Airworthiness Directives; Boeing Model 727-200 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-227-AD; Amendment 39-11409; AD 99-23-13]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 727-200 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to all Boeing Model 727-200 series airplanes, that requires

repetitive inspections to detect cracks in certain areas between the

upper and lower sills of the number 1 cargo door, and repair, if

necessary. This amendment is prompted by reports indicating that

fatigue cracks were found in certain structures adjacent to the number

1 cargo door cutout at the forward and aft doorway frames. The actions

specified by this AD are intended to detect and correct such fatigue

cracking, which could result in rapid decompression of the fuselage and

consequent reduced structural integrity of the airplane.

DATES: Effective December 17, 1999.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of December 17, 1999.

ADDRESSES: The service information referenced in this AD may be

obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,

Washington 98124-2207. This information may be examined at the Federal

Aviation Administration (FAA), Transport Airplane Directorate, Rules

Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of

the Federal Register, 800 North Capitol Street, NW., suite 700,

Washington, DC.

FOR FURTHER INFORMATION CONTACT: Walter Sippel, Aerospace Engineer,

Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056; telephone (425) 227-2774; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to all Boeing Model 727-200 series

airplanes was published in the Federal Register on July 15, 1998 (63 FR

38123). That action proposed to require repetitive inspections to

detect cracks in certain areas between the upper and lower sills of the

number 1 cargo door, and repair, if necessary.

Explanation of Changes Made to the Proposal

The FAA has revised this final rule to clarify the inspection

requirement contained in the proposed AD. Whereas the proposal

specified a close visual inspection, as recommended in Boeing Service

Bulletin 727-53A0219, Revision 1, dated May 8, 1997, the FAA has

revised this final rule to clarify that its intent is to require a

detailed visual inspection. Additionally, a note has been added to the

final rule to define that inspection.

In addition, in the notice of proposed rulemaking (NPRM), the FAA

stated that this AD is considered interim action until final action is

identified, at which time the FAA may consider further rulemaking.

Since the issuance of the NPRM, the FAA has determined that no further

action is required at this time. No modification to address the unsafe

condition is currently available, and the FAA finds that the

inspections required by this AD are adequate for continued safe

operation.

Also, throughout the proposed rule, the FAA referred to Boeing

Service Bulletin 727-53A0219, Revision 1, as an ``alert'' service

bulletin. The reference to this service bulletin as an alert is

erroneous. The original issue of the service bulletin is considered an

alert service bulletin; however, the FAA does not consider Revision 1

an alert. Therefore, this final rule refers to Boeing Service Bulletin

727-53A0219, Revision 1, as ``the service bulletin.''

Comments

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

Support for the Proposal

One commenter supports the proposed rule.

Request to Allow Inspection of Each Frame Separately

One commenter states that it does not agree that a high frequency

eddy current (HFEC) inspection of both forward and aft frames should be

required within 3,000 flight cycles if a repair has only been

accomplished on one frame or the other. The commenter makes no specific

request; however, the FAA infers that the commenter is requesting to be

allowed to inspect forward and aft frames at separate intervals, if

only one of the frames has been repaired.

The FAA concurs with the commenter's request. There is no technical

reason to require inspections of repaired and non-repaired frames at

the same time. Therefore, the FAA has determined that it would be more

appropriate to allow inspection of the forward or aft frame at the

threshold corresponding to its configuration repaired or non-repaired

rather than requiring that forward and aft frames both be inspected at

the threshold for repaired structure if repair has been accomplished on

one or the other. As proposed, paragraph (c) of this AD already allows

for repeat inspections of repaired structure to be accomplished

separately, at a different interval than non-repaired structure.

Therefore, only paragraphs (a)(1), (a)(2), and (a)(3) of the final rule

have been revised accordingly.

Request to Include Instructions for Inspection

One commenter requests that either the service bulletin or the

proposed AD be revised to include instructions for the inspections to

be performed at 3,000 flight cycles. The commenter states that

[[Page 61488]]

the service bulletin includes accomplishment instructions only for the

inspections to be performed at 15,000 flight cycles.

The FAA partially concurs with the commenter's request. The FAA

notes that the access requirements and instructions for the repetitive

detailed visual inspections of the frame web are the same at both 3,000

and 15,000 flight cycles. (However, at the repetitive interval of

15,000 flight cycles, an HFEC inspection is also required.) The

instructions for the detailed visual inspection (which, as stated

previously, is identified in the service bulletin as a close visual

inspection) and HFEC inspections are defined in the Accomplishment

Instructions of the service bulletin, which references Figures 1, 2,

and 3 for additional instructions. The FAA finds that clarification of

the source of the access requirements and instructions for the detailed

visual inspection is necessary. Therefore, paragraph (a) of this final

rule has been revised to specify that the inspections are to be

accomplished in accordance with the Accomplishment Instructions of the

service bulletin.

