[Federal Register Volume 64, Number 55 (Tuesday, March 23, 1999)]
[Proposed Rules]
[Pages 13936-13938]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-7025]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-16-AD]
Airworthiness Directives; McDonnell Douglas Helicopter Systems
Model 600N Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to McDonnell Douglas Helicopter
Systems (MDHS) Model 600N helicopters. This proposal would require
applying serial numbers to several life-limited components related to
pitch control and removing and replacing the components according to
new life-limits. This proposal is prompted by fatigue tests that
indicate a need for shorter service lives for these components. The
actions specified by the proposed AD are intended to prevent failure of
the collective pitch control tubes, collective stick housings, and
collective pitch tube assemblies, which can cause loss of collective
pitch control, and subsequent loss of control of the helicopter.
DATES: Comments must be received by May 24, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 98-SW-16-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137. 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 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, 2601 Meacham Blvd., Room 663, Fort
Worth, Texas.
FOR FURTHER INFORMATION CONTACT: Frederick A. Guerin, Aerospace
Engineer, Airframe Branch, Los Angeles Aircraft Certification Office,
3960 Paramount Blvd., Lakewood, California 90712, telephone (562) 627-
5232, fax (562) 627-5210.
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 should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
[[Page 13937]]
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 No. 98-SW-16-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, Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 98-SW-16-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
Discussion
This document proposes the adoption of a new AD that is applicable
to MDHS Model 600N helicopters. This proposal would require three
actions: (1) applying serial numbers to the collective pitch control
tubes, part number's (P/N's) 369A7348 and 369H7809, and collective
stick housings, P/N's 369A7347 and 369A7820; (2) adding the co-pilot
collective pitch control tube, P/N 369A7809, to the Airworthiness
Limitations section, Component Mandatory Replacement Schedule (CMRS),
of the maintenance manual; and (3) reducing the service lives from
those stated in the Airworthiness Limitations section, CMRS, of the
pilot collective pitch control tube, P/N 369A7348, collective stick
housings, P/N's 369A7347, 369A7820, and 369H7837, and collective pitch
tube assemblies, P/N's 369H7354-3 and 369H7838-3. The following table
shows the current life-limits and the proposed life-limits.
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Proposed life-
limit (hours Current life-limit (hours
P/N Component time-in- time-in-service)
service)
----------------------------------------------------------------------------------------------------------------
369A7347........................... Housing, collective stick...... 450 Unlimited
369A7348........................... Tube, collective pitch control. 400 Unlimited
369H7354-3......................... Tube assembly, collective pitch 600 1,500
(pilot).
369A7809........................... Tube, collective pitch (co- 1,800 Not Determined
pilot).
369A7820........................... Housing, collective stick...... 450 Unlimited
369H7837........................... Housing, collective stick...... 450 Unlimited
369H7838-3......................... Tube assembly, collective pitch 1,000 1,500
(co-pilot).
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This proposal is prompted by fatigue tests that indicate a need for
shorter service lives for these components. The actions specified by
the proposed AD are intended to prevent failure of the collective pitch
control tubes, collective stick housings, and collective pitch tube
assemblies, which can cause loss of collective pitch control, and
subsequent loss of control of the helicopter.
The FAA has reviewed McDonnell Douglas Helicopter Systems Service
Bulletin SB600N-009, dated February 24, 1998, that lists the service
numbers to be applied to the four components for the listed aircraft
serial numbers.
Since an unsafe condition has been identified that is likely to
exist or develop on other MDHS Model 600N helicopters of the same type
design, the proposed AD would require applying serial numbers to
several life-limited components related to pitch control and removing
and replacing several components according to new life-limits. The
actions would be required to be accomplished in accordance with the
service bulletin described previously.
The FAA estimates that 16 helicopters of U.S. registry would be
affected by this proposed AD, that it would take approximately 0.5 work
hour per helicopter to apply the serial numbers, and that the average
labor rate is $60 per work hour. Based on these figures, the total cost
impact of the proposed AD on U.S. operators is estimated to be $480.
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 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:
McDonnell Douglas Helicopter Systems: Docket No. 98-SW-16-AD.
Applicability: Model 600N helicopters, certificated in any
category.
Note 1: This AD applies to each helicopter identified in the
preceding applicability
[[Page 13938]]
provision, regardless of whether it has been otherwise 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 request approval for an alternative method of
compliance in accordance with paragraph (e) 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 failure of the collective pitch control tubes,
collective stick housings, and collective pitch tube assemblies,
loss of collective pitch control, and subsequent loss of control of
the helicopter, accomplish the following:
(a) On or before reaching 400 hours time-in-service (TIS), apply
the serial number (S/N) listed in McDonnell Douglas Helicopter
System Service Bulletin No. 600N-009, dated February 24, 1998 (SB),
to the two collective stick housings, P/N's 369A7347 and 369A7820;
the pilot collective pitch control tube, P/N 369A7348; and the co-
pilot collective pitch control tube, P/N 369A7809, in the most
visible spot for the specified aircraft S/N.
(b) Remove and replace the following flight control components
according to the stated life-limits:
------------------------------------------------------------------------
Life-Limit
P/N Component (hours TIS)
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1369A7347.................... Housing, collective stick 450
369A7348..................... Tube, collective pitch 400
control (pilot).
369H7354-3................... Tube assembly, collective 600
pitch (pilot).
369A7809..................... Tube, collective pitch 1,800
control (co-pilot).
369A7820..................... Housing, collective stick 450
369H7837..................... Housing, collective stick 450
369H7838-3................... Tube assembly, collective 1,000
pitch (co-pilot).
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(c) Create a component history card or equivalent record in the
helicopter log and record the helicopter TIS at installation for
each of the components listed in paragraph (b) of this AD.
(d) This AD revises the Airworthiness Limitations Section of the
maintenance manual by reducing the life-limits of the pilot
collective pitch control tube, the collective stick housings, and
the collective pitch tube assemblies, and adding the co-pilot
collective pitch control tube to the Airworthiness Limitations
section, Component Mandatory Replacement Schedule.
(e) 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.
(f) 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.
Issued in Fort Worth, Texas, on March 16, 1999.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-7025 Filed 3-22-99; 8:45 am]
BILLING CODE 4910-13-U
