[Federal Register Volume 64, Number 175 (Friday, September 10, 1999)]
[Proposed Rules]
[Pages 49105-49109]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-23478]


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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 64, No. 175 / Friday, September 10, 1999 / 
Proposed Rules  

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-323-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200, -200PF, and -
200CB Series Airplanes Powered by Rolls-Royce RB211-535C/E4/E4B 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain Boeing Model 757-200, -200PF, and 
-200CB series airplanes, that would have required modification of the 
engine thrust control cable installation, and repetitive inspections to 
detect certain discrepancies of the cables, pulleys, pulley brackets, 
and cable travel; and repair, if necessary. That proposal was prompted 
by reports of failure of certain engine thrust control cables. This new 
action would revise the proposed rule by extending the compliance time 
for certain actions, revising certain inspection procedures, and adding 
a requirement for a one-time inspection to determine the part number of 
thrust control cable pulleys and replacement of existing pulleys with 
new pulleys, if necessary. The actions specified by this new proposed 
AD are intended to prevent failure of certain engine thrust control 
cables, which could result in a severe asymmetric thrust condition 
during landing, and consequent reduced controllability of the airplane.

DATES: Comments must be received by October 5, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-323-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information 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, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-1547; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-323-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 98-NM-323-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain Boeing Model 757-200, -200PF, and -200CB series airplanes, was 
published as a notice of proposed rulemaking (NPRM) in the Federal 
Register on February 17, 1999 (64 FR 7822). That NPRM would have 
required modification of the engine thrust control cable installation, 
and repetitive inspections to detect certain discrepancies of the 
cables, pulleys, pulley brackets, and cable travel; and repair, if 
necessary. That NPRM was prompted by reports of failure of certain 
engine thrust control cables. That condition, if not corrected, could 
result in a severe asymmetric thrust condition during landing, and 
consequent reduced controllability of the airplane.

Actions Since Issuance of Previous Proposal

    Due consideration has been given to the comments received in 
response to the NPRM. Certain of these comments and the information 
they provided have led the FAA to consider making certain significant 
changes to the proposal. These comments and the changes prompted by 
them are explained below.

Request to Extend Compliance Time

    One commenter requests that the compliance time for the thrust 
control cable inspection [specified in paragraph (a) of the NPRM] be 
extended from 18 months or 6,000 flight hours after the effective date 
of this AD (whichever occurs first) to 24 months or 6,000 flight hours 
after the effective date of this AD (whichever occurs first). The 
commenter states that, for some operators, 6,000 flight hours would not 
closely correspond to 18 months.
    The FAA concurs with the commenter's request to extend the 
compliance time somewhat. The FAA's intent is that the inspection 
specified in the proposal be performed during a regularly scheduled 
maintenance visit,

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when the airplane is at a base where special equipment and trained 
personnel are readily available, if necessary. The FAA has determined 
that an interval of 24 months better corresponds to operators' normal 
maintenance schedules than an interval of 18 months. The FAA does not 
consider that such an extension of the compliance time to 24 months 
would adversely affect safety. Therefore, as the commenter requests, 
paragraph (a) of this supplemental NPRM has been revised accordingly. 
Similarly, the repetitive interval for the inspection specified in 
paragraph (a) of this supplemental NPRM has been revised from the 
earlier of 18 months or 6,000 flight hours to the earlier of 24 months 
or 6,000 flight hours, and paragraphs (c) and (d) of this supplemental 
NPRM [i.e., paragraphs (b) and (c) of the original NPRM] have been 
revised to incorporate a compliance time of 24 months or 6,000 flight 
hours after the effective date of this AD, whichever occurs first.

Request To Revise Inspection Procedure

    Two commenters request that the ``Thrust Control Cable Inspection 
Procedure,'' specified in paragraph (a) and described in Appendix 1 of 
the proposal, be revised to focus on minimizing the possibility of 
failure of an engine thrust control cable. One of the commenters 
suggests that the procedure be revised to eliminate all steps that 
don't contribute to the intent of the AD. The same commenter also 
suggests that the inspection procedure would be enhanced by adding an 
inspection of the cable joints.
    The FAA concurs with the commenters' request, and the ``Thrust 
Control Cable Inspection Procedure'' specified in Appendix 1 of this 
supplemental NPRM has been revised accordingly.