Request to Revise Threshold for Initial Inspection of Repaired

Airplanes

One commenter requests that paragraphs (a)(2) and (a)(3) of the

proposed rule be revised to increase the threshold, for the initial

inspection of airplanes on which repairs have been accomplished

previously, from 3,000 to 30,000 flight cycles. The commenter

substantiates its request by stating that cracking has not been

detected on repaired structure on any airplane in its fleet.

The FAA does not concur with the commenter's request. The FAA has

determined that repairs accomplished previously on the affected

airplanes may not be adequate to ensure the safety of the airplane

fleet. As explained in the Discussion section of the notice of proposed

rulemaking (NPRM), cracking of repaired structure has been detected on

several airplanes. In one case, cracking of repaired structure was

detected prior to the accumulation of 3,000 flight cycles after the

repair. Based on these data, the FAA has determined that 3,000 flight

cycles represents an appropriate interval for affected airplanes to

continue to operate safely. No change to the final rule is necessary in

this regard.

Request for Justification of Inspection Threshold

One commenter requests that the FAA provide justification for the

inspection threshold stated in paragraph (a)(2) of the proposed rule.

The commenter states that paragraph (a)(2) requires an inspection

within 3,000 flight cycles after repair, and remarks that, ``It does

not seem logical to require HFEC within 3,000 cycles from repair and

then repeat at 15,000 cycle intervals.'' The commenter requests that

paragraph (a)(2) be revised to require repetitive inspections at 3,000

flight cycle intervals and HFEC inspections at 15,000 flight cycles.

The FAA does not concur. The FAA finds that the commenter

misunderstands the inspection threshold stated in paragraph (a)(2) of

the proposed rule. That paragraph requires that airplanes on which a

repair in accordance with the service bulletin has been accomplished be

inspected within 3,000 flight cycles after the effective date of this

AD, not after the installation of the repair, as the commenter

suggests. As discussed previously, the FAA has determined that repairs

accomplished previously on the affected airplanes may not be adequate

to ensure the safety of the airplane fleet. The FAA finds that a

compliance time of 3,000 flight cycles after the effective date of this

AD will provide operators with enough time to inspect repaired

structure while still ensuring that any cracks are detected in a timely

manner. No change to the final rule is necessary in this regard.

Request to Remove Requirements for FAA Approval of Repairs and

Inspections

Two commenters request that the inspection methods and intervals

for repaired airplanes be the same as those specified in the service

bulletin for non-repaired airplanes. Along with this, the commenters

request the removal of the requirement to obtain FAA-approval of

certain repairs and repetitive inspections from paragraphs (a)(3),

(b)(2), and (c)(2) of the proposed AD. The commenters contend that it

would be cost prohibitive to survey and evaluate their entire fleets

for previous repairs, and to coordinate repair and inspection methods

and intervals with Boeing and the FAA. One of the commenters further

states that it is impractical to require operators to develop special

inspection methods for each repair, and that inspection criteria for

any repair should be defined in the service bulletin or proposed AD,

and should be generic enough to apply to any repair that might exist in

the area. One of the commenters also states that the requirements for

approval of inspections and methods proposed in the NPRM were not

mentioned in the service bulletin.

The FAA does not concur with the commenters' request. As discussed

previously, the FAA has determined that repairs accomplished previously

on the affected airplanes may not be adequate to ensure the safety of

the fleet of airplanes. As stated in the Discussion section of the

NPRM, at least one incident has been reported in which a previously

repaired aft frame web and frame inner chord were found completely

severed. Therefore, the FAA finds that the affected airplanes,

including those on which repairs have been accomplished previously,

must be inspected as proposed in the NPRM.

The FAA also notes that the proposed method and inspection

intervals are the same as those specified in paragraph IV

(``Appendix'') of the service bulletin, except when the repair was

accomplished in accordance with a method approved by Boeing. (As stated

in the ``Differences Between Proposed Rule and Relevant Alert Service

Bulletin'' section of the proposal, although the service bulletin

specifies that the manufacturer be contacted for disposition of certain

repair conditions, this AD requires repair of those conditions to be

accomplished in accordance with a method approved by the FAA.) Because

a method of repair obtained from Boeing is not defined in the service

bulletin, it is unknown if the inspection procedures specified in the

service bulletin are sufficient to adequately ensure the safety of the

affected airplanes.

