Airworthiness Directives; Boeing Model 727 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-121-AD; Amendment 39-11199; AD 99-12-52]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 727 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment

adopting Airworthiness Directive (AD) T99-12-52 that was sent

previously to all known U.S. owners and operators of all Boeing Model

727 series airplanes by individual telegrams. This AD requires a boost

pump dry bay inspection to detect leakage of fuel through an arced-

through conduit, and corrective action, as necessary. This AD also

requires repetitive detailed visual inspections of the in-tank fuel

boost pump wiring to detect chafing of the wire insulation, evidence of

electrical arcing, or arc-through of the conduit wall on Model 727

series airplanes, and applicable corrective action; and installation of

sleeving over the in-tank fuel boost pump wires as a method to protect

the wiring from chafing. This action is prompted by reports of severe

wear of in-tank fuel boost pump wiring, and arc-through of the

surrounding conduit on two Model 727 series airplanes. The actions

specified by this AD are intended to prevent fuel tank explosion

resulting from arc-through of the fuel boost pump wiring conduits.

DATES: Effective June 28, 1999, to all persons except those persons to

whom

[[Page 33395]]

it was made immediately effective by telegraphic AD T99-12-52, issued

May 24, 1999, which contained the requirements of this amendment.

The incorporation by reference of certain publications listed in

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

of June 28, 1999.

Comments for inclusion in the Rules Docket must be received on or

before August 23, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 99-NM-121-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056.

The applicable service information 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; or at the

Office of the Federal Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Jon Regimbal, Aerospace Engineer,

Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,

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

Washington 98055-4056; telephone (425) 227-2687; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Issuance of Telegraphic AD T99-12-51

On May 21, 1999, the FAA issued telegraphic AD T99-12-51, which is

applicable to all Boeing Model 727 series airplanes, to require a boost

pump dry bay inspection to detect leakage of fuel through an arced-

through conduit, and corrective action, as necessary.

Telegraphic AD T99-12-51 was prompted by reports of severe wear of

the in-tank fuel boost pump wiring, and arc-through of the surrounding

conduit on two Model 727 series airplanes that had accumulated in

excess of 50,000 total flight hours. The wear and arc-through condition

of the conduit surrounding the in-tank fuel boost pump wiring has been

attributed to chafing between the in-tank fuel boost pump wiring and

the wall of the surrounding conduit, exposing the electrical conductor

of the boost pump power wire and placing it in contact with the

aluminum wall of the conduit, resulting in arc-through of the conduit

wall. Arc-through of the conduit presents an ignition source inside the

fuel tank. In addition, the resultant hole in the conduit provides a

path for fuel to leak from the fuel tank. The actions required by

telegraphic AD T99-12-51 were intended to detect and correct fuel boost

pump wiring conduits which have experienced severe chafing and

electrical arcing, resulting in burn-through of the conduit. This

condition, if not corrected, could result in ignition of fuel vapors in

a fuel tank, and a fuel tank explosion.

Issuance of Telegraphic AD T99-12-52

On May 24, 1999, the FAA issued telegraphic AD T99-12-52,

applicable to all Model 727 series airplanes, which superseded

telegraphic AD T99-12-51 to continue to require a boost pump dry bay

inspection to detect leakage of fuel through an arced-through conduit,

and corrective action, as necessary.

Telegraphic AD T99-12-52 adds a requirement for repetitive detailed

visual inspections of the in-tank fuel boost pump wiring to detect

chafing of the wire insulation, evidence of electrical arcing, or arc-

through of the conduit wall on Model 727 series airplanes, and

applicable corrective action. In addition, this telegraphic AD requires

installation of sleeving over the in-tank fuel boost pump wires as a

method to protect the wiring from chafing. If the initial inspection of

the wiring is performed before the inspection of the fuel boost pump

dry bay for fuel leaks, the inspection of the fuel boost pump dry bay

for fuel leaks is not required.

Telegraphic AD T99-12-52 was prompted by the same reports that are

described in the Summary of this AD and in telegraphic AD T99-12-51.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin

727-28A0126, dated May 24, 1999, which describes procedures for

performing a boost pump dry bay inspection to detect leakage of fuel

through an arced-through conduit. That alert service bulletin also

describes procedures for performing detailed inspections of the in-tank

fuel boost pump wire bundles, installing wire bundle sleeving,

replacing the conduit if fuel leakage is detected, and performing

applicable corrective actions. In addition, the alert service bulletin

describes procedures for performing leak checks of the replaced conduit

and installing the new fuel boost pump wire.

