This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

55540

Vol. 62, No. 207

Monday, October 27, 1997

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96–NM–12–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 757 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 all Boeing Model

757 series airplanes, that would have

required the replacement of certain

discrepant ram air turbine (RAT)

deployment actuator assemblies that

were shipped improperly. That proposal

was prompted by reports of certain RAT

actuators that failed to deploy upon

command due to interference in the

actuator locking mechanism caused by

damage incurred during shipping of the

actuators. This new action revises the

proposed rule to require the use of an

FAA-approved maintenance program in

lieu of the use of shipping procedures

prescribed in that proposal. Failure of

the RAT to deploy, specifically during

a dual engine failure, would result in

loss of hydraulic power and would

adversely affect the continued safe flight

and landing of the airplane.

DATES: Comments must be received by

November 26, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 96–NM–

12–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:

Sheila I. Mariano, Aerospace Engineer,

Systems and Equipment Branch, ANM–

130S, FAA, Transport Airplane

Directorate, Seattle Aircraft Certification

Office (ACO), 1601 Lind Avenue, SW.,

Renton, Washington; telephone (425)

227–2675; 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

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 96–NM–12–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.

96–NM–12–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

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 757 series airplanes was

published in the Federal Register on

August 6, 1996 (61 FR 40758). That

NPRM would have required the

replacement of certain discrepant ram

air turbine (RAT) deployment actuator

assemblies with units that have been

modified (repaired and reidentified) and

shipped in a specific fashion prior to

installation. It also proposed to require

that any RAT installed on an airplane in

the future must have been modified and

shipped properly prior to installation.

That NPRM was prompted by several

reports indicating that certain RAT

deployment actuators failed to deploy

upon command due to interference in

the actuator locking mechanism. The

interference condition was caused by

damage that had been incurred during

shipping of the actuator assembly.

The actions specified by that NPRM

were intended to ensure that the RAT is

deployed when commanded to do so.

Failure of the RAT to deploy,

specifically during a dual engine failure,

would result in loss of hydraulic power,

which would adversely affect the

continued safe flight and landing of the

airplane.

Explanation of New Service

Information

Since the issuance of that NPRM, the

FAA has reviewed and approved two

new Arkwin Industries service

bulletins. (Arkwin Industries, Inc., is the

manufacturer of the subject RAT

deployment actuator assemblies.) These

new service bulletins are essentially

identical to the original issues, but

contain certain changes regarding

warranty, shipping, and price and

availability information. Arkwin

Industries Service Bulletin 1211233–29–

21–3, Revision 3, dated February 7,

1997, includes the warranty and

shipping information for the RAT.

Arkwin Industries Service Bulletin

1211233–29–21–4, Revision 3, dated

February 7, 1997, includes clarification

of price and availability information.

Consideration of Comments Received

Since the issuance of that NPRM, the

FAA has given due consideration to the

comments received in response to the
Federal Register / Vol. 62, No. 207 / Monday, October 27, 1997 / Proposed Rules 55541

NPRM. Certain of these comments and

the information they provided have led

the FAA to consider making certain

significant changes to the proposal.

These comments and the changes

prompted by them are explained below:

Request to Require Revision of the

Maintenance Program

Several commenters request that the

proposal be revised to allow operators to

change their FAA-approved

maintenance program to incorporate the

procedures specified in the proposal.

These commenters express concern over

the difficulty there will be in attempting

to use standard recordkeeping

procedures to show compliance with

the proposed provisions that would

mandate the use of a particular shipping

container and shipping sleeve when

transporting the actuator assemblies.

The commenters also suggest that the

personnel involved in shipping and

receiving usually are not familiar with

the stringent recordkeeping

requirements imposed by the AD

process; as a result, implementation of

the proposed rule could prove costly

and difficult. The commenters state that,

while the proposed rule attempts to

associate shipping requirements with

the task of installing the modified RAT

on the airplane, in actuality, the

technician who signs the paperwork for

installing the RAT cannot be held

responsible for determining whether the

RAT has been shipped in the proper

container during the various stages of

transport. Further, these commenters

point out that airworthy parts are

successfully shipped every day within

every operator’s FAA-approved

maintenance program, so it is

unnecessary to create and maintain a

separate AD procedure specifically for

shipping the subject actuator assembly.

