Airworthiness Directives; Boeing Model 737-600, -700, -800, and -900 Series Airplanes, 733-735 [05-169]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 70, Number 3 (Wednesday, January 5, 2005)]
[Proposed Rules]
[Pages 733-735]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-169]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19986; Directorate Identifier 2004-NM-247-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, -800, and -
900 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), 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 737-600, -700, -800, and -900 series 
airplanes. This proposed AD would require installing and testing an 
updated version of the operational program software of the flight 
control computers. This proposed AD is prompted by a report of an 
airplane pitching up with rapidly decreasing indicated airspeed after 
the flightcrew set a new altitude into the autopilot. We are proposing 
this AD to prevent anomalous autopilot operation that produces a 
hazardous combination of airplane attitude and airspeed, which could 
result in loss of control of the airplane.

DATES: We must receive comments on this proposed AD by February 22, 
2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to https://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to https://
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.

[[Page 734]]

     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 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 
https://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-2004-19986; the directorate identifier for this 
docket is 2004-NM-247-AD.

FOR FURTHER INFORMATION CONTACT:
    Technical information: Gregg Nesemeier, Aerospace Engineer, Systems 
and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6479; fax (425) 917-6590.
    Plain language information: Marcia Walters, marcia.walters@faa.gov.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

    The FAA has implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, new AD actions are posted on DMS 
and assigned a docket number. We track each action and assign a 
corresponding directorate identifier. The DMS AD docket number is in 
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane 
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier 
(``Old Docket Number'') as a cross-reference for searching purposes.

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-2004-19986; 
Directorate Identifier 2004-NM-247-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 https://
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 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 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 https://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at https://www.faa.gov/language and https://
www.plainlanguage.gov.

Examining the Docket

    You can examine the AD docket on the Internet at https://
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 received a report that a Boeing Model 737-700 series airplane 
pitched up with rapidly decreasing indicated airspeed (IAS) after the 
flightcrew set a new altitude into the autopilot. During the incident, 
the airplane was leveling from a climb at 4,000 feet when the 
flightcrew set the altitude select knob of the autopilot mode control 
panel (MCP) to continue to climb to 8,000 feet. The flight data 
recorder indicated that the airplane had attained a pitch attitude of 
27[deg] nose-high and an airspeed of 135 knots IAS (near or into 
stickshaker) before the flightcrew recovered from the pitch up. Post-
flight assessment of this event revealed an anomaly in the software of 
the enhanced digital flight control system (EDFCS) flight control 
computers (FCCs); if the altitude select knob of the MCP is rotated 
during a 200 millisecond window between the altitude capture and 
altitude hold modes, a new reference altitude between the previously 
selected altitude and the newly selected altitude is stored as the 
reference. The altitude hold control law then attempts to fly to this 
new reference altitude. This condition can result in a pitch-up to an 
excessive, nose-high altitude with anomalous autopilot operation that 
produces a hazardous combination of airplane attitude and airspeed, and 
if not corrected, could result in loss of control of the airplane.
    The EDFCS FCCs and their software on certain Model 737-600, -800, 
and -900 series airplanes are identical to those on the affected Model 
737-700 series airplane. Therefore, all of these models may be subject 
to the same unsafe condition.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 737-22A1164, dated 
May 20, 2004. The service bulletin describes procedures for installing 
and testing an updated version of the operational program software of 
the EDFCS FCCs. 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.

Costs of Compliance

    There are about 155 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 34 airplanes of 
U.S. registry. The proposed actions would take about 2 work hours per 
airplane, at an average labor rate of $65 per work hour. Required parts 
would cost about $0 per airplane. Based on these figures, the estimated 
cost of the proposed AD for U.S. operators is $4,420, or $130 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

[[Page 735]]

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 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-2004-19986; Directorate Identifier 2004-NM-
247-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by February 22, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 737-600, -700, -800, and -
900 series airplanes, certificated in any category, as listed in 
Boeing Alert Service Bulletin 737-22A1164, dated May 20, 2004.

Unsafe Condition

    (d) This AD was prompted by a report of an airplane pitching up 
with rapidly decreasing indicated airspeed after the flightcrew set 
a new altitude into the autopilot. We are issuing this AD to prevent 
anomalous autopilot operation that produces a hazardous combination 
of airplane attitude and airspeed, which could result in loss of 
control of the airplane.

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 and Test Updated Software

    (f) Within 12 months after the effective date of this AD, 
install and test an updated version of the operational program 
software of the enhanced digital flight control system (EDFCS) 
flight control computers (FCCs), in accordance with Boeing Alert 
Service Bulletin 737-22A1164, dated May 20, 2004.

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 December 27, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-169 Filed 1-4-05; 8:45 am]
BILLING CODE 4910-13-P