Airworthiness Directives; Enstrom Helicopter Corporation Helicopters

[Federal Register Volume 77, Number 117 (Monday, June 18, 2012)]
[Rules and Regulations]
[Pages 36131-36134]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-14634]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0562; Directorate Identifier 2012-SW-038-AD; 
Amendment 39-17068; AD 2012-11-05]
RIN 2120-AA64


Airworthiness Directives; Enstrom Helicopter Corporation 
Helicopters

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: We are superseding an existing airworthiness directive (AD) 
for Enstrom Helicopter Corporation (Enstrom) Model F-28C, F-28C-2, F-
28F, 280C, 280F, 280FX, TH-28, 480, and 480B helicopters to add another 
trim relay to the applicability and to revise the modification 
instructions. This AD is prompted by the discovery that another part-
numbered trim relay, inadvertently omitted from the current AD, may 
contain the same unsafe condition. These actions are intended to 
prevent failure of the cyclic trim system and subsequent loss of 
control of the helicopter.

DATES: This AD becomes effective July 3, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of July 3, 
2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of 
January 23, 2012 (77 FR 729, January 6, 2012).
    We must receive comments on this AD by August 17, 2012.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
    <bullet> Fax: 202-493-2251.
    <bullet> Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200

[[Page 36132]]

New Jersey Avenue SE., Washington, DC 20590-0001.
    <bullet> 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 St., Menominee, Michigan, 49858-0490; 
telephone: 906-863-1200; email: [email protected]; 
Web site: http://www.enstromhelicopter.com/enstrom_new/enstrom_support_tec.html. You may review a copy of 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, Enstrom Program 
Manager, FAA, Chicago Aircraft Certification Office, 2300 East Devon 
Avenue, Room 107, Des Plaines, Illinois, 60018; telephone (847) 294-
7135; email: [email protected].

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 December 14, 2011, we issued AD 2011-26-10, amendment 39-16900 
(77 FR 729, January 6, 2012) for Enstrom Model F-28C, F-28C-2, F-28F, 
280C, 280F, 280FX, TH-28, 480, and 480B helicopters with a trim relay, 
part-number (P/N) KUP14D55-472, M83536/10-015M, or M83536/10-024M. That 
AD requires modifying the lateral and longitudinal trim actuator 
assemblies by replacing the actuator and limit switch bracket to 
provide a positive stop for the trim actuator. In the event of a trim 
actuator runaway, the new bracket will stop the actuator, causing the 
circuit breaker to trip before any significant loss of control occurs. 
After the trim actuator assemblies are modified, that AD requires 
performing operational (ground) and flight tests to determine that the 
trim relay is working correctly. That AD was prompted by reports of 4 
failures in the cyclic trim system in the field, 2 that occurred on the 
Enstrom Model 480B helicopter and 2 that occurred on the Enstrom Model 
F28 helicopter. These failures resulted in reduced controllability of 
the helicopter. We issued that AD to prevent failure of the cyclic trim 
system and subsequent loss of control of the helicopter.

Comments

    Since we issued immediately adopted AD 2011-26-10, we received one 
comment from Enstrom, the manufacturer, and Revision 4 to Enstrom 
Service Directive Bulletin No. 0110, dated January 23, 2012 (SDB 0110), 
for Model F-28C, F-28C-2, F-28F, 280C, 280F, and 280FX helicopters. In 
its comment, the manufacturer stated that the list of affected part 
numbers for the F-28 series and 280 series helicopter should include P/
N KUP14D55-24 and that this P/N was erroneously left off of Enstrom's 
original Service Directive Bulletin. It stated that the same safety 
concerns also exist with this relay and that adding this P/N will not 
affect the cost analysis or fleet size as these aircraft were included 
in the initial calculations.
    We agree with the commenter that the additional part numbered relay 
contained in Enstrom SDB 0110 should be added to the applicability 
section of the AD because it may contain the same unsafe condition. 
Also, we agree that the revised compliance instructions contained in 
SDB 0110 should be required.

