Airworthiness Directives; Boeing Model 767 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-278-AD; Amendment 39-11316; AD 99-19-29]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 767 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 certain Boeing Model 767 series airplanes, that requires

repetitive inspections of certain H-11 tension bolts at each side-of-

body kick-load fitting and on the lower splice plate (both located on

the wing rear spar) to detect damaged or broken bolts; and follow-on

actions, if necessary. This amendment also requires eventual

replacement of the existing bolts with new, improved bolts, which

constitutes terminating action for the repetitive inspections. This

amendment is prompted by a report that an operator found two broken H-

11 tension bolts on the side-of-body kick-load fitting on one airplane.

The actions specified by this AD are intended to prevent cracking of

the bolts due to stress corrosion, which could result in reduced

structural integrity of the wing-to-body joint structure.

DATES: Effective October 20, 1999.

The incorporation by reference of certain publications listed in

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

of October 20, 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: James G. Rehrl, Aerospace Engineer,

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

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

Washington 98055-4056; telephone (425) 227-2783; 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 certain Boeing Model 767 series

airplanes was published in the Federal Register on November 23, 1998

(63 FR 64657). That action proposed to require repetitive inspections

of certain H-11 tension bolts at each side-of-body kick-load fitting

and on the lower splice plate (both located on the wing rear spar) to

detect damaged, broken, or improperly sealed bolts; and follow-on

actions, if necessary. That action also proposed to require eventual

replacement of the existing bolts with new, improved bolts, which

constitutes terminating action for the repetitive inspections.

Comments

Interested persons have been afforded an opportunity to participate

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

the four comments received.

Two commenters support the proposed rule, and one commenter does

not object to the proposed rule.

Editorial Changes to the Final Rule

The FAA has determined that it is necessary to clarify the detailed

visual inspection of paragraph (a)(1) of the requirements of this AD.

The FAA has added the words ``of the bolts,'' to further clarify the

inspection area. The final rule has been changed accordingly.

Request to Delete Certain Descriptive Language

One commenter, the manufacturer, requests that the FAA delete the

words ``improperly sealed'' from paragraphs (a) and (b) of the proposed

AD. The commenter states that because the most significant influence of

the H-11 bolt fracture is the presence of high pre-load, which cannot

be determined by inspection, any anomalies in the bolt sealant will

have no effect on the bolt fracture, unless the bolt is highly pre-

loaded. The commenter also suggests that using the condition of the H-

11 bolt sealant as a guide for bolt replacement will cause unnecessary,

unscheduled airplane down time and confusion, as it is likely that

improperly sealed bolts will be found. The commenter further adds that

a clear definition of an ``improperly sealed bolt'' is not provided in

either the Boeing Service Bulletin or the Notice of Proposed Rulemaking

(NPRM).

The FAA concurs with the request to delete certain descriptive

language of the AD, as requested by the commenter. The FAA has revised

this language throughout the final rule.

Request to Revise the Compliance Time for the Terminating Action

One commenter requests that the FAA revise the proposed compliance

time for the terminating action from 6,000 flight cycles to 9,000

flight cycles. The commenter states that the issue of H-11 bolts

fracture is more dependent on calendar time rather than flight cycles.

This additional allowance of time would provide high cycle usage

operators an equivalent of 48 months calendar time that is provided for

low cycle usage operators.

The FAA concurs with this request, and has revised paragraph (c) of

the final rule accordingly.

Explanation of Change Made to Proposal

The FAA has added a note to the final rule to clarify the

definition of a detailed visual inspection.

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 previously

described. 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 177 Model 767 series airplanes of the

affected design in the worldwide fleet. The FAA estimates that 70

airplanes of U.S. registry will be affected by this AD.

It will take approximately 2 work hours per airplane to accomplish

the required inspection of the kick-load fitting, at an average labor

rate of $60 per work hour. Based on these figures, the cost impact of

the inspection of the kick-load fitting required by this AD on U.S.

operators is estimated to be $8,400, or $120 per airplane, per

inspection cycle.

