Federal Register / Vol. 65, No. 83 / Friday, April 28, 2000 / Proposed Rules 24889

Applicability: All Model DHC–7–100 series

airplanes and all Model DHC–8–100, –200,

and –300 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 (b) 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 unusual handling

characteristics and consequent reduced

controllability during ground operations due

to incorrect methods of weighing and

balancing the airplane, accomplish the

following:

(a) Within 60 days after the effective date

of this AD, perform a one-time inspection of

maintenance records to determine the

method used during the most recent weight

and balance check of the airplane.

(1) If the maintenance records indicate that

platform scales or bottle jacks at the

undercarriage jacking points were used

during the most recent weight and balance

check, no further action is required by this

AD.

(2) If the maintenance records indicate that

wing jacks were used during the most recent

weight and balance check, or if the

maintenance records do not verify the use of

platform scales or bottle jacks at the

undercarriage jacking points, prior to further

flight, accomplish a weight and balance

check of the airplane in accordance with the

applicable de Havilland Weight and Balance

Manual procedures specified in paragraph

(a)(2)(i), (a)(2)(ii), (a)(2)(iii), (a)(2)(iv),

(a)(2)(v), (a)(2)(vi), or (a)(2)(vii), of this AD.

(i) For Model DHC–7–100 series airplanes:

Accomplish the actions in accordance with

de Havilland Weight and Balance Manual

PSM 1–7–8, Issue 1, dated November 1978.

(ii) For Model DHC–7–101 series airplanes:

Accomplish the actions in accordance with

de Havilland Weight and Balance Manual

PSM 1–7C–8, Issue 1, dated November 1978.

(iii) For Model DHC–7–102 series

airplanes: Accomplish the actions in

accordance with de Havilland Weight and

Balance Manual PSM 1–71–8, Issue 2, dated

February 1982.

(iv) For Model DHC–7–103 series

airplanes: Accomplish the actions in

accordance with de Havilland Weight and

Balance Manual PSM 1–71C–8, Issue 1, dated

November 1979.

(v) For Model DHC–8–100 series airplanes:

Accomplish the actions in accordance with

de Havilland Weight and Balance Manual

PSM 1–8–8, Issue 3, dated March 1996.

(vi) For Model DHC–8–200 series

airplanes: Accomplish the actions in

accordance with de Havilland Weight and

Balance Manual PSM 1–82–8, Issue 2, dated

March 1996.

(vii) For Model DHC–8–300 series

airplanes: Accomplish the actions in

accordance with de Havilland Weight and

Balance Manual PSM 1–83–8, Issue 3, dated

March 1996.

Alternative Methods of Compliance

(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, New York

Aircraft Certification Office (ACO), FAA,

Engine and Propeller Directorate. Operators

shall submit their requests through an

appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, New York ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the New York ACO.

Special Flight Permits

(c) 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.

Note 3: The subject of this AD is addressed

in Canadian airworthiness directive CF–98–

32R1, dated March 11, 1999.

Issued in Renton, Washington, on April 24,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–10671 Filed 4–27–00; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–78–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 737–100, –200, –300, –400, and

–500 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to certain

Boeing Model 737–100, –200, –300,

–400, and –500 series airplanes. That

AD currently requires inspection of the

fueling float switch wiring in the center

fuel tank to detect discrepancies,

accomplishment of corrective actions,

and installation of double Teflon

sleeving over the wiring of the float

switch. In lieu of the above mentioned

requirements, that AD provides for

deactivation of the float switch. This

proposed action would eliminate the

option for deactivation of the float

switch and require, for all affected

airplanes, repetitive inspections of the

float switch wiring to detect

discrepancies; replacement of the float

switch and wiring, if necessary; and

replacement of the double Teflon

sleeving. For certain airplanes, this

action also would add a new

requirement for inspection and

installation of partial double Teflon

sleeving in a certain area. The actions

specified by the proposed AD are

intended to detect and correct chafing of

the direct current powered float switch

wiring insulation in the center fuel tank

and the resultant arcing from the wiring

to the in-tank conduit, which could

present an ignition source inside the

fuel tank and result in a consequent fire

or explosion.

