[Federal Register Volume 64, Number 190 (Friday, October 1, 1999)]
[Proposed Rules]
[Pages 53275-53280]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-25597]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-22-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 747 series 
airplanes. This proposal would require repetitive inspections to detect 
discrepancies of the cables, fittings, and pulleys of the engine thrust 
control cable installation, and replacement, if necessary. This 
proposal would also require certain preventative actions on the engine 
thrust control cable installation for certain airplanes. This proposal 
is prompted by reports of failure of engine thrust control cables. The 
actions specified by the proposed AD are intended to prevent such 
failures, which could result in a severe asymmetric thrust condition 
during landing, and consequent reduced controllability of the airplane.

DATES: Comments must be received by November 15, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-22-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00

[[Page 53276]]

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: Dionne M. Stanley, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2250; 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 99-NM-22-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. 99-NM-22-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    In 1985, the FAA received a report indicating that an engine thrust 
control cable had failed following application of reverse thrust during 
landing on a Boeing Model 747-200B series airplane. This failure caused 
engine number 1 to advance to full forward thrust while engine numbers 
2, 3, and 4 remained in full reverse thrust. The airplane exited the 
runway and eventually slid to a stop with consequent hull damage.
    In addition, engine thrust control cables have failed on other 
Boeing airplane models that have installations similar to those on the 
Model 747 series airplane. In 1992, the FAA received a report of 
uncommanded thrust increase of the right engine on a Model 767-200 
series airplane during engine start. The FAA recently received two 
reports of uncommanded throttle lever movement on Model 757-200 series 
airplanes. In all of these events, subsequent investigation revealed 
that the engine thrust control cable had severed. Such failure of a 
thrust control cable could result in a severe asymmetric thrust 
condition during landing, and consequent reduced controllability of the 
airplane.

Other Relevant Rulemaking

    As a result of the 1985 event and other problems associated with 
the engine thrust control cable installation, the following AD's were 
issued to address design deficiencies on Model 747 series airplanes 
that could potentially result in an engine thrust control cable 
failure:
     AD 85-25-55, amendment 39-5326 (51 FR 20250, June 4, 
1986);
     AD 86-10-10, amendment 39-5318 (51 FR 18571, May 21, 
1986);
     AD 89-08-09, amendment 39-6188 (54 FR 14643, April 12, 
1989);
     AD 89-19-07, amendment 39-6322 (54 FR 38210, September 15, 
1989); and
     AD 93-17-06, amendment 39-8677 (58 FR 45831, August 31, 
1993).
    In addition, the FAA has issued two NPRM's to address this 
condition on other Boeing airplane models that have an engine thrust 
control cable installation similar to the Model 747 series airplane:
     NPRM 98-NM-323-AD (64 FR 7822, February 17, 1999), which 
applies to certain Model 757-200 series airplanes; and
     NPRM 98-NM-363-AD (64 FR 18386, April 14, 1999), which 
applies to certain Model 767 series airplanes.

Explanation of Relevant Service Information

    The FAA has reviewed and approved the following service bulletins:
     Boeing Service Bulletin 747-76-2019, dated June 9, 1971, 
describes procedures for modification of the strut bulkhead assembly to 
enlarge the holes through which the engine thrust control cables pass.
     Boeing Service Bulletin 747-76-2067, Revision 1, dated 
November 19, 1987, describes procedures for a one-time inspection of 
the nacelle strut idler pulleys to determine the type of pulleys 
installed, and replacement of any aluminum-type pulleys with phenolic-
type pulleys. The service bulletin also describes procedures for a 
detailed inspection to detect wear of the engine thrust control cables 
in any area where aluminum-type pulleys are installed, and replacement 
of the cables, if necessary.
     Boeing Service Bulletin 747-76A2068, Revision 3, dated 
August 22, 1991; including Notice of Status Change 747-76A2068 NSC 2, 
dated December 12, 1991; describes procedures for repetitive 
inspections of aluminum pulley bracket assemblies and adjacent support 
structure to detect cracking, and replacement of damaged parts, if 
necessary. The service bulletin also describes procedures for 
replacement of aluminum idler pulley brackets with steel brackets. Such 
replacement would eliminate the need for the repetitive inspections.
     Boeing Alert Service Bulletin 747-76A2073, Revision 1, 
dated July 28, 1988, describes procedures for a detailed inspection of 
the engine thrust control cables and pulley mounting bracket screws in 
the area aft and above main entry door number 2 on the left and right 
sides of the airplane to detect wear, and replacement of the cable, if 
necessary. The alert service bulletin also describes procedures for a 
modification of the pulley mounting bracket.
     Boeing Service Bulletin 747-53-2327, Revision 2, dated 
September 24, 1998, describes procedures for repetitive inspections of 
certain upper deck floor beams to detect cracking, and repair of any 
cracks found or reinforcement of those floor beams. The service 
bulletin also describes procedures for a detailed inspection to measure 
the clearance between the engine thrust control cables and the cable 
penetration holes in that area, and modification of the holes or 
replacement of the plate, if necessary.
    Accomplishment of the actions specified in the service bulletins 
described previously, and the repetitive inspections specified in this 
proposed AD, is intended to adequately address the identified unsafe 
condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would

