[Federal Register Volume 63, Number 76 (Tuesday, April 21, 1998)]
[Rules and Regulations]
[Pages 19653-19655]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10461]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-SW-52-AD; Amendment 39-10481; AD 98-09-02]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Helicopter Systems
Model 369 (YOH-6A), 369A (OH-6A), 369D, 369E, 369F, 369FF, 369H, 369HE,
369HM, 369HS, and 500N Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to McDonnell Douglas Helicopter Systems (MDHS) Model
369 (YOH-6A), 369A (OH-6A), 369D, 369E, 369F, 369FF, 369H, 369HE,
369HM, and 369HS helicopters, that currently requires replacing
overrunning clutch outer races (outer races) having certain heat
treatment numbers. This amendment requires replacing all outer races
with airworthy outer races, regardless of the heat treatment number,
and is applicable to a particular model helicopter that was not
included in the existing AD (Model 500N helicopters). This amendment is
prompted by several reports of failed clutch races having heat
treatment numbers other than the ones addressed in the earlier AD. The
actions specified by this AD are intended to prevent failure of the
overrunning clutch assembly outer race, which could result in loss of
engine drive to the rotor system and a subsequent forced landing.
DATES: Effective May 6, 1998. The incorporation by reference of certain
publications listed in the regulations is approved by the Director of
the Federal Register as of May 6, 1998.
Comments for inclusion in the Rules Docket must be received on or
before June 22, 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-52-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
The service information referenced in this AD may be obtained from
McDonnell Douglas Helicopter Systems, Technical Publications, Bldg.
530/B11, 5000 E. McDowell Road, Mesa, Arizona 85205-9797. This
information may be examined at the FAA, Office of the Regional Counsel,
Southwest Region,
[[Page 19654]]
2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137; or at the Office
of the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
FOR FURTHER INFORMATION CONTACT: Mr. Bruce Conze, Aerospace Engineer,
FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960
Paramount Boulevard, Lakewood, California 90712, telephone (562) 627-
5261, fax (562) 627-5210.
SUPPLEMENTARY INFORMATION: On April 15, 1988, the FAA issued AD 88-10-
04, Amendment 39-5897 (53 FR 16384, May 9, 1988) to require replacing
outer races, part number (P/N) 369A5352, serial number (S/N) 0692
through 0927, with airworthy outer races in accordance with paragraphs
a through g of the Procedures section of McDonnell Douglas Helicopter
Company Service Information Notice HN-215/DN-156/EN-46/FN-34, dated
March 18, 1988. On March 17, 1989, the FAA issued AD 88-10-04 R1,
Amendment 39-6173 (54 FR 12590, March 28, 1989), to limit the scope of
AD 88-10-04, to require replacing only outer races, P/N 369A5352, S/N
0692 through 0927, having heat treatment (HT) number HT 255534. The
revision to AD 88-10-04 was prompted by a determination that only outer
races with heat treatment batch numbers ``HT 255534'' had been
improperly processed during manufacture. That condition, if not
corrected, could result in failure of the overrunning clutch assembly
outer race, loss of engine drive to the rotor system and a subsequent
forced landing.
Since the issuance of that AD and the revision to the AD, MDHS has
received additional reports of failed outer races with heat treatment
numbers other than HT 255534. Additionally, the FAA has determined that
the AD should also be applicable to the Model 500N helicopter. This
model was not in existence when the previous AD was issued.
Since an unsafe condition has been identified that is likely to
exist or develop on other MDHS Model 369, 369A, 369D, 369E, 369F,
369FF, 369H, 369HE, 369HM, 369HS, 500N, YOH-6A, and OH-6A, helicopters
of the same type design, this AD supersedes AD 88-10-04 and the
revision, AD 88-10-04 R1, to require, within the next 50 hours time-in-
service (TIS), removing the outer races, P/N 369A5352, S/N 0692 through
S/N 0927, and replacing it with airworthy outer races, P/N 369A5352-5,
together with a wave washer, P/N W1593-018. The short compliance time
involved is required because the previously described critical unsafe
condition can result in a forced landing of the helicopter. Therefore,
the replacement of parts is required within the next 50 hours TIS, and
this AD must be issued immediately.
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.
The FAA estimates that 2000 MDHS Model 369, 369A, 369D, 369E, 369F,
369FF, 369H, 369HE, 369HM, 369HS, 500N, YOH-6A, and OH-6A helicopters
of U.S. registry will be affected by this AD, that it will take
approximately 2 hours to accomplish the parts replacement, and that the
average labor rate is $60 per hour. Required parts will cost
approximately $1,614 per helicopter. Based on these figures, the total
cost impact of the AD on U.S. operators is estimated to be $3,468,000.
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-52-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, Incorporation by
reference, 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 removing Amendment 39-5897 (53 FR
16384, May 9, 1988) and Amendment 39-6173 (54 FR 12590, March 28,
1989), and by adding a new airworthiness directive (AD), Amendment 39-
10481, to read as follows:
AD 98-09-02 McDonnell Douglas Helicopter Systems: Amendment 39-
10481. Docket No. 97-SW-52-AD. Supersedes AD 88-10-04, Amendment 39-
5897 and AD 88-10-04 R1, Amendment 39-6173.
Applicability: Model 369, 369A, 369D, 369E, 369F, 369FF, 369H,
369HE, 369HM,
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369HS, 500N, YOH-6A, and OH-6A helicopters, certificated in any
category.
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 (c) 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 within 50 hours time-in-service after the
effective date of this AD, unless accomplished previously.
To prevent failure of the overrunning clutch assembly outer
race, which could result in loss of engine drive to the rotor system
and a subsequent forced landing, accomplish the following:
(a) Inspect the overrunning clutch outer race, part number (P/N)
369A5352, to determine its serial number (S/N) in accordance with
paragraphs A through C of the Accomplishment Instructions contained
in McDonnell Douglas Helicopter Systems Service Information Notice
HN-215.2, DN-156.2, EN-46.2, FN-34.2, NN-010, dated March 18, 1997
(service information notice).
(b) Remove any overrunning clutch outer race, P/N 369A5352,
having a S/N of 0692 through 0927, and replace it with an airworthy
overrunning clutch outer race, P/N 369A5352-5, together with a wave
washer, P/N W1593-018, in accordance with the service information
notice.
(c) 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, FAA. 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.
(d) 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 helicopter to a location where
the requirements of this AD can be accomplished.
(e) The inspection and replacement shall be done in accordance
with McDonnell Douglas Helicopter Systems Service Information Notice
HN-215.2, DN-156.2, EN-46.2, FN-34.2, NN-010, dated April 11, 1997.
This incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies may be obtained from McDonnell Douglas Helicopter
Systems, Technical Publications, Bldg. 530/B11, 5000 E. McDowell
Road, Mesa, Arizona 85205-9797. Copies may be inspected at the FAA,
Office of the Regional Counsel, Southwest Region, 2601 Meacham
Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(f) This amendment becomes effective on May 6, 1998.
Issued in Fort Worth, Texas, on April 14, 1998.
Eric Bries,
Acting Manager, Rotorcraft Directorate,
Aircraft Certification Service.
[FR Doc. 98-10461 Filed 4-20-98; 8:45 am]
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