Federal Register / Vol. 63, No. 121 /Wednesday, June 24, 1998 /Rules and Regulations 34271

Issued in Renton, Washington, on June 16,

1998.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–16492 Filed 6–23–98; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–178–AD; Amendment

39–10611; AD 98–11–52]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 737–100, –200, –300, –400, and

–500 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This document publishes in

the Federal Register an amendment

adopting airworthiness directive (AD)

T98–11–52 that was sent previously to

all known U.S. owners and operators of

Boeing Model 737–100, –200, –300,

–400, and –500 series airplanes by

individual telegrams. This AD requires

removal of the fuel boost pump wiring

in the conduits of the wing and center

fuel tanks; an inspection to detect

damage of the wiring, and corrective

action, if necessary; and eventual

installation of teflon sleeving over the

electrical cable. This action is prompted

by reports of severe wear of the fuel

boost pump wiring due to chafing

between the wiring and the surrounding

conduit inside the fuel tank; pin-holesized holes in the conduit that appear to

be the result of arc-through of the

conduit; and exposure of the main tank

boost pump wire conductor inside a

conduit and signs of arcing to the wall

of the conduit. The actions specified by

this AD are intended to detect and

correct chafing and electrical arcing

between the fuel boost pump wiring and

the surrounding conduit, which, if not

corrected, could result in arc-through of

the conduit, and consequent fire or

explosion of the fuel tank.

DATES: Effective June 29, 1998, to all

persons except those persons to whom

it was made immediately effective by

telegraphic AD T98–11–52, issued on

May 14, 1998, 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 29,

1998.

Comments for inclusion in the Rules

Docket must be received on or before

August 24, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 98–NM–

178–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: Dorr

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:

Issuance of Telegraphic AD T98–10–51

On May 7, 1998, the FAA issued

telegraphic AD T98–10–51, applicable

to all Model 737–100, –200, –300, –400,

and –500 series airplanes, to require

removal of the fuel boost pump wiring

in the conduits of the wing fuel tanks;

a one-time detailed visual inspection to

detect damage of the wiring;

reinstallation of the wiring with teflon

sleeving, or replacement of damaged

wiring with new wiring and teflon

sleeving; and submission of damaged

parts to Boeing. Telegraphic AD T98–

10–51 was prompted by reports of

severe wear of the fuel boost pump

wiring due to chafing between the intank fuel boost pump wiring and the

surrounding conduit inside the fuel

tank, and pin-hole-sized holes in two

sections of the fuel boost pump conduit

that appeared to be the result of arcthrough of the conduit. The actions

required by that telegraphic AD were

intended to detect and correct such

chafing, which could result in arcthrough of the conduit, and consequent

fire or explosion of the fuel tank.

Issuance of Telegraphic AD T98–11–51

On May 10, 1998, the FAA issued

telegraphic AD T98–11–51, which is

applicable to all Model 737–100, –200,

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

That AD superseded telegraphic AD

T98–10–51 to continue to require

removal of the fuel boost pump wiring

in the conduits of the wing fuel tanks;

a detailed visual inspection to detect

damage of the wiring; and corrective

action, if necessary. Additionally, that

telegraphic AD required eventual

installation of teflon sleeving over the

electrical cable, which terminated the

requirements of the telegraphic AD.

Telegraphic AD T98–11–51 was

prompted by a report indicating that the

left main tank boost pump power wire

conductor was exposed at three areas

inside the conduit. At least one of the

areas exhibited signs of arcing to the

wall of the conduit. In addition, several

reports of severe chafing had been

received since the issuance of

telegraphic AD T98–10–51. The actions

required by telegraphic AD T98–11–51

were intended to detect and correct

chafing and electrical arcing between

the fuel boost pump wiring and the

surrounding conduit, which, if not

corrected, could result in arc-through of

the conduit, and consequent fire or

explosion of the fuel tank.

In telegraphic AD T98–11–51, the

FAA required inspection of airplanes

that had accumulated between 40,000

and 50,000 total flight hours based on

the significance of the problems on the

high-time airplanes reported at that

time, and the lack of available data for

airplanes that had accumulated between

40,000 and 50,000 total flight hours.

However, the FAA indicated in that

telegraphic AD that it would continue to

monitor inspection reports to determine

whether an adjustment to the

compliance time was warranted.

