
[Federal Register Volume 80, Number 95 (Monday, May 18, 2015)]
[Rules and Regulations]
[Pages 28172-28175]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-11732]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-1537; Directorate Identifier 2015-SW-014-AD; 
Amendment 39-18160; AD 2015-08-51]
RIN 2120-AA64


Airworthiness Directives; The Enstrom Helicopter Corporation

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are publishing a new airworthiness directive (AD) for 
Enstrom Helicopter Corporation (Enstrom) Model F-28A, 280, F-28C, F-
28C-2, F-28C-2R, 280C, F-28F, F-28F-R, 280F, 280FX, and 480 
helicopters. This AD was sent previously to all known U.S. owners and 
operators of these helicopters and supersedes Emergency AD (EAD) 2015-
04-51, dated February 12, 2015. This AD requires inspecting certain 
main rotor spindles (spindles) for cracks and reporting the inspection 
results to the FAA. This AD is prompted by a fatal accident and reports 
of spindles with cracks. The actions specified in this AD are intended 
to detect a crack in a spindle and prevent loss of a main rotor blade 
and subsequent loss of control of the helicopter.

DATES: This AD becomes effective June 2, 2015 to all persons except 
those persons to whom it was made immediately effective by EAD 2015-08-
51, issued on April 10, 2015, which contains the requirements of this 
AD.
    We must receive comments on this AD by July 17, 2015.

[[Page 28173]]


ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     Fax: 202-493-2251.
     Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
     Hand Delivery: Deliver to the ``Mail'' address between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the Docket Operations Office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the economic evaluation, any 
comments received, and other information. The street address for the 
Docket Operations Office (telephone 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.
    For service information identified in this AD, contact Enstrom 
Helicopter Corporation, 2209 22nd Street, Menominee, MI; telephone 
(906) 863-1200; fax (906) 863-6821; or at www.enstromhelicopter.com. 
You may review the referenced service information at the FAA, Office of 
the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Gregory J. Michalik, Senior Aerospace 
Engineer, Chicago Aircraft Certification Office, Small Airplane 
Directorate, FAA, 2300 East Devon Ave., Des Plaines, IL 60018; (847) 
294-7135; email gregory.michalik@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments prior to it becoming effective. However, we 
invite you to participate in this rulemaking by submitting written 
comments, data, or views. We also invite comments relating to the 
economic, environmental, energy, or federalism impacts that resulted 
from adopting this AD. The most helpful comments reference a specific 
portion of the AD, explain the reason for any recommended change, and 
include supporting data. To ensure the docket does not contain 
duplicate comments, commenters should send only one copy of written 
comments, or if comments are filed electronically, commenters should 
submit them only one time. We will file in the docket all comments that 
we receive, as well as a report summarizing each substantive public 
contact with FAA personnel concerning this rulemaking during the 
comment period. We will consider all the comments we receive and may 
conduct additional rulemaking based on those comments.

Discussion

    On February 12, 2015, we issued EAD 2015-04-51, which was prompted 
by a fatal accident. Preliminary results of the investigation indicated 
that the accident was caused by a crack in the spindle, which resulted 
in the main rotor blade separating from the helicopter. The crack was 
discovered at the last thread of the spindle retention nut threads. 
While the investigation could not determine when the crack initiated, 
it was able to determine that the crack existed, undetected, for a 
significant amount of time before the separation. EAD 2015-04-51 
required, before further flight, conducting a magnetic particle 
inspection (MPI) in any spindle that had 5,000 or more hours time-in-
service (TIS) or where the hours TIS of the spindle is not known. If 
there was a crack in the spindle, EAD 2015-04-51 required replacing it 
before further flight. EAD 2015-04-51 also required reporting the 
inspection results to the FAA within 72 hours.
    Since we issued EAD 2015-04-51, inspection reports received by the 
FAA indicate approximately 20% of the spindles reported with TIS data 
had evidence of cracks. The FAA also received inspection reports of 
spindles without TIS data which did not have evidence of cracks. The 
inspection reports include spindles with cracks at less than 5,000 
hours TIS. With analysis of available data, we determined the need to 
expand the applicability to include spindles with 1,500 or more hours 
TIS.
    On April 10, 2015, we issued EAD 2015-08-51, which supersedes EAD 
2015-04-51. EAD 2015-08-51 retains all of the requirements of EAD 2014-
04-51 except it reduces the TIS of the spindles to be inspected from 
5,000 hours to 1,500 hours. EAD 2015-08-51 was sent previously to all 
known U.S. owners and operators of these helicopters.

FAA's Determination

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs.