The FAA partially concurs with the

commenters’ requests. The FAA

acknowledges that, through the

maintenance program, compliance with

the required actions can be more easily

demonstrated. Therefore, the FAA has

changed the proposed AD to require that

operators revise their FAA-approved

maintenance program to include the use

of the shipping container and shipping

sleeve assembly specified in Arkwin

Industries Service Bulletin 1211233–29–

21–4, Revision 3, dated February 7,

1997, whenever the deployment

actuator of the RAT is removed from the

airplane. This action is described in

paragraph (a) of this AD.

However, the FAA does not concur

that stringent recordkeeping

requirements will prove costly and

difficult. The FAA contends that by

revising the maintenance program, the

operators may choose how to track

proper shipment of the RAT’s. This may

be demonstrated through the use of

shipping tags, which the FAA contends

would not cause an undue burden on

the operators. In addition, the FAA does

not concur with the commenter’s

statement that the technician who signs

the paperwork for installing the RAT

cannot be held responsible for

determining whether proper shipping

procedures were followed. The FAA

finds that, through the maintenance

program, an individual (e.g., technician

or installer) may be designated to ensure

that proper shipping procedures were

used to prevent damage during

shipment.

In addition, the FAA acknowledges

the commenter’s statement that within

every operator’s FAA-approved

maintenance program, airworthy parts

can be shipped successfully, so there is

no reason to maintain a separate AD

procedure for shipping the RAT actuator

assemblies. However, in this case, there

are no FAA requirements for shipping

RAT actuators because the FAA did not

foresee that the actuators would be

susceptible to damage during shipment.

In addition, the FAA finds that practices

may vary among operators when

shipping airworthy parts. Therefore, in

order to minimize the probability of

damage to the actuators, the FAA

concludes that the requirements for

shipping the actuators must be included

in this AD and added to the operator’s

maintenance program.

Request to Exempt Certain Actuators

One commenter, a U.S. operator,

requests that a stipulation be added to

the proposal to ‘‘exempt’’ those

actuators that have been modified and

delivered directly from Boeing to

operators as equipment on new

airplanes. As an alternative to this

suggestion, the commenter requests that

the proposal include data from Boeing

or Arkwin that indicate the serial

numbers of actuators that meet the

specifications of Arkwin Industries

Service Bulletin 1211233–29–21–4,

Revision 2, dated June 17, 1994. As

justification for these requests, this

commenter states that the majority of its

RAT deployment actuator assemblies

were received as on-aircraft equipment

when the airplanes were delivered new

from Boeing. All of these on-aircraft

actuators have been modified, as

indicated by the ‘‘B’’ suffix on the serial

number; however, this operator has no

way of knowing whether these specific

actuators were shipped (prior to

installation) in accordance with the

Arkwin service bulletin.

The FAA partially concurs with the

commenter’s request. However, in

responding to this commenter, the FAA

finds that some clarification is

necessary:

The commenter’s justification

suggests that modified actuators having

a ‘‘B’’ suffix in the serial number should

be exempt because they were delivered

by the manufacturer as equipment on a

new airplane. This justification assumes

that the manufacturer shipped the

actuator properly. While this may be

true, the FAA considers that the

identified problems will recur if the

RAT is removed and shipped after

delivery (i.e., as a replacement to

another facility). Therefore, those

operators that have received the

modified ‘‘B’’ RAT as delivered on the

airplane are ‘‘exempt’’ only if it can be

verified that the RAT was not removed

or shipped after delivery of the airplane.

As far as the commenter’s request for

the serial numbers of actuators that meet

the specifications of Arkwin Industries

Service Bulletin 1211233–29–21–4,

Revision 2, the FAA reiterates that all of

the actuators—all serial numbers from

00001 and subsequent—are suspect if

they have not been modified and/or

have not been shipped properly. The

FAA finds that the only way to know if

a modified actuator is not susceptible to

the failures (and thus ‘‘exempt’’ from

the requirements of this AD) is to know

that it has been shipped properly.

Besides reviewing shipping records or

tags, the only other way to determine

this is to know whether the actuator had

been removed from an airplane and then

shipped.

In light of this comment, the FAA

finds that it is appropriate to revise the

proposal to require that operators first

inspect the identification plate on the

deployment actuator of the RAT to

determine the actuator serial number.