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require repetitive inspections to detect discrepancies of the cables, 
fittings, and pulleys, and replacement of discrepant parts. This 
proposal would also require certain preventative actions on the engine 
thrust control cable installation for certain airplanes. The actions 
would be required to be accomplished in accordance with the procedure 
included in Appendix 1. of this proposed AD, the airplane maintenance 
manual, and the service bulletins described previously, except as 
discussed below.

Differences Between Proposed Rule and Service Bulletins

    Operators should note that this proposed AD would require all of 
the specified actions to be accomplished within 18 months after the 
effective date of this AD. The service bulletins recommend that these 
actions should be accomplished at various times, mostly ``at the 
earliest opportunity where manpower and facilities are available.'' In 
developing an appropriate compliance time for the proposed actions, the 
FAA considered not only the degree of urgency associated with 
addressing the subject unsafe condition, but also the number of 
proposed requirements and the availability of required parts. The FAA 
has determined that 18 months represents an appropriate interval of 
time allowable wherein all of these actions can be accomplished during 
scheduled airplane maintenance and an ample number of required parts 
will be available for modification of the U.S. fleet within the 
proposed compliance period. The FAA also finds that such a compliance 
time will not adversely affect the safety of the affected airplanes.
    Operators should note that Boeing Service Bulletin 747-76-2067 
specifies that the inspection to detect wear of the control cables 
described by that service bulletin may be accomplished in accordance 
with an ``operator's comparable procedure.'' However, this proposed AD 
specifies that the inspection be accomplished in accordance with the 
procedures specified in Chapter 20-21-03 of the Boeing 747 Maintenance 
Manual. An ``operator's comparable procedure'' may be used only if 
approved as an alternative method of compliance in accordance with 
paragraph (h) of this AD.
    Operators also should note that Boeing Service Bulletin 747-76-2067 
applies to certain Model 747 series airplanes equipped with Pratt & 
Whitney Model JT9D-70A engines or General Electric Model CF6 series 
engines. However, paragraph (c) of this proposed AD would apply only to 
Model 747 series airplanes equipped with General Electric Model CF6 
series engines identified in the service bulletin. The engine thrust 
control cable installation is different on Model 747 series airplanes 
equipped with Pratt & Whitney Model JT9D-70A engines, and the unsafe 
condition discussed previously does not exist on those airplanes.
    Boeing Service Bulletin 747-76A2068 describes procedures for 
repetitive inspections of aluminum pulley bracket assemblies and 
adjacent support structure to detect cracking, and replacement of 
damaged parts, if necessary, as well as procedures for replacement of 
aluminum idler pulley brackets with steel brackets. This proposed AD 
would require only the replacement of aluminum idler pulley brackets 
with steel brackets. Mandating this terminating action is based on the 
FAA's determination that, in this case, long-term continued operational 
safety would be better assured by a modification to remove the source 
of the problem, rather than by repetitive inspections.
    Although Boeing Alert Service Bulletin 747-76A2073 describes 
procedures for a detailed inspection of the engine thrust control 
cables and pulley mounting bracket screw in the area aft and above main 
entry door number 2 on the left and right sides of the airplane to 
detect wear, this AD proposes only to mandate the detailed inspection 
of the engine thrust control cables in that area, and replacement of 
the cable, if necessary; and the modification of the pulley mounting 
bracket. The alert service bulletin also provides the option to modify 
the bracket within 750 hours of the detailed inspection whereas this AD 
would require both actions to be accomplished at the same time.
    Operators also should note that, although Boeing Service Bulletin 
747-53-2327 also describes procedures for inspection of certain upper 
deck floor beams, and repair of any cracks found or reinforcement of 
those floor beams, as applicable, this AD proposes to mandate only the 
detailed inspection to measure the clearance between the engine thrust 
control cables and the cable penetration holes in that area. The 
inspection, repair, and reinforcement of certain upper deck floor beams 
are mandated by AD 92-24-07, amendment 39-8412 (57 FR 53436, November 
10, 1992). The detailed inspection to measure the clearance between the 
engine thrust control cables and the cable penetration holes was 
incorporated into the service bulletin after AD 92-24-07 was issued. 
Therefore, the FAA is proposing to mandate that part of the service 
bulletin in this AD. In addition, for airplanes on which insufficient 
clearance is measured, the proposed AD adds an additional inspection of 
the cable for wear in that area, and would require replacement of the 
cable, if necessary.

