Federal Register / Vol. 63, No. 150 /Wednesday, August 5, 1998 / Proposed Rules 41739

jackscrews, which could result in reduced

controllability of the airplane, accomplish

the following:

Restatement of Requirements of Paragraphs

(a) and (b) of AD 98–05–09

(a) Perform an inspection of the trim

actuator of the horizontal stabilizer to verify

jackscrew integrity and to detect excessive

wear of the tie rod, in accordance with

Commodore Jet Service Bulletin SB 1121–27–

023, dated August 14, 1996, or Revision 1,

dated May 28, 1997 (for Model 1121, 1121A,

and 1121B series airplanes); Westwind

Service Bulletin SB 1123–27–046, dated

August 14, 1996, or Revision 1, dated May

28, 1997 (for Model 1123 series airplanes); or

Westwind Service Bulletin SB 1124–27–133,

dated August 14, 1996, or Revision 1, dated

May 28, 1997 (for Model 1124 and 1124A

series airplanes); as applicable; at the time

specified in paragraph (a)(1) or (a)(2) of this

AD, as applicable.

(1) For airplanes that have accumulated

6,000 or more total flight cycles, or on which

the horizontal trim actuator has accumulated

2,000 or more flight cycles, as of April 10,

1998 (the effective date of AD 98–05–09,

amendment 39–10370): Inspect within 50

flight hours after April 10, 1998. Repeat the

inspection thereafter at intervals not to

exceed 300 flight hours (for Model 1121,

1121A, 1121B, and 1123 series airplanes); or

400 flight hours (for Model 1124 and 1124A

series airplanes); as applicable.

(2) For airplanes that have accumulated

less than 6,000 total flight cycles, and on

which the horizontal trim actuator has

accumulated less than 2,000 total flight

cycles, as of April 10, 1998: Inspect at the

time specified in paragraph (a)(2)(i) or

(a)(2)(ii) of this AD, as applicable.

(i) For Model 1121, 1121A, 1121B, and

1123 series airplanes: Inspect within 300

flight hours after April 10, 1998. Repeat the

inspection thereafter at intervals not to

exceed 300 flight hours.

(ii) For Model 1124 and 1124A series

airplanes: Inspect within 400 flight hours

after April 10, 1998. Repeat the inspection

thereafter at intervals not to exceed 400 flight

hours.

(b) If any discrepancy is found during any

inspection required by paragraph (a) of this

AD, prior to further flight, replace the

actuator or tie rod, as applicable, in

accordance with Commodore Jet Service

Bulletin SB 1121–27–023, dated August 14,

1996, or Revision 1, dated May 28, 1997 (for

Model 1121, 1121A, and 1121B series

airplanes); Westwind Service Bulletin SB

1123–27–046, dated August 14, 1996, or

Revision 1, dated May 28, 1997 (for Model

1123 series airplanes); or Westwind Service

Bulletin 1124–27–133, dated August 14,

1996, or Revision 1, dated May 28, 1997 (for

Model 1124 and 1124A series airplanes); as

applicable.

New Requirements of this AD

(c) Within 18 months after the effective

date of this AD, replace the trim actuator of

the horizontal stabilizer with a modified trim

actuator with modified jackscrew assemblies

(part number 21164–362 and –363 for Model

1121, 1121A, and 1121B series airplanes; part

number 21164–360 and –361 for Model 1123

series airplanes; or part number 21164–360

and –361 for Model 1124 and 1124A series

airplanes), in accordance with Commodore

Jet Service Bulletin SB 1121–27–025, dated

December 22, 1997 (for Model 1121, 1121A,

and 1121B series airplanes); Westwind

Service Bulletin SB 1123–27–047, dated

September 1, 1997 (for Model 1123 series

airplanes); or Westwind Service Bulletin SB

1124–27–136, dated September 1, 1997 (for

Model 1124 and 1124A series airplanes); as

applicable. Accomplishment of this

replacement terminates the repetitive

inspections required by this AD.

(d) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager,

International Branch, ANM–116, 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, International Branch,

ANM–116.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Manager, International

Branch, ANM–116.

(e) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to

a location where the requirements of this AD

can be accomplished.

Note 3: The subject of this AD is addressed

in Israeli airworthiness directive 27–97–09–

02, dated September 4, 1997.

Issued in Renton, Washington, on July 29,

1998.

