Airworthiness Directives; Boeing Model 747 Series Airplanes

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

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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

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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

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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