[Federal Register Volume 70, Number 30 (Tuesday, February 15, 2005)]
[Proposed Rules]
[Pages 7687-7689]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-2827]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20347; Directorate Identifier 2004-NM-226-AD]
RIN 2120-AA64


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

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

ACTION: Notice of proposed rulemaking (NPRM).

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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.

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.

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

[[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
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                                                                   Average labor                     Cost per
                  Boeing model                      Work hours     rate per hour       Parts         airplane
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737-300, -400, and -500 series airplanes........               1             $65             $15             $80
737-600, -700, -700C, -800, and -900 series                    2              65              15             145
 airplanes......................................
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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

[[Page 7689]]

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.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  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
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             Boeing models                         As listed in
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737-300, -400, and -500 series           Boeing Alert Service Bulletin
 airplanes.                               737-34A1821, dated July 15,
                                          2004.
737-600, -700, -700C, -800 and -900      Boeing Alert Service Bulletin
 series airplanes.                        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.

    Issued in Renton, Washington, on February 2, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-2827 Filed 2-14-05; 8:45 am]
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