Certain actuators would be required to

be removed and replaced immediately;

namely:

1. Any actuator having Boeing part

number (P/N) S271N102–4 (Arkwin P/N

1211233–004) or Boeing P/N

S271N102–5 (Arkwin P/N 1211233–

005) and a serial number of 00001

through 00631 inclusive, with no suffix

letter ‘‘B’’; or

2. Any actuator having Boeing P/N

S271N102–4 (Arkwin P/N 1211233–

004) or Boeing P/N S271N102–5

(Arkwin P/N 1211233–005) and a serial

number of 00001 through 00631

inclusive, with a suffix letter ‘‘B’’; or a

serial number of 00632 or subsequent;

and if that actuator had been removed

previously from an airplane and

shipped in the extended position.
55542 Federal Register / Vol. 62, No. 207 / Monday, October 27, 1997 / Proposed Rules

No action would be required if the

actuator has Boeing P/N S271N102–4

(Arkwin P/N 1211233–004) or Boeing P/

N S271N102–5 (Arkwin P/N 1211233–

005), and has a serial number of 00001

through 00631 inclusive, with a suffix

letter ‘‘B’’; or has a serial number of

00632 or subsequent; and if it is

determined that the actuator had not

been removed previously from an

airplane, or if the actuator had been

removed and shipped in accordance

with Arkwin Industries Service Bulletin

1211233–29–21–4, Revision 2 or

Revision 3.

Request to Allow In-House

Modification

One operator requests that the

proposal be revised to allow operators to

modify the actuator assemblies in-house

if they have the equipment to

successfully modify and test the unit in

a manner equivalent to that described in

the referenced Arkwin service bulletin.

This commenter points out that NOTE

2 of the proposal and the Arkwin

service bulletins imply that only

Arkwin can successfully accomplish

this modification; however, the

commenter maintains that this is not the

case. Further, the commenter states that,

if the unit is modified in-house, the

safety concerns related to the problems

of transporting of the units between

Arkwin and its customers would be

minimized.

The FAA concurs. The FAA

acknowledges that Arkwin is not the

only supplier that can modify and test

the units. The proposal has been revised

to indicate that the modification may be

accomplished by Arkwin or any other

FAA-approved facility.

Requests to Permit a Functional Test

Only

Several commenters request that the

proposal be revised to permit operators

to perform only a functional test to

verify deployment of the RAT in those

cases where the RAT has not been

removed, reworked, or subsequently

shipped. These commenters state that

they have been performing an on-wing

functional check of the RAT at every

scheduled ‘‘C’’ check, and have found

no RAT that has failed to deploy. These

commenters consider this type of

functional test to be sufficient to verify

proper operation of the RAT.

The FAA does not concur. The FAA

does not consider that a functional test

is sufficient to detect the type of latent

failures caused by the damaged lock

rods, pins, etc. Although failures have

been discovered during functional

testing of airplanes in production, there

have been at least two in-service

failures, which were not detected prior

to delivery of the airplane. These

problems were related to damage that

was incurred during the shipping of the

RAT to the aircraft manufacturer prior

to delivery. The FAA has identified the

RAT’s that were not shipped correctly

as those with serial numbers 00001

through 00631 inclusive; these actuators

must be inspected. Those RAT’s with

serial numbers 00632 and subsequent

that were delivered on the airplane must

also be inspected if they have been

removed or shipped after delivery of the

airplane.

Requests To Extend Compliance Time

Several commenters request that the

compliance time for replacing

discrepant RAT deployment actuators

be extended beyond the proposed 30

months. These commenters are

concerned that an ample number of

replacement actuators would not be

available for the affected fleet. One

commenter states that Arkwin has

committed to a turnaround time of 30

days for modifying the actuators;

however, this commenter, a U.S.

operator, indicates that if it were

required to replace all 31 of the

actuators in its fleet, neither it nor

Arkwin could meet the 30-month

compliance deadline. Another

commenter points out that if all of the

631 (non-modified) actuators needed to

be replaced, Arkwin would have to

process 21 units per month during the

30-month compliance time; however,

the commenter states that

representatives from Arkwin indicated

that they ‘‘could not handle 21 units per

month.’’

The FAA does not concur. The 30-

month compliance time was determined

after discussions with both Boeing and

Arkwin. That compliance period takes

into consideration not only the safety

implications, but the availability of

necessary parts to retrofit the U.S. fleet

and the practical aspect of performing

the required actions during an interval

of regularly scheduled maintenance.

The FAA has received no indication

from Arkwin that an ample number of

parts would not be available within the

compliance time. In additon, as

discussed previously, Arkwin is not the

only supplier that can modify and test

the units. In light of this, the FAA finds

no technical reason for revising the 30-

month compliance time.

