Airworthiness Directives; Boeing Model 727 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-73-AD; Amendment 39-8842, AD 94-05-04]

Airworthiness Directives; Boeing Model 727 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 727 series airplanes, that requires

incorporation of certain structural modifications. This amendment is

prompted by an evaluation by the Model 727 Structures Working Group,

comprised of aircraft operators, manufacturers, and the FAA. This

Working Group evaluated Boeing service bulletins that must be included

as part of the ``Aging Airplane Structural Modification Program.'' The

actions specified by this AD are intended to prevent degradation in the

structural capabilities of the affected airplanes. The actions also

reflect the FAA's decision that long term continued operational safety

should be assured by actual modification of the airframe rather than

repetitive inspections.

DATES: Effective April 21, 1994.

The incorporation by reference of certain publications listed in

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

of April 21, 1994.

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 (206) 227-2774; fax (206) 227-1181.

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

Aviation Regulations to include an airworthiness directive (AD) that is

applicable to certain Boeing Model 727 series airplanes was published

in the Federal Register on August 31, 1993 (58 FR 45861). That action

proposed to require incorporation of certain structural modifications.

Interested persons have been afforded an opportunity to participate

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

the comments received.

One commenter supports the proposed rule.

One commenter requests that the FAA issue one rulemaking action

that would combine the requirements of this proposal, which proposes to

require the modifications listed in Boeing Document Number D6-54860,

``Aging Airplane Service Bulletin Structural Modification and

Inspection Program--Model 727,'' Revision G, dated March 5, 1993, with

the proposal to require the inspections listed in that Boeing Document.

That rulemaking action was proposed in AD Docket 93-NM-72-AD (58 FR

45863, August 31, 1993). This commenter requests that these two

rulemaking actions be combined with AD 90-06-09, Amendment 39-6488 (55

FR 8370, March 7, 1990), which references Revision C, of Boeing

Document Number D6-54860, dated December 11, 1989, for purposes of

easing operators' tracking compliance with these three separate

rulemaking actions. The FAA does not concur. The FAA's normal policy in

this regard is that when an AD requires a substantive change, such as a

change in the existing AD's requirements, the existing AD (AD 90-06-09)

is superseded by being removed from the system and a new AD added.

However, to supersede the existing AD and replace it with a new one

having a new AD number, would serve no purpose in terms of the ability

of affected operators to track compliance with the AD and maintain

accurate records of compliance. In consideration of the consequent

workload associated with revising maintenance records to enter new AD

numbers to demonstrate compliance with requirements accomplished

previously, the FAA has determined that a less burdensome approach is

to issue a separate AD. This final rule is issued as a separate AD

action since combining these rulemaking actions would necessitate

recordkeeping changes to reflect new AD numbers. The FAA does not

intend to supersede or revise AD 90-06-09. As such, the modifications

required by this AD do not supersede the requirements of AD 90-06-09;

operators must continue to comply with the requirements of that AD.

Furthermore, the FAA's intent in keeping the requirement to accomplish

the inspections listed in the Boeing Document separated from the

requirement to accomplishment the modifications listed in the Boeing

Document was to minimize the recordkeeping burden to the operators;

i.e., operators will not be required to make recordkeeping changes to

their inspection entries whenever revisions are made to modification

requirements and vice versa.

Several commenters request that proposed paragraph (a) be revised

to clarify that only the structural modifications listed in Appendices

A.3, B.3, and C.3 of the Boeing Document must be accomplished. Since

the proposal stated that the modifications were listed in ``Section 3

and Appendices A., B., and C.,'' of the Boeing Document, these

commenters contend that the possibility exists for misinterpretation.

Section 3 of the Boeing Document lists structural modifications that

are required by AD 90-06-09 and Appendices A. and B. list structural

inspections that are included in AD Docket 93-NM-72-AD (58 FR 45863,

August 31, 1993), which proposes to require structural inspections of

older airplanes. The FAA concurs. The FAA finds that these commenters'

suggestion to reference the specific appendices of the Boeing Document

(rather than the generalization cited in the proposal) would avoid any

possibility for misinterpretation. Therefore, paragraph (a) of the

final rule has been revised accordingly.