DATES: Comments must be received by

June 12, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 99–NM–

78–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

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: Dorr

M. Anderson, Aerospace Engineer,

Propulsion Branch, ANM–140S, FAA,

Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind

Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2684;

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

24890 Federal Register / Vol. 65, No. 83 / Friday, April 28, 2000 / Proposed Rules

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–78–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–78–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On February 23, 1999, the FAA issued

AD 99–05–12, amendment 39–11060 (64

FR 10213, March 3, 1999), applicable to

certain Boeing Model 737–100, –200,

–300, –400, and –500 series airplanes.

[A correction of that AD was published

in the Federal Register on March 9,

1999 (64 FR 11533).] That AD requires

removal of the fueling float switch and

wiring in the center fuel tank and

inspection of the float switch wiring to

detect discrepancies, and either

reinstallation of existing float switch

and wiring, or replacement of the float

switch and wiring with a new float

switch and wiring. That action also

requires installation of double Teflon

sleeving over the wiring of the float

switch. In lieu of the above mentioned

requirements, that AD requires

deactivation of the float switch,

accomplishment of specific fueling

procedures, and installation of Caution

signs. That action was prompted by a

report indicating that chafing of the

direct current (DC) powered float switch

wiring insulation in the center fuel tank

has occurred on several airplanes. The

requirements of that AD are intended to

detect and correct such chafing and the

resultant arcing from the wiring to the

in-tank conduit, which could present an

ignition source inside the fuel tank and

consequent fire/explosion.

Actions Since Issuance of Previous Rule

Since the issuance of that AD, the

airplane manufacturer has examined

fueling float switch wiring removed

from the center fuel tank of airplanes

that have accumulated between 4,000

and 20,000 total flight hours. Significant

wire chafing was observed on wiring

removed from airplanes that have

accumulated as few as 12,000 total flight

hours.

In addition, the FAA finds that the

conduit-enclosed float switch wiring

installation is not a fail-safe design.

Therefore, the FAA finds that repetitive

inspections to detect discrepancies of

the fueling float switch wiring in the

center fuel tank are necessary to ensure

safe operation.

Furthermore, when AD 99–05–12 was

issued, it contained provisions for

deactivation of the center tank float

switch, and reinstallation of any

existing float switch wiring having worn

insulation. In the preamble to that AD,

the FAA indicated that the actions

required by that AD were considered

‘‘interim action’’ and that further

rulemaking action was being

considered. Such further rulemaking

could include a requirement for

replacement of the existing float switch

and wiring with a new float switch and

wiring for any airplane on which the

float switch was deactivated or on

which an existing float switch with

worn insulation was reinstalled. The

FAA now has determined that further

rulemaking action is indeed necessary,

and this proposed AD follows from that

determination.

Other Relevant Rulemaking

On January 26, 1999, the FAA issued

AD 99–03–04, amendment 39–11018 (64

FR 4959, February 2, 1999), which

requires modification of certain Model

737 series airplanes to provide shielding

and separation of the fuel system wiring

(that is routed to the fuel tanks) from

adjacent wiring. That AD is intended to

prevent electrical transients induced by

electromagnetic interference or

electrical short circuit conditions that

could cause arcing of fuel system wiring

or fuel quantity indication system

probes. Such electrical transients would

not cause ignition of fuel vapors in the

fuel tank unless the wiring or probes in

the tank had a latent short circuit

condition between probe terminals,

between probe to structure, between

terminal block to structure, between intank wires, or between an in-tank wire

to structure. This proposed rule is

intended to address a separate possible

source of ignition in the fuel tanks:

arcing from the float switch wiring to

the in-tank conduit that burns through

the conduit wall into the fuel tank.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Alert Service Bulletin 737–

28A1132, Revision 2, dated June 17,

1999. Except as discussed below, the

procedures described in Revision 2 are

essentially similar to those described in

the original issue and Revision 1 of the

alert service bulletin, which were

referenced as the appropriate sources of

service information for the actions in

AD 99–05–12.

For airplanes that have accumulated

between 10,000 and 30,000 total flight

hours, Revision 2 of the alert service

bulletin describes procedures for a

detailed visual inspection of the fueling

float switch wiring in the center fuel

tank at the exit of the conduit on the

front spar; replacement of the float

switch and wiring with a new float

switch and wiring, if necessary; and

installation of partial double Teflon

sleeving over the wiring of the float

switch.

