AD 2007-07-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 777 | Airworthiness Directives; Boeing Model 777 Airplanes |
Unsafe Condition
ASCPC failure during flight that could stop airflow into the airplane, inhibit the cabin altitude warning message, and cause an incorrect display of cabin altitude, potentially leading to depressurization without warning.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect to determine the part number of the left and right ASCPCs. Install new ASCPC software if necessary.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 90 days after the effective date of the AD.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All Boeing Model 777-200, -200LR, -300, and -300ER series airplanes, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
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.
Document Text
Show stored source text (verify against official source)
[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: E7-5897]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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 <a href="http://dms.dot.gov">http://dms.dot.gov</a> and follow
the instructions for sending your comments electronically.
<bullet> Government-wide rulemaking Web site: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a> 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 <a href="http://dms.dot.gov">http://dms.dot.gov</a>, 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
<a href="http://dms.dot.gov">http://dms.dot.gov</a>.
Examining the Docket
You may examine the AD docket on the Internet at <a href="http://dms.dot.gov">http://dms.dot.gov</a>, 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:
<a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
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
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.