Related Service Information

    Enstrom has issued Service Directive Bulletin No. 0119, Revision 1, 
dated April 1, 2015, for all serial numbered Model F-28A, F-28C, F-28F, 
280, 280C, 280F, and 280FX helicopters with a main rotor spindle, part 
number (P/N) 28-14282-11 and 28-14282-13. Enstrom has also issued 
Service Directive Bulletin No. T-050, Revision 1, dated April 1, 2015, 
for Model 480 helicopters, serial numbers 5001 through 5004 and 5006, 
and with a main rotor spindle, P/N 28-14282-13, except those aircraft 
modified with tension-torsion straps. Both service directives specify, 
for any spindle that has been in service more than 3,500 hours, within 
5 hours TIS, sending the spindle to Enstrom for an MPI. For any spindle 
with less than 3,500 hours TIS, the service directives specify sending 
the spindle to Enstrom for an MPI at or before it reaches 3,500 hours 
TIS. The service directives also specify repeating the MPI every 300 
hours for spindles with over 3,500 hours TIS.

AD Requirements

    This AD requires conducting an MPI before further flight to 
determine if a crack exists in any spindle that has 1,500 or more hours 
TIS or where the hours TIS of the spindle is not known. If there is a 
crack in the spindle, this AD requires replacing it before further 
flight. The MPI of the spindle must be conducted by a Level II or Level 
III inspector qualified in the MPI method in the Aeronautics Sector 
according to the EN4179 or NAS410 standard or equivalent. This AD also 
requires reporting certain information to the FAA within 72 hours.

Differences Between This AD and the Service Information

    This AD requires that the MPI be conducted by a Level II or Level 
III inspector or equivalent and that the results of the MPI be reported 
to the FAA, whereas the service information specifies that the MPI be 
accomplished by or reported to Enstrom. This AD requires an MPI on 
spindles with 1,500 or more hours TIS, whereas the service information 
specifies performing an initial MPI on spindles with 3,500 or more 
hours TIS. This AD does not require a recurring inspection, whereas the 
service information specifies to repeat the MPI every 300 hours TIS for 
spindles with over 3,500 hours TIS. This AD requires the MPI before 
further

[[Page 28174]]

flight, whereas the service information specifies that it be 
accomplished within 5 hours TIS.

Interim Action

    We consider this AD to be an interim action. The inspection reports 
that are required by this AD will enable us to obtain better insight 
into the root cause and extent of the cracking, and eventually to 
develop final action to address the unsafe condition. Once final action 
has been identified, we might consider further rulemaking.

Costs of Compliance

    We estimate that this AD affects 323 helicopters of U.S. Registry 
and that operators may incur the following costs to comply with this 
AD. Inspecting the spindles will take about 15 work-hours per 
helicopter and reporting the required inspection information will take 
about 0.5 work-hour. We estimate an average labor rate of $85 per work-
hour, for a total cost of $1,318 per helicopter and $425,714 for the 
U.S. fleet. Replacing a spindle will cost $8,164 for parts and no 
additional work-hours.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a current valid OMB control number. The control 
number for the collection of information required by this AD is 2120-
0056. The paperwork cost associated with this AD has been detailed in 
the Costs of Compliance section of this document and includes time for 
reviewing instructions, as well as completing and reviewing the 
collection of information. Therefore, all reporting required by this AD 
is mandatory. Comments concerning the accuracy of this burden and 
suggestions for reducing the burden should be directed to the FAA at 
800 Independence Ave. SW., Washington, DC 20591. ATTN: Information 
Collection Clearance Officer, AES-200.

FAA's Justification and Determination of the Effective Date

    Providing an opportunity for public comments prior to adopting 
these AD requirements would delay implementing the safety actions 
needed to correct this known unsafe condition. Therefore, we found and 
continue to find that the risk to the flying public justifies waiving 
notice and comment prior to the adoption of this rule because the 
previously described unsafe condition can adversely affect the 
controllability of the helicopter and the initial required action must 
be accomplished before further flight.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment before issuing this AD 
were impracticable and contrary to the public interest and good cause 
existed to make the AD effective immediately by EAD 2015-08-51, issued 
on April 10, 2015, to all known U.S. owners and operators of these 
helicopters. These conditions still exist and the AD is hereby 
published in the Federal Register as an amendment to section 39.13 of 
the Federal Aviation Regulations (14 CFR 39.13) to make it effective to 
all persons.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD 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.
    For the reasons discussed, I certify that this AD:
    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);
    3. Will not affect intrastate aviation in Alaska to the extent that 
it justifies making a regulatory distinction; and
    4. 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.
    We prepared an economic evaluation of the estimated costs to comply 
with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
Reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2015-08-51 The Enstrom Helicopter Corporation (Enstrom): Amendment 
39-18160; Docket No. FAA-2015-1537; Directorate Identifier 2015-SW-
014-AD.