Accomplishment of the actions

specified in the alert service bulletin 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

supersede AD 99–05–12 to continue to

require inspection of the fueling float

switch wiring in the center fuel tank to

detect discrepancies, accomplishment of

corrective actions, and installation of

double Teflon sleeving over the wiring

of the float switch. The proposed AD

would remove the option for

deactivation of the float switch, which

was provided in AD 99–05–12, and, for

airplanes on which such deactivation

was accomplished previously, would

require accomplishment of the

inspection to detect discrepancies of the

fueling float switch wiring in the center

fuel tank, corrective actions, and

installation of double Teflon sleeving.

For certain airplanes, the proposed AD

also would add a new requirement for

inspection and installation of partial

double Teflon sleeving over the wiring

of the fueling float switch in the center

fuel tank. The proposed AD also would

require repetitive inspections of the

float switch wiring to detect

discrepancies; replacement of the float

switch and wiring, if necessary; and

replacement of the double Teflon

sleeving. The actions would be required

Federal Register / Vol. 65, No. 83 / Friday, April 28, 2000 / Proposed Rules 24891

to be accomplished in accordance with

the alert service bulletin described

previously, except as discussed below.

Differences Between Proposed Rule and

Alert Service Bulletin

Operators should note that the alert

service bulletin only describes a onetime inspection of the float switch

wiring and installation of double Teflon

sleeving for airplanes that were not

originally manufactured with double

Teflon sleeving. However, this proposed

AD would require repetitive inspections

of the fueling float switch wiring in the

center fuel tank to detect discrepancies;

replacement of the float switch and

wiring, if necessary; and replacement of

the double Teflon sleeving for all

affected Model 737–100, –200, –300,

–400, and –500 series airplanes. As

stated previously, the conduit-enclosed

float switch wiring installation is not a

fail-safe design; therefore, repetitive

inspections are necessary to ensure safe

operation.

Operators also should note that this

proposed AD would be applicable to all

Model 737–100, –200, –300, –400, and

–500 series airplanes; on which the

center wing tanks are activated;

excluding those airplanes equipped

with center wing tank volumetric topoff

systems, or alternate current (AC)

powered center tank float switches. The

effectivity listing of Boeing Alert Service

Bulletin 737–28A1132, Revision 2,

dated June 17, 1999, includes Model

737–200, –300, –400, and –500 series

airplanes having L/N 1 through 3108.

The effectivity listing of Revision 2 of

the alert service bulletin does not

include airplanes on which Teflon

sleeving was installed during

production (i.e., L/N 3109 and

subsequent). However, as explained

above, this proposed AD would require

repetitive inspections of the fueling float

switch wiring in the center fuel tank to

detect discrepancies; replacement of the

float switch and wiring, if necessary;

and replacement of the double Teflon

sleeving with new sleeving. Therefore,

airplanes on which Teflon sleeving was

installed during production would not

be exempt from these repetitive actions.

Operators also should note that,

although the alert service bulletin

allows deactivation of the center tank

float switch for up to 18 months in lieu

of installation of partial double Teflon

sleeving, this proposed AD would only

allow deactivation of the fueling float

switch in the event that exposed copper

conductor is detected during the

inspection specified in paragraph (h) of

this AD, and would require replacement

of the float switch and wiring, and

installation of double Teflon sleeving,

within 90 days after deactivation. This

proposed AD also would no longer

allow deactivation in lieu of the

inspection and sleeving installation

specified in paragraph (b) of this AD.

For those airplanes on which the float

switch was deactivated prior to the

effective date of this AD in accordance

with paragraph (c) of AD 99–05–12, this

proposed AD would require reactivation

of the float switch; inspections of the

fueling float switch wiring in the center

fuel tank to detect discrepancies;

replacement of the float switch and

wiring, if necessary; and installation of

double Teflon sleeving; within 12

months after the effective date of this

AD.

Explanation of Change Made to

Restatement of AD 99–05–12

Paragraph (a) of this proposed rule,

which is restated from AD 99–05–12,

states that the paragraph applies to

airplanes having line numbers 1 through

3108 inclusive. Paragraph (a) of AD 99–

05–12 did not specify that the paragraph

applied to particular line numbers. The

FAA has determined that airplanes

having line numbers 3109 and

subsequent have double Teflon sleeving

installed over the wiring of the float

switch during production. Therefore, it

is not necessary for operators of these

airplanes to accomplish paragraph (a).

[The appropriate inspection procedures

for airplanes having line numbers 3109

and subsequent are specified in

paragraph (k) of this AD.]