With regard to the commenters' contentions that developing special

inspection methods for each repair will be cost prohibitive, the FAA

finds that the commenters' concerns are based on repairs for large

areas of damage. The FAA has determined that it is not possible to

specify generic repair and inspection methods in the service bulletin

or in the AD for large areas of damage. Such repairs would be unique

because of the amount of damage that could occur. However, the FAA

anticipates that there should be few initial cases of extensive damage

for which FAA approval will be required, and after the initial

inspections, the repetitive inspections are intended to detect any

damage (i.e., cracking), before it becomes extensive. No change to the

final rule is necessary in this regard.

Request to Increase Repetitive Inspection Interval

One commenter requests that the proposed rule be revised to delete

the requirement in paragraph (c)(1) to perform an HFEC inspection of

repaired structure within 3,000 flight cycles. The commenter states

that it does not expect

[[Page 61489]]

that cracking would occur within 3,000 flight cycles after the

installation of that repair, and remarks, as stated previously, that,

``It does not seem logical to require HFEC within 3,000 cycles from

repair and then repeat at 15,000 cycle intervals.''

The FAA does not concur with the commenter's request. As discussed

in the NPRM, there is concern that repairs accomplished previously on

the affected airplanes may not be adequate to ensure the safety of the

airplane fleet. The FAA finds that a threshold of 3,000 flight cycles

after accomplishment of the repair provides operators adequate time to

inspect repaired structure and ensures that any cracking will be

detected in a timely manner. No change to the final rule is necessary

in this regard.

Request to Revise Accomplishment Instructions

Two commenters request that the proposed rule be revised to explain

that removal of certain parts (including attachment hardware and seal

retainer) is not necessary for accomplishment of the close visual

inspection. One commenter requests that the proposed AD be revised to

include a NOTE to this effect. That commenter justifies its request by

stating that removal of certain parts is not necessary to visually

inspect the frame. The other commenter expresses concern that

accomplishing the procedures associated with removing the seal

retainer--e.g., drilling fasteners through the frame, scraping sealant

and paint finishes from the frame--every 3,000 flight cycles would

increase the probability of manmade damage to the structure. The

commenter states that an inspection program in which the seal retainer

and cargo liner are not required to be removed should have about the

same damage tolerance rating as the inspection program proposed in the

NPRM, at about half the cost. The same commenter also suggests that the

repetitive inspection interval for the HFEC inspection could be reduced

from 15,000 to 6,000 flight cycles to account for not removing such

parts during the visual inspections.

The FAA does not concur with the commenters' requests. The FAA has

determined that cracking may initiate under the seal retainer and

around the number 6 door stop. The FAA finds that to gain access to the

web area to perform the detailed visual inspections, it is necessary to

remove the same parts that are removed for the detailed and HFEC

inspections of the doorway cutout frame webs, inner and outer chords,

bear strap, and skin panel.

With regard to the commenter's concern about increasing the risk of

structural damage, the FAA acknowledges that such removal of parts does

increase the risk of manmade damage. However, the risk of such manmade

damage must be balanced with the necessity to detect and correct

operational damage such as that the inspections associated with this AD

is intended to detect. In this case, the manufacturer's recommendation,

as contained in the service bulletin, is for the removal of the seal

retainer and the cargo liner. In consideration of the manufacturer's

recommendation, as well as the nature and location of known cracking,

the FAA has determined that it is necessary to remove such parts for

the detailed visual and HFEC inspections.

With regard to the commenter's assertion that an inspection program

that doesn't require removal of the seal retainer and cargo liner

``should'' have the same damage tolerance rating as the inspection

program proposed in the NPRM, the FAA finds that the commenter provides

no technical justification for such a claim. However, should the

commenter develop an inspection procedure that can be shown to provide

an adequate level of safety, the commenter may apply for approval of an

alternative method of compliance in accordance with paragraph (d) of

this AD.

No change to the final rule is necessary in this regard.

Request to Allow Credit for Inspections Accomplished Previously

Two commenters request that credit be given for inspections

performed previously. The commenters state that the actions specified

in the proposed AD have been accomplished prior to the effective date

of this AD. One of the commenters specifically requests that the

compliance time for the initial inspection be extended from 3,000

flight cycles after the effective date of this AD to 4,000 flight

cycles after the effective date of this AD, if inspections have been

accomplished in accordance with Boeing Service Bulletin 727-53A0219,

Revision 1, dated May 8, 1997. The commenter justifies its request by

stating that it has found no crack on any affected airplane in its

fleet. The commenter's rationale is that accomplishing the inspection

at the threshold proposed in the NPRM would be very costly because it

would impact the operator's normal maintenance schedules.