(a) Applicability

    This AD applies to Enstrom Model F-28A, 280, F-28C, F-28C-2, F-
28C-2R, 280C, F-28F, F-28F-R, 280F, and 280FX helicopters, all 
serial numbers; and Enstrom Model 480 helicopters, serial numbers 
5001 through 5006; with a main rotor spindle (spindle), part number 
(P/N) 28-14282-11 or 28-14282-13, installed, certificated in any 
category. This AD applies to any helicopter that has a spindle with 
1,500 or more hours time-in-service (TIS) or where the hours TIS of 
the spindle is not known.

(b) Unsafe Condition

    This AD defines the unsafe condition as a crack in the spindle, 
which, if not detected, could result in loss of a main rotor blade 
and subsequent loss of control of the helicopter.

(c) Affected ADs

    This AD supersedes Emergency AD 2015-04-51, Directorate 
Identifier 2015-SW-002-AD, dated February 12, 2015.

(d) Effective Date

    This AD becomes effective June 2, 2015 to all persons except 
those persons to whom it was made immediately effective by Emergency 
AD 2015-08-51, issued on April 10, 2015, which contains the 
requirements of this AD.

 (e) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has been 
accomplished on or after February 11, 2015.

[[Page 28175]]

(f) Required Actions

    (1) Before further flight, conduct a magnetic particle 
inspection (MPI) of the spindle to determine if a crack exists, 
paying particular attention to the threaded portion of the spindle. 
The MPI of the spindle must be conducted by a Level II or Level III 
inspector qualified in the MPI in the Aeronautics Sector according 
to the EN4179 or NAS410 standard or equivalent. If there is a crack 
in the spindle, replace it with an airworthy spindle before further 
flight.
    (2) Within 72 hours after accomplishing the MPI, report the 
information requested in Appendix 1 to this AD by mail to the 
Manager, Chicago Aircraft Certification Office, Federal Aviation 
Administration, ATTN: Gregory J. Michalik, 2300 East Devon Ave., Des 
Plaines, IL, 60018; by fax to (847) 294-7834; or email to 
gregory.michalik@faa.gov.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Chicago Aircraft Certification Office, FAA, may 
approve AMOCs for this AD. Send your proposal to: Gregory J. 
Michalik, Senior Aerospace Engineer, Chicago Aircraft Certification 
Office, Small Airplane Directorate, FAA, 2300 East Devon Ave., Des 
Plaines, IL, 60018; (847) 294-7135; email gregory.michalik@faa.gov.
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.
    (3) Any AMOC approved previously in accordance with EAD 2015-04-
51, dated February 12, 2015, is approved as an AMOC for the 
corresponding requirements in paragraph (f)(1) of this AD.

(h) Additional Information

    Enstrom Helicopter Corporation Service Directive Bulletin No. 
0119, Revision 1, dated April 1, 2015, and Enstrom Helicopter 
Corporation Service Directive Bulletin No. T-050, Revision 1, dated 
April 1, 2015, which are not incorporated by reference, contain 
additional information about the subject of this AD. For service 
information identified in this AD, contact Enstrom Helicopter 
Corporation, 2209 22nd Street, Menominee, MI; telephone (906) 863-
1200; fax (906) 863-6821; or at www.enstromhelicopter.com. You may 
review this service information at the FAA, Office of the Regional 
Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas 76137.

(i) Subject

    Joint Aircraft Service Component (JASC) Code: 6220, Main Rotor 
Head.

Appendix 1 to AD 2015-08-51

Spindle Inspection (Sample Format)

    Provide the following information by mail to the Manager, 
Chicago Aircraft Certification Office, Federal Aviation 
Administration, ATTN: Gregory J. Michalik, 2300 East Devon Ave., Des 
Plaines, IL, 60018; by fax to (847) 294-7834; or email to 
gregory.michalik@faa.gov.

Aircraft Registration No.:
Helicopter Model:
Helicopter Serial Number:
Helicopter Owner or Operator:
Contact Phone No.:
Spindle Part Number and Serial Number:
Total Hours Time-in-Service (TIS) on Spindle:
Total Hours TIS on Helicopter (if hours TIS on spindle were not 
available):
Who Performed the Inspection:
Date and Location Inspection was Accomplished:
Crack Found? If yes, describe the crack size, location, orientation 
(provide a sketch or picture):
    Provide Any Other Comments:

    Issued in Fort Worth, Texas, on May 8, 2015.
Lance T. Gant,
Acting Directorate Manager, Rotorcraft Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-11732 Filed 5-15-15; 8:45 am]
BILLING CODE 4910-13-P


