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

[Federal Register Volume 62, Number 177 (Friday, September 12, 1997)]
[Rules and Regulations]
[Pages 47933-47934]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-24194]



[[Page 47933]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-SW-04-AD; Amendment 39-10130; AD 97-19-10]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Sikorsky Aircraft-manufactured Model S-64E and S-
64F helicopters, that currently requires initial and repetitive 
inspections of the main gearbox assembly second stage lower planetary 
plate (plate) for cracks, and removal and replacement of the plate if 
cracks are found; and daily inspections of certain main transmission 
oil filter packs for magnesium chips, and removal and replacement of 
the main transmission if chips are found. The AD also provides for 
reworking and re-identifying the plate, as well as establishes a 
retirement life for the plate, including those that have been reworked 
and re-identified. This amendment requires, for Model S-64E 
helicopters, inspections and rework of the plate and establishes a new 
retirement life for the plate. This amendment is prompted by the type 
certificate holder's reports that four plates were discovered to have 
cracks, three of which had been reworked in accordance with the 
existing AD. The actions specified by this AD are intended to add 
another plate to the applicability of the AD, remove the requirements 
of AD 77-20-01 for the Model S-64F and prevent failure of the plate on 
the Model S-64E due to fatigue cracking, which could lead to failure of 
the main gearbox and subsequent loss of control of the helicopter.

DATES: Effective October 17, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 17, 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, OR 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) 222-5157, fax 
(817) 222-5783.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 77-20-01, 
Amendment 39-3045 (42 FR 51565, September 29, 1977), which was revised 
by Amendment 39-3064 (42 FR 56600, October 27, 1977), and is applicable 
to Sikorsky Aircraft-manufactured Model S-64E and S-64F helicopters, 
was published in the Federal Register on October 11, 1996 (61 FR 
53339). That action proposed to require, at 1,300 hours time-in-service 
(TIS), a fluorescent magnetic particle inspection of the plate, part 
number (P/N) 6435-20229-102, for cracks, replacement of the plate if a 
crack is found, and reworking the plate if no crack is found. The 
action also proposed to require, at 1,500 hours TIS, and thereafter at 
intervals not to exceed 70 hours TIS, for reworked plate, P/N 6435-
20229-102, reidentified as P/N 6435-20229-102-TS-107 after rework, and 
for plate, P/N 6435-20229-104, a borescope inspection for cracks and 
replacement of the plate if a crack is found. Finally, it was proposed 
that these part-numbered plates be retired upon reaching 2,600 hours 
TIS.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter states that the AD should not be applicable to Model 
S64F helicopters as in the existing AD because of differences in part 
numbers between that model helicopter and the Model S64E helicopter. 
The FAA concurs, and did not include Model S64F helicopters in the 
applicability portion of the proposal, nor in this final rule.
    A second commenter addressed restricted category Model CH54A 
helicopters. This AD does not affect those model helicopters--only 
Model S64E helicopters. The FAA anticipates issuing another AD 
applicable to Model CH54A helicopters at a later date.
    After careful review of the available data, including the comments 
previously noted, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed except for adding 
``reidentified as'' prior to P/N 6435-20229-102-TS-107, and ``after 
rework'' after that P/N. The FAA has determined that these non-
substantive changes will neither increase the economic burden on any 
operator nor increase the scope of the AD.
    The FAA estimates that 8 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 8 work hours per 
helicopter to accomplish the inspections and 56 hours to remove and 
replace the main gearbox assembly, if necessary, 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 $94,720; $3,840 to accomplish the 
inspections, and $90,880 to replace the plate in the main gearbox 
assembly in all 8 helicopters, if necessary.
    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:

[[Page 47934]]

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-3045 (42 FR 
51565, September 29, 1977) and 39-3064 (42 FR 56600, October 27, 1977), 
and by adding a new airworthiness directive (AD), Amendment 39-10130, 
to read as follows:

97-19-10 Erickson Air-Crane Co.: Amendment 39-10130. Docket No. 96-
SW-04-AD. Supersedes AD 77-20-01, Amendment 39-3045 and Amendment 
39-3064.

    Applicability: Sikorsky Aircraft-manufactured Model S-64E 
helicopters, with main gearbox assembly second stage lower planetary 
plate (plate), part number (P/N) 6435-20229-102, reidentified as P/N 
6435-20229-102-TS-107 after rework, or P/N 6435-20229-104, 
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 (d) 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 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 plate, part number (P/N) 6435-20229-102 and P/N 6435-
20229-102-TS-107, at 1,300 hours total time-in-service (TIS), 
inspect and rework or replace the plate, as appropriate, in 
accordance with the Accomplishment Instructions, paragraph 2A., 
steps (1), and (3) through (11), of Erickson Air-Crane Co. Service 
Bulletin No. 64B35-7C, dated November 8, 1995.
    (b) For any plate, P/N 6435-20229-102, that has been reworked 
and identified with ``TS-107'', and for plate, P/N 6435-20229-104, 
at 1,500 hours TIS and thereafter at intervals not to exceed 70 
hours TIS, inspect the plate in accordance with the Accomplishment 
Instructions, paragraph 2B., step (1), of Erickson Air-Crane Co. 
Service Bulletin No. 64B35-7C, dated November 8, 1995. If a crack is 
found, replace the main gearbox assembly with an airworthy assembly.
    (c) This AD revises the airworthiness limitation section of the 
maintenance manual by establishing a retirement life of 2,600 hours 
TIS for the main gearbox assembly second stage planetary plate, P/N 
6435-20229-102, reidentified as P/N 6435-20229-102-TS-107 after 
rework, and P/N 6435-20229-104.
    (d) 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.

    (e) 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.
    (f) The inspections and rework or replacement, as necessary, 
shall be done in accordance with Erickson Air-Crane Co. Service 
Bulletin No. 64B35-7C, 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, OR 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.
    (g) This amendment becomes effective on October 17, 1997.

    Issued in Fort Worth, Texas, on September 5, 1997.
Larry M. Kelly,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-24194 Filed 9-11-97; 8:45 am]
BILLING CODE 4910-13-U

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