One commenter requests that the proposal be revised to permit

deviations to the modifications required by proposed paragraph (a) to

be accomplished in accordance with FAA-approved data, e.g., Structural

Repair Manuals; FAA Form 8110-3, Statement of Compliance with the

Federal Aviation Regulations; etc. The commenter's intent for

requesting this change is to gain authorization to make minor

deviations, such as oversizing fasteners and substituting materials,

without obtaining approval for an alternative method of compliance for

each deviation. The FAA does not concur. The FAA has determined that

the Manager, Seattle Aircraft Certification Office, must approve any

such deviations to the AD's requirements. Given that possible new

relevant issues might be revealed during this process, it is imperative

that the FAA, at this level, have such feedback. Only by reviewing

deviation approvals can the FAA be assured of this feedback and of the

adequacy of the repair methods. However, when the FAA has obtained an

adequate sampling of the quality, type, and extent of repairs being

made as a result of this AD, the FAA anticipates that it will, at some

future date, authorize manufacturer's Designated Engineering

Representatives to approve minor deviations to the modifications

required by this final rule, as it has done in the past regarding the

requirements of AD 90-06-09, and other aging fleet AD's.

One commenter noted that the economic impact information in the

proposal reflects an extremely low estimate ($55 per work hour) of the

labor rate incurred by industry. This commenter stated that a more

realistic labor rate would be in the range of $60 to $100 per work

hour. From this comment, the FAA infers that the commenter is

requesting that the economic impact information be revised and computed

using a higher labor rate figure. The FAA does not concur. The figure

of $55 per work hour used in the economic impact information, below,

was based upon data provided to the FAA by various operators in

industry. As such, the FAA uses this figure based upon the best data

available to date.

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 change previously

described. The FAA has determined that this change will neither

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

the AD.

There are approximately 1,635 Model 727 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 within the

initial threshold of 4 years. The cost to modify each airplane is

estimated to be $260,155. This cost includes the price of modification

kits, which is $186,180 per airplane, and the estimated number of work

hours to accomplish the modifications, which is 1,345 work hours at $55

per work hour. It does not include downtime, planning, set up,

familiarization, or tool acquisition costs. Based on these figures, the

total cost impact of the AD on U.S. operators is estimated to be

$18,210,850 over the 4-year time period.

The total 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.

The FAA recognizes that the obligation to maintain aircraft in an

airworthy condition is vital, but sometimes expensive. Because AD's

require specific actions to address specific unsafe conditions, they

appear to impose costs that would not otherwise be borne by operators.

However, because of the general obligation of operators to maintain

aircraft in an airworthy condition, this appearance is deceptive.

Attributing those costs solely to the issuance of this AD is

unrealistic because, in the interest of maintaining safe aircraft, most

prudent operators would accomplish the required actions even if they

were not required to do so by the AD.

A full cost-benefit analysis has not been accomplished for this AD.

As a matter of law, in order to be airworthy, an aircraft must conform

to its type design and be in a condition for safe operation. The type

design is approved only after the FAA makes a determination that it

complies with all applicable airworthiness requirements. In adopting

and maintaining those requirements, the FAA has already made the

determination that they establish a level of safety that is cost-

beneficial. When the FAA, as in this AD, makes a finding of an unsafe

condition, this means that this cost-beneficial level of safety is no

longer being achieved and that the required actions are necessary to

restore that level of safety. Because this level of safety has already

been determined to be cost-beneficial, a full cost-benefit analysis for

this AD would be redundant and unnecessary.

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 14 CFR part

39 of the Federal Aviation Regulations as follows:

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PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-05-04 Boeing: Amendment 39-8842. Docket 93-NM-73-AD.

Applicability: Model 727 series airplanes, as listed in Boeing

Document D6-54860, ``Aging Airplane Service Bulletin Structural

Modification and Inspection Program--Model 727,'' Revision G, dated

March 5, 1993; certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent structural failure, accomplish the following:

(a) Prior to reaching the incorporation thresholds listed in

Boeing Document Number D6-54860, ``Aging Airplane Service Bulletin

Structural Modification and Inspection Program--Model 727,''

Revision G, dated March 5, 1993, or within the next 4 years after

the effective date of this AD, whichever occurs later, accomplish

the structural modifications listed in Appendices A.3, B.3, and C.3

of the Boeing Document.

Note 1: The modifications required by this paragraph do not

terminate the inspection requirements of any other AD unless that AD

specifies that any such modification constitutes terminating action

for the inspection requirements.

(b) 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.

(c) Special flight permits may be issued in accordance with

Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the

airplane to a location where the requirements of this AD can be

accomplished.

(d) The modifications shall be done in accordance with Boeing

Document Number D6-54860, ``Aging Airplane Service Bulletin

Structural Modification and Inspection Program--Model 727,''

Revision G, dated March 5, 1993, which contains the following list

of effective pages:

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Revision sym

Page No. shown on Date shown on page

page

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List of active pages, pages G (These pages are not dated.)

c.1 and c.2.

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---Note: The issue date of this document is indicated only on

page d.7; no other page of the document is dated.

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.

(e) This amendment becomes effective on April 21, 1994.

Issued in Renton, Washington, on February 18, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-4276 Filed 3-21-94; 8:45 am]

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