Also, the FAA has clarified the

inspection requirement contained in AD

99–05–12. Whereas the AD specified a

visual inspection, the FAA has revised

the restatement of requirements in this

proposed AD to clarify that its intent is

to require a detailed visual inspection.

Additionally, a note has been added to

the proposed AD to define that

inspection.

Cost Impact

There are approximately 2,870 Model

737–100, –200, –300, –400, and –500

series airplanes of the affected design in

the worldwide fleet. The FAA estimates

that 1,121 airplanes of U.S. registry

would be affected by this proposed AD.

The removal and inspection of the

fueling float switch in the center fuel

tank and installation of double Teflon

sleeving that is provided as an option

for compliance with AD 99–05–12, and

would be required as a repetitive

inspection in this proposed AD, takes

approximately 18 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour.

Required parts cost approximately $30

per airplane. Based on these figures, the

cost impact of the removal and

inspection of the float switch and

installation of double Teflon sleeving on

U.S. operators is estimated to be

$1,244,310, or $1,110 per airplane, per

inspection cycle.

For operators required to accomplish

the inspection of the float switch at the

exit of the conduit on the front spar and

installation of partial double Teflon

sleeving that are proposed in this AD

action, it would take approximately 3

work hours per airplane to accomplish,

at an average labor rate of $60 per work

hour. Required parts would cost

approximately $5 per airplane. Based on

these figures, the cost impact of the

proposed inspection of the float switch

at the exit of the conduit on the front

spar and installation of partial double

Teflon sleeving of this AD on U.S.

operators is estimated to be $185 per

airplane.

The cost impact figures discussed

above are based on assumptions that no

operator has yet accomplished any of

the current or 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 a substantial direct

effect 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,

it is determined that this proposal

would not have federalism implications

under Executive Order 13132.

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

24892 Federal Register / Vol. 65, No. 83 / Friday, April 28, 2000 / Proposed Rules

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.

§ 39.13 [Amended]

2. Section 39.13 is amended by

removing amendment 39–11060 (64 FR

11533, March 9, 1999), and by adding a

new airworthiness directive (AD), to

read as follows:

Boeing: Docket 99–NM–78–AD. Supersedes

AD 99–05–12, Amendment 39–11060.

Applicability: Model 737–100, –200, –300,

–400, and –500 series airplanes, on which the

center wing tanks are activated; excluding

those airplanes equipped with center wing

tank volumetric topoff systems, or alternate

current (AC) powered center tank float

switches; certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

otherwise 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)(1) 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 chafing of the direct

current powered float switch wiring

insulation in the center fuel tank and the

resultant arcing from the wiring to the intank conduit, which could present an

ignition source inside the fuel tank and result

in a consequent fire or explosion, accomplish

the following:

Restatement of Requirements of AD 99–05–

12

Compliance Time for Initial Inspection

(a) For airplanes having line numbers (L/

N) 1 through 3108 inclusive: Prior to the

accumulation of 30,000 total flight hours, or

within 30 days after March 18, 1999 (the

effective date of AD 99–05–12), whichever

occurs later, accomplish the requirements of

paragraph (b) or (c) of this AD. For airplanes

on which the requirements of this paragraph

are accomplished after the effective date of

this AD: Except as provided in paragraph

(h)(2)(i) of this AD, only the requirements of

paragraph (b) of this AD may be

accomplished.

Initial Inspection: Procedures

(b) Remove the fueling float switch and

wiring from the center fuel tank and perform

a detailed visual inspection of the float

switch wiring to detect discrepancies (i.e.,

evidence of electrical arcing, exposure of the

copper conductor, presence or scent of fuel

on the electrical wires, or worn insulation),

in accordance with Part 1 of the

Accomplishment Instructions of Boeing Alert

Service Bulletin 737–28A1132, dated

December 2, 1998; Revision 1, dated January

15, 1999; or Revision 2, dated June 17, 1999.

After the effective date of this AD, only

Revision 2 may be used. Pay particular

attention to the wire bundle where it passes

through the wing pylon vapor seals and

under the wire bundle clamps.

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.’’

Initial Inspection: Follow-On Actions

(1) If no discrepancy is detected, prior to

further flight, accomplish either paragraph

(b)(1)(i) or (b)(1)(ii) of this AD.

(i) Measure the resistance between the

wires and the float switch housing, in

accordance with the alert service bulletin.

