Federal Register / Vol. 62, No. 240 / Monday, December 15, 1997 / Rules and Regulations 65597

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96–NM–147–AD; Amendment

39–10244; AD 97–26–01]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 737–100, –200, –300, –400, and

–500 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain Boeing Model 737–

100, –200, –300, –400, and –500 series

airplanes, that requires repetitive

inspections to detect galling on the

input shaft and bearing of the standby

rudder power control unit (PCU), and

replacement of the standby rudder

actuator with a serviceable actuator, if

necessary. This amendment also

requires eventual replacement of the

input bearing of the standby PCU with

an improved bearing, which constitutes

terminating action for the inspections to

detect galling. This amendment is

prompted by a review of the design of

the flight control systems on Model 737

series airplanes. The actions specified

by this AD are intended to prevent

galling on the input shaft and bearing of

the standby PCU, which could result in

uncommanded movement of the rudder

or increased pedal forces. These

conditions, if not corrected, could result

in reduced controllability of the

airplane.

DATES: Effective January 20, 1998.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of January 20,

1998.

ADDRESSES: The service information

referenced in this AD may be obtained

from Dowty Aerospace Los Angeles,

1700 Business Center Drive, Duarte,

California 91010–2859. This

information may be examined at the

Federal Aviation Administration (FAA),

Transport Airplane Directorate, Rules

Docket, 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:

Kenneth W. Frey, Aerospace Engineer,

Systems and Equipment Branch, ANM–

130S, FAA, Transport Airplane

Directorate, Seattle Aircraft Certification

Office, 1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–2673; fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an airworthiness directive (AD)

that is applicable to all Boeing Model

737–100, –200, –300, –400, and –500

series airplanes was published in the

Federal Register on August 28, 1996 (61

FR 44234). That action proposed to

require operational tests of the standby

rudder power control unit (PCU) to

ensure correct operation of the rudder,

and correction of any discrepancy

found; and repetitive inspections to

detect galling on the input shaft and

bearing of the standby PCU, and

replacement of the standby rudder

actuator with a serviceable actuator, if

necessary. That action also proposed to

require eventual replacement of the

input bearing of the standby PCU with

an improved bearing, which would

constitute terminating action for the

inspections to detect galling.

Actions Since the Issuance of the

Proposal

Since the issuance of the proposal, the

FAA has reviewed and approved Dowty

Aerospace Los Angeles Service Bulletin

1150–27–04, dated December 5, 1996,

which describes procedures to replace

the input shaft assembly and related

hardware with a new, improved input

shaft. The new input shaft uses radial

bearings, which will prevent galling on

the input shaft and bearing. Paragraph

(b) of this final rule has been revised to

reference the Dowty Aerospace service

bulletin as an appropriate source of

service information for accomplishment

of the replacement.

In addition, since the issuance of the

proposal, the manufacturer has advised

the FAA that the replacement of the

input bearing of the standby PCU with

an improved bearing has been

incorporated on airplanes having line

numbers 2815 and subsequent.

Therefore, the FAA has revised the

applicability of this final rule to include

only airplanes having line numbers 1

through 2814 inclusive.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Request To Revise Statement of

Findings of Critical Design Review

Team

One commenter requests the second

paragraph of the Discussion section that

appeared in the preamble to the

proposed rule be revised to accurately

reflect the findings of the Critical Design

Review (CDR) team. The commenter

asks that the FAA delete the one

sentence in that paragraph that reads:

‘‘The recommendations of the team

include various changes to the design of

the flight control systems of these

airplanes, as well as correction of

certain design deficiencies.’’ The

commenter suggests that the following

sentences should be added: ‘‘The team

did not find any design issues that

could lead to a definite cause of the

accidents that gave rise to this effort.

The recommendations of the team

include various changes to the design of

the flight control systems of these

airplanes, as well as incorporation of

certain design improvements in order to

enhance its already acceptable level of

safety.’’

