[Federal Register Volume 68, Number 39 (Thursday, February 27, 2003)]
[Rules and Regulations]
[Pages 8994-8996]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-4474]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-SW-06-AD; Amendment 39-13064; AD 2003-04-15]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
76A, B, and C Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) for 
the specified Sikorsky Aircraft Corporation (Sikorsky) model 
helicopters. This action requires determining the manufacturer of a 
certain part-numbered rotor brake disc (RBD) and if the manufacturer is 
Parker Hannifin Corporation (PHC), re-identifying the RBD as 
appropriate. This action also requires before the first flight of the 
next day following any day in which a certain RBD was used, visually 
inspecting the RBD for a crack. If a crack is found, this AD also 
requires replacing the RBD with an airworthy RBD or deactivating it as 
applicable depending on the nature of the crack. This amendment is 
prompted by the discovery that certain RBDs manufactured by PHC were 
improperly heat treated resulting in ``soft'' RBDs that have an 
increased wear rate compared to those heat treated in accordance with 
the type design requirement. Further investigation reveals that 
``soft'' RBDs develop cracks more frequently than previously 
manufactured RBDs. The actions specified in this AD are intended to 
prevent failure of the RBD, damage to the rotor blades and nearby 
hydraulic and fuel lines, and subsequent loss of control of the 
helicopter.

DATES: Effective February 27, 2003.
    Comments for inclusion in the Rules Docket must be received on or 
before April 28, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 2003-SW-06-AD, 2601 Meacham Blvd., Room 
663, Fort Worth, Texas 76137. You may also send comments electronically 
to the Rules Docket at the following address: [email protected].

FOR FURTHER INFORMATION CONTACT: Terry Fahr, Aviation Safety Engineer, 
Boston Aircraft Certification Office, 12 New England Executive Park, 
Burlington, MA 01803, telephone (781) 238-7155, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: This amendment adopts a new AD for the 
specified Sikorsky model helicopters. This amendment is prompted by the 
discovery that a certain part-numbered RBD manufactured by PHC was 
improperly heat treated resulting in ``soft'' RBDs that have an 
increased wear rate compared to those heat treated in accordance with 
the type design requirement. Further investigation reveals that 
``soft'' RBDs develop cracks more frequently than previously 
manufactured RBDs. The actions specified in this AD are intended to 
prevent failure of the RBD, damage to the rotor blades and nearby 
hydraulic and fuel lines, and subsequent loss of control of the 
helicopter.
    The FAA has reviewed Sikorsky Alert Service Bulletin (ASB) Nos. 76-
66-36, dated November 12, 2002, and 76-66-37, dated January 31, 2003. 
ASB No. 76-66-36 describes a one-time visual inspection of the RBD to 
determine the manufacturer and to reidentify the RBD if necessary. ASB 
No. 76-66-36 also specifies an initial and recurring inspection for 
certain reidentified RBDs. ASB No. 76-66-37 specifies removing certain 
RBDs from service and provides interim instructions for operating the 
helicopter until a replacement RBD is installed.
    This unsafe condition is likely to exist or develop on other 
helicopters of these same type designs. Therefore, this AD is being 
issued to prevent failure of the RBD, damage to the rotor blades and 
nearby hydraulic and fuel lines, and subsequent loss of control of the 
helicopter. This AD requires the following:
    [sbull] Before further flight, determine the manufacturer of each 
RBD by examining the part number (P/N) markings. This AD requires no 
further action if the manufacturer is BF Goodrich or Goodyear.
    [sbull] If the RBD is manufactured by PHC, reidentify it with a P/N 
76363-09103-104 or -105, as applicable, depending on the serial number 
of the RBD. If you cannot determine the PHC RBD serial number or the 
manufacturer, reidentify the RBD with P/N 76363-09103-104.
    [sbull] Before the first flight of the next day following any day 
in which the RBD was used, visually inspect each RBD, P/N 76363-09103-
104, for a crack.
    [sbull] If you find a crack through the entire RBD thickness or two 
or more surface cracks between adjacent boltholes, replace the RBD with 
an airworthy RBD before further flight. If you find a surface crack or 
surface cracks separated by the boltholes, replace the RBD with an 
airworthy RBD or deactivate it before further flight.
    [sbull] Replace PHC RBD, P/N 76363-09103-104, with an airworthy RBD 
on or before May 31, 2003, or within 60 days after the effective date 
of this AD, whichever occurs later.
    [sbull] Replacement RBD, P/N 76363-09103-104, is not airworthy.
    The short compliance time involved is required because the 
previously described critical unsafe condition can adversely affect the 
controllability of the helicopter. Therefore determining the 
manufacturer, reidentifying the RBD as specified, inspecting the RBD 
for a crack, and either replacing the RBD or deactivating it is 
required before further flight 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 165 helicopters will be affected by this AD, 
that it will take approximately 2 work hours to determine the 
manufacturer of the RBD, 1 hour to reidentify the RBD, 2 hours to 
inspect the RBD, and 6 hours to replace the RBD. The average labor rate 
is $60 per work hour. Required parts will cost approximately $1,250 per 
helicopter. Based on these figures, the total cost impact of the AD on 
U.S. operators is estimated to be $315,150 per helicopter, assuming all 
RBDs were