The FAA does not concur that a change to the final rule is

necessary to give credit for work accomplished previously. With regard

to inspections accomplished prior to the effective date of this AD,

operators are always given credit for work accomplished previously, by

means of the phrase in the compliance section of the AD that reads

``required as indicated, unless accomplished previously.''

The FAA does not concur with the commenter's request for an

extension of the compliance time from 3,000 to 4,000 flight cycles

after the effective date of this AD. The FAA has determined that an

interval of 4,000 flight cycles would not address the identified unsafe

condition in a timely manner. Though the commenter has not found

cracking on any airplanes in its fleet, other operators have. The FAA

finds the proposed compliance time of 3,000 flight cycles for

initiating the required actions to be warranted, in that it represents

an appropriate interval of time allowable for affected airplanes to

continue to operate without compromising safety. No change to the final

rule is necessary in this regard.

Request to Revise Supplemental Structural Inspection Document

(SSID)

One commenter, who otherwise supports the proposed rule, notes that

the area subject to the proposed inspections is already subject to

inspections in accordance with AD 98-11-03, amendment 39-10530 (63 FR

27455, May 19, 1998), which is the Supplemental Structural Inspection

Program (SSIP) AD. The commenter therefore requests that the inspection

be deleted from the SSIP.

The FAA finds that no change to the final rule is necessary in this

regard. Boeing, not the FAA, is responsible for revisions to the SSID.

However, the FAA will suggest to Boeing that, in the next revision to

the SSID, the inspections required by this AD should be deleted from

the SSID, and the service bulletin referenced by this AD should be

added to Section 9 of the SSID, as provided for by the SSIP.

Request to Simplify the Format of the AD

One commenter requests that the proposed rule be revised to

simplify the format. The commenter provided an example of how the

proposed AD could be simplified; however, no justification is given for

the commenter's request.

The FAA does not concur with the commenter's request. The FAA

infers from the comment that the commenter finds the format of the

proposed AD difficult to follow. The FAA acknowledges that there are

certain complexities to the AD. However, as described in the preamble

of the NPRM,

[[Page 61490]]

this AD differs from the service bulletin only in the fact that repair

of certain conditions would be required to be accomplished in

accordance with the method approved by the FAA rather than the

manufacturer. This AD is intended to ensure that cracking is detected

in a timely manner on both repaired and unrepaired airplanes. Based on

the reports of cracking that the FAA has received, which were described

in the preamble of the proposed rule, the FAA finds that the

commenter's proposed format would not ensure that any cracking would be

detected in a timely manner. No change to the final rule is necessary

in this regard.

Request to Revise Cost Impact

One commenter, who otherwise supports the proposed rule, requests

that the cost of necessary repairs be included in the cost impact of

the proposed AD. The commenter states that the cost impact does not

include the time required to install repairs if cracking is found

during an inspection.

The FAA does not concur with the commenter's request. The cost

impact of the AD is limited only to the cost of actions actually

required by the rule. It does not consider the costs of ``on

condition'' actions (that is, actions taken to correct an unsafe

condition if found), because those actions would be required to be

accomplished, regardless of AD direction, in order to correct an unsafe

condition identified in an airplane and to ensure operation of that

airplane in an airworthy condition, as required by the Federal Aviation

Regulations. No change to the final rule is necessary in this regard.

Conclusion

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the changes described

previously. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

Cost Impact

There are approximately 1,100 airplanes of the affected design in

the worldwide fleet. The FAA estimates that 770 airplanes of U.S.

registry will be affected by this AD, that it will take approximately

60 work hours per airplane to accomplish the required inspections, and

that the average labor rate is $60 per work hour. Based on these

figures, the cost impact of the inspections required by this AD on U.S.

operators is estimated to be $2,772,000, or $3,600 per airplane, per

inspection cycle.

The cost impact figure discussed above is based on assumptions that

no operator has yet accomplished any of the 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 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 not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) will not have a

significant economic impact, positive or negative, on a substantial

number of small entities under the criteria of the Regulatory

Flexibility Act. A final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it 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, Incorporation by

reference, 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 adding the following new

airworthiness directive:

99-23-13 Boeing: Amendment 39-11409. Docket 97-NM-227-AD.

Applicability: All Model 727-200 series airplanes, 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 (d) 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 detect and correct fatigue cracking between the upper and

lower sills of the number 1 cargo door, which could result in rapid

decompression of the fuselage and consequent reduced structural

integrity of the airplane, accomplish the following:

Initial Inspection

(a) Perform a detailed visual inspection or a high frequency

eddy current (HFEC) inspection (as applicable) to detect cracks in

the forward and aft frames (web, inner chord, and outer chord), bear

strap, and fuselage skin between the upper and lower sills of the

number 1 cargo door at BS 560 and BS 620. Accomplish the inspection

at the time specified in paragraph (a)(1), (a)(2), or (a)(3) of this

AD, as applicable.