The FAA does not find that a revision

to this final rule in the manner

suggested by the commenter is

necessary, since the Discussion section

of a proposed rule does not reappear in

a final rule. The FAA acknowledges that

the CDR team did not find any design

issue that could lead to a definite cause

of the accidents that gave rise to this

effort. However, as a result of having

conducted the CDR of the flight control

systems on Boeing Model 737 series

airplanes, the team indicated that there

are a number of recommendations that

should be addressed by the FAA for

each of the various models of the Model

737. In reviewing these

recommendations, the FAA has

concluded that they address unsafe

conditions that must be corrected

through the issuance of AD’s. Therefore,

the FAA does not concur that these

design changes merely ‘‘enhance [the

Model 737’s] already acceptable level of

safety.’’

Request To Delete Operational Test

Requirement

Several commenters request that the

requirement to perform the operational

tests to cycle hydraulic fluid through

the standby rudder PCU and to ensure

correct operation of the rudder when the

standby hydraulic system is powered)

be deleted from the proposal. These

commenters point out that the Boeing

Service Letter referenced in paragraph

(a) of the proposal does not provide a

description of procedures to perform the

operational tests and does not include

instructions to correct any discrepancies

found. Another commenter requests that

paragraph (a) be deleted from the

proposal because it is not a technically

sound approach to eliminating galling.

This commenter states that the only way

to prevent galling is to upgrade the

input bearing of the standby hydraulic

system.
65598 Federal Register / Vol. 62, No. 240 / Monday, December 15, 1997 / Rules and Regulations

The FAA concurs that replacement of

the input bearing of the standby

hydraulic system with a new, improved

(upgraded) input bearing is a technically

sound approach to eliminate galling.

The requirement to replace the input

bearing with a new, improved input

bearing within 3 years, as specified in

the proposed AD, supports that

approach. Accordingly, this final rule

has been revised to delete the proposed

requirement for operational tests. The

FAA finds that, until the replacement of

the input bearing is required, repetitive

inspections to detect galling of the input

shaft and bearing, and replacement with

a serviceable standby rudder actuator, if

necessary (as specified in the proposed

AD), will positively address the unsafe

condition.

Request To Extend the Compliance

Time for Operational Tests

Several commenters request that the

compliance time be extended for the

operational tests discussed previously.

The commenters request that the

compliance time for the repetitive

operational tests be extended from the

proposed ‘‘at intervals not to exceed 250

hours time-in-service’’ to ‘‘at intervals

not to exceed 800 hours time-inservice.’’ The commenters state that the

recent FAA MSG–3 analysis on the

hydraulic fluid compound revealed that

the appropriate interval for the

operational test is every 800 hours timein-service.

As explained previously, the FAA has

removed the requirement for operational

tests from the final rule; however, this

final rule is considered to be interim

action. The FAA may consider further

rulemaking to require operational tests

of the standby system and correction of

any discrepancies. The FAA will

consider the results of the previously

discussed MSG–3 analysis in

determining an appropriate compliance

time for future proposed operational

tests.

Request To Extend the Compliance

Times for Inspections for Galling

Several commenters request that the

compliance time for the initial and

repetitive inspections for galling be

extended from 3,000 hours time-inservice to ‘‘18 months or 4,500 hours

time-in-service’’ for the proposed

inspections to detect galling on the

input shaft and bearing of the standby

rudder PCU. The commenters state that

18 months or 4,500 hours time-inservice closely corresponds to a ‘‘C’’

check, which allows operators to

schedule maintenance at a heavy

maintenance base without impacting

safety. One commenter suggests that the

initial inspection and repetitive interval

inspections should be extended to

46,000 flight hours. (The FAA infers

that the ‘‘46,000’’ flight hours is a

typographical error and that the

commenter actually requests an

extension to 4,600 flight hours.)