Explanation of Requirements of the Rule

Since the unsafe condition described is likely to exist or develop

on other airplanes of the same type design, the FAA issued telegraphic

AD T99-12-52 to prevent fuel tank explosion resulting from arc-through

of the fuel boost pump wiring conduits. This AD supersedes telegraphic

AD T99-12-51 to continue to require a boost pump dry bay inspection to

detect leakage of fuel through an arced-through conduit, and corrective

action, as necessary. This AD adds a requirement for repetitive

detailed visual inspections of the in-tank fuel boost pump wiring to

detect chafing of the wire insulation, evidence of electrical arcing,

or arc-through of the conduit wall on Model 727 series airplanes, and

applicable corrective action. In addition, this AD requires

installation of sleeving over the in-tank fuel boost pump wires as a

method to protect the wiring from chafing. If the initial inspection of

the wiring is performed before the inspection of the boost pump dry bay

for fuel leaks, the inspection of the fuel boost pump dry bay for fuel

leaks is not required.

Except as described in the ``Differences'' paragraph below, the

actions are required to be accomplished in accordance with Boeing All

Operator Message (AOM) M-7200-99-04035, dated May 21, 1999, (for the

boost pump dry bay inspection), and Boeing Alert Service Bulletin 727-

28A0126, dated May 24, 1999, (for the boost pump dry bay inspection and

the wiring inspection).

Differences Between This AD and the Service Information

Although the Boeing AOM describes general procedures for inspecting

the fuel boost pump wire bundles and installing new fuel boost pump

wire bundles and sleeving, the FAA considers that use of the more

specific instructions included in Boeing Alert Service Bulletin 727-

28A0126, dated May 24, 1999, is necessary to ensure that the wire

inspections are performed properly.

However, if the wire bundle inspection or wire bundle replacement

has been accomplished in accordance with the Boeing AOM, these actions

may provide the basis for an alternative method of compliance as

provided in paragraph (l) of this AD.

Since it was found that immediate corrective action was required,

notice and opportunity for prior public comment thereon were

impracticable and contrary to the public interest, and good cause

existed to make the AD effective immediately by individual telegrams

issued on May 24, 1999, to all known U.S. owners and operators of all

Model 727 series airplanes. These conditions still exist, and the AD is

hereby published in the Federal

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Register as an amendment to section 39.13 of the Federal Aviation

Regulations (14 CFR 39.13) to make it effective to all persons.

Explanation of Changes Made to the Final Rule

The FAA has determined that reference to a certain paragraph that

was included in the ``Differences'' paragraph and in NOTE 1 of

Telegraph AD T99-12-52 is incorrect. The FAA has revised this AD to

correctly reference paragraph (l) instead of paragraph (e).

Interim Action

In the preamble to AD T99-12-51, the FAA indicated that the actions

required by that AD were considered ``interim action'' and that further

rulemaking action was being considered. The FAA now has determined that

further rulemaking action is indeed necessary, and this AD follows from

that determination.

Comments Invited

Although this action is in the form of a final rule that involves

requirements affecting flight safety and, thus, was not preceded by

notice and an opportunity for public comment, comments are invited on

this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All

communications received on or before the closing date for comments will

be considered, and this rule may be amended in light of the comments

received. Factual information that supports the commenter's ideas and

suggestions is extremely helpful in evaluating the effectiveness of the

AD action and determining whether additional rulemaking action would be

needed.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the rule that might

suggest a need to modify the 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 that

summarizes each FAA-public contact concerned with the substance of this

AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this rule must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 99-NM-121-AD.'' The postcard will be date stamped and

returned to the commenter.

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.

The FAA has determined that this regulation is an emergency

regulation that must be issued immediately to correct an unsafe

condition in aircraft, and that it is not a ``significant regulatory

action'' under Executive Order 12866. It has been determined further

that this action involves an emergency regulation under DOT Regulatory

Policies and Procedures (44 FR 11034, February 26, 1979). If it is

determined that this emergency regulation otherwise would be

significant under DOT Regulatory Policies and Procedures, a final

regulatory evaluation will be prepared and placed in the Rules Docket.