(A) If the resistance is less than 200

megohms, prior to further flight, replace the

float switch and wiring with a new float

switch and wiring, and install double Teflon

sleeving over the wiring of the float switch,

in accordance with the alert service bulletin.

For airplanes on which the actions required

by this paragraph were accomplished prior to

the effective date of this AD in accordance

with AD 99–05–12, amendment 39–11060: If

the replacement float switch and wiring are

not available, prior to further flight,

accomplish the requirements specified in

paragraphs (c) and (d) of this AD.

(B) If the resistance is greater than or equal

to 200 megohms, prior to further flight, blow

dirt out of the conduit, install double Teflon

sleeving over the wiring of the float switch,

and reinstall the existing float switch, in

accordance with the alert service bulletin.

(ii) Replace the float switch and wiring

with a new float switch and wiring, and

install double Teflon sleeving over the wiring

of the float switch, in accordance with the

alert service bulletin. For airplanes on which

the actions required by this paragraph were

accomplished prior to the effective date of

this AD in accordance with AD 99–05–12,

amendment 39–11060: If the replacement

float switch and wiring are not available,

prior to further flight, accomplish the

requirements specified in paragraphs (c) and

(d) of this AD.

(2) If any worn insulation is detected, and

if no copper conductor is exposed, and if no

evidence of arcing is detected; accomplish

the requirements specified in either

paragraph (b)(1)(i) or (b)(1)(ii) of this AD.

After the effective date of this AD, only the

requirements of paragraph (b)(1)(ii) may be

accomplished.

(3) If any electrical arcing or exposed

copper conductor is detected, prior to further

flight, accomplish either paragraph (b)(3)(i)

or (b)(3)(ii) of this AD.

(i) Replace any section of the electrical

conduit where the arcing occurred with a

new section, in accordance with the alert

service bulletin, and accomplish the

requirements specified in paragraph (b)(1)(ii)

of this AD.

(ii) Perform a detailed visual inspection to

detect fuel leaks of the electrical conduit, in

accordance with the alert service bulletin.

(A) If no fuel leak is detected, prior to

further flight, accomplish the requirements

specified in paragraph (b)(1)(ii) of this AD.

For airplanes on which the inspection

required by paragraph (b)(3)(ii) was

accomplished PRIOR to the effective date of

this AD in accordance with AD 99–05–12,

amendment 39–11060: Repeat the inspection

required by paragraph (b)(3)(ii) of this AD

thereafter at intervals not to exceed 1,500

flight hours, until the replacement required

by paragraph (b)(3)(ii)(B) or (f) of this AD is

accomplished. For airplanes on which the

inspection required by paragraph (b)(3)(ii) is

accomplished AFTER the effective date of

this AD: Within 1,500 flight hours or 6

months after accomplishment of the

inspection in accordance with paragraph

(b)(3)(ii) of this AD, whichever occurs first,

replace the electrical conduit with new

conduit in accordance with Boeing Alert

Service Bulletin 737–28A1132, Revision 2.

The existing float switch, wiring, and double

Teflon sleeving may be reinstalled after

replacement of the conduit.

(B) If any fuel leak is detected, prior to

further flight, replace any section of the

electrical conduit where the leak is with a

new section, in accordance with the alert

service bulletin. Prior to further flight after

accomplishment of the replacement,

accomplish the requirements specified in

paragraph (b)(1)(ii) of this AD.

Accomplishment of electrical conduit

replacement constitutes terminating action

for the repetitive inspection requirements of

paragraph (b)(3)(ii)(A) of this AD.

(4) If any presence or scent of fuel on the

electrical wires is detected, prior to further

flight, locate the source of the leak and

replace the damaged conduit with a new

conduit, in accordance with the alert service

bulletin; and accomplish the requirements

specified in either paragraph (b)(1)(i) or

(b)(1)(ii) of this AD, unless accomplished

previously in accordance with paragraph

(b)(1), (b)(2), or (b)(3) of this AD.

Deactivation of Float Switch

(c) Accomplish the requirements specified

in either paragraph (c)(1) or (c)(2) of this AD,

in accordance with Part 2 of the

Accomplishment Instructions of Boeing Alert

Service Bulletin 737–28A1132, dated

December 2, 1998; Revision 1, dated January

15, 1999; or Revision 2, dated June 17, 1999.

Except as provided by paragraph (h)(2)(i) of

this AD, after the effective date of this AD,

the requirements of this paragraph may no

longer be accomplished.

