Document Headings

                    Document headings vary by document type but may contain                    the following:                  
                -                       the agency or agencies that issued and signed a document                    
                -                       the number of the CFR title and the number of each part                      the document amends, proposes to amend, or is directly                      related to                    
                -                       the agency docket number / agency internal file number                    
                -                       the RIN which identifies each regulatory action listed in                      the Unified Agenda of Federal Regulatory and Deregulatory                      Actions                    

                    See the                                          Document Drafting Handbook                                        for more details.                  

###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. FAA-2004-19986; Directorate Identifier 2004-NM-247-AD] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration (FAA), DOT. 

# ACTION:

Notice of proposed rulemaking (NPRM). 

# 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 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.       ( print 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                         *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-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                     *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 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                     *http://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                     *http://www.faa.gov/​language*                     and                     *http://www.plainlanguage.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 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° 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                           ( print 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. 

§ 39.13 

2. The FAA amends § 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