Request for Redesign of the Actuator as

Terminating Action

One commenter raises concerns about

the design of the affected actuators,

which apparently makes them

particularly susceptible to the addressed

problems. This commenter states that

Boeing has agreed with the validity of

this concern and has taken an action

item to review the design of the entire

actuator. This commenter requests that

the proposal be revised to mandate

repetitive deployment checks, until an

improved actuator design is developed

and a relevant service bulletin is issued.

The commenter maintains that, until a

modification solution is developed,

deployment checks will offer an

equivalent level of safety.

The FAA does not concur. While a

design solution would be ideal, to date

there has been no new design of the

actuator developed. Further, the FAA

finds that deployment checks alone

would not adequately address the

unsafe condition that prompted this AD

action. Deployment checks will not

detect damage to the lock rods, pins,

etc., that could eventually prevent

deployment of the RAT. The failure

condition is not dynamic; it is gradual,

and the deployment checks would not

detect the degradation of the pins and

rods until an actual failure occurred.

The intent of this proposed AD is to

detect and correct the failure conditions

before the RAT actuator system is

needed during flight.

Requests To Withdraw Proposal

Several commenters suggest that the

issuance of the proposed AD is not

warranted. Two commenters consider

that the proposed requirements for

using special shipping procedures are

inappropriate for an AD. One

commenter considers that its routine

maintenance program of inspection and

operational checks of the actuators at

regular intervals is adequate for

detecting and correcting the problems

addressed by the proposed AD. Another

commenter considers that no safety

problem exists, because the failure of

the RAT actuator to deploy was

reviewed in accordance with § 25.1309

of the Federal Aviation Regulations (14

CFR 25.1309) and was demonstrated to

be an extremely improbable event.

The FAA infers from these statements

that the commenters request that the

proposal be withdrawn. The FAA does

not concur; nor does the FAA concur

with the statement that use of an AD to

address the problem is inappropriate.

According to section 39.1 of the Federal

Aviation Regulations (14 CFR 39.1), the

issuance of an AD is based on the

finding that an unsafe condition exists

or is likely to develop in aircraft of a

particular type design. Regardless of the

cause or the source of an unsafe

condition, the FAA has the authority to

issue an AD when it is found that an

unsafe condition is likely to exist or
Federal Register / Vol. 62, No. 207 / Monday, October 27, 1997 / Proposed Rules 55543

develop on other products of the same

type design.

Further, it is within the FAA’s

authority to issue AD’s to require

actions to address unsafe conditions

that are not otherwise being addressed

(or addressed adequately) by normal

maintenance procedures. The FAA may

address such unsafe conditions by

requiring specific steps to be taken or by

requiring revisions to maintenance

programs as a condition under which

airplanes may continue to be operated.

While the subject of this AD relates to

a problem with the RAT actuator

identified during regular maintenance

procedures, the FAA points out that

reports of this problem came from

several different operators. From the

data garnered from these reports, the

FAA has identified the existence of an

unsafe condition. As a result, the FAA

is proposing to issue this AD to address

the unsafe condition.

Since the root of the unsafe condition

relates to damage incurred during the

current shipping process, the FAA has

determined that a requirement to add

the use of the shipping container and

sleeve in accordance with the

maintenance program is appropriate.

Request To Clarify Part Numbers and

Serial Numbers of Affected Actuators

One commenter requests that the

proposal be revised to specify the

correct Boeing part number of one of the

affected RAT deployment actuators.

This commenter points out that the

actuator identified as ‘‘Boeing part

number 1211233–4’’ should be ‘‘Boeing

part number S271N102–4.’’ This same

commenter notes that the applicability

statement of the proposed rule included

the serial numbers for the actuators

having part number S271N102–5, but it

did not include the serial numbers for

the other affected actuator.

The FAA concurs that some

clarification is necessary on both points

brought up by the commenter:

First, the FAA acknowledges that the

correct Boeing part number of one of the

affected actuators is ‘‘S271N102–4,’’ and

has corrected this number in the

supplemental NPRM.

Second, the serial numbers listed in

the applicability statement of the

proposal as ‘‘00001 and subsequent’’

apply to both of the affected actuators

(part numbers S271N102–4 and

S271N102–5). The applicability

statement of this supplemental NPRM

has been revised to clarify this.