FAA's Determination

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

Related Service Information

    We reviewed Enstrom SDB No. T-039, Revision 3, dated July 6, 2011 
(SDB T-039), for Model TH-28, 480, and 480B helicopters and Enstrom SDB 
0110, for Model F-28C, F-28C-2, F-28F, 280C, 280F, and 280FX 
helicopters. SDB T-039 specifies, for helicopters with a trim relay, P/
N M83536/10-024M, procedures for modifying the lateral and longitudinal 
trim actuator assembly using the cyclic trim assembly kit (modification 
kit), P/N 4230045-1, and specifies performing an operational check and 
flight test to determine if the trim is operating correctly after the 
modification. SDB 0110 specifies, for helicopters with a trim relay, P/
N KUP14D55-24, KUP14D55-472, M83536/10-015M, or M83536/10-024M, 
procedures for modifying the lateral and longitudinal trim actuator 
assembly using the modification kit, P/N 28-01063-1, and specifies 
performing an operational check and flight test to determine if the 
trim is operating correctly after the modification. The SDBs state that 
the modification kits contain the upgraded bracket.

AD Requirements

    In addition to those part-numbered trim relays contained in the 
applicability section of the current AD 2011-26-10, this AD adds trim 
relay P/N KUP14D55-24. Also, this AD adopts the revised modification 
instructions for the Model F-28C, F-28C-2, F-28F, 280C, 280F, and 280FX 
helicopters contained in SDB 0110. Otherwise, this AD retains most of 
the requirements of AD 2011-26-10, which requires modifying the lateral 
and longitudinal trim actuator assembly, using modification kit, P/N 
28-01063-1, for the Model F-28C, F-28C-2, F-28F, 280C, 280F, and 280FX 
helicopters and modification kit, P/N 4230045-1, for the Model TH-28, 
480, and 480B helicopters, and verifying that the modification has been 
completed properly by performing an operational and flight test after 
the modification is complete.
    The actions required by this AD are to be accomplished by following 
specified

[[Page 36133]]

portions of the SDBs described previously.

Differences Between This AD and the Service Information

    The SDBs specify, before further flight, to insert a special 
addendum into the Emergency Procedures section of the Flight Manual, 
and this AD does not require this action.

Costs of Compliance

    We estimate that this AD will affect 207 helicopters of U.S. 
Registry. We estimate that operators may incur the following costs in 
order to comply with this AD. For Model 480, 480B, and TH-28, modifying 
the actuator assemblies will require 8 work hours at a cost of $85 per 
hour and parts will cost $327; the cost per helicopter will be $1,007. 
For Model 280C, 280F, 280FX, F-28C, F-28C-2, and F-28F, modifying the 
actuator assemblies will require 8 work hours at a cost of $85 per 
hour; parts will cost $383; and the cost per helicopter will be $1,063.

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 find that 
the risk to the flying public justifies waiving notice and comment 
prior to the adoption of this rule because the required corrective 
actions must be accomplished within 5 hours time-in-service, a very 
short time period based on the average flight-hour utilization rate of 
these helicopters.
    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we determined that notice and opportunity for 
public comment before issuing this AD are impracticable and contrary to 
the public interest and that good cause exists for making this 
amendment effective in less than 30 days.

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 removing Amendment 39-16900 (77 FR 
729, January 6, 2012), and adding the following new airworthiness 
directive (AD):

2012-11-05 Enstrom Helicopter Corporation: Amendment 39-17068; 
Docket No. FAA-2012-0562; Directorate Identifier 2012-SW-038-AD.

(a) Applicability

    This AD applies to the Enstrom Model F-28C, F-28C-2, F-28F, 
280C, 280F, 280FX, TH-28, 480, and 480B helicopters with a trim 
relay, part-number (P/N) KUP14D55-24, KUP14D55-472, M83536/10-015M, 
or M83536/10-024M, certificated in any category.
    Note to paragraph (a) of this AD: This AD does not apply to the 
specified helicopters with a reversible trim motor, P/N 28-16621 
(Ford Motor Company C1AZ-14553A) or P/N AD1R-10 (Signal Electric).