Cost Impact

    There are approximately 624 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 182 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 engine thrust control cable 
integrity, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of this proposed inspection on U.S. 
operators is estimated to be $32,760, or $180 per airplane, per 
inspection cycle.
    For airplanes identified in Boeing Service Bulletin 747-76-2019 (30 
U.S.-registered airplanes), it would take approximately 4 work hours 
per airplane to accomplish the proposed modification, at an average 
labor rate of $60 per work hour. No parts are required. Based on these 
figures, the cost impact of this proposed modification on U.S. 
operators is estimated to be $7,200, or $240 per airplane.
    For airplanes identified in Boeing Service Bulletin 747-76-2067, 
Revision 1 (12 U.S.-registered airplanes), it would take approximately 
6 work hours per airplane to accomplish the proposed inspection of the 
nacelle strut idler pulleys, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of this proposed one-time 
inspection on U.S. operators is estimated to be $4,320, or $360 per 
airplane.
    For airplanes identified in Boeing Service Bulletin 747-76A2068, 
Revision 3 (4 U.S.-registered airplanes), it would take approximately 
16 work hours per airplane to accomplish the proposed replacement, at 
an average labor rate of $60 per work hour.
    Required parts would cost approximately $2,000 per airplane. Based 
on these figures, the cost impact of this proposed replacement on U.S. 
operators is estimated to be $11,840, or $2,960 per airplane.
    For airplanes identified in Boeing Alert Service Bulletin 747-
76A2073, Revision 1 (12 U.S.-registered airplanes), it would take 
approximately 4 work hours per airplane to accomplish the proposed 
action, at an average labor rate of $60 per work hour. The cost of 
required parts would be minimal. Based

[[Page 53278]]

on these figures, the cost impact of this proposed action on U.S. 
operators is estimated to be $2,880, or $240 per airplane.
    Currently, there are no airplanes identified in Boeing Service 
Bulletin 747-53-2327, Revision 2, and subject to this AD, on the U.S. 
Register. However, should an affected airplane be imported and placed 
on the U.S. Register in the future, it would require approximately 1 
work hour to accomplish this proposed inspection, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
this one-time inspection would be $60 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) 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 99-NM-22-AD.

    Applicability: Model 747-100, -100B, -100B SUD, -200B, -200C, -
200F, -300, SR, and SP series airplanes; certificated in any 
category; equipped with Pratt & Whitney Model JT9D-3 or -7 series 
engines, General Electric Model CF6-45 or -50 series engines, or 
Rolls-Royce Model RB211-524B, C, or D series engines.

    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 (h) 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 failures, which could 
result in a severe asymmetric thrust condition during landing, and 
consequent reduced controllability of the airplane, accomplish the 
following:

    Note 2: For the purposes of this AD, a detailed 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.''

Repetitive Inspections

    (a) For all airplanes: Within 18 months after the effective date 
of this AD, accomplish the ``Thrust Control Cable Inspection 
Procedure'' specified in Appendix 1. (including Figure 1) of this AD 
to verify the integrity of the engine thrust control cables. Prior 
to further flight, replace any discrepant component found, in 
accordance with the procedures described in the Boeing 747 
Maintenance Manual. Repeat the detailed inspection thereafter at 
intervals not to exceed 18 months.

Modification

    (b) For airplanes identified in Boeing Service Bulletin 747-76-
2019, dated June 9, 1971: Within 18 months after the effective date 
of this AD, modify the strut bulkhead assembly to enlarge the holes 
(2 places in each strut) through which the engine thrust control 
cables pass, in accordance with the service bulletin.

Inspection/Replacement

    (c) For airplanes equipped with General Electric Model CF6 
series engines and identified in Boeing Service Bulletin 747-76-
2067, Revision 1, dated November 19, 1987: Within 18 months after 
the effective date of this AD, perform a one-time inspection of each 
nacelle strut idler pulley to determine the type of pulley 
installed, in accordance with the service bulletin.

    Note 3: This paragraph does not apply to airplanes equipped with 
Pratt & Whitney Model JT9D-70 engines.