The FAA concurs with the

commenters’ request to revise the

compliance time to 18 months or 4,500

hours time-in-service (whichever occurs

later) since the last inspection. The FAA

finds that this extension of the

compliance time will not adversely

affect safety, and will more closely

correspond to the operators’ scheduled

‘‘C’’ checks. The FAA has revised

paragraph (a) of this final rule

accordingly.

Requests To Revise the Compliance

Time for Replacement of the Input

Bearing

One commenter (the airplane

manufacturer) requests that the

proposed compliance time for

replacement of the input bearing be

changed from 3 to 4 years after the

effective date of the AD. The commenter

states that the inspection should be

accomplished at least once in 4 years,

and the inspection should detect any

units that are galled. Another

commenter requests that the

replacement be required by August 1,

1997. This commenter states that the

National Transportation Safety Board

(NTSB) suggests that date in a

recommendation to the FAA.

The FAA does not concur that the

compliance time should be revised. In

developing an appropriate compliance

time for this action, the FAA considered

not only the degree of urgency

associated with addressing the subject

unsafe condition, but the availability of

required parts and the practical aspect

of accomplishing the required

replacement within an interval of time

that parallels normal scheduled

maintenance for the majority of affected

operators. The manufacturer has

advised that an ample number of

required parts will be available for

modification of the U.S. fleet within the

compliance period. However, under the

provisions of this final rule, the FAA

may approve requests for adjustments to

the compliance time if data are

submitted to substantiate that such

adjustments would provide an

acceptable level of safety.

Request To Delete (or Make Optional)

the Replacement Requirement

Several commenters request that the

proposed replacement requirement be

deleted to provide more time to review

the retrofit program. One commenter

suggests that the requirement should be

optional, as long as the inspection to

detect galling on the PCU input shaft is

carried out repetitively every 46,000

flight hours. The commenter does not

provide a justification for the

recommended 46,000 flight hours. (The

FAA infers that the ‘‘46,000’’ flight

hours is a typographical error and that

the commenter actually requests a

compliance time of 4,600 flight hours.)

The FAA does not concur with the

commenters’ requests. Although the

repetitive inspections required by this

final rule may detect galled units before

the galling progresses to a level that

would affect the flight control system,

the inspections do not ensure that

galling will not occur. The replacement

of the input bearing with a new,

improved bearing, as described in the

Dowty Aerospace service bulletin

discussed previously, will positively

address the subject unsafe condition

and provide an acceptable level of

safety.

The FAA has determined that long

term continued operational safety will

be better assured by modifications or

design changes to remove the source of

the problem, rather than by repetitive

inspections. Long term inspections may

not be providing the degree of safety

assurance necessary for the transport

airplane fleet. This, coupled with a

better understanding of the human

factors associated with numerous

repetitive inspections, has led the FAA

to consider placing less emphasis on

special procedures and more emphasis

on design improvements. The

replacement requirement is in

consonance with these considerations.

Request To Revise the Cost Estimate

One commenter, the airplane

manufacturer, requests that the cost

estimate for the proposed inspections be

revised from $60 to $120 per airplane,

per inspection cycle. The FAA

acknowledges that the correct cost

estimate is $120 per airplane, per

inspection cycle, and has revised the

cost impact information, below,

accordingly.

Conclusion

After careful review of the available

data, including the comments noted

above, the FAA has determined that air

safety and the public interest require the

adoption of the rule with the changes

previously described. The FAA has

determined that these changes will

neither significantly increase the

economic burden on any operator nor

increase the scope of the AD.
Federal Register / Vol. 62, No. 240 / Monday, December 15, 1997 / Rules and Regulations 65599

Cost Impact

There are approximately 2,830 Model

737 series airplanes of the affected

design in the worldwide fleet. The FAA

estimates that 1,037 airplanes of U.S.

registry would be affected by this

proposed AD.

The FAA estimates that it will take

approximately 2 work hours per

airplane to accomplish the required

inspections, at an average labor rate of

$60 per work hour. Based on these

figures, the cost impact of the required

inspections on U.S. operators is

estimated to be $124,440, or $120 per

airplane, per inspection cycle.

