10226 Federal Register / Vol. 62, No. 44 / Thursday, March 6, 1997 / Proposed Rules

the requirement of AD 67–04–01 to repeat the

inspection at intervals of 6 months.

Paragraph (b)(2) permits the reinspection

interval to be extended to 18 months once the

specified protective paint system is installed.

(1) As a result of the inspection required

by paragraph (a) of this AD:

(i) If no corrosion is detected, repeat the

inspection thereafter at intervals not to

exceed 6 months (26 weeks) until the actions

specified in paragraph (b)(2) of this AD are

accomplished.

(ii) If any corrosion is detected, prior to

further flight, either repair the corroded part

with an FAA-approved repair; or replace the

corroded part with a new or serviceable part

of the same part number; or replace the

corroded part with a part approved by the

FAA. Thereafter, continue to perform the

inspection at intervals not to exceed 6

months (26 weeks) until paragraph (b)(2) of

this AD is accomplished.

(2) Within 12 months after the effective

date of this AD, install the protective paint

system in accordance with Grumman

Gulfstream I Aircraft Service Change No. 190,

dated June 28, 1971. After installation,

continue to perform the inspection required

by this paragraph at intervals not to exceed

18 months.

(c) For airplanes on which a protective

paint system has been installed previously in

accordance with Grumman Gulfstream I

Aircraft Service Change No. 190, dated June

28, 1971: Accomplish paragraphs (c)(1) and

(c)(2) of this AD. As of the effective date of

this AD, the inspections required by this

paragraph shall be accomplished in

accordance with Grumman Gulfstream I

Aircraft Service Change No. 190, dated June

28, 1971.

Note 6: The repeated inspection referred to

in this paragraph is the same inspection

previously required by AD 67–04–01.

Paragraph (c)(1) of this AD merely restates

the requirement of AD 67–04–01 to repeat the

inspection at intervals of 12 months.

Paragraph (c)(2) permits the reinspection

interval to be extended to 18 months.

(1) As a result of the inspection required

by paragraph (a) of this AD:

(i) If no corrosion is detected, repeat the

inspection thereafter at intervals not to

exceed 12 months until paragraph (c)(2) of

this AD is accomplished.

(ii) If any corrosion is detected, prior to

further flight, either repair the corroded part

with an FAA-approved repair; or replace the

corroded part with a new or serviceable part

of the same part number; or replace the

corroded part with a part approved by the

FAA. Thereafter, continue to perform the

inspection at intervals not to exceed 12

months until paragraph (c)(2) of this AD is

accomplished.

(2) Within 18 months since the last

inspection accomplished in accordance with

paragraph (c)(1) of this AD (i.e., the last

inspection accomplished in accordance with

AD 67–04–01), repeat the inspection

specified in paragraph (c)(1) of this AD.

(i) If no corrosion is detected, repeat the

inspection thereafter at intervals not to

exceed 18 months.

(ii) If any corrosion is detected, prior to

further flight, repair in accordance with the

service change. After repair, continue to

perform the inspection at intervals not to

exceed 18 months.

(d)(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, Atlanta

Aircraft Certification Office (ACO), FAA,

Small 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, Atlanta ACO.

(2) Alternative methods of compliance,

approved previously in accordance with AD

67–04–01, amendment 39–1234, are

approved as alternative methods of

compliance with this AD.

Note 7: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Atlanta ACO.

(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. Issued in Renton,

Washington, on February 27, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–5463 Filed 3–5–97; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 97–NM–19–AD]

RIN 2120–AA64

Airworthiness Directives; Gulfstream

Aerospace Corporation Model G–159

(G–I) 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

Gulfstream Model G–159 (G–I)

airplanes, that currently requires

repetitive inspections to detect chafe

wear on the upper diagonal engine

mount tube, and replacement or repair,

if necessary. This action would require

the installation of chafe guards at the

engine mounts, which would terminate

the currently required inspections. It

also would require that the chafe guards

then be repetitively inspected for chafe

wear. This proposal is prompted by the

development of a modification that will

provide better protection of the subject

area against future chafe wear. The

actions specified by the proposed AD

are intended to prevent excessive chafe

wear in the area of the upper diagonal

engine mount tubes and trusses; if not

detected and corrected, such wear could

result in failure of the engine mount

assembly and possible separation of the

engine from the airplane.

DATES: Comments must be received by

April 14, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 97–NM–

19–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

Gulfstream Aerospace Corporation,

Technical Operations Department, P.O.

Box 2206, M/S D–10, Savannah, Georgia

31402–2206. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Christina Marsh, Aerospace Engineer,

Airframe and Propulsion Branch, ACE–

117A, FAA Small Airplane Directorate,

Atlanta Aircraft Certification Office,

Campus Building, 1701 Columbia

Avenue, Suite 2–160, College Park,

Georgia 30337–2748; telephone (404)

305–7362; fax (404) 305–7348.

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
Federal Register / Vol. 62, No. 44 / Thursday, March 6, 1997 / Proposed Rules 10227

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 97–NM–19–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–103, Attention: Rules Docket No.