Issuance of Telegraphic AD T98–11–52

Since the issuance of telegraphic AD

T98–11–51, the FAA has received

inspection results indicating that

exposed copper wire and significant

chafing was found on other Model 737–

200 series airplanes that had

accumulated flight hours below those

specified in earlier reports.

The FAA has determined that it is

necessary to expand the inspection

requirement to airplanes that have

accumulated less than 40,000 total flight

hours. This is necessary to ensure that

these airplanes have not also developed

a problem with chafing and electrical

arcing between the fuel boost pump

wiring and the surrounding conduit.

When telegraphic AD T98–11–51

superseded telegraphic AD T98–10–51,

the FAA had received inspection reports

indicating that the center fuel tank boost

pump wiring was not showing chafing

and did not present a safety of flight

problem on Model 737–100 and –200

series airplanes. (It should be noted that

the center fuel tank boost pump wiring
34272 Federal Register / Vol. 63, No. 121 /Wednesday, June 24, 1998 /Rules and Regulations

is located in the main tanks, not within

the center fuel tank itself.) As a result,

the requirement for inspection of the

center fuel tank boost pump wiring on

Model 737–100 and –200 series

airplanes was removed in telegraphic

AD T98–11–51. Inspection results

received since the issuance of

telegraphic AD T98–11–51 indicate that

chafing has occurred in the center fuel

tank boost pump wiring of some Model

737–100 and –200 series airplanes.

Telegraphic AD T98–11–52 restores the

requirement to inspect the center fuel

tank boost pump wiring on all affected

models.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Alert Service Bulletin 737–

28A1120, dated April 24, 1998, as

revised by Notices of Status Change

NSC 01, dated May 7, 1998, NSC 02,

dated May 8, 1998, and NSC 03, dated

May 9, 1998. The alert service bulletin

describes procedures for removal of the

fuel boost pump wiring in the conduits

of the wing fuel tanks and center fuel

tanks; an inspection to detect damage of

the wiring; and corrective action, if

necessary. (The corrective actions

include replacing the wiring or conduit

with new or serviceable parts.) This

alert service bulletin also describes

procedures for eventual installation of

teflon sleeving over the electrical cable.

The NSC’s provide information

concerning optional parts and

procedures.

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 T98–11–52

to detect and correct chafing and

electrical arcing between the fuel boost

pump wiring and the surrounding

conduit, which, if not corrected, could

result in arc-through of the conduit, and

consequent fire or explosion of the fuel

tank. This AD supersedes telegraphic

AD T98–11–51 to continue to require

removal of the fuel boost pump wiring

in the conduits of the wing fuel tanks;

a detailed visual inspection to detect

damage of the wiring; and corrective

action, if necessary. Additionally, this

AD continues to require eventual

installation of teflon sleeving over the

electrical cable, which terminates the

requirements of the AD.

This AD requires inspection of

airplanes that have accumulated less

than 40,000 total flight hours. In

addition, this AD adds a requirement for

inspection of the fuel boost pump

wiring in the conduits of the center fuel

tanks on Model 737–100 and –200 series

airplanes that have accumulated 40,000

or more total flight hours.

The actions are required to be

accomplished in accordance with alert

service bulletin and notices of status

change described previously.

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 14, 1998, to all

known U.S. owners and operators of all

Boeing Model 737–100, –200, –300,

–400, and –500 series airplanes. These

conditions still exist, and the AD is

hereby published in the Federal

Register as an amendment to section

39.13 of the Federal Aviation

Regulations (14 CFR 39.13) to make it

effective to all persons.

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 98–NM–178–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.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

98–11–52 BOEING: Amendment 39–10611.

Docket 98–NM–178–AD.

Applicability: All Model 737–100, –200,

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

certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability
Federal Register / Vol. 63, No. 121 /Wednesday, June 24, 1998 /Rules and Regulations 34273

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)(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 and electrical

arcing between the fuel boost pump wiring

and the surrounding conduit, which, if not

corrected, could result in arc-through of the

conduit, and consequent fire or explosion of

the fuel tank, accomplish the following:

(a) For all airplanes that have accumulated

50,000 or more total flight hours as of the

effective date of this AD: Prior to further

flight, remove the fuel boost pump wiring

from the in-tank conduit for the aft boost

pumps in main tanks #1 and #2, and perform

a detailed visual inspection to detect damage

of the wiring, in accordance with the

procedures specified in Boeing Alert Service

Bulletin 737–28A1120, dated April 24, 1998,

as revised by Notices of Status Change NSC

01, dated May 7, 1998, NSC 02, dated May

8, 1998, and NSC 03, dated May 9, 1998.