The FAA estimates that it will take

approximately 2 work hours per

airplane to accomplish the required

replacement, at an average labor rate of

$60 per work hour. The cost of the

replacement parts is estimated to be

$793 per airplane. Based on these

figures, the cost impact of the required

replacement is estimated to be $946,781,

or $913 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 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.

For the reasons discussed above, I

certify that this action (1) is not a

‘‘significant regulatory action’’ under

Executive Order 12866; (2) is not a

‘‘significant rule’’ under DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979); and (3)

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 final evaluation has

been prepared for this action and it is

contained in the Rules Docket. A copy

of it 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:

97–26–01 Boeing: Amendment 39–10244.

Docket 97–NM–147–AD.

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

–400, and –500 series airplanes, having line

numbers 1 through 2814 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

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 uncommanded movement of

the rudder or increased rudder pedal forces,

and consequent reduced controllability of the

airplane, accomplish the following:

(a) Within 18 months or 4,500 hours timein-service after the effective date of this AD,

whichever occurs later; and thereafter at

intervals not to exceed 18 months or 4,500

hours time-in-service, whichever occurs

later: Perform an inspection to detect galling

on the input shaft and bearing of the standby

rudder PCU by accomplishing paragraphs

(a)(1) through (a)(10) of this AD.

(1) Shut off all hydraulic power.

(2) Gain access to the standby rudder

actuator.

(3) Disconnect the input rod from the

standby actuator.

(4) Using a push/pull spring scale

(minimum +/¥10% accuracy at 1.0 pound;

preferably one having a peak load memory

function), push on the standby rudder

actuator input lever with sufficient force to

move the lever from the neutral position up

to, but not touching, the aft stop. The scale

must be contacting the input lever at

approximately the clevis bolt centerline.

While applying the load required to move the

lever, the scale must be maintained at an

angle perpendicular to the lever arm (not to

exceed 20 degrees from perpendicular). The

force required to move the input lever

throughout this range of motion must not

exceed one pound.

(5) Repeat the test specified in paragraph

(a)(4) of this AD, moving the lever arm from

the aft stop position up to the forward stop,

but not touching. The force required to move

the input lever throughout this range of

motion must not exceed one pound.

(6) Repeat the test specified in paragraph

(a)(4) of this AD, moving the lever arm from

the forward stop position back to the neutral

position. The force required to move the

input lever throughout this range of motion

must not exceed one pound.

(7) If the actuator force encountered during

any of the procedures required by paragraph

(a)(4), (a)(5), or (a)(6) of this AD exceeds one

pound, prior to further flight, replace the

standby rudder actuator with a serviceable

actuator, and test the standby rudder actuator

in accordance with the procedure specified

in paragraph (a)(9) of this AD.

(8) If the actuator force encountered during

any of the procedures required by paragraph

(a)(4), (a)(5), or (a)(6) of this AD is one pound

or less, prior to further flight, reconnect the

input rod to the standby rudder actuator, and

test the standby rudder actuator in

accordance with the procedure specified in

paragraph (a)(9) of this AD.

(9) Perform a functional test of the standby

rudder actuator in accordance with

Maintenance Manual 737–100/–200, Chapter

27–21–141, removal/installation (for Model

737–100 and –200 series airplanes); or

maintenance Manual 737–300/–400/–500,

Chapter 27–21–24, removal/installation (for

Model 737–300, –400, and –500 series

airplanes).

(10) Restore the airplane to its normal

condition.

(b) Within 3 years after the effective date

of this AD, replace the input bearing of the

standby rudder PCU with an improved

bearing in accordance with Dowty Aerospace

Los Angeles Service Bulletin 1150–27–04,

dated December 5, 1996; or in accordance

with a method approved by the Manager,

Seattle Aircraft Certification Office (ACO),

FAA, Transport Airplane Directorate.