    (1) If no aluminum-type pulley is installed, no further action 
is required by this paragraph.
    (2) If any aluminum-type pulley is installed, prior to further 
flight, accomplish paragraphs (c)(2)(i) and (c)(2)(ii) of this AD in 
accordance with the service bulletin.
    (i) Replace any aluminum-type pulley with a phenolic-type pulley 
having Boeing part number BACP30F4.
    (ii) Except as provided by paragraph (d) of this AD: Perform a 
detailed inspection of the engine thrust control cables in any area 
where an aluminum-type pulley was installed, to detect wear. If any 
wear outside the criteria contained in Chapter 20-21-03 of the 
Boeing 747 Maintenance Manual is found, prior to further flight, 
replace the cable with a new cable, in accordance with the service 
bulletin. If any wear within the criteria contained in the 
maintenance manual is found, no further action is required by this 
paragraph.

    Note 4: Accomplishment of the actions specified in Boeing 
Service Bulletin 747-76-2067, dated September 26, 1986, is 
acceptable for compliance with the actions required by paragraph (c) 
of this AD.

    (d) Where Boeing Service Bulletin 747-76-2067, Revision 1, dated 
November 19, 1987, specifies that the actions required by paragraph 
(c)(2)(ii) of this AD may be accomplished in accordance with an 
``operator's comparable procedure,'' the actions must be 
accomplished in accordance with the applicable chapters of the 
Boeing 747 Maintenance Manual, as specified in the service bulletin.

Replacement

    (e) For airplanes identified in Boeing Service Bulletin 747-
76A2068, Revision 3, dated August 22, 1991; including Notice of 
Status Change 747-76A2068 NSC 2, dated December 12, 1991: Within 18 
months after the effective date of this AD, replace aluminum idler 
pulley brackets with steel brackets, in accordance with paragraphs 
E., F., G., and H. of the Accomplishment Instructions of the service 
bulletin.

Inspection/Modification

    (f) For airplanes identified in Boeing Alert Service Bulletin 
747-76A2073, Revision 1, dated July 28, 1988: Within 18 months after 
the effective date of this AD, accomplish

[[Page 53279]]

paragraphs (f)(1) and (f)(2) of this AD, in accordance with the 
alert service bulletin.
    (1) Perform a detailed inspection of the engine thrust control 
cables and pulley mounting bracket screws in the area aft and above 
main entry door number 2 on the left and right sides of the airplane 
to detect damage. If any damage is found, prior to further flight, 
replace the cable with a new cable.
    (2) Modify the pulley mounting bracket.

    Note 5: Accomplishment of the actions specified in Boeing Alert 
Service Bulletin 747-76A2073, dated February 4, 1988, is acceptable 
for compliance with the actions required by paragraph (f) of this 
AD.

Inspection/Modification/Replacement

    (g) For Model 747-100B SUD series airplanes identified in Boeing 
Service Bulletin 747-53-2327, Revision 2, dated September 24, 1998, 
with angle assemblies having Boeing part numbers 015U0454-63 and 
015U0454-64 installed at body station 970: Within 18 months after 
the effective date of this AD, perform a detailed inspection to 
measure the clearance between the engine thrust control cables and 
the cable penetration holes, in accordance with the Cable Chafing 
Inspection of the Accomplishment Instructions of the service 
bulletin. If insufficient clearance exists, as specified in the 
service bulletin, prior to further flight, accomplish paragraphs 
(g)(1) and (g)(2) of this AD.
    (1) Modify the cable penetration holes or replace the plate, as 
applicable, in accordance with Figure 7 of the service bulletin.
    (2) Perform a detailed inspection of the engine thrust control 
cables in any area of the plate to detect wear, in accordance with 
Chapter 20-21-03 of the Boeing 747 Maintenance Manual. If any wear 
outside the criteria contained in the maintenance manual is found, 
prior to further flight, replace the cable with a new cable, in 
accordance with the procedures described in the Boeing 747 
Maintenance Manual. If any wear within the criteria contained in the 
maintenance manual is found, no further action is required by this 
paragraph.

Alternative Methods of Compliance

    (h) 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 6: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (i) 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 accomplished.

Appendix 1. Thrust Control Cable Inspection Procedure

1. General

    A. Clean the cables, if necessary, for the inspection, in 
accordance with Boeing 747 Maintenance Manual 12-21-05.
    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 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.
    B. Perform a detailed 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 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 inspection to ensure that the means of 
locking the joints are intact (wire locking, cotter pins, turnbuckle 
clips, etc.). Install any missing parts.
    B. Perform a detailed inspection of the swaged portions of 
swaged end fitting to detect surface cracks or corrosion. Replace 
the cable assembly if cracks or corrosion are found.
    C. Perform a detailed 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 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 inspection to ensure that pulleys are free 
to rotate. Replace pulleys which are not free to rotate.

BILLING CODE 4910-13-U

[[Page 53280]]

[GRAPHIC] [TIFF OMITTED] TP01OC99.059



    Issued in Renton, Washington, on September 27, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-25597 Filed 9-30-99; 8:45 am]
BILLING CODE 4910-13-C