(b) For all airplanes that have accumulated

less than 50,000 total flight hours as of

receipt of telegraphic AD T98–11–51: Prior to

the accumulation of 40,000 total flight hours,

or within 14 days after the effective date of

this AD, whichever occurs later, remove the

fuel boost pump wiring from the in-tank

conduit for the aft boost pumps in main tanks

#1 and #2, and perform a detailed visual

inspection to detect damage of the wiring, in

accordance with the procedures specified in

Boeing Alert Service Bulletin 737–28A1120,

dated April 24, 1998, as revised by Notices

of Status Change NSC 01, dated May 7, 1998,

NSC 02, dated May 8, 1998, and NSC 03,

dated May 9, 1998.

(c) For all airplanes: Remove the fuel boost

pump wiring from the in-tank conduit for the

center tank left and right boost pumps, and

perform a detailed visual inspection to detect

damage of the wiring, in accordance with the

procedures specified in Boeing Alert Service

Bulletin 737–28A1120, dated April 24, 1998,

as revised by Notices of Status Change NSC

01, dated May 7, 1998, NSC 02, dated May

8, 1998, and NSC 03, dated May 9, 1998.

Accomplish the inspection at the earliest of

the times specified in paragraphs (c)(1),

(c)(2), and (c)(3).

(1) For Model 737–300, –400, and –500

series airplanes: Inspect prior to the

accumulation of 40,000 total flight hours, or

within 14 days after the effective date of this

AD, whichever occurs later.

(2) For Model 737–100 and –200 series

airplanes: Inspect prior to the accumulation

of 40,000 total flight hours, or within 10 days

after the effective date of this AD, whichever

occurs later.

(3) For all airplanes: Inspect prior to the

accumulation of 50,000 total flight hours, or

within 5 days after the effective date of this

AD, whichever occurs later.

(d) For all airplanes: Prior to the

accumulation of 30,000 total flight hours or

within 45 days after the effective date of this

AD, whichever occurs later, remove the fuel

boost pump wiring from the in-tank conduit

for the aft boost pumps in main tanks #1 and

#2, and the center tank left and right boost

pumps, and perform a detailed visual

inspection to detect damage of the wiring, in

accordance with the procedures specified in

Boeing Alert Service Bulletin 737–28A1120,

dated April 24, 1998, as revised by Notices

of Status Change NSC 01, dated May 7, 1998,

NSC 02, dated May 8, 1998, and NSC 03,

dated May 9, 1998.

(e) If red, yellow, blue, or green wire

insulation cannot be seen through the outer

jacket of the electrical cable during any

inspection required by this AD: Prior to

further flight, accomplish paragraph (e)(1),

(e)(2), or (e)(3) of this AD in accordance with

procedures specified in Boeing Alert Service

Bulletin 737–28A1120, dated April 24, 1998,

as revised by Notices of Status Change NSC

01, dated May 7, 1998, NSC 02, dated May

8, 1998, and NSC 03, dated May 9, 1998.

(1) Install teflon sleeving over the electrical

cable, and reinstall the cable. Or

(2) Reinstall the electrical cable without

teflon sleeving over the cable. Within 500

flight hours after accomplishment of the

reinstallation, repeat the inspection

described in paragraph (d) of this AD; and

install teflon sleeving over the cable. Or

(3) Replace the electrical cable with new

cable without teflon sleeving. Within 18

months or 6,000 flight hours, whichever

occurs first, repeat the inspection specified in

paragraph (d) of this AD, and install teflon

sleeving over the cable.

(f) If red, yellow, blue, or green wire

insulation can be seen through the outer

jacket of the electrical cable during any

inspection required by this ad, but no

evidence of electrical arcing is found: Prior

to further flight, accomplish either paragraph

(f)(1) or (f)(2) of this AD in accordance with

the procedures specified in Boeing Alert

Service Bulletin 737–28A1120, dated April

24, 1998, as revised by Notices of Status

Change NSC 01, dated May 7, 1998, NSC 02,

dated May 8, 1998, and NSC 03, dated May

9, 1998.

(1) Replace the damaged electrical cable

with a new cable, install teflon sleeving over

the cable, and reinstall the cable. Or

(2) Replace the electrical cable with a new

cable without teflon sleeving. Within 18

months or 6,000 flight hours, whichever

occurs first, repeat the inspection described

in paragraph (d) of this AD; and install teflon

sleeving over the cable.

