Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S- 64F Helicopters

[Federal Register Volume 62, Number 100 (Friday, May 23, 1997)]
[Rules and Regulations]
[Pages 28321-28322]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-12855]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-SW-34-AD; Amendment 39-10028; AD 97-10-15]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S-
64F Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to Sikorsky Aircraft-manufactured Model S-64F helicopters, 
that requires inspections, and replacement, if necessary, of the main 
gearbox second stage lower planetary plate (plate). This amendment is 
prompted by two incidents in which the plate was found cracked. The 
actions specified by this AD are intended to prevent failure of the 
plate due to fatigue cracking, which could lead to failure of the main 
gearbox and subsequent loss of control of the helicopter.

DATES: Effective June 27, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 27, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Erickson Air-Crane Co., 3100 Willow Springs Rd., P.O. Box 
3247, Central Point, Oregon 97502. This information may be examined at 
the FAA, Office of the Assistant Chief Counsel, 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.

FOR FURTHER INFORMATION CONTACT: Mr. Uday Garadi, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 2601 
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5114, fax 
(817) 222-5961.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an AD that is 
applicable to Sikorsky Aircraft-manufactured Model S-64F helicopters 
was published in the Federal Register on October 11, 1996 (61 FR 
53337). That action proposed to require an inspection, prior to the 
first flight of each day, of the main oil filter for the main gearboxes 
containing a plate with more than 2,000 hours time-in-service (TIS) for 
magnesium contamination and, if magnesium contamination is present, 
replacement of the main gearbox assembly. For main gearbox assemblies 
containing a plate with more than 2,000 hours TIS, that action also 
proposed to require an inspection of the plate within the next 100 
hours TIS after the effective date of this AD, and thereafter at 
intervals not to exceed 500 hours TIS; and replacement of the plate if 
necessary. Finally, that action proposed to require, at the next 
overhaul of the main gearbox assembly, inspection and rework of plates 
that are not cracked.
    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 minor editorial changes, and a 
correction to the estimated cost impact to include the number of work 
hours to inspect the main gearbox oil filter pack and the number of 
work hours to rework the plate. 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 6 helicopters of U.S. registry will be 
affected by this proposed AD, that it will take approximately 8 work 
hours per helicopter to accomplish the borescope inspection, 1 work 
hour to inspect the main gearbox oil filter pack, 140 work hours to 
remove and replace the main gearbox assembly, if necessary, and 20 work 
hours to rework the plate; and that the average labor rate is $60 per 
work hour. Required parts will cost $8,000 per helicopter. Based on 
these figures, the total cost impact of this AD on U.S. operators is 
estimated to be $108,480; $2,880 to accomplish the borescope 
inspections, and $105,600 to replace the plate in the main gearbox 
assembly in all 6 helicopters, if necessary. Daily preflight 
inspections of the main gearbox oil filter pack will cost $60 per 
helicopter for each day flight is conducted.
    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.
    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, 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.

[[Page 28322]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
(AD) to read as follows:

AD 97-10-15  Erickson Air-Crane Co: Amendment 39-10028. Docket No. 
95-SW-34-AD.

    Applicability: Sikorsky Aircraft-manufactured Model S-64F 
helicopters, with main gearbox second stage lower planetary plate, 
part number (P/N) 6435-20516-101, installed, 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 as indicated, unless accomplished 
previously.
    To prevent failure of the main gearbox second stage lower 
planetary plate (plate) due to fatigue cracking, which could lead to 
failure of the main gearbox and subsequent loss of control of the 
helicopter, accomplish the following:
    (a) For main gearbox assemblies containing plate, P/N 6435-
20516-101, with 2,000 hours time-in-service (TIS) or more:
    (1) Prior to the first flight of each day, inspect the main oil 
filter for magnesium contamination. If magnesium contamination is 
discovered, replace the main gearbox assembly.
    (2) Within the next 100 hours TIS after the effective date of 
this AD, and thereafter at intervals not to exceed 500 hours TIS, 
inspect, and, if necessary, replace the main gearbox assembly in 
accordance with the Accomplishment Instructions of Section 2, 
Paragraph B, of Erickson Service Bulletin No. 64F35-2A dated 
November 8, 1995.
    (b) At the next overhaul of the main gearbox assembly, inspect 
and rework the plate, P/N 6435-20516-101, in accordance with Section 
2, Paragraphs C(1) and (3) through (11) of Erickson Service Bulletin 
No. 64F35-2A, dated November 8, 1995.
    (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, Rotorcraft Certification Office, 
Rotorcraft Directorate, FAA. Operators shall submit their requests 
through an FAA Principal Maintenance Inspector, who may concur or 
comment and then send it to the Manager, Rotorcraft Certification 
Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft 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 rework shall be done in accordance with 
Erickson Air-Crane Co. Service Bulletin No. 64F35-2A, dated November 
8, 1995. 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 Erickson Air-Crane 
Co., 3100 Willow Springs Rd., P.O. Box 3247, Central Point, Oregon 
97502. Copies may be inspected at the FAA, Office of the Assistant 
Chief Counsel, 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 June 27, 1997.

    Issued in Fort Worth, Texas, on May 9, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-12855 Filed 5-22-97; 8:45 am]
BILLING CODE 4910-13-U

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