[Federal Register Volume 62, Number 191 (Thursday, October 2, 1997)]
[Rules and Regulations]
[Pages 51593-51594]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-25970]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-SW-30-AD; Amendment 39-10149; AD 97-20-12]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Helicopter Systems
Model MD-900 Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to McDonnell Douglas Helicopter Systems (MDHS) Model MD-900
helicopters, that requires removing certain serial-numbered main rotor
swashplate bearings (bearings) and replacing them with airworthy
bearings. This amendment is prompted by reports that inspections of
several helicopters revealed that the outer bearing race had been
rotating relative to the swashplate assembly, which was evidenced by
wear marks in the rotating swashplate. The actions specified by this AD
are intended to prevent possible heat accumulation and resulting damage
to the bearing caused by the bearing races rotating relative to the
bearing seat, which could result in degraded helicopter response to
pilot control input and possible loss of control of the helicopter.
EFFECTIVE DATE: November 6, 1997.
FOR FURTHER INFORMATION CONTACT: Mr. Greg DiLibero, Aerospace Engineer,
FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Blvd.,
Lakewood, California 90712, telephone (310) 627-5231, fax (310) 627-
5210.
SUPPLEMENTARY INFORMATION: 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 MDHS Model MD-900 helicopters was
published in the Federal Register on January 29, 1997 (62 FR 4217).
That action proposed to require, before further flight, inspecting the
bearing, part number (P/N) 900C3010100-101, to determine if a bearing
having serial number (S/N) 059150-E0019, S/N 059150-E0020, S/N 059150-
E0021, S/N 059150-E0022, S/N 059150-E0023, S/N 059150-E0024, S/N
059150-E0025, S/N 059150-E0026, S/N 059150-E0027, S/N 059150-E0028, S/N
059150-E0029, or S/N 059150-E0030 is installed; and, if installed,
removing and replacing that bearing with an airworthy bearing.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. No comments were received on the
proposal or the FAA's determination of the cost to the public. The FAA
has determined that air safety and the public interest require the
adoption of the rule as proposed, with two changes. The FAA has
determined that special flight permits may be issued to operate the
helicopter to a location where the requirements of this AD can be
accomplished. This is now stated in paragraph (i) of the AD. Also, the
FAA has determined that this AD should only apply to the Model MD-900
helicopters, not the Model MD-900 ``series'' helicopters. Therefore,
the word ``series'' is removed from the applicability paragraph of this
AD. The FAA has determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD.
The FAA estimates that 20 helicopters of U.S. registry will be
affected by this AD, that it will take approximately 1.5 work hours per
helicopter to determine the bearing's S/N, 12 work hours per helicopter
to remove and replace a bearing, and that the average labor rate is $60
per work hour. Replacement bearings would cost $8,765 per helicopter,
however, replacement bearings are covered by a manufacturer's warranty.
Based on these figures, the total cost impact of the AD on U.S.
operators is estimated to be $5,400, assuming five helicopters will
require removal and replacement of the bearing.
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
[[Page 51594]]
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.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it 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:
97-20-12 McDonnell Douglas Helicopter Systems: Amendment 39-10149.
Docket No. 96-SW-30-AD.
Applicability: Model MD-900 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 (h) 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 before further flight, unless accomplished
previously.
To prevent possible heat accumulation and resulting damage to
the main rotor swashplate bearing (bearing) caused by the bearing
races rotating relative to the bearing seat, which could result in
degraded helicopter response to pilot control input and possible
loss of control of the helicopter, accomplish the following:
(a) Disconnect the lower end of the main rotor pitch links.
Disconnecting the drive link may make the inspection easier.
(b) Cut the safety wire and remove the inner and outer labyrinth
seals, part number (P/N) 900C2010194-101 and P/N 900C201190-101,
respectively, and the inner and outer bearing retaining rings.
(c) Inspect the bearing, part number (P/N) 900C3010100-101, to
determine if it has one of the following serial numbers (S/N): S/N
059150-E0019, S/N 059150-E0020, S/N 059150-E0021, S/N 059150-E0022,
S/N 059150-E0023, S/N 059150-E0024, S/N 059150-E0025, S/N 059150-
E0026, S/N 059150-E0027, S/N 059150-E0028, S/N 059150-E0029, or S/N
059150-E0030.
Note 2: S/N's similar to those above were produced without the
character ``E'' in the number. This AD is only concerned with those
that contain the character ``E''.
(d) Enter into the helicopter Log Book the bearing S/N.
(e) If a bearing having one of the S/N's stated in paragraph (c)
of this AD is installed on the helicopter, remove the bearing and
replace it with an airworthy bearing prior to further flight.
(f) Prior to the installation of a swashplate assembly, inspect
the bearing in accordance with the requirements of this AD.
(g) Report the results of all inspections required by this AD
within 72 hours to the Manager, Los Angeles Aircraft Certification
Office, 3960 Paramount Blvd., Lakewood, California 90712. Reporting
requirements have been approved by the Office of Management and
Budget and assigned OMB control number 2120-0056.
(h) 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 3: 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.
(i) 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.
(j) This amendment becomes effective on November 6, 1997.
Issued in Fort Worth, Texas, on September 24, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-25970 Filed 10-1-97; 8:45 am]
BILLING CODE 4910-13-U