(g) If any evidence of electrical arcing but

no evidence of fuel leakage is found on the

removed electrical cable during any

inspection required by this AD: Prior to

further flight, accomplish paragraphs (g)(1)

and (g)(2) of this AD in accordance with the

procedures specified in Boeing Alert Service

Bulletin 737–28A1120, dated April 24, 1998,

as revised by Notices of Status Change NSC

01, dated May 7, 1998, NSC 02, dated May

8, 1998, and NSC 03, dated May 9, 1998.

(1) Verify the integrity of the conduit in

accordance with the instructions contained

in NSC 03 to the alert service bulletin. And

(2) Accomplish either paragraph (g)(2)(i) or

(g)(2)(ii) of this AD in accordance with the

alert service bulletin.

(i) Replace the damaged electrical cable

with a new cable, install teflon sleeving over

the cable, and reinstall the cable. Or

(ii) Replace the electrical cable with a new

cable without teflon sleeving. Within 18

months or 6,000 flight hours, whichever

occurs first, repeat the inspection described

in paragraph (d) of this AD; and install teflon

sleeving over the cable.

(h) If any evidence of fuel is found on the

removed electrical cable during any

inspection required by this AD: Prior to

further flight, accomplish paragraphs (h)(1)

and (h)(2) of this AD in accordance with the

procedures specified in Boeing Alert Service

Bulletin 737–28A1120, dated April 24, 1998,

as revised by Notices of Status Change NSC

01, dated May 7, 1998, NSC 02, dated May

8, 1998, and NSC 03, dated May 9, 1998.

(1) Replace the conduit section where

electrical arcing was found. And

(2) Accomplish either paragraph (h)(2)(i) or

(h)(2)(ii) of this AD.

(i) Replace the damaged electrical cable

with a new cable, install teflon sleeving over

the cable, and reinstall the cable. Or

(ii) Replace the electrical cable with a new

cable without teflon sleeving. Within 18

months or 6,000 flight hours, whichever

occurs first, repeat the inspection described

in paragraph (d) of this AD; and install teflon

sleeving over the cable.

(i) For Groups 1 and 2 airplanes, as

identified in Boeing Alert Service Bulletin

737–28A1120, dated April 24, 1998:

Concurrent with the first accomplishment of

corrective action in accordance with

paragraph (e), (f), (g), or (h) of this AD, as

applicable, replace the case ground wire with

a new wire in accordance with Boeing Alert

Service Bulletin 737–28A1120, dated April

24, 1998; as revised by Notices of Status

Change NSC 01, dated May 7, 1998, NSC 02,

dated May 8, 1998, and NSC 03, dated May

9, 1998.

(j) Installation of teflon sleeving over any

electrical cable that is new or has been

inspected in accordance with paragraph (a),

(b), (c), or (d) of this AD, constitutes

terminating action for the requirements of

this AD.

(k) If any damage specified in paragraph (f),

(g), or (h) of this AD is found during any

inspection required by this AD, within 10

days after accomplishing the inspection

required by paragraph (a), (b), (c), or (d) of

this AD, as applicable, accomplish

paragraphs (k)(1) and (k)(2) of this AD.

Information collection requirements

contained in this regulation have been

approved by the Office of Management and

Budget (OMB) under the provisions of the

Paperwork Reduction Act of 1980 (44 U.S.C.

3501 et seq.) and have been assigned OMB

Control Number 2120–0056.

(1) Submit any damaged electrical cables

and conduits to Boeing, in accordance with

Boeing Alert Service Bulletin 737–28A1120,

dated April 24, 1998, as revised by Notices

of Status Change NSC 01, dated May 7, 1998,
34274 Federal Register / Vol. 63, No. 121 /Wednesday, June 24, 1998 /Rules and Regulations

NSC 02, dated May 8, 1998, and NSC 03,

dated May 9, 1998; include the serial number

of the airplane, the number of total flight

hours and flight cycles accumulated on the

airplane, and the location of the electrical

cable on the airplane.

(2) For airplanes that are inspected after

the effective date of this AD, submit the serial

number of the airplane, the number of total

flight hours and flight cycles accumulated on

the airplane, and the location of the electrical

cable on the airplane to the Manager, Seattle

Aircraft Certification Office (ACO), FAA,

Transport Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington 98055–

4056; fax (425) 227–1181.

(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

ACO. Operators shall submit their requests

through an appropriate FAA Principal

Maintenance Inspector, who may add

comments and then send it to the Manager,

Seattle ACO.

