[Federal Register Volume 63, Number 219 (Friday, November 13, 1998)]
[Rules and Regulations]
[Pages 63390-63391]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30335]



[[Page 63390]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-294-AD; Amendment 39-10887; AD 96-04-11 R1]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200 Series Airplanes 
Equipped With Rolls Royce Model RB211-535E4/E4B Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment revises an existing airworthiness directive 
(AD), applicable to certain Boeing Model 757-200 series airplanes, that 
currently requires a revision to the Airplane Flight Manual to ensure 
that the flightcrew activates the engine cowl thermal anti-ice (CTAI) 
system for both engines at the top of descent to avoid engine rundown 
(loss of engine power). This amendment clarifies the relationship 
between two existing AD's. The actions specified in this AD are 
intended to ensure that the flightcrew activates the engine cowl 
thermal anti-ice system for both engines prior to descent; activation 
of the engine CTAI system in the middle of descent could result in a 
compressor stall and subsequent engine rundown of multiple engines.

DATES: Effective November 30, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before January 12, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-294-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Information pertaining to this amendment 
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Kathrine Rask, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington; telephone (425) 227-
1547; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: On February 15, 1996, the FAA issued AD 96-
04-11, amendment 39-9523 (61 FR 6935, February 23, 1996), applicable to 
certain Boeing Model 757-200 series airplanes, to require a revision to 
the FAA-approved Airplane Flight Manual to ensure that the flightcrew 
activates the engine cowl thermal anti-ice (CTAI) system for both 
engines at the top of descent to avoid engine rundown (loss of engine 
power). That action was prompted by reports that, after the flightcrew 
activated the engine CTAI during descent, engine rundown occurred due 
to unknown reasons. The actions required by that AD are intended to 
ensure that the flightcrew activates the engine CTAI system for both 
engines prior to descent; activation of the engine CTAI system in the 
middle of descent could result in a compressor stall and subsequent 
engine rundown of multiple engines.
    In the preamble to AD 96-04-11, the FAA indicated that the actions 
required by that AD were considered interim action. Rolls Royce had 
advised the FAA that it was developing a modification that will 
positively address the identified unsafe condition.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the FAA issued AD 97-02-12, 
amendment 39-9897 (62 FR 4899, February 3, 1997). That AD applies to 
Rolls Royce Model RB211-535E4 and -535E4-B turbofan engines installed 
on Boeing Model 757-200 series airplanes. It requires installation of 
an improved fuel flow governor that incorporates revised minimum 
compressor discharge P4 stop settings. That AD indicates that 
installation of these improved fuel flow governors on both engines of 
Model 757 series airplanes constitutes terminating action for the 
requirements of AD 96-04-11.
    Consequently, the FAA has determined that further rulemaking is 
necessary to revise AD 96-04-11 to clarify the relationship of that AD 
to AD 97-02-12 by indicating that installation of the improved fuel 
flow governors (as required by AD 97-02-12) terminates the requirements 
of AD 96-04-11.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of this same type design, this AD 
revises AD 96-04-11 to continue to require a revision to the Airplane 
Flight Manual to ensure that the flightcrew activates the engine cowl 
thermal anti-ice (CTAI) system for both engines at the top of descent 
to avoid engine rundown (loss of engine power). This AD merely 
clarifies the relationship between AD 96-04-11 and AD 97-02-12.

Determination of Rule's Effective Date

    Since this AD merely provides information regarding the effect of 
another AD, and does not change the existing requirements, it is found 
that notice and opportunity for prior public comment hereon are 
unnecessary, and that good cause exists for making this amendment 
effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire.
    Communications shall identify the Rules Docket number and be 
submitted in triplicate to the address specified under the caption 
ADDRESSES. All communications received on or before the closing date 
for comments will be considered, and this rule may be amended in light 
of the comments received. Factual information that supports the 
commenter's ideas and suggestions is extremely helpful in evaluating 
the effectiveness of the AD action and determining whether additional 
rulemaking action would be needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-294-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does

[[Page 63391]]

not have sufficient federalism implications to warrant the preparation 
of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by removing amendment 39-9523 (61 FR 
6935, February 23, 1996), and by adding a new airworthiness directive 
(AD), amendment 39-10887, to read as follows:

96-04-11  R1 Boeing: Amendment 39-10887. Docket 98-NM-294-AD. 
Revises AD 96-04-11, amendment 39-9523.

    Applicability: Model 757-200 series airplanes, equipped with 
Rolls Royce Model RB211-535E4/E4B engines; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To reduce the risk of engine rundown during idle descents, 
accomplish the following:
    (a) Within 30 days after March 11, 1996 (the effective date of 
AD 96-04-11, amendment 39-9523), revise the Limitations Section of 
the FAA-approved Airplane Flight Manual (AFM) to include the 
following statement. This may be accomplished by inserting a copy of 
this AD in the AFM.

``Limitations Section 1

    In order to reduce the risk of engine rundown during idle 
descents, activate the engine cowl thermal anti-ice system for both 
engines prior to idle descents above flight level (FL) 200. Below FL 
200, use normal engine cowl thermal anti-ice system procedures (as 
defined in the AFM).
    Note: The Master Minimum Equipment List (MMEL) for Model 757 
series airplanes currently specifies that an airplane may be 
dispatched with an engine anti-ice valve locked in the closed 
position. The requirement of this section to activate the engine 
cowl thermal anti-ice system prior to descent will prevent the 
dispatch of airplanes with an engine anti-ice valve locked in the 
closed or open position. Where differences exist between the current 
specification of the MMEL and the requirements of this AFM 
limitation, the AFM limitation prevails.''

    Note 1: AD 97-02-12, amendment 39-9897, requires installation of 
improved fuel flow governors (FFG) on both engines of Boeing Model 
757-200 series airplanes. Accomplishment of this installation 
constitutes terminating action for the requirements of this AD.

    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Operations Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (c) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished.
    (d) This amendment becomes effective on November 30, 1998.

    Issued in Renton, Washington, on November 4, 1998.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-30335 Filed 11-12-98; 8:45 am]
BILLING CODE 4910-13-U