It will take approximately 23 work hours per airplane to accomplish

the required inspection of the splice plate, at an average labor rate

of $60 per work hour. Based on these figures, the cost impact of the

inspection of the splice plate required by this AD on U.S.

[[Page 49978]]

operators is estimated to be $96,600, or $1,380 per airplane, per

inspection cycle.

It will take approximately 140 work hours per airplane to

accomplish the required replacement, at an average labor rate of $60

per work hour. Parts will be provided by the manufacturer at no cost to

the operators. Based on these figures, the cost impact of the

replacement required by this AD on U.S. operators is estimated to be

$588,000, or $8,400 per airplane.

The cost impact figures discussed above are 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:

99-19-29 Boeing: Amendment 39-11316. Docket 98-NM-278-AD.

Applicability: Model 767 series airplanes, line positions 1

through 177 inclusive, 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 prevent cracking of the H-11 tension bolts on the side-of-

body kick-load fitting due to stress corrosion, which could result

in reduced structural integrity of the wing-to-body joint structure,

accomplish the following:

(a) Within 90 days after the effective date of this AD: Perform

a detailed visual inspection of the four H-11 tension bolts at each

side-of-body kick-load fitting located on the wing rear spar to

detect damaged or broken bolts; and accomplish the requirements in

either paragraph (a)(1) or (a)(2) of this AD, in accordance with the

Accomplishment Instructions of Boeing Service Bulletin 767-57A0064,

Revision 1, dated July 9, 1998.

(1) Option 1: Repeat the detailed visual inspection of the bolts

at each side-of-body kick-load fitting thereafter at intervals not

to exceed 90 days, until accomplishment of the actions specified in

paragraph (c) of this AD. Or

(2) Option 2: Perform a detailed visual inspection of the four

H-11 tension bolts on the lower splice plate located on the wing

rear spar to detect damaged or broken bolts. Repeat the detailed

inspection of each side-of-body kick-load fitting and the lower

splice plate thereafter at intervals not to exceed 18 months, until

accomplishment of the actions specified in paragraph (c) of this AD.

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.''

(b) If evidence of any damaged or broken bolt is detected, prior

to further flight, replace the discrepant bolt with a new, improved

bolt in accordance with Boeing Service Bulletin 767-57A0064,

Revision 1, dated July 9, 1998. Thereafter, repeat the detailed

inspection in either paragraph (a)(1) or (a)(2) of this AD, as

applicable, until accomplishment of the actions specified in

paragraph (c) of this AD.

(c) Within 9,000 flight cycles or 48 months after the effective

date of this AD, whichever occurs first, replace all four H-11

tension bolts at each side-of-body kick-load fitting with new,

improved bolts, and perform a detailed visual inspection to detect

any damaged or broken bolt of the lower splice plate located on the

wing rear spar, in accordance with Boeing Service Bulletin 767-

57A0064, Revision 1, dated July 9, 1998. If any damaged or broken

bolt is detected during the inspection, prior to further flight,

replace the discrepant bolt with a new, improved bolt in accordance

with Boeing Service Bulletin 767-57A0064, Revision 1, dated July 9,

1998. Accomplishment of the actions specified in this paragraph

constitutes terminating action for the repetitive inspection

requirements of this AD.

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 Aircraft Certification

Office (ACO), FAA, Transport Airplane Directorate. Operators shall

submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Seattle ACO.

Note 3: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Seattle ACO.

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) The inspections and replacements shall be done in accordance

with Boeing Service Bulletin 767-57A0064, Revision 1, dated July 9,

1998. 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 October 20, 1999.

[[Page 49979]]

Issued in Renton, Washington, on September 2, 1999.

Dorenda D. Baker,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-23471 Filed 9-14-99; 8:45 am]

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