Request To Clarify Service Bulletin

References

One commenter requests that the

proposal be revised to specify the

correct number of the Arkwin Industries

service bulletin as ‘‘1211233–29–21–3.’’

This commenter points out that several

references to this service bulletin in the

proposal indicated its number as

‘‘1211233–19–21–3.’’

The FAA acknowledges that because

of a typographical error of the service

bulletin number in the service bulletin,

the number was incorrectly shown in

several places in the proposal. This

information has been corrected in this

supplemental NPRM.

Request To Revise Cost Impact

Information

One commenter requests that the cost

impact information be expanded to

include the costs incurred if the RAT

actuator is shipped to Arkwin to be

fixed. The commenter points out that

the information presented in the

preamble to the proposal appears to

analyze the costs only for those cases

where an operator itself fixes the

actuator. This commenter asserts that, if

the actuators are returned to Arkwin for

modification, the airplane will need to

have a replacement RAT actuator

installed in the interim; this will

increase the costs associated with the

AD.

The FAA concurs that the cost

information could be expanded to

include other scenarios. Arkwin

Industries has advised the FAA that the

cost for returning the actuator to them

for retrofit would be approximately

$22.33 per actuator. The FAA has added

this information to the cost impact

information, below.

Conclusion

Since certain of the changes discussed

previously expand the scope of the

originally proposed rule, the FAA has

determined that it is necessary to reopen

the comment period to provide

additional opportunity for public

comment.

Cost Impact

There are approximately 631 Boeing

Model 757 series airplanes of the

affected design in the worldwide fleet.

The FAA estimates that 389 airplanes of

U.S. registry would be affected by this

AD.

The proposed revision to the FAAapproved maintenance program would

take approximately 2 work hours per

operator to accomplish, at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of this

proposed requirement on U.S. operators

is estimated to be $120 per operator.

The proposed inspection and

replacement of the RAT deployment

actuator would take approximately 4

work hours per airplane, at an average

labor rate of $60 per work hour.

Required replacement parts would cost

approximately $4,832 per airplane. (If

the unit is under warranty, the required

parts would be provided by the actuator

manufacturer at no cost to the operator.

If the actuator is returned to the vendor

for modification, the charge would be

approximately $22.33 per actuator.)

Based on these figures, the cost impact

of this proposed requirement on U.S.

operators is estimated to be between

$240 and $5,072 per airplane.

The cost impact figures discussed

above are based on the 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. However, the

FAA has been advised that the proposed

requirement to replace the RAT

deployment actuator [paragraph (b)] has

been accomplished previously on

approximately 13 airplanes of U.S.

registry. Therefore, the future cost

impact of this proposed AD on U.S.

operators is reduced by approximately

$65,936.

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.
55544 Federal Register / Vol. 62, No. 207 / Monday, October 27, 1997 / Proposed Rules

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: Amendment 39– . Docket 96–NM–

12–AD.

Applicability: Model 757 series airplanes;

equipped with ram air turbine (RAT)

deployment actuators having Boeing part

number (P/N) S271N102–4 (Arkwin P/N

1211233–004) or Boeing P/N S271N102–5

(Arkwin P/N 1211233–005), and having a

serial number of 00001 and subsequent;

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 (d) 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 the failure of the actuators used

to deploy the ram air turbine (RAT),

accomplish the following:

(a) Within 120 days after the effective date

of this AD, revise the FAA-approved

maintenance program to require verification

that the shipping container and shipping

sleeve assembly, as specified in Arkwin

Industries Service Bulletin 1211233–29–21–

4, Revision 3, dated February 7, 1997, was

used in shipping the actuator to a location

where it is to be installed.

Note 2: Once the maintenance program has

been revised to include the procedures

specified in this paragraph, operators are not

required to subsequently record

accomplishment each time that an actuator is

shipped.

(b) Within 30 months after the effective

date of this AD, inspect the identification

plate on the deployment actuator of the RAT

to determine the actuator serial numbers, in

accordance with Arkwin Industries Service

Bulletin 1211233–29–21–3, Revision 2, dated

June 17, 1994, or Revision 3, dated February

7, 1997.