A copy of it, if filed, 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:

99-12-52 Boeing: Amendment 39-11199. Docket 99-NM-121-AD.

Supersedes Telegraphic AD T99-12-51.

Applicability: All Model 727 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 (l) 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 fuel tank explosion resulting from arc-through of the

fuel boost pump wiring conduits, accomplish the following:

(a) For airplanes with 50,000 or more total flight hours as of

the date of receipt of AD T99-12-51, within 5 days after the

effective date of this AD, accomplish the requirements of paragraph

(c) of this AD.

(b) For airplanes with less than 50,000 total flight hours as of

the date of receipt of AD T99-12-51, prior to the accumulation of

30,000 total flight hours, or within 10 days after receipt of this

AD, whichever occurs later, accomplish the requirements of paragraph

(c) of this AD.

Initial Inspection and Corrective Action

(c) Except as provided in paragraphs (d) and (e) of this AD,

perform a boost pump dry bay inspection and applicable follow-on

corrective actions, in accordance with steps 1 through 6 of the

``Boost Pump Dry Bay Inspection,'' specified in Boeing All Operator

Message M-7200-99-04035, dated May 21, 1999, or in accordance with

Boeing Alert Service Bulletin 727-28A0126, dated May 24, 1999.

(d) For airplanes on which the actions specified in step 5-E-

of Boeing All Operator Message M-7200-99-04035, dated May 21, 1999,

are accomplished, the fuel tank in which the conduit has been

replaced must be refueled prior to accomplishing step 6.

(e) Accomplishment of the requirements of paragraph (c) of this

AD is not required if the requirements of paragraph (i) of this AD

are accomplished within the times specified in paragraph (a) or (b)

of this AD, as applicable.

New Requirements of This AD

(f) For airplanes with 50,000 or more total flight hours as of

the effective date of this AD, within 20 days after the effective

date of this AD, accomplish the requirements of paragraph (i) of

this AD.

(g) For airplanes with less than 50,000 total flight hours, but

more than 30,000 total flight hours, as of the effective date of

this AD, within 30 days after the effective date of this AD,

accomplish the requirements of paragraph (i) of this AD.

(h) For airplanes with 30,000 total flight hours or fewer, as of

the effective date of this AD, within 90 days after the effective

date of this AD, accomplish the requirements of paragraph (i) of

this AD.

[[Page 33397]]

Detailed Visual Inspection, Corrective Action, and Installation

(i) Perform a detailed visual inspection of the in-tank fuel

boost pump wire bundles, and applicable corrective actions; and,

except as provided in paragraph (j) of this AD, install sleeving

over the wire bundles; in accordance with Boeing Alert Service

Bulletin 727-28A0126, dated May 24, 1999.

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 mirrors, magnifying lenses, etc. may be used. Surface cleaning

and elaborate access procedures may be required.

Installation: Possible Deferral

(j) Installation of sleeving over the wire bundles, as required

by paragraph (i) of this AD, may be deferred if, within 18 months or

6,000 flight hours, whichever occurs first, after accomplishment of

the inspection and applicable corrective actions required by

paragraph (i), the following actions are accomplished: Perform a

detailed visual inspection of the in-tank fuel boost pump wire

bundles, and applicable corrective actions; and install sleeving

over the wire bundles; in accordance with Boeing Alert Service

Bulletin 727-28A0126, dated May 24, 1999.

Repetitive Inspections and Corrective Actions

(k) Repeat the detailed visual inspection and applicable

corrective actions required by paragraphs (i) and (j) of this AD at

intervals not to exceed 30,000 flight hours.

Alternative Methods of Compliance

(l) 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

(m) 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

(n) The actions shall be done in accordance with Boeing All

Operator Message (AOM) M-7200-99-04035, dated May 21, 1999, or

Boeing Alert Service Bulletin 727-28A0126, dated May 24, 1999, as

applicable. 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.

(o) This amendment becomes effective on June 28, 1999, to all

persons except those persons to whom it was made immediately

effective by telegraphic AD T99-12-52, issued on May 24, 1999, which

contained the requirements of this amendment.

Issued in Renton, Washington, on June 15, 1999.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-15775 Filed 6-22-99; 8:45 am]

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