Request To Add Requirement for Pulley Replacement

    One commenter, the airplane manufacturer, suggests that the intent 
of the proposed AD would be enhanced by inclusion of a requirement for 
replacement of existing phenolic thrust control cable pulleys in the 
struts with aluminum pulleys. The commenter states that phenolic 
pulleys have seized due to delamination and loss of bearing 
lubrication, which would result in chafing of the engine thrust control 
cables. The commenter notes that this replacement is described in 
Boeing Service Letter 757-SL-76-004-A, dated July 21, 1997.
    The FAA concurs with the commenter's request. Therefore, a new 
paragraph (b) has been added to this supplemental NPRM, which would 
require, for airplanes having line numbers 1 through 636 inclusive, a 
one-time inspection of the thrust control cable pulleys in the struts 
to determine the part number of the pulleys, and replacement of 
phenolic pulleys with new aluminum pulleys. Such replacement would be 
required to be accomplished in accordance with the Boeing 757 Airplane 
Maintenance Manual. A new Note 2 also has been added to this 
supplemental NPRM to provide references for the location of the pulleys 
to be inspected in accordance with paragraph (b) of this proposed AD.

Request To Revise Cost Impact

    One commenter, the airplane manufacturer, requests that the ``Cost 
Impact'' section of the proposal be revised to remove the statement 
that the manufacturer will provide certain parts at no cost to the 
operators. The FAA concurs with the commenter's request and has revised 
the Cost Impact section of this supplemental NPRM in accordance with 
new cost data provided by the manufacturer.

Explanation of Additional Change to the Original NPRM

    The Cost Impact section in this supplemental NPRM has been revised 
to increase the number of affected airplanes in the worldwide fleet as 
well as on the U.S. Register from the numbers stated in the original 
NPRM. Since the issuance of the NPRM, more airplanes have been 
delivered by the manufacturer; thus the number of affected airplanes 
has increased. No change to the applicability statement of the AD has 
been made or is necessary.

Conclusion

    Since these changes expand the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.

Cost Impact

    There are approximately 483 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 248 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 3 work hours per airplane to accomplish 
the proposed inspection to verify the integrity of the thrust control 
cables, at an average labor rate of $60 per work hour. Based on these 
figures, the cost impact of this inspection proposed by this AD on U.S. 
operators is estimated to be $44,640, or $180 per airplane, per 
inspection cycle.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed inspection to determine the part number of the thrust 
control cable pulleys, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of this inspection proposed by 
this AD on U.S. operators is estimated to be $14,880, or $60 per 
airplane, per inspection cycle.
    For airplanes identified in Boeing Service Bulletin 757-76-1 (8 
U.S.-registered airplanes), it would take approximately 2 work hours 
per airplane to accomplish the proposed guide bracket removal, at an 
average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$960, or $120 per airplane.
    For airplanes identified in Boeing Service Bulletin 757-76-0005 (14 
U.S.-registered airplanes), it would take approximately 14 work hours 
per airplane to accomplish the proposed replacement, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $1,410 per airplane. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be $31,500, 
or $2,250 per airplane.
    For airplanes identified in Boeing Alert Service Bulletin 757-
30A0018, Revision 1 (167 U.S.-registered airplanes), it would take 
approximately 2 work hours per airplane to accomplish the proposed 
installation and adjustment, at an average labor rate of $60 per work 
hour. Required parts would cost approximately $192 per airplane. Based 
on these figures, the cost impact of the proposed AD on U.S. operators 
is estimated to be $52,104, or $312 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1)

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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) if promulgated, 
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. A copy of the draft regulatory evaluation 
prepared for this action is contained in the Rules Docket. A copy of it 
may be obtained by contacting 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.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 adding the following new 
airworthiness directive:

Boeing: Docket 98-NM-323-AD.

    Applicability: Model 757-200, -200PF, and -200CB series 
airplanes powered by Rolls-Royce RB211-535C/E4/E4B turbofan engines, 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (f) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent engine thrust control cable failure, which could 
result in a severe asymmetric thrust condition during landing, and 
consequent reduced controllability of the airplane, accomplish the 
following:

Inspections and Corrective Actions

    (a) Within 24 months or 6,000 flight hours after the effective 
date of this AD, whichever occurs first: Accomplish the ``Thrust 
Control Cable Inspection Procedure'' specified in Appendix 1. 
(including Figure 1) of this AD to verify the integrity of the 
thrust control cables. Prior to further flight, repair any 
discrepancy found in accordance with the procedures described in the 
Boeing 757 Maintenance Manual. Repeat the inspection thereafter at 
intervals not to exceed 24 months or 6,000 flight hours, whichever 
occurs first.
    (b) For airplanes having line numbers 1 through 636 inclusive: 
Within 24 months or 6,000 flight hours after the effective date of 
this AD, whichever occurs first, perform a one-time inspection of 
the 8 engine thrust control cable pulleys in the struts (4 in each 
strut) to determine the part number (P/N) of each pulley. If any 
pulley having P/N 65B80977-1 is installed, prior to further flight, 
replace it with a pulley having P/N 255T1232-7, in accordance with 
the procedures described in the Boeing 757 Airplane Maintenance 
Manual.