97–NM–19–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

In 1967, the FAA issued AD 67–17–

05, amendment 39–511 (32 FR 7248,

May 16, 1967), applicable to certain

Gulfstream Model G–159 airplanes, to

require repetitive visual inspections to

detect chafe wear on the upper diagonal

engine mount tubes, part number (P/N)

159W10172–11 (left engine) and P/N

159W10172–13 (right engine).

Depending upon the depth of wear

found during any inspection, the AD

requires that the tube(s) either be

replaced or repaired, and the repetitive

visual inspections continued thereafter

at intervals of 200 hours time-in-service.

That AD also provides for optional

terminating action for these visual

inspections, which consists of installing

a chafe guard (P/N 159WP10017–11) on

each of the upper diagonal trusses. If an

operator elects to install these chafe

guards, the AD requires that the chafe

guards be repetitively inspected to

detect wear thereafter at intervals of

2,500 hours time-in-service.

That action was prompted by reports

of excessive chafe wear found on the

engine mount tubes on some airplanes.

The chafe wear was determined to be

caused by the tube coming into contact

with the engine exhaust tail pipe

blanket. The requirements of that AD

are intended to detect and correct chafe

wear of the engine mount tube; if such

wear is left unchecked, it could result in

the failure of the engine mount

assembly and possible separation of the

engine from the airplane.

Actions Since Issuance of Previous Rule

As part of its on-going program to

address issues relevant to the continued

operational safety of the aging transport

fleet, the FAA, along with Gulfstream

Aerospace Corporation and several U.S.

and non-U.S. operators of the affected

airplanes, agreed to undertake the task

of identifying and implementing

procedures to ensure the continuing

structural airworthiness of aging

commuter class airplanes. This group

recently reviewed selected customer

bulletins and aircraft service changes,

applicable to Gulfstream Model G–159

airplanes, to be recommended for

mandatory rulemaking action to ensure

the continued operational safety of these

airplanes.

Explanation of Relevant Service

Information

The group reviewed and

recommended Grumman Gulfstream I

Aircraft Service Change No. 180, dated

October 17, 1966, for mandatory

regulatory action. That service change

describes procedures for a one-time

initial inspection to detect chafe wear of

the upper diagonal trusses [P/N

159W10172–5 (left-hand nacelle) and P/

N 159W10172–7 (right-hand nacelle),

and replacement of worn parts, if

necessary.

The service change also describes

procedures for installing chafe guards

[part number 159WP10017–11] after the

inspection of the trusses is

accomplished. The chafe guards are

intended to provide better protection of

the subject area against future chafe

wear. Once these chafe guards are

installed, the service change

recommends that an inspection of the

chafe guards be conducted thereafter at

intervals of 2,500 hours time-in-service.

(The installation of the chafe guards

and continuing inspections, as

described in this service change, are the

same actions that were provided as

optional terminating action for the

visual inspections of the engine mount

tubes in AD 67–17–05.)

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 67–17–05. It would

continue to require the repetitive visual

inspections to detect chafe wear of the

engine mount tube, and repair or

replacement of the tube(s), if necessary.

These inspections would be required to

continue until (1) a one-time inspection

is performed to detect chafe wear of the

upper diagonal truss, and (2) chafe

guards are installed. (Once the chafe

guards are installed, the previously

required visual inspections of the

engine mount tubes would be

terminated.) The proposed AD also

would require that, after the chafe

guards are installed, an inspection of the

chafe guards be conducted at intervals

of 2,500 hours time-in-service. These

actions would be required to be

accomplished in accordance with the

aircraft service change described

previously.

Cost Impact

There are approximately 146

Gulfstream Model G–159 airplanes of

the affected design in the worldwide

fleet. The FAA estimates that 72

airplanes of U.S. registry would be

affected by this proposed AD.

The actions that are currently

required by AD 67–17–05 take

approximately 4 work hours per

airplane to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of the

currently required actions on U.S.

operators is estimated to be $17,280, or

$240 per airplane, per inspection.

The installation of the chafe guards

that is proposed in this AD action

would take approximately 40 work

hours per airplane to accomplish, at an

average labor rate of $60 per work hour.

Required parts would cost

approximately $152 per airplane. Based

on these figures, the cost impact of the

proposed requirements of this AD on

U.S. operators is estimated to be

$183,744, or $2,552 per airplane.

The inspections of the chafe guards

that are proposed in this AD action

would take approximately 4 work hours

per airplane to accomplish, at an

average labor rate of $60 per work hour.

Based on these figures, the cost impact

of the currently required actions on U.S.

operators is estimated to be $17,280, or

$240 per airplane, per inspection.

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 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
10228 Federal Register / Vol. 62, No. 44 / Thursday, March 6, 1997 / Proposed Rules

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

removing amendment 39–511 (32 FR

7248, May 16, 1967), and by adding a

new airworthiness directive (AD), to

read as follows:

Gulfstream Aerospace Corporation (formerly

Grumman): Docket 97–NM–19–AD.

Supersedes AD 67–17–05, Amendment

39–511.