(1) Deactivate the center tank float switch

(i.e., cut the two wires for the float switch at

the splices on the front spar and cap and

Federal Register / Vol. 65, No. 83 / Friday, April 28, 2000 / Proposed Rules 24893

stow the four wire ends), paint a Caution that

shows a conservative maximum fuel capacity

for the center tank on the underside of the

right-hand wing near the fueling station door,

and install an INOP placard on the fueling

panel.

(2) Deactivate the center tank float switch

(i.e., cut, stow, and splice the two wires for

the float switch at the splices on the front

spar), and paint a Caution that shows a

conservative maximum fuel capacity for the

center tank on the underside of the righthand wing near the fueling station door.

Deactivation of Float Switch: Additional

Requirements

(d) For airplanes on which the

requirements specified in paragraph (c) of

this AD have been accomplished:

Accomplish the requirements specified in

paragraphs (d)(1), (d)(2), and (d)(3) of this

AD. Except as provided by paragraph (h)(2)(i)

of this AD, after 12 months after the effective

date of this AD, the requirements of this

paragraph may no longer be accomplished.

(1) Operators must ensure that airplane

fueling crews are properly trained in

accordance with the procedures specified in

Boeing Telex M–7200–98–04486, dated

December 1, 1998, or procedures approved

by the FAA. This one-time training must be

accomplished prior to utilizing the

procedures specified in paragraph (d)(3) of

this AD.

(2) Prior to fueling the airplane, perform a

check to verify that the fueling panel center

tank quantity indicator is operative. Repeat

this check thereafter prior to fueling the

airplane. If the fueling panel center tank

quantity indicator is not operative, prior to

further flight, replace the fueling panel center

tank quantity indicator with a serviceable

part.

(3) One of the two manual fueling

procedures for the center fuel tank must be

used for each fueling occurrence, in

accordance with Boeing Telex M–7200–98–

04486, dated December 1, 1998, or a method

approved by the FAA.

Note 3: For the purposes of this AD, the

term ‘‘the FAA,’’ is defined in paragraph (d)

of this AD as ‘‘the cognizant Principal

Maintenance Inspector (PMI).’’

Note 4: Where there are differences

between Boeing Alert Service Bulletin 737–

28A1132 and this AD, the AD prevails.

Deactivation of Float Switch: Dispatch

(e) Dispatch with the center fuel tank float

switch deactivated, in accordance with

Boeing Alert Service Bulletin 737–28A1132,

dated December 2, 1998; Revision 1, dated

January 15, 1999; or Revision 2, dated June

17, 1999; is allowed until replacement float

switches and wiring are available for

installation. Where there are differences

between the Master Minimum Equipment

List (MMEL) and the AD, the AD prevails.

Except as provided by paragraph (h)(2)(i) of

this AD, after 12 months after the effective

date of this AD, the requirements of this

paragraph may no longer be accomplished.

New Requirements of This AD

Replacement of Conduit

(f) For airplanes having L/N 1 through 3108

inclusive, on which the inspection required

by paragraph (b)(3)(ii) of this AD has been

accomplished prior to the effective date of

this AD in accordance with AD 99–05–12,

amendment 39–11060, and on which

replacement of the conduit specified in

paragraph (b)(3)(ii)(B) has NOT been

accomplished: Within 1,500 flight hours or 6

months after the effective date of this AD,

whichever occurs first, replace the electrical

conduit with new conduit in accordance

with Boeing Alert Service Bulletin 737–

28A1132, Revision 2, dated June 17, 1999.

Following replacement of the conduit, the

existing float switch, wiring, and double

Teflon sleeving may be reinstalled. Such

replacement of the conduit constitutes

terminating action for the repetitive

inspection requirements of paragraph

(b)(3)(ii)(A) of this AD.

Initial Inspection: Airplanes With

Deactivated Float Switch

(g) For airplanes having line numbers 1

through 3108 inclusive on which paragraphs

(c) and (d) have been accomplished prior to

the effective date of this AD: Within 12

months after the effective date of this AD,

reactivate the center tank float switch in

accordance with Boeing Alert Service

Bulletin 737–28A1132, Revision 2, dated

June 17, 1999; and accomplish the

requirements of paragraph (b) of this AD.

Following accomplishment of paragraph (b)

of this AD, ‘‘Cautions’’ painted and placards

installed in accordance with paragraph (c) of

this AD may be removed from the airplane.