(1) If the actuator bears Boeing part number

(P/N) S271N102–4 (Arkwin P/N 1211233–

004) or Boeing P/N S271N102–5 (Arkwin P/

N 1211233–005), and has a serial number of

00001 through 00631 inclusive (with no ‘‘B’’

suffix): Prior to further flight, remove the

RAT deployment actuator and repair or

replace it, in accordance with the Arkwin

Industries service bulletins previously

referenced in paragraph (b) of this AD or in

accordance with a method approved by the

Manager, Seattle Aircraft Certification Office

(ACO), FAA, Transport Airplane Directorate.

Note 3: Arkwin Industries Service Bulletin

1211233–29–21–3, Revision 2, dated June 17,

1994, or Revision 3, dated February 7, 1997,

recommends that the actuator unit be

returned to Arkwin Industries for

modification, since specialized equipment is

needed to perform the rework of the unit.

However, any FAA-approved facility may

modify the unit, provided that it has the

appropriate equipment to successfully

modify and test the unit in accordance with

a method approved by the Manager, Seattle

ACO, or in accordance with the Arkwin

Industries service bulletins referenced in

paragraph (b) of this AD.

(2) Prior to further flight, remove the RAT

deployment actuator and repair or replace it,

in accordance with Arkwin Industries

Service Bulletin 1211233–29–21–3, Revision

2, dated June 17, 1994, or Revision 3, dated

February 7, 1997, if the actuator:

(i) Has Boeing P/N S271N102–4 (Arkwin P/

N 1211233–004) or Boeing P/N S271N102–5

(Arkwin P/N 1211233–005); and

(ii) Has a serial number of 00001 through

00631 inclusive, with a suffix letter ‘‘B;’’ or

has a serial number of 00632 or subsequent;

and

(iii) Has been removed previously from an

airplane and shipped in the extended

position and not in accordance with Arkwin

Industries Service Bulletin 1211233–29–21–

4, Revision 2, dated June 17, 1994, or

Revision 3, dated February 7, 1997.

Note 4: Shipping records or tags may be

reviewed to determine whether the actuator

was shipped in accordance with Arkwin

Industries Service Bulletin 1211233–29–21–

4, Revision 2 or Revision 3.

Note 5: Arkwin Industries Service Bulletin

1211233–29–21–4, Revision 2 or Revision 3,

provide procedures for proper identification

of the necessary reusable shipping container

and shipping sleeve assembly that is to be

used when transporting or shipping the RAT

deployment actuator assembly. Use of this

container and sleeve will prevent damage to

the assembly during shipping.

(3) No further action is required by

paragraph (b) of this AD, if the actuator:

(i) Has Boeing P/N S271N102–4 (Arkwin P/

N 1211233–004) or Boeing P/N S271N102–5

(Arkwin P/N 1211233–005); and

(ii) Has a serial number of 00001 through

00631 inclusive, with a suffix letter ‘‘B;’’ or

has a serial number of 00632 or subsequent;

and

(iii) Has not been removed previously from

an airplane, or has been removed and

shipped in the extended position, in

accordance with Arkwin Industries Service

Bulletin 1211233–29–21–4, Revision 2, dated

June 17, 1994, or Revision 3, dated February

7, 1997.

(c) As of 30 months after the effective date

of this AD, no person shall install on any

airplane a RAT deployment actuator

assembly, having Boeing P/N S271N102–4

(Arkwin P/N 1211233–004) or Boeing P/N

S271N102–5 (Arkwin P/N 1211233–005), and

having serial number 00001 and subsequent;

unless the conditions, as specified in both

paragraphs (c)(1) and (c)(2) of this AD apply:

(1) The actuator assembly has been

modified (repaired and reidentified) in

accordance with Arkwin Industries Service

Bulletin 1211233–29–21–3, Revision 2, dated

June 17, 1994, or Revision 3, dated February

7, 1997; or the actuator is replaced with a

new actuator from Arkwin Industries, Inc.;

and

(2) Prior to installation, the actuator was

shipped (i.e., to the place where installation

is accomplished) in accordance with Arkwin

Industries Service Bulletin 1211233–29–21–

4, Revision 2, dated June 17, 1994, or

Revision 3, dated February 7, 1997.

(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, 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.

Note 6: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle 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 October

20, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–28318 Filed 10–24–97; 8:45 am]

BILLING CODE 4910–13–U

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 52

[NH–7157b; FRL–5906–9]

Approval and Promulgation of

Implementation Plans; New Hampshire

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Notice of proposed rulemaking.

SUMMARY: The EPA is proposing action

on State Implementation Plan (SIP)

revisions submitted by the State of New

Hampshire. The EPA is proposing