D. L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–20835 Filed 8–4–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–53–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 767 Series 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

certain Boeing Model 767 series

airplanes. This proposal would require

a detailed visual inspection to detect

corrosion inside the forward trunnion

joint of the main landing gear (MLG);

follow-on actions; and repair, if

necessary. The proposal also provides

for optional terminating action for the

repetitive inspections. This proposal is

prompted by reports of corrosion at the

forward trunnion thrust face, tabs, and

the internal threads of the forward

trunnion of the MLG due to moisture in

the forward trunnion joint. The actions

specified by the proposed AD are

intended to prevent corrosion of the

forward trunnion joint, which could

lead to a stress corrosion fracture of the

forward trunnion and possible

consequent collapse of the MLG.

DATES: Comments must be received by

September 21, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 97–NM–

53–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:

James G. Rehrl, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Seattle Aircraft Certification Office,

1601 Lind Avenue, SW., Renton,

Washington; telephone (425) 227–2783;

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

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
41740 Federal Register / Vol. 63, No. 150 /Wednesday, August 5, 1998 / Proposed Rules

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 97–NM–53–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.

97–NM–53–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA has received several reports

of corrosion at the forward trunnion

thrust face and tabs, and at the internal

threads of the forward trunnion of the

outer cylinder of the main landing gear

(MLG) on Boeing Model 767 series

airplanes. During the first overhaul of

those airplanes, similar corrosion

damage was found on several of the

MLG’s that were removed from these

airplanes. These MLG’s had

accumulated between 20,000 and 26,000

total hours time-in-service, and between

7,000 and 9,000 total landings. The

presence of corrosion, due to moisture

in the trunnion joint, could lead to

stress corrosion cracking of the forward

trunnion. Such stress corrosion

cracking, if not corrected, could result

in a stress corrosion fracture of the

forward trunnion and possible

consequent collapse of the MLG.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Alert Service Bulletin 767–

32A0127, dated January 29, 1996, which

describes procedures for performing a

detailed visual inspection to detect

corrosion inside the forward trunnion

joint of the MLG; follow-on actions; and

repair, if necessary. The follow-on

actions include either application of

chrome plating to the forward trunnion,

or application of corrosion-inhibiting

compound to the forward trunnion and

repetitive inspections for corrosion

thereafter. Application of the chrome

plating to the forward trunnion would

eliminate the need for the repetitive

inspections.

The service bulletin references

Component Maintenance Manual 32–

11–40, dated June 1, 1994, as an

additional source of service information.

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

require accomplishment of the actions

specified in the alert service bulletin

described previously.

Cost Impact

There are approximately 455 Boeing

Model 767 series airplanes of the

affected design in the worldwide fleet.

The FAA estimates that 151 airplanes of

U.S. registry would be affected by this

proposed AD.

It would take approximately 8 work

hours per airplane to accomplish the

proposed visual inspection, at an

average labor rate of $60 per work hour.

Based on these figures, the cost impact

of the proposed inspection on U.S.

operators is estimated to be $72,480, or

$480 per airplane, per inspection cycle.

The cost impact figures above do not

account for the time to gain access to the

forward trunnion joint or to return a

main landing gear to service. In this

case, however, the access and close-up

work hours may account for the

predominant portion of the total cost

impact of this proposed AD. It is

estimated that it would take

approximately 65 work hours to gain

access to both forward trunnion joints,

and 89 work hours to return the airplane

to service. If these costs are included,

the cost impact for the proposed visual

inspections would be approximately

$1,467,720, or $9,720 per airplane, per

inspection cycle.

The repair of the forward trunnions

(two per airplane), which would include

both corrosion blend-out repairs as well

as the application of chrome plate to

certain portions of the forward trunnion,

would take approximately 72 work

hours to accomplish, at an average labor

rate of $60 per work hour. The cost of

the repair kits would be approximately

$16,000 per airplane. Based on these

figures, the cost impact of the proposed

repair on U.S. operators is estimated to

be $3,068,320, or $20,320 per airplane.

The cost impact figures discussed

above are based on assumptions that no

operator has yet accomplished any of

the 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 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

proposal would not have sufficient

federalism implications to warrant the

preparation of a Federalism Assessment.

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

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

adding the following new airworthiness

directive:

Boeing: Docket 97–NM–53–AD.

Applicability: Model 767 series airplanes,

manufacturer’s line positions 001 through

455 inclusive, certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

modified, altered, or repaired in the area

subject to the requirements of this AD. For

airplanes that have been modified, altered, or

repaired so that the performance of the

requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (c) 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
Federal Register / Vol. 63, No. 150 /Wednesday, August 5, 1998 / Proposed Rules 41741

been eliminated, the request should include

specific proposed actions to address it.

