[Federal Register Volume 70, Number 12 (Wednesday, January 19, 2005)]
[Proposed Rules]
[Pages 2980-2982]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-991]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20081; Directorate Identifier 2004-NM-132-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 and 777-300 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 777-200 and -300 series airplanes. This 
proposed AD would require modification of the operational program 
software (OPS) of the air data inertial reference unit (ADIRU). This 
proposed AD is prompted by a report of the display of erroneous heading 
information to the pilot due to a defect in the OPS of the ADIRU. We 
are proposing this AD to prevent the display of erroneous heading 
information to the pilot, which could result in loss of the main 
sources of attitude data, consequent high pilot workload, and 
subsequent deviation from the intended flight path.

DATES: We must receive comments on this proposed AD by March 7, 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,

[[Page 2981]]

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 
Boeing Commercial Airplanes, P.O. 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-2005-20081; the directorate identifier for this docket is 
2004-NM-132-AD.

FOR FURTHER INFORMATION CONTACT: Paul Feider, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6467; 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-2005-20081; 
Directorate Identifier 2004-NM-132-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 a report of the display of erroneous heading 
information to the pilot due to a defect in the operational program 
software (OPS) of the air data inertial reference unit (ADIRU) on 
certain Model 777 series airplanes. Investigation revealed a timing 
defect in the ADIRU Auto Navigation Realign Logic, which could 
potentially result in the use of a ``stale'' update, which would then 
produce incorrect heading information with a variable error magnitude. 
This condition, if not corrected, could result in loss of the main 
sources of attitude data, consequent high pilot workload, and 
subsequent deviation from the intended flight path.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 777-34A0082, Revision 1, 
dated December 19, 2002. The service bulletin describes procedures for 
modification of the OPS of the ADIRU. The modification includes 
installing new OPS in the flight compartment at the maintenance access 
terminal (MAT), or, as an option, replacing the hard drive for the 
existing OPS in the MAT and/or the Portable MAT. 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, except as discussed under 
``Difference Between the Proposed AD and Service Information.''

Difference Between the Proposed AD and Service information

    Although the service information recommends accomplishing the 
modification ``at the earliest opportunity when manpower, parts, and 
facilities are available,'' we have determined that this imprecise 
compliance time would not address the identified unsafe condition in a 
timely manner. However, the manufacturer has recommended that the 
compliance time not exceed 6 months. In developing an appropriate 
compliance time for this AD, we considered not only the manufacturer's 
recommendation, but the degree of urgency associated with addressing 
the subject unsafe condition, the average utilization of the affected 
fleet, and the time necessary to perform the modification. In light of 
all of these factors, we find a compliance time of 6 months for 
completing the required modification to be warranted, in that it 
represents an appropriate interval of time for affected airplanes to 
continue to operate without compromising safety.

Costs of Compliance

    There are about 409 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 130 airplanes of 
U.S. registry. The proposed actions would take about 1 work hour per 
airplane, at an average labor rate of $65 per work hour. Required parts 
would be free of charge. Based on these figures, the estimated cost of 
the proposed AD for U.S. operators is $8,450, or $65 per airplane.

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 will not have federalism 
implications under Executive Order 13132. This proposed AD will 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.

[[Page 2982]]

    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.


Sec.  39.13  [Amended]

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

Boeing: Docket No. FAA-2005-20081; Directorate Identifier 2004-NM-
132-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by March 7, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200 and -300 series 
airplanes, certificated in any category; as listed in Boeing Service 
Bulletin 777-34A0082, Revision 1, dated December 19, 2002.

Unsafe Condition

    (d) This AD was prompted by a report of the display of erroneous 
heading information to the pilot due to a defect in the operational 
program software (OPS) of the air data inertial reference unit 
(ADIRU). The Federal Aviation Administration is issuing this AD to 
prevent the display of erroneous heading information to the pilot, 
which could result in loss of the main sources of attitude data, 
consequent high pilot workload, and subsequent deviation from the 
intended flight path.

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.

Modification

    (f) Within 6 months after the effective date of this AD: Modify 
the OPS of the ADIRU by doing the applicable actions specified in 
the Accomplishment Instructions of Boeing Service Bulletin 777-
34A0082, Revision 1, dated December 19, 2002.

Alternative Methods of Compliance (AMOCs)

    (g) 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 January 7, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-991 Filed 1-18-05; 8:45 am]
BILLING CODE 4910-13-P