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

(1) For any forward or aft frame (web, inner chord, and outer

chord), bear strap, or fuselage skin that has not been repaired in

accordance with Boeing Service Bulletin 727-53A0219, Revision 1,

dated May 8, 1997: Inspect prior to the accumulation of 30,000 total

flight cycles, or within 3,000 flight cycles after the effective

date of this AD, whichever occurs later, in accordance with the

Accomplishment Instructions of the service bulletin.

(2) For any forward or aft frame (web, inner chord, and outer

chord) that has been repaired in accordance with Boeing Service

Bulletin 727-53A0219, Revision 1, dated May 8, 1997: Inspect within

3,000 flight cycles after the effective date of this AD, in

accordance with the Accomplishment Instructions of the service

bulletin.

(3) For any bear strap, fuselage skin, or a combination of the

frame web and chord (inner or outer) on either the forward or aft

frame that has been repaired in accordance with Boeing Service

Bulletin 727-53A0219, Revision 1, dated May 8, 1997: Inspect within

3,000 flight cycles after the effective date of this AD, in

accordance with a method

[[Page 61491]]

approved by the Manager, Seattle Aircraft Certification Office

(ACO), FAA, Transport Airplane Directorate.

Note 3: Where there are differences between this AD and the

referenced service bulletin, the AD prevails.

Note 4: The inspections specified in paragraph (a)(3) of this AD

are not defined in the service bulletin.

Repetitive Inspections

(b) If no crack is detected during any inspection required by

paragraph (a) of this AD, accomplish paragraph (b)(1) or (b)(2) of

this AD, as applicable.

(1) For any forward or aft frame (web, inner chord, and outer

chord), bear strap, or fuselage skin identified in paragraphs (a)(1)

and (a)(2) of this AD: Repeat the detailed visual and HFEC

inspections required by paragraph (a) of this AD thereafter at the

times specified in paragraphs (b)(1)(i) and (b)(1)(ii) of this AD.

(i) Repeat the detailed visual inspection of the frame web at

intervals not to exceed 3,000 flight cycles.

(ii) Repeat the detailed visual and HFEC inspections (as

applicable) of the frame web, frame inner and outer chords, bear

strap, and fuselage skin thereafter at intervals not to exceed

15,000 flight cycles.

(2) For any bear strap, fuselage skin, or a combination of the

frame web and chord (inner or outer) on either the forward or aft

frame identified in paragraph (a)(3) of this AD: Repeat the

inspections of the repaired bear strap, fuselage skin, or

combination of a repaired frame web and chord (inner or outer)

thereafter at intervals not to exceed those approved by the Manager,

Seattle ACO.

Repair

(c) If any crack is detected during any inspection required by

paragraph (a) of this AD, prior to further flight, accomplish

paragraph (c)(1) or (c)(2) of this AD, as applicable.

(1) For any crack detected in the frame web, inner chord, or

outer chord: Repair in accordance with Boeing Service Bulletin 727-

53A0219, Revision 1, dated May 8, 1997. Prior to the accumulation of

3,000 flight cycles after accomplishment of the repair, accomplish

the detailed visual and HFEC inspections specified in paragraph (a)

of this AD. Repeat the detailed visual inspection of the frame web

thereafter at intervals not to exceed 3,000 flight cycles. Repeat

the detailed visual and HFEC inspections (as applicable) of the

frame web, inner chord, and outer chord thereafter at intervals not

to exceed 15,000 flight cycles.

(2) For any crack detected in the fuselage skin, bear strap, or

a combination of the frame web and chord (inner or outer): Repair

and perform repetitive inspections in accordance with both a method

and repetitive inspection interval approved by the Manager, Seattle

ACO.

Note 5: The repairs and inspections specified in paragraph

(c)(2) of this AD are not defined in the service bulletin.

Alternative Methods of Compliance

(d) 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 ACO. 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

(e) 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.

Incorporation by Reference

(f) Except as provided by paragraphs (a)(3), (b)(2), and (c)(2)

of this AD, the actions shall be done in accordance with Boeing

Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997. This

incorporation by reference was approved by the Director of the

Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part

51. Copies may be obtained from Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be

inspected at the FAA, Transport Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on December 17, 1999.

Issued in Renton, Washington, on November 3, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-29329 Filed 11-10-99; 8:45 am]

BILLING CODE 4910-13-P