Compliance: Required as indicated, unless

accomplished previously.

To prevent corrosion of the forward

trunnion joint of the main landing gear

(MLG), which could lead to a stress corrosion

fracture of the forward trunnion and possible

consequent collapse of the MLG, accomplish

the following:

(a) Within 6 years since the outer cylinder

of the MLG was new, last overhauled, or

installed (replaced) after the last corrosion

repair in accordance with Boeing Alert

Service Bulletin 767–32A0127, dated January

29, 1996; or within 18 months after the

effective date of this AD; whichever occurs

later: Perform a detailed visual inspection to

detect corrosion inside the forward trunnion

joint and the internal threads of the MLG; in

accordance with the Accomplishment

Instructions of Boeing Alert Service Bulletin

767–32A0127, dated January 29, 1996.

(1) If no corrosion of the forward trunnion

joint is found, prior to further flight,

accomplish either paragraph (a)(1)(i) or

(a)(1)(ii) of this AD.

(i) Apply chrome plating to the forward

trunnion thrust and tab faces in accordance

with the alert service bulletin.

Accomplishment of this application of

chrome plating constitutes terminating action

for the requirements of this AD.

(ii) Apply corrosion-inhibiting compound

to the forward trunnion joint in accordance

with the Accomplishment Instructions of the

alert service bulletin. Repeat the detailed

visual inspection thereafter at intervals not to

exceed six years or until chrome plating is

applied to the forward trunnion thrust and

tab faces in accordance with the alert service

bulletin.

(2) If any corrosion of the forward trunnion

joint is found, prior to further flight,

accomplish either paragraph (a)(2)(i) or

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

(i) Repair the forward trunnion and apply

chrome plating to the forward trunnion

thrust and tab faces in accordance with the

alert service bulletin. Accomplishment of

this application of chrome plating constitutes

terminating action for the requirements of

this AD.

(ii) Repair the forward trunnion and apply

corrosion-inhibiting compound to the

forward trunnion joint in accordance with

the alert service bulletin. Repeat the detailed

visual inspection thereafter at intervals not to

exceed six years or until chrome plating is

applied to the forward trunnion thrust and

tab faces in accordance with the alert service

bulletin.

(b) Replacement, repair, or overhaul of the

outer cylinder of the MLG that includes the

application of chrome plating to the forward

trunnion thrust and tab faces in accordance

with Boeing Alert Service Bulletin 767–

32A0127, dated January 29, 1996, constitutes

terminating action for the requirements of

this AD.

(c) 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 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

(d) 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 July 29,

1998.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–20834 Filed 8–4–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–04–AD]

RIN 2120–AA64

Airworthiness Directives; de Havilland

Model DHC–8–100, –200, and –300

Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Supplemental notice of

proposed rulemaking; reopening of

comment period.

SUMMARY: This document revises an

earlier proposed airworthiness directive

(AD), applicable to certain de Havilland

Model DHC–8–100, –200, and –300

series airplanes, that would have

required modification of the flight

compartment door. That proposal was

prompted by a report that the door lock

mechanism of the flight compartment

door jammed and could not be opened

using the alternate release mechanism.

This new action would add repetitive

inspections for wear of the flight

compartment door hinges following

modification, and repair or replacement

of the hinges with new hinges, if

necessary. This new action also revises

the applicability of the existing AD. The

actions specified by this new proposed

AD are intended to prevent failure of the

alternate release mechanism of the flight

compartment door, which could delay

or impede the evacuation of the

flightcrew during an emergency. Such

failure also could result in the

flightcrew not being able to assist

passengers in the event of an

emergency.

DATES: Comments must be received by

August 31, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 97–NM–

04–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

Bombardier, Inc., Bombardier Regional

Aircraft Division, Garratt Boulevard,

Downsview, Ontario M3K 1Y5, Canada.

This information may be examined at

the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW.,

Renton, Washington; or at the FAA

Engine and Propeller Directorate, New

York Aircraft Certification Office, 10

Fifth Street, Third Floor, Valley Stream,

New York.

FOR FURTHER INFORMATION CONTACT: Ezra

Sasson, Aerospace Engineer, Systems

and Equipment Branch, ANE–172, FAA,

New York Aircraft Certification Office,

Engine and Propeller Directorate, 10

Fifth Street, Third Floor, Valley Stream,

New York 11581; telephone (516) 256–

7520; fax (516) 568–2716.

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