[Federal Register Volume 62, Number 219 (Thursday, November 13, 1997)]
[Proposed Rules]
[Pages 60808-60810]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-29820]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-157-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 737-100, -200, -300, -400,
and -500 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes to revise an existing airworthiness
directive (AD), applicable to all Boeing Model 737-100, -200, -300, -
400, and -500 series airplanes, that currently requires a one-time
inspection to determine the part number of the engage solenoid valve of
the yaw damper on the rudder power control unit, and replacement of the
valve with a valve having a different part number, if necessary. That
AD was prompted by a review of the design of the flight control systems
on Model 737 series airplanes. The actions specified by that AD are
intended to prevent sudden uncommanded yawing of the airplane due to
potential failures within the yaw damper system, and consequent injury
to passengers and crewmembers. This action would make certain editorial
changes to clarify the requirements of the existing AD.
DATES: Comments must be received by December 29, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-157-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
[[Page 60809]]
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Tin Truong, Aerospace Engineer, ANM-
130S, FAA, Transport Airplane Directorate, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2764; 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 97-NM-157-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 97-NM-157-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On April 24, 1997, the FAA issued AD 97-09-15, amendment 39-10011
(62 FR 24325, May 5, 1997), applicable to all Boeing Model 737-100, -
200, -300, -400, and -500 series airplanes, to require a one-time
inspection to determine the part number of the engage solenoid valve of
the yaw damper, and replacement of the valve with a valve having a
different part number, if necessary. That action was prompted by a
review of the design of the flight control systems on Model 737 series
airplanes. The requirements of that AD are intended to prevent sudden
uncommanded yawing of the airplane due to potential failures within the
yaw damper system, and consequent injury to passengers and crewmembers.
Actions Since Issuance of Previous Rule
Since the issuance of AD 97-09-15, the FAA has re-reviewed the
requirements of paragraph (a) and the information specified in ``Note
3'' of that AD.
The FAA finds that, as paragraph (a) of AD 97-09-15 is currently
worded, operators could misinterpret exactly which engage solenoid
value of the yaw damper must be inspected. Therefore, the FAA has
revised the phrase ``engage solenoid valve of the yaw damper'' to read
``engage solenoid valve of the yaw damper on the rudder power control
unit (PCU).''
The FAA also finds that paragraph (a) of AD 97-09-15 specifies only
the Boeing part number (P/N) for some affected parts. For clarification
purposes, the FAA has revised paragraph (a) of the existing AD to
include both the Boeing P/N and the vendor P/N's for all affected
parts.
The FAA also has revised paragraph (a) of the existing AD to
reference Chapter 22-11-61 (for Model 737-100 and -200 series
airplanes) and Chapter 22-12-21 (for Model 737-300, -400, and -500
series airplanes) of the Boeing Maintenance Manual as the appropriate
sources of service information for accomplishment of the actions
required by that paragraph.
Furthermore, the FAA finds that some engage solenoid valves may be
labeled with only the name ``Bertea,'' rather than ``Parker'' or
``Parker-Bertea.'' Therefore, the FAA has revised ``Note 3'' of AD 97-
09-15 to include such information regarding the labeling of the engage
solenoid valves.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would revise AD 97-09-15 to continue to require a one-time
inspection to determine the part number of the engage solenoid valve of
the yaw damper on the rudder PCU, and replacement of the valve with a
valve having a different part number, if necessary. The proposed AD
would make certain editorial changes to clarify the requirements of the
existing AD.
Cost Impact
There are approximately 2,675 Boeing Model 737 series airplanes of
the affected design in the worldwide fleet. The FAA estimates that
1,091 airplanes of U.S. registry would be affected by this proposed AD.
The FAA estimates that it would take approximately 1 work hour per
airplane to accomplish the proposed one-time inspection, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the inspection proposed by this AD on U.S. operators is
estimated to be $65,460, or $60 per airplane. The requirements of this
AD will add no new costs to affected operators.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed requirements of
this AD action, and that no operator would accomplish those actions in
the future if this AD were not adopted.
Regulatory Impact
The regulations 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.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part
[[Page 60810]]
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 removing amendment 39-10011 (62 FR
24325, May 5, 1997), and by adding a new airworthiness directive (AD),
to read as follows:
Boeing: Docket 97-NM-157-AD. Revises AD 97-09-15, Amendment 39-
10011.
Applicability: All Model 737-100, -200, -300, -400, and -500
series airplanes, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (b) 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 sudden uncommanded yawing of the airplane due to
potential failures within the yaw damper system, and consequent
injury to passengers and crewmembers, accomplish the following:
(a) Perform a one-time inspection of the engage solenoid valve
of the yaw damper on the rudder power control unit (PCU) to
determine the part number (P/N) of the valve. If any valve having
Parker P/N 59600-5011 (Boeing P/N 10-60811-9), Parker P/N 59600-5007
(Boeing P/N 10-60811-3), or Parker P/N 59600-5003 (Boeing P/N 10-
60811-1) is installed, prior to further flight, replace it with a
valve having Parker P/N 881600-1001 (Boeing P/N 10-60811-13), Sterer
P/N 45080-1 (Boeing P/N 10-60811-8), or Sterer P/N 45080 (Boeing P/N
10-60811-3). Accomplish the actions in accordance with procedures
specified in Chapter 22-11-61 (for Model 737-100 and -200 series
airplanes) or Chapter 22-12-21 (for Model 737-300, -400, and -500
series airplanes) of the Boeing Maintenance Manual, as applicable.
Accomplish the inspection at the earlier of the times specified in
paragraphs (a)(1) and (a)(2) of this AD.
(1) Within 5 years or 15,000 flight hours after June 9, 1997
(the effective date of AD 97-09-15, amendment 39-10011), whichever
occurs first.
(2) At the next time the PCU is sent to a repair facility.
Note 2: Boeing In-Service Activities Report 95-03-2725-10, dated
February 16, 1995 (for Model 737-100 and -200 series airplanes), or
95-04-2725-10, dated February 24, 1995 (for Model 737-300, -400, and
-500 series airplanes), provides additional information concerning
interchangeability of solenoid valve part numbers.
Note 3: Operators should note that, as specified in paragraph
(a) of this AD, both the Parker and Sterer P/N's have the same
Boeing P/N (10-60811-3). If, upon inspection, Boeing P/N 10-60811-3
is found to be installed, operators must ascertain the vendor P/N.
Parts having Boeing P/N 10-60811-3 and Parker P/N 59600-5007 must be
replaced and are not considered to be acceptable replacement parts.
In addition, some engage solenoid valves may be labeled with only
the name ``Bertea,'' rather than ``Parker'' or ``Parker-Bertea.''
(b) 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 Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Seattle ACO.
Note 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(c) 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 November 6, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-29820 Filed 11-12-97; 8:45 am]
BILLING CODE 4910-13-U