(l)(2) Alternative methods of compliance,

approved previously in accordance with

telegraphic AD T98–10–51 or telegraphic AD

T98–11–51 are approved as alternative

methods of compliance with this AD.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

(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.

(n) The actions shall be done in accordance

with Boeing Alert Service Bulletin 737–

28A1120, dated April 24, 1998, as revised by

Notices of Status Change NSC 01, dated May

7, 1998, NSC 02, dated May 8, 1998, and NSC

03, dated May 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.

(o) This amendment becomes effective on

June 29, 1998, to all persons except those

persons to whom it was made immediately

effective by telegraphic AD T98–11–52,

issued on May 14, 1998, which contained the

requirements of this amendment.

Issued in Renton, Washington, on June 12,

1998.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–16308 Filed 6–23–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–181–AD; Amendment

39–10625; AD 98–13–34]

RIN 2120–AA64

Airworthiness Directives; Empresa

Brasileira de Aeronautica, S.A.

(EMBRAER), Model EMB–145 Series

Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to all EMBRAER Model

EMB–145 series airplanes. This action

requires repetitive emergency extension

(free-fall) functional tests of the nose

landing gear (NLG), and lubrication of

all NLG hinge points, to ensure that the

NLG extends and locks down properly;

and corrective action, if necessary. This

amendment is prompted by issuance of

mandatory continuing airworthiness

information by a foreign civil

airworthiness authority. The actions

specified in this AD are intended to

prevent failure of the NLG to extend and

lock down properly, which could result

in damage to the airplane structure, and

consequent reduced controllability of

the airplane upon landing.

DATES: Effective July 9, 1998.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of July 9, 1998.

Comments for inclusion in the Rules

Docket must be received on or before

July 24, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 98–NM–

181–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

The service information referenced in

this AD may be obtained from Empresa

Brasileira de Aeronautica S.A.

(EMBRAER), P.O. Box 343—CEP 12.225,

Sao Jose dos Campos—SP, Brazil. This

information may be examined at the

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington; or at the FAA, Small

Airplane Directorate, Atlanta Aircraft

Certification Office, One Crown Center,

1895 Phoenix Boulevard, suite 450,

Atlanta, Georgia; or at the Office of the

Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Curtis Jackson, Aerospace Engineer,

Airframe and Propulsion Branch, ACE–

117A, FAA, Small Airplane Directorate,

Atlanta Aircraft Certification Office,

One Crown Center, 1895 Phoenix

Boulevard, suite 450, Atlanta, Georgia

30349; telephone (770) 703–6083; fax

(770) 703–6097.

SUPPLEMENTARY INFORMATION: The

Departmento de Aviacao Civil (DAC),

which is the airworthiness authority for

Brazil, recently notified the FAA that an

unsafe condition may exist on all

EMBRAER Model EMB–145 series

airplanes. The DAC advises that it has

received a report indicating that the

nose landing gear (NLG) on a Model

EMB–145 series airplane failed to

extend and lock down upon landing,

even after accomplishment of the

procedures for abnormal emergency

landing gear extension by the override

switch and free-fall mechanism. As a

result, the airplane landed with the NLG

not fully locked in the down position,

which resulted in minor damage to the

airplane structure. The exact cause of

the failure of the NLG to extend and

lock down properly has not been

determined at this time. This condition,

if not corrected, could result in damage

to the airplane structure, and

consequent reduced controllability of

the airplane upon landing.

Explanation of Relevant Service

Information

EMBRAER has issued Alert Service

Bulletin 145–32-A029, dated April 15,

1998, which describes procedures for

performing repetitive emergency

extension (free-fall) functional tests of

the NLG, and lubrication of all NLG

hinge points, to ensure that the NLG

extends and locks down properly; and

corrective action, if necessary.

Corrective actions include performing a

normal system functional test of the

NLG for five cycles, and repeating the

emergency extension functional test of

the NLG.

EMBRAER Alert Service Bulletin

145–32-A029, dated April 15, 1998,

references two chapters in the

EMBRAER Aircraft Maintenance

Manual (AMM) as additional sources of

information to accomplish the

functional test procedures. Chapter 32–

34–00 of the AMM describes procedures

for the emergency extension (free-fall)

functional test, and Chapter 32–30–00 of

the AMM describes procedures for the

normal system functional extension test.

The DAC classified this alert service

bulletin as mandatory and issued