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[Federal Register Volume 62, Number 207 (Monday, October 27, 1997)]
[Proposed Rules]
[Pages 55540-55544]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-28318]

      
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Proposed Rules
                                                Federal Register
________________________________________________________________________

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.

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

[[Page 55540]]

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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.

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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

[[Page 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.

[[Page 55542]]

    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 Sec. 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

[[Page 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 FAA-approved 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.

[[Page 55544]]

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.

Sec. 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
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