[[Page 8995]]

manufactured by PHC, are with the affected S/N range, must be remarked, 
do not have sufficient cracking to warrant immediate replacement, and 
the rotor brake is not used until the day prior to the day that all 
RBDs are replaced.

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 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. 2003-SW-06-AD.'' The postcard will be date stamped and 
returned to the commenter.
    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

2003-04-15 Sikorsky Aircraft Corporation: Amendment 39-13064. Docket 
No. 2003-SW-06-AD.

    Applicability: Model S-76A, B, and C 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 
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 (d) 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 rotor brake disc (RBD), damage to the 
rotor blades and nearby hydraulic and fuel lines, and subsequent 
loss of control of the helicopter, accomplish the following:
    (a) Before further flight, determine the manufacturer of each 
RBD by examining the part number (P/N) markings, and perform the 
required actions as follows:
    (1) If the P/N is 76363-09101-102, the manufacturer is Goodyear. 
No further action is required by this AD.
    (2) If the P/N 76363-09103-102 is pressure stamped on the RBD, 
the manufacturer is BF Goodrich. No further action is required by 
this AD.
    (3) If the P/N 76363-09103-102 is electrolytically etched on the 
RBD, the manufacturer is Parker Hannifin Corporation (PHC). For each 
PHC RBD with a P/N 76363-09103-102 and serial number (S/N) other 
than 38 through 379, remark the P/N as P/N 76363-09103-105 using the 
vibropeen method. No further action is required by this AD.
    (4) If the RBD serial number or the manufacturer cannot be 
determined and for PHC RBDs with P/N 76363-09103-102 and S/N's 38 
through 379, reidentify or mark the P/N as 76363-09103-104 or 
replace the RBD in accordance with paragraph (c) of this AD.

    Note 2: Sikorsky Aircraft Corporation Alert Service Bulletin 
(ASB) Nos. 76-66-36, dated November 12, 2002, and ASB 76-66-37, 
dated January 31, 2003, pertain to the subject of this AD.

    (b) Before the first flight of the next day following any day in 
which the RBD was used, visually inspect each RBD, P/N 76363-09103-
104, for a crack, and perform the following actions. See Figure 1.
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[[Page 8996]]

[GRAPHIC] [TIFF OMITTED] TR27FE03.219

    (1) If you find a crack through the entire RBD thickness as 
shown in Figure 1, View A, replace the RBD with an airworthy RBD, 
other than P/N 76363-09103-104, before further flight.
    (2) If you find two or more surface cracks between adjacent 
boltholes as shown in Figure 1, View B, replace the RBD with an 
airworthy RBD, other than P/N 76363-09103-104, before further 
flight.
    (3) If you find a surface crack or surface cracks separated by 
the boltholes as shown in Figure 1, View C, replace the RBD with an 
airworthy RBD, other than P/N 76363-09103-104, or deactivate the RBD 
before further flight.

    Note 3: Short ``glazing'' cracks are not a cause for rejection.


    Note 4: PHC Component Maintenance Manual with Illustrated Parts 
List PH030-21300MM, Rotor Brake Assembly, P/N 030-21300, Revision C, 
dated November 1, 2002, pertains to the subject of this AD.

    (c) Replace PHC RBD, P/N 76363-09103-104, with an airworthy RBD 
on or before May 31, 2003, or within 60 days after the effective 
date of this AD, whichever occurs later. Any replacement RBD, P/N 
76363-09103-104, is not airworthy.
    (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, Boston 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, Boston Aircraft Certification Office.

    Note 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Boston Aircraft Certification Office.

    (e) Special flight permits will not be issued.
    (f) This amendment becomes effective on February 27, 2003.

    Issued in Fort Worth, Texas, on February 14, 2003.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 03-4474 Filed 2-26-03; 8:45 am]
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