer (FMC) map shifts on several Boeing Model 737-400 series airplanes with dual FMCs, using operational program software (OPS) version U10.4A. In one of these incidents, the flightcrew did not know they were 5 miles off-course until the air traffic controller contacted them. During all incidents, the VERIFY POSITION message was correctly shown on the control display unit (CDU), but the actual navigation performance Start Printed Page 7688(ANP) value did not agree with the observed FMC position error. Also, the required navigation performance (RNP) message, UNABLE REQD NAV PERF, was not displayed since the ANP value was less than the RNP value. Although the flightcrew is alerted to the position differences, they do not know that the ANP value is incorrect. Testing conducted by the airplane manufacturer has shown that under some conditions, the FMC OPS, version U10.5, does not give reliable ANP data. An incorrect ANP value displayed on the CDU of the FMC to the flightcrew, if not corrected, could prevent adequate alerting of a potential navigation error that could result in a near miss with other airplanes or terrain or collision if other warning systems also fail.

The FMC OPS, with versions U10.3, U10.4, U10.4A, and U10.5, on certain Model 737-300, -500, -600, -700, -700C, -800 and -900 series airplanes are identical to those on the affected Model 737-400 series airplanes. Therefore, all of these models may be subject to the same unsafe condition.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 737-34A1801, dated July 15, 2004; and Boeing Alert Service Bulletin 737-34A1821, dated July 15, 2004. The service bulletins describe procedures for installing updated version U10.5A of the OPS, part number (P/N) 549849-014, in the left and right FMCs, and doing other specified actions. The other specified actions include the following:

  • For Model 737-600, -700, -700C, -800, and -900 series airplanes: Installing the compatible, model/engine database (MEDB) software, P/N BCG-00N-H6, in the left and right FMCs;
  • For all airplanes: Installing the current version of the navigational database (NDB) software in the left and right FMCs;
  • For all airplanes: Installing the software options database (OPC) in the left and right FMCs, using the OPC software that was originally installed before installation of the updated version of the OPS;
  • For Model 737-600, -700, -700C, -800, and -900 series airplanes: Doing configuration checks of the left and right FMCs to ensure that the following software is correctly installed: The updated version of the OPS, compatible version of the MEDB software, and OPC software;
  • For Model 737-300, -400, and -500 series airplanes: Doing a configuration check of the left and right FMCs to ensure that the updated version of the OPS and OPC software is correctly installed; and
  • For all airplanes: Replacing the existing OPS disk set in the airplane's software media binder with new OPS disk set, P/N 10-62225-1013. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously.”

Difference Between the Proposed AD and the Service Information

The service information does not specify what action to take if the incorrect software version (of the OPS, model/engine database if applicable, or software options database) is found installed on any FMC during any configuration check. However, this proposed AD would require reinstallation of the applicable software, if necessary.

Clarification of Proposed Requirements

The service bulletins provide procedures for doing configuration checks of the left and right FMCs to ensure that the updated version of the OPS, the compatible version of the MEDB software, and the OPC software are installed. We have determined that certificated maintenance personnel must perform these configuration checks.

Costs of Compliance

There are about 3,482 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 1,312 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Boeing modelWork hoursAverage labor rate per hourPartsCost per airplane
737-300, -400, and -500 series airplanes1$65$15$80
737-600, -700, -700C, -800, and -900 series airplanes26515145

Authority for This Rulemaking

The FAA's authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. 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.

This rulemaking is promulgated 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 proposed AD.

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 Start Printed Page 7689section for a location to examine the regulatory evaluation.

Start List of Subjects

List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

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

Boeing: Docket No. FAA-2005-20347; Directorate Identifier 2004-NM-226-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by April 1, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the airplanes listed in Table 1 of this AD, certificated in any category:

Table 1.—Applicability

Boeing modelsAs listed in
737-300, -400, and -500 series airplanesBoeing Alert Service Bulletin 737-34A1821, dated July 15, 2004.
737-600, -700, -700C, -800 and -900 series airplanesBoeing Alert Service Bulletin 737-34A1801, dated July 15, 2004.

Unsafe Condition

(d) This AD was prompted by one operator reporting flight management computer (FMC) map shifts on several Model 737-400 series airplanes with dual FMCs, using operational program software (OPS) version U10.4A. We are issuing this AD to prevent the FMC from displaying the incorrect actual navigation performance value to the flightcrew, which could prevent adequate alerting of a potential navigation error. This condition could result in a near miss with other airplanes or terrain, or collision if other warning systems also fail.

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.

Install Updated Version of OPS

(f) Within 180 days after the effective date of this AD, install the updated version of the OPS in the left and right FMCs; and, before further flight, do all the other specified actions. Do the installation and other specified actions by accomplishing all of the actions in the Accomplishment Instructions of the applicable service bulletin, as listed in Table 1 of this AD. Where the service bulletin specifies a configuration check, certificated maintenance personnel must perform the configuration check.

Reinstall Software, If Necessary

(g) If the incorrect software version of the OPS, model/engine database if applicable, or software options database is found installed on any FMC during any configuration check required by paragraph (f) of this AD: Before further flight, reinstall the software, as applicable. Do the reinstallation of any software in accordance with the Accomplishment Instructions of the applicable service bulletin, as listed in Table 1 of this AD.

Alternative Methods of Compliance (AMOCs)

(h) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Start Signature

Issued in Renton, Washington, on February 2, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 05-2827 Filed 2-14-05; 8:45 am]

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