    Note 2: The location of the pulleys to be inspected in 
accordance with paragraph (b) of this AD is specified in Chapters 
53-11-53-04, 76-11-52-01, and 76-11-52-02 of the Boeing 757 
Illustrated Parts Catalog.

Modifications

    (c) For airplanes identified in Boeing Service Bulletin 757-76-
1, dated May 18, 1984: Within 24 months or 6,000 flight hours after 
the effective date of this AD, whichever occurs first, remove the 
guide bracket of the engine thrust control cable located on the 
front spar of the right wing in accordance with the service 
bulletin.
    (d) For airplanes identified in Boeing Service Bulletin 757-76-
0005, dated May 5, 1988: Within 24 months or 6,000 flight hours 
after the effective date of this AD, whichever occurs first, remove 
the engine thrust control cable breakaway stop assemblies, and 
replace sections of the engine thrust control cables with smaller 
diameter cables in accordance with the service bulletin.
    (e) For airplanes identified in Boeing Alert Service Bulletin 
757-30A0018, Revision 1, dated September 17, 1998: Within 60 days 
after the effective date of this AD, install a support bracket 
assembly between the window heat wire bundle and the engine thrust 
control cable; and adjust the wire bundle clearance, as necessary, 
to parallel the minimum clearance specified in the alert service 
bulletin.

Alternative Method of Compliance

    (f) 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 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Appendix 1.--Thrust Control Cable Inspection Procedure

Special Flight Permits

    (g) Special flight permits may be issued in accordance with 
sections 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 acomplished. Issued in Renton, 
Washington, on September 2, 1999.

1. General

    A. Clean the cables, if necessary, for the inspection, in 
accordance with Boeing 757 Maintenance Manual 12-21-31.
    B. Use these procedures to verify the integrity of the thrust 
control cable system. The procedures must be performed along the 
entire cable run for each engine. To ensure verification of the 
portions of the cables which are in contact with pulleys and 
quadrants, the thrust control must be moved by operation of the 
thrust and/or the reverse thrust levers to expose those portions of 
the cables.
    C. The first task is an inspection of the control cable wire 
rope. The second task is an inspection of the control cable 
fittings. The third task is an inspection of the pulleys.

    Note: These three tasks may be performed concurrently at one 
location of the cable system on the airplane, if desired, for 
convenience.

2. Inspection of the Control Cable Wire Rope

    A. Perform a detailed visual inspection to ensure that the cable 
does not contact parts other than pulleys, quadrants, cable seals, 
or grommets installed to control the cable routing. Look for 
evidence of contact with other parts. Correct the condition if 
evidence of contact is found.

    Note: For the purposes of this procedure, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

    B. Perform a detailed visual inspection of the cable runs to 
detect incorrect routing, kinks in the wire rope, or other damage. 
Replace the cable assembly if:
    (1) One cable strand had worn wires where one wire cross section 
is decreased by more than 40 percent (see Figure 1),
    (2) A kink is found, or
    (3) Corrosion is found.
    C. Perform a detailed visual inspection of the cable: To check 
for broken wires, rub a cloth along the length of the cable. The 
cloth catches on broken wires.
    (1) Replace the 7x7 cable assembly if there are two or more 
broken wires in 12 continuous inches of cable or there are three or 
more broken wires anywhere in the total cable assembly.
    (2) Replace the 7x19 cable assembly if there are four or more 
broken wires in 12 continuous inches of cable or there are six or 
more broken wires anywhere in the total cable assembly.

3. Inspection of the Control Cable Fittings

    A. Perform a detailed visual inspection to ensure that the means 
of locking the joints

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are intact (wire locking, cotter pins, turnbuckle clips, etc.). 
Install any missing parts.
    B. Perform a detailed visual inspection of the swaged portions 
of swaged end fittings to detect surface cracks or corrosion. 
Replace the cable assembly if cracks or corrosion are found.
    C. Perform a detailed visual inspection of the unswaged portion 
of the end fitting. Replace the cable assembly if a crack is 
visible, if corrosion is present, or if the end fitting is bent more 
than 2 degrees.
    D. Perform a detailed visual inspection of the turnbuckle. 
Replace the turnbuckle if a crack is visible or if corrosion is 
present.

4. Inspection of Pulleys

    A. Perform a detailed visual inspection to ensure that pulleys 
are free to rotate. Replace pulleys which are not free to rotate.

BILLING CODE 4910-13-P

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[GRAPHIC] [TIFF OMITTED] TP10SE99.000



Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-23478 Filed 9-9-99; 8:45 am]
BILLING CODE 4910-13-C