Applicability: All Model G–159 (G–I)

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

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 (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

been eliminated, the request should include

specific proposed actions to address it.

Compliance: Required as indicated, unless

accomplished previously.

To prevent excessive chafe wear of the

engine mount tube and upper diagonal truss,

which could lead to failure of the engine

mount assembly and possible separation of

the engine from the airplane, accomplish the

following:

(a) For airplanes on which chafe guards, P/

N 159WP10017–11, have not been installed

on each upper diagonal truss prior to the

effective date of this AD: Accomplish

paragraphs (a)(1), (a)(2), and (a)(3) of this AD:

(1) Restatement of Requirements of AD 67–

17–05: Within 100 hours time-in-service after

May 16, 1967 (the effective date of AD 67–

17–05, amendment 39–411), visually inspect

to detect chafe wear of the lower half of the

upper diagonal engine mount tubes having

part number (P/N) 159W10172–11 (left

engine) and P/N 159W10172–13 (right

engine).

(i) If no chafe wear is detected: Repeat this

inspection thereafter at intervals not to

exceed 200 hours time-in-service until the

requirements of paragraph (a)(2) are

accomplished.

(ii) If any tube is found to have wear depth

greater than 0.030 inch (as measured from the

outer edge of the tube): Prior to further flight,

replace the tube with a tube of the same part

number or with an FAA-approved equivalent

part. After replacement, repeat the inspection

required by this paragraph at intervals not to

exceed 200 hours time-in-service until the

requirements of paragraph (a)(2) are

accomplished.

(iii) If any tube is found to have wear depth

of 0.030 inch deep or less, as measured from

the outer edge of the tube: Prior to further

flight, either repair the tube in accordance

with an FAA-approved repair, or replace the

tube with a part of the same part number or

with an FAA-approved equivalent part. After

repair or replacement, repeat the inspection

required by this paragraph at intervals not to

exceed 200 hours time-in-service until the

requirements of paragraph (a)(2) are

accomplished.

(2) One-Time Inspection of Upper Diagonal

Truss and Installation of Chafe Guards.

Within 600 hours time-in-service after the

effective date of this AD, perform a one-time

visual inspection to detect chafe wear of the

left-hand and right-hand upper diagonal

truss, P/N’s 159W10172–5 (left-hand nacelle)

and P/N 159W10172–7 (right-hand nacelle),

in accordance with Grumman Gulfstream

Service Change No. 180, dated October 17,

1966. Once this inspection is completed, the

repetitive inspections required by paragraph

(a)(1) of this AD may be terminated.

(i) If there is no evidence of chafe wear on

the truss; or if there is evidence of chafe wear

and the depth of wear is .030 inch or less

(measured from the surface of the tube): Prior

to further flight, install a chafe guard, P/N

159WP10017–11, on the truss.

(ii) If there is any evidence of chafe wear

and the depth of wear exceeds .030 inch

measured (from the surface of the tube): Prior

to further flight, install a new upper diagonal

truss and install a chafe guard, P/N

159WP10017–11, on the truss.

(3) Continuing Inspections of Chafe

Guards. Within 2,500 hours time-in-service

after installation of the chafe guards required

by paragraph (a)(2) of this AD, perform an

inspection of the undersurface of each chafe

guard for evidence of chafe wear, in

accordance with Grumman Gulfstream

Service Change No. 180, dated October 17,

1966.

(i) If no chafe wear is detected: Repeat the

inspection at intervals not to exceed 2,500

hours time-in-service.

(ii) If any chafe wear is detected: Prior to

further flight, replace the chafe guard with a

new or serviceable part. After replacement,

repeat the inspection for chafe wear of the

chafe guard thereafter at intervals not to

exceed 2,500 hours time-in-service.

(b) For airplanes on which chafe guards, P/

N 159WP10017–11, have been installed on

each upper diagonal truss prior to the

effective date of this AD: Within 2,500 hours

time-in-service after the last inspection of the

chafe guard required by paragraph (c) of AD

67–17–05, repeat that inspection to detect

chafe wear of the chafe guards in accordance

with Grumman Gulfstream Service Change

No. 180, dated October 17, 1966.

(1) If no chafe wear is detected: Repeat the

inspection thereafter at intervals not to

exceed 2,500 hours time-in-service.

(2) If any chafe wear is detected: Prior to

further flight, replace the chafe guard with a

new or serviceable part. After replacement,

repeat the inspection thereafter at intervals

not to exceed 2,500 hour time-in-service.

(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, Atlanta

Aircraft Certification Office (ACO), FAA,

Small 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, Atlanta ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Atlanta 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 February

27, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–5462 Filed 3–5–97; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 97–NM–16–AD]

RIN 2120–AA64

Airworthiness Directives; Gulfstream

Aerospace Corporation Model G–159

(G–I) 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

Gulfstream Model G–159 (G–I)

airplanes, that currently requires

modification and repetitive inspections

for cracks in the main landing gear

(MLG) retract cylinder attachment

fittings. This action would require the

installation of improved attachment

fittings which, when accomplished,