[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
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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