[Federal Register Volume 62, Number 221 (Monday, November 17, 1997)]
[Rules and Regulations]
[Pages 61223-61225]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-30058]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-SW-17-AD; Amendment 39-10206; AD 97-12-02]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Helicopter Systems
MD900 Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: This amendment supersedes an existing priority letter
airworthiness
[[Page 61224]]
directive (AD), applicable to McDonnell Douglas Helicopter Systems
(MDHS) Model MD900 helicopters, which prohibits flight or ground
operations of helicopters with a certain adjustable collective drive
link assembly (link assembly) installed. This amendment requires
installation of a redesigned airworthy link assembly after which
further operations are permitted. This amendment is prompted by recent
incidents in which the link assembly failed during flight. The actions
specified by this AD are intended to prevent failure of the link
assembly, which could result in loss of control of the helicopter.
DATES: Effective December 2, 1997.
Comments for inclusion in the Rules Docket must be received on or
before January 16, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 97-SW-17-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
FOR FURTHER INFORMATION CONTACT: Mr. Greg DiLibero, Aerospace Engineer,
FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Blvd.,
Lakewood, California 90712, telephone (562) 627-5231, fax (562) 627-
5210.
SUPPLEMENTARY INFORMATION: On May 29, 1997, the FAA issued priority
letter AD 97-12-02, applicable to MDHS Model MD900 helicopters with
collective drive link assembly (link assembly) part number (P/N)
900C2010233-103 and P/N 900C2010233-105, installed, which prohibits
flight or ground operations of the helicopters. That action was
prompted by recent incidents in which the link assembly failed during
flight. The link assembly is part of the primary collective flight
control system. Based on these incidents and further testing by the
manufacturer, the FAA determined that further operations with either
affected link assembly installed constituted an unsafe condition. That
condition, if not corrected, could result in failure of the link
assembly and subsequent loss of control of the helicopter.
Since the issuance of that AD, MDHS has issued MDHS Service
Bulletin (SB) No. SB900-055R1, dated June 5, 1997, for the installation
of a redesigned link assembly. The FAA has determined that installation
of redesigned link assembly, P/N 900C2010233-107, will correct the
unsafe condition. Additionally, in AD 97-12-02, the FAA has noted that
the applicability section incorrectly stated that the AD applied to
Model MD900 helicopters with P/N 900C2010233-103 and P/N 900C2010233-
105 installed. The AD should have stated that it applied to Model MD900
helicopters with P/N 900C2010233-103 or P/N 900C2010233-105 installed.
This imprecision in word choice is corrected in this AD.
Since an unsafe condition has been identified that is likely to
exist or develop on other MDHS Model MD900 helicopters of the same type
design, this AD supersedes AD 97-12-02 to require installation of a
redesigned link assembly. This AD also clarifies the applicability
statement that could be incorrectly interpreted to mean that two link
assemblies must be installed in order for the AD to be applicable.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this rule by
submitting such written data, views, or arguments as they may desire.
Communications should identify the Rules Docket number and be submitted
in triplicate to the address specified under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments submitted will be
available, both before and after the closing date for comments, in the
Rules Docket for examination by interested persons. A report that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 97-SW-17-AD.'' The postcard will be date stamped and
returned to the commenter.
The regulations adopted herein will not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, may be obtained from the Rules Docket at the
location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends part 39 of
the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive
to read as follows:
97-12-02 McDonnell Douglas Helicopter Systems: Amendment 39-10206.
Docket No. 97-SW-17-AD. Supersedes priority letter AD 97-12-02.
Applicability: Model MD900 helicopters, with adjustable
collective drive link assembly (link assembly), part number (P/N)
900C2010233-103 or -105, installed, certificated in any category.
[[Page 61225]]
Note 1: This AD applies to each helicopter identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For helicopters that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must use the authority
provided in paragraph (b) to request approval from the FAA. This
approval may address either no action, if the current configuration
eliminates the unsafe condition, or different actions necessary to
address the unsafe condition described in this AD. Such a request
should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any helicopter from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the link assembly, which could result in
loss of control of the helicopter, accomplish the following:
(a) Before further flight, remove the link assembly, P/N
900C2010233-103 or -105, and replace with link assembly, P/N
900C2010233-107.
(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, Los Angeles Aircraft Certification
Office. Operators shall submit their requests through an FAA
Principal Maintenance Inspector, who may concur or comment and then
send it to the Manager, Los Angeles Aircraft Certification Office.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles Aircraft Certification Office.
(c) Special flight permits will not be issued.
(d) This amendment becomes effective on December 2, 1997.
Issued in Fort Worth, Texas, on November 6, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-30058 Filed 11-14-97; 8:45 am]
BILLING CODE 4910-13-U