Replacement of the input bearing with an

improved bearing in accordance with the

service bulletin 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

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.
65600 Federal Register / Vol. 62, No. 240 / Monday, December 15, 1997 / Rules and Regulations

(e) Except as provided by paragraph (b) of

this AD, the replacement shall be done in

accordance with Dowty Aerospace Los

Angeles Service Bulletin 1150–27–04, dated

December 5, 1996. 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 Dowty Aerospace Los Angeles,

1700 Business Center Drive, Duarte,

California 91010–2859. 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.

(f) This amendment becomes effective on

January 20, 1998.

Issued in Renton, Washington, on

December 8, 1997.

Stewart R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–32590 Filed 12–12–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–259–AD; Amendment

39–10247; AD 97–26–04]

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 amendment adopts a

new airworthiness directive (AD) that is

applicable to all Boeing Model 737–100,

–200, –300, –400, and –500 series

airplanes. This amendment requires a

one-time inspection to determine if

certain ailerons are installed on the

airplane. This amendment also requires

removing any defective aileron,

scrapping it, and replacing it with a new

or serviceable aileron. This amendment

is prompted by reports of failure of the

aileron due to an inappropriate repair

procedure. The actions specified in this

AD are intended to detect and correct

defective ailerons, which could result in

in-flight separation of an aileron from

the airplane and consequent reduced

controllability of the airplane.

DATES: Effective December 30, 1997.

Comments for inclusion in the Rules

Docket must be received on or before

February 13, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 97–NM–

259–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Information concerning this

amendment may be obtained from or

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Greg

Schneider or Nenita Odesa, Aerospace

Engineers, Airframe Branch, ANM–

120S, FAA, Transport Airplane

Directorate, Seattle Aircraft Certification

Office, 1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–2028 or (425) 227–2557; fax

(425) 227–1181.

SUPPLEMENTARY INFORMATION: The FAA

has received two reports of failure of the

aileron on Boeing Model 737 series

airplanes. In one incident, a two-foot

section of an aileron separated from the

airplane during descent, which resulted

in vibration of the flight controls. In the

second incident, 30 percent of an

aileron separated from the airplane

during climb. The flightcrew had to

input a significant amount of trim to

straighten the wings to a level position

prior to landing. This airplane had

accumulated 34 flight cycles since its

ailerons were rebuilt by Tramco Inc.

(doing business as BFGoodrich (BFG)

Aerospace, Repair Station HN6R593N).

Investigation revealed that the cause

of these failures has been attributed to

an inappropriate repair procedure

accomplished by BFG Aerospace.

During the process of rebuilding

ailerons, part number 65–46454–XX, for

Boeing Model 737–100, –200, –300,

–400, and –500 series airplanes, BFG

Aerospace did not use proper

procedures in the preparation of the

aileron surface prior to the lay-up of the

skin panel. As a result, the contact

surface between the skin and core did

not provide adequate adhesion

properties for the bonded skin panel.

BFG Aerospace has not located all of

the defective ailerons and has not

provided documentation which verifies

removal of the defective ailerons from

service.

Defective ailerons that are installed on

an airplane, if not detected and

corrected, could result in in-flight

separation of an aileron from the

airplane, which could result in reduced

controllability of the airplane.

Explanation of the Requirements of the

Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other Boeing Model 737–

100, –200, –300, –400, and –500 series

airplanes of the same type design, this

AD is being issued to detect defective

ailerons installed on an airplane, which

could result in in-flight separation of an

aileron from the airplane and

consequent reduced controllability of

the airplane. This AD requires a onetime visual inspection to determine if

certain ailerons are installed on the

airplane. This AD also requires

removing any defective aileron,

scrapping it, replacing it with a new or

serviceable aileron, and submitting an

inspection report to the FAA, if

necessary.

Determination of Rule’s Effective Date

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good

cause exists for making this amendment

effective in less than 30 days.

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