Initial Inspection and Follow-On Actions

(h) For airplanes having line numbers 1

through 3108 inclusive on which the actions

required by paragraph (b) or (c) of this AD

have NOT been accomplished prior to the

effective date of this AD: Prior to the

accumulation of 10,000 total flight hours or

within 90 days after the effective date of this

AD, whichever occurs later, except as

provided by paragraph (i) of this AD, perform

a detailed visual inspection to detect

exposure of the copper conductor of the float

switch wiring at the exit of the conduit on

the front spar in accordance with Part 3 of

the Accomplishment Instructions of Boeing

Alert Service Bulletin 737–28A1132,

Revision 2, dated June 17, 1999.

(1) If no exposed copper conductor is

detected, prior to further flight, install partial

double Teflon sleeving over the wiring of the

float switch in accordance with the alert

service bulletin, and, prior to the

accumulation of 30,000 total flight hours,

accomplish paragraph (b) of this AD.

(2) If any exposed copper conductor is

detected, accomplish the requirements of

paragraphs (h)(2)(i), (h)(2)(ii), and (h)(2)(iii)

of this AD.

(i) Prior to further flight, accomplish the

deactivation requirements specified in

paragraphs (c) and (d) of this AD. And,

(ii) Within 90 days after deactivation,

remove the float switch and wiring and

replace with a new float switch and wiring,

and install double Teflon sleeving over the

wiring of the float switch, in accordance with

Part 1 of the Accomplishment Instructions of

the alert service bulletin, and reactivate the

switch. Accomplishment of the requirements

of this paragraph constitutes terminating

action for the inspection required by

paragraph (b) of this AD. And,

(iii) Following accomplishment of

paragraph (h)(2)(ii) of this AD, ‘‘Cautions’’

painted and placards installed in accordance

with paragraph (c) of this AD may be

removed from the airplane.

Exception to Requirements of Paragraph (h)

(i) Airplanes on which the inspection

required by paragraph (b) of this AD is

accomplished within 90 days after the

effective date of this AD are not required to

be inspected in accordance with paragraph

(h) of this AD.

Repetitive Inspections: Compliance Times

(j) For all airplanes: Accomplish the

inspection specified in paragraph (k) of this

AD at the time specified in paragraph (j)(1),

(j)(2), or (j)(3), as applicable, and repeat the

inspection thereafter at intervals not to

exceed 30,000 flight hours.

(1) For airplanes having line numbers 1

through 3108 inclusive on which a new float

switch and wiring was installed in

accordance with paragraph (b)(1)(ii) or

(h)(2)(ii) of this AD, OR on which no

discrepancy was found during the inspection

specified in paragraph (b) of this AD and the

existing float switch and wiring were

reinstalled: Inspect within 30,000 flight

hours after installation of double Teflon

sleeving.

(2) For airplanes having line numbers 1

through 3108 inclusive on which worn

insulation of the existing float switch wiring

was found during the inspection specified in

paragraph (b) of this AD and the existing float

switch and wiring were reinstalled: Inspect

within 15,000 flight hours after installation of

the double Teflon sleeving.

(3) For airplanes having line numbers 3109

and subsequent: Inspect prior to the

accumulation of 30,000 total flight hours.

Repetitive Inspections: Procedures

(k) Remove the fueling float switch and

wiring from the center fuel tank and perform

a detailed visual inspection of the float

switch wiring to detect discrepancies (i.e.,

evidence of electrical arcing, exposure of the

copper conductor, presence or scent of fuel

on the electrical wires, or worn insulation),

in accordance with Part 1 of the

Accomplishment Instructions of Boeing Alert

Service Bulletin 737–28A1132, Revision 2,

dated June 17, 1999. Pay particular attention

to the wire bundle where it passes through

the wing pylon vapor seals and under the

wire bundle clamps.

Repetitive Inspections: Follow-On Actions

(1) If no discrepancy is detected, prior to

further flight, accomplish either paragraph

(k)(1)(i) or (k)(1)(ii) of this AD.

(i) Measure the resistance between the

wires and the float switch housing, in

accordance with the alert service bulletin.

(A) If the resistance is less than 200

megohms, prior to further flight, replace the

float switch and wiring with a new float

24894 Federal Register / Vol. 65, No. 83 / Friday, April 28, 2000 / Proposed Rules

switch and wiring, and replace the double

Teflon sleeving over the wiring of the float

switch with new sleeving, in accordance

with the alert service bulletin.

