Airworthiness Directives; Boeing Model 777 Airplanes

[Federal Register Volume 72, Number 63 (Tuesday, April 3, 2007)]
[Rules and Regulations]
[Pages 15820-15822]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-5897]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-27736; Directorate Identifier 2007-NM-001-AD; 
Amendment 39-15010; AD 2007-07-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777 Airplanes

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

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Boeing Model 777 airplanes. This AD requires a one-time inspection to 
determine the part number of the left and right air supply and cabin 
pressure controllers (ASCPCs) and installation of new ASCPC software if 
necessary. This AD results from a report of an ASCPC failure during 
flight. We are issuing this AD to prevent an ASCPC failure that could 
stop airflow into the airplane, inhibit the cabin altitude warning 
message, and cause an incorrect display of cabin altitude. These 
failures could result in depressurization of the airplane without 
warning.

DATES: This AD becomes effective April 18, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of April 18, 
2007.
    We must receive comments on this AD by June 4, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
    <bullet> Fax: (202) 493-2251.
    <bullet> 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.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT: David Webber, Aerospace Engineer, 
Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98057-3356; telephone (425) 917-6451; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    We have received a report indicating that the left air supply and 
cabin pressure controller (ASCPC) incorrectly shut off the right air 
conditioning pack and the left bleed, and erratically opened and closed 
the isolation valves, on a Model 777 airplane during flight. This 
resulted in periods of loss of conditioned inflow to the cabin and 
flight deck. The flightcrew descended the airplane to 10,000 feet and 
returned to the airport. Investigation into this event revealed that 
the actions of the ASCPC resulted from a solder defect in the 
Aeronautical Radio, Inc. (ARINC) 629 hardware that occurred during 
manufacturing. The manufacturing error

[[Page 15821]]

was determined to be an isolated event. However, subsequent analysis 
revealed a software deficiency within the ASCPC that would not detect 
this single point failure. This defect caused an intermittent open to 
ARINC 629 built-in-test (BIT) 13 for all input words. This, in turn, 
caused the ASCPC to enter the auxiliary power unit-to-pack takeoff 
(APT) mode above 30,000 feet. The ASCPC internal BIT did not detect the 
defect and allowed the ASCPC to continue to operate. This condition, if 
not corrected, could stop airflow into the airplane, inhibit the cabin 
altitude warning message, and cause an incorrect display of cabin 
altitude. These failures could result in depressurization of the 
airplane without warning.

Relevant Service Information

    We have reviewed Boeing Service Bulletin 777-36A0026, Revision 1, 
dated February 8, 2007. The service bulletin describes procedures for 
installing new ASCPC operational program software (OPS) to prevent the 
failures caused by the solder defect. The software also includes 
updates that are not related to the defect.
    The replacement software is different from the existing software as 
follows:
    <bullet> APT logic is revised to improve fault tolerance.
    <bullet> ARINC 629 integrity tests are added.
    <bullet> Composite critical fault counter (CCFC) is revised to be 
reset to zero upon determination that no validated critical faults have 
occurred within the last one hour.
    <bullet> List of parameters that are stored in the compact flash 
disk are updated.
    <bullet> ARINC 429 wraparound BIT logic is revised to correct a 
fault isolation error.
    <bullet> Core software for the central processing module (CPM) of 
the modular digital controller (MDC) is revised to initialize an un-
initiated variable that could result in nuisance ASCPC faults.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. For this reason, we 
are issuing this AD to prevent an ASCPC failure that could stop airflow 
into the airplane, inhibit the cabin altitude warning message, and 
cause an incorrect display of cabin altitude. These failures could 
result in depressurization of the airplane without warning. This AD 
requires a one-time inspection to determine the part number of the left 
and right ASCPCs and installation of new ASCPC software if necessary.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists to make this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed in the ADDRESSES section. Include ``Docket No. FAA-2007-
27736; Directorate Identifier 2007-NM-001-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD that might 
suggest a need to modify it.
    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 AD. Using the search function of that web 
site, 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 may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.

Examining the Docket

    You may 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 Docket Management System 
receives them.

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 have determined that this AD will not have federalism 
implications under Executive Order 13132. This 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.
    For the reasons discussed above, I certify that the 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 AD and placed it in the AD docket. 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:


[[Page 15822]]


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


Sec.  39.13  [Amended]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2007-07-05 Boeing: Amendment 39-15010. Docket No. FAA-2007-27736; 
Directorate Identifier 2007-NM-001-AD.

Effective Date

    (a) This AD becomes effective April 18, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 777-200, -200LR, -300, 
and -300ER series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from a report of an air supply and cabin 
pressure controller (ASCPC) failure during flight. We are issuing 
this AD to prevent an ASCPC failure that could stop airflow into the 
airplane, inhibit the cabin altitude warning message, and cause an 
incorrect display of cabin altitude. These failures could result in 
depressurization of the airplane without warning.

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.

Inspection To Determine Part Number (P/N) of the ASCPCs

    (f) For all airplanes: Within 90 days after the effective date 
of this AD, perform an inspection of the left and right ASCPCs to 
determine the part number.

ASCPC Software Installation

    (g) For airplanes on which any ASCPC having P/N 1152972-4 is 
found during the inspection required by paragraph (f) of this AD: 
Within 90 days after the effective date of this AD, install new 
ASCPC operational program software (OPS) in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 777-36A0026, 
Revision 1, dated February 8, 2007.

Installation of Certain OPS Software Prohibited

    (h) As of the effective date of this AD, installation of OPS P/N 
3673-GRS-101-00, P/N 3670-GRS-102-00, or P/N 3671-GRS-103-00 is 
prohibited.
    (i) As of the effective date of this AD, no person may install 
an ASCPC, P/N 111152972-4, on any airplane, unless it has had ASCPC 
OPS P/N 3676-GRS-104-00 installed in accordance with paragraph (g) 
of this AD.

Credit for Actions Done Using Previous Service Information

    (j) Actions accomplished before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 777-36A0026, dated 
December 19, 2006, are considered acceptable for compliance with the 
corresponding actions specified in this AD.

Alternative Methods of Compliance (AMOCs)

    (k)(1) 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.
    (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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

Material Incorporated by Reference

    (l) You must use Boeing Service Bulletin 777-36A0026, Revision 
1, dated February 8, 2007, to perform the actions that are required 
by this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for a copy of this service information. You 
may review copies at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue, SW., Renton, Washington; or at the National Archives 
and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on March 21, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-5897 Filed 4-2-07; 8:45 am]
BILLING CODE 4910-13-P

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