(b) Unsafe Condition

    This AD defines the unsafe condition as a failure of a trim 
relay in the cyclic trim system. This condition could result in 
reduced controllability of the helicopter and subsequent loss of 
control of the helicopter.

(c) Other Affected ADs

    This AD supersedes AD 2011-26-10, Amendment 39-16900 (77 FR 729, 
January 6, 2012).

(d) Effective Date

    This AD becomes effective July 3, 2012.

(e) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(f) Required Actions

    Within 5 hours time-in-service (TIS) or at the next annual or 
100 hour TIS inspection, whichever occurs first:
    (1) For the Enstrom Model F-28C, F-28C-2, F-28F, 280C, 280F, and 
280FX helicopters, modify the lateral and longitudinal trim actuator 
assemblies using the cyclic trim assembly kit (modification kit), P/
N 28-01063-1, in accordance with the instructions in paragraph 6.1 
of the Enstrom Service Directive Bulletin (SDB) No. 0110, Revision 
4, dated January 23, 2012 (SDB No. 0110 R4), except when the 
instructions specify using ``Aeroshell 22 grease'' or ``VC-3 Vibra-
tite thread locker,'' you may use an equivalent product.
    (2) For the Enstrom Model TH-28, 480, and 480B helicopters, 
modify the lateral and longitudinal trim actuator assemblies using 
the modification kit, P/N 4230045-1, in accordance with the 
instructions in paragraph 6.1 of the Enstrom SDB No. T-039, Revision 
3, dated July 6, 2011 (SDB No. T-039 R3), except when the 
instructions specify using ``Aeroshell 22 grease'' or ``VC-3 Vibra-
tite thread locker,'' you may use an equivalent product, and you are 
not required to contact Enstrom Customer Service.
    (3) After modifying the lateral and longitudinal trim actuator 
assemblies in accordance with paragraphs (f)(1) or (f)(2) of this 
AD, before further flight, operationally test the trim limits in 
accordance with paragraph 6.2. of the SDB for your model helicopter, 
and determine during a flight test whether there is appropriate trim 
authority in accordance with paragraph 6.3. of the SDB for your 
model helicopter.

(g) Special Flight Permits

    A one-time special-flight permit may be issued in accordance 
with 14 CFR 21.197 and 21.199 provided the helicopter is operated 
with the trim system circuit breaker pulled.

[[Page 36134]]

(h) 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, Enstrom Program Manager, FAA, Chicago Aircraft 
Certification Office, 2300 East Devon Avenue, Room 107, Des Plaines, 
Illinois, 60018; telephone (847) 294-7135; fax (847) 294-7834; 
email: [email protected].
    (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.

 (i) Subject

    Joint Aircraft Service Component (JASC) Code: 6710: Main Rotor 
Control.

 (j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the following service 
information under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use the following service information to do the 
actions required by this AD, unless the AD specifies otherwise.
    (3) The following service information was approved for IBR on 
July 3, 2012.
    (i) Enstrom Service Directive Bulletin No. 0110, Revision 4, 
dated January 23, 2012, for Model F-28C, F-28C-2, F-28F, 280C, 280F, 
and 280FX helicopters.
    (4) The following service information was approved for IBR on 
January 23, 2012 (77 FR 729, January 6, 2012).
    (i) Enstrom Service Directive Bulletin No. T-039, Revision 3, 
dated July 6, 2011, for Model TH-28, 480, and 480B helicopters.
    (5) For service information identified in this AD, contact 
Enstrom Helicopter Corporation, 2209 22nd St., Menominee, Michigan, 
49858-0490; telephone: 906-863-1200; email: 
[email protected]; Web site: http://www.enstromhelicopter.com/enstrom_new/enstrom_support_tec.html.
    (6) You may review a copy of the referenced service information 
at the FAA, Office of the Regional Counsel, Southwest Region, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas 76137 or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Fort Worth, Texas, on May 17, 2012.
Kim Smith,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2012-14634 Filed 6-15-12; 8:45 am]
BILLING CODE 4910-13-P

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