(B) If the resistance is greater than or equal

to 200 megohms, prior to further flight, blow

dirt out of the conduit, replace the double

Teflon sleeving over the wiring of the float

switch with new sleeving, and reinstall the

existing float switch, in accordance with the

alert service bulletin.

(ii) Replace the float switch and wiring

with a new float switch and wiring, and

replace the double Teflon sleeving over the

wiring of the float switch with new sleeving,

in accordance with the alert service bulletin.

(2) If any worn insulation is detected, and

if no copper conductor is exposed, and if no

evidence of arcing is detected: Prior to

further flight, accomplish the requirements

specified in paragraph (k)(1)(ii) of this AD.

(3) If any electrical arcing or exposed

copper conductor is detected, prior to further

flight, accomplish either paragraph (k)(3)(i)

or (k)(3)(ii) of this AD.

(i) Replace any section of the electrical

conduit where the arcing occurred with a

new section, in accordance with the alert

service bulletin, and accomplish the

requirements specified in paragraph (k)(1)(ii)

of this AD.

(ii) Perform a detailed visual inspection to

detect fuel leaks of the electrical conduit, in

accordance with the alert service bulletin.

(A) If no fuel leak is detected, prior to

further flight, accomplish the requirements

specified in paragraph (k)(1)(ii) of this AD.

Within 1,500 flight hours or 6 months after

accomplishment of the inspection specified

in paragraph (k)(3)(ii), whichever occurs first,

replace the electrical conduit with new

conduit, in accordance with Boeing Alert

Service Bulletin 737–28A1132, Revision 2,

dated June 17, 1999. The existing float

switch, wiring, and double Teflon sleeving

may be reinstalled after replacement of the

conduit.

(B) If any fuel leak is detected, prior to

further flight, replace any section of the

electrical conduit where the leak is with a

new section, in accordance with the alert

service bulletin. Prior to further flight after

accomplishment of the replacement,

accomplish the requirements specified in

paragraph (k)(1)(ii) of this AD.

(4) If any presence or scent of fuel on the

electrical wires is detected, prior to further

flight, locate the source of the leak and

replace the damaged conduit with a new

conduit, in accordance with the alert service

bulletin; and accomplish the requirements

specified in either paragraph (k)(1)(i) or

(k)(1)(ii) of this AD, unless accomplished

previously in accordance with paragraph

(k)(1), (k)(2), or (k)(3) of this AD.

Alternative Methods of Compliance

(l)(1) 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 5: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Manager, Seattle ACO.

(2) Alternative methods of compliance,

approved previously in accordance with AD

99–05–12, amendment 39–11060, are

approved as alternative methods of

compliance with this AD.

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.

Issued in Renton, Washington, on April 24,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–10670 Filed 4–27–00; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–69–AD]

RIN 2120–AA64

Airworthiness Directives; McDonnell

Douglas Model DC–10 Series

Airplanes, and KC–10A and KDC–10

(Military) Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to all

McDonnell Douglas Model DC–10 series

airplanes, and KC–10A and KDC–10

(military) airplanes. This proposal

would require certain modifications of

the thrust reverser control and

indication system and wiring on each

engine. This proposal is prompted by a

determination that the current thrust

reverser systems do not adequately

preclude unwanted deployment of a

thrust reverser. The actions specified by

the proposed AD are intended to

prevent unwanted deployment of a

thrust reverser, which could

significantly jeopardize continued safety

of flight and landing of the airplane.

DATES: Comments must be received by

June 12, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000–NM–

69–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays.

The service information referenced in

the proposed rule may be obtained from

Boeing Commercial Aircraft Group,

Long Beach Division, 3855 Lakewood

Boulevard, Long Beach, California

90846, Attention: Technical

Publications Business Administration,

Dept. C1–L51 (2–60). This information

may be examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at

the FAA, Transport Airplane

Directorate, Los Angeles Aircraft

Certification Office, 3960 Paramount

Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

Philip Kush, Aerospace Engineer,

Propulsion Branch, ANM–140L, FAA,

Transport Airplane Directorate, Los

Angeles Aircraft Certification Office,

3960 Paramount Boulevard, Lakewood,

California 90712–4137; telephone (562)

627–5263; fax (562) 627–5210.

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 2000–NM–69–AD.’’ The

postcard will be date stamped and

returned to the commenter.