Document ID: FAA-2017-0052-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Bell Helicopter Textron Inc. Helicopters
Posted Date: 2018-08-02T04:00Z

[Federal Register Volume 83, Number 149 (Thursday, August 2, 2018)]
[Proposed Rules]
[Pages 37764-37766]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-16495]

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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
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  Federal Register / Vol. 83, No. 149 / Thursday, August 2, 2018 / 
Proposed Rules  

[[Page 37764]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0052; Product Identifier 2016-SW-081-AD]
RIN 2120-AA64

Airworthiness Directives; Bell Helicopter Textron Inc. 
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to supersede airworthiness directive (AD) 2015-04-
04 for Bell Helicopter Textron Inc. (Bell) Model 412 and 412EP 
helicopters. AD 2015-04-04 requires revising the Rotorcraft Flight 
Manual (RFM) and installing a placard to limit flights to visual flight 
rules (VFR) and prohibiting night operations because of failing 
inverters. This proposed AD would require replacing the inverters with 
a new inverter. The actions in this proposed AD are intended to correct 
an unsafe condition on these products.

DATES: We must receive comments on this proposed AD by October 1, 2018.

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 by searching for and locating Docket No. FAA-2017-
0052; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this proposed AD, the economic evaluation, any comments received and 
other information. The street address for Docket Operations (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 proposed rule, contact 
Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, TX 76101; 
telephone (817) 280-3391; fax (817) 280-6466; or at http://www.bellcustomer.com/files/. You may review service information at the 
FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood 
Pkwy, Room 6N-321, Fort Worth, TX 76177.

FOR FURTHER INFORMATION CONTACT: Tim Beauregard, Aviation Safety 
Engineer, DSCO Branch, AIR-7J0, FAA, 10101 Hillwood Pkwy, Fort Worth, 
TX 76177; telephone (817) 222-4357; email [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    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 might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, 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 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 proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
We may change this proposal in light of the comments we receive.

Discussion

    We issued AD 2015-04-04, Amendment 39-18106 (80 FR 9594, February 
24, 2015), for Bell Model 412 and 412EP helicopters with an inverter 
part number (P/N) 412-375-079-101 or 412-375-079-103 with a serial 
number 29145 or higher. AD 2015-04-04 was prompted by numerous failures 
of inverters. The failure of one inverter can result in smoke in the 
cockpit, making landing at night and during instrument meteorological 
conditions difficult. If two inverters fail, then the pilot will lose 
primary flight and navigation displays, autopilot, and alternate 
current powered engine and transmission indicators.
    To address this condition, Bell issued Alert Service Bulletin (ASB) 
412-13-156, dated April 25, 2013, which specifies inspecting inverter 
part number (P/N) 412-375-079-101 and either repairing it or replacing 
it with inverter P/N 412-375-079-103 to prevent failure. Because the 
specific cause of the inverter failures had not been verified, and 
since inverter failures continued after Bell issued the ASB, we 
determined the actions specified in the ASB did not correct the unsafe 
condition. Therefore, AD 2015-04-04 requires revising the RFM and 
installing a placard in full view of the pilot to limit flights to VFR 
only and prohibit night operations.

Actions Since AD 2015-04-04 Was Issued

    Since we issued AD 2015-04-04, Bell determined the root causes of 
the failures were an external connector that caused a short circuit 
inside inverter P/N 412-375-079-101 and components chafing because of 
variations in the assembly process and packaging tolerances for 
inverter P/N 412-375-079-103. Bell introduced an improved inverter, P/N 
412-375-079-105, and retrofit kits to replace inverter P/N 412-375-079-
101 or 412-375-079-103 on helicopters with serial numbers 33001 or 
higher. These replacements and repairs correct the unsafe condition by 
providing 250 voltage amperes (VA) of total power instead of 500 VA, 
thereby reducing the input power to the inverter.

[[Page 37765]]

FAA's Determination

    We are proposing 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

    We reviewed Bell Alert Service Bulletin (ASB) 412-15-164, dated 
March 13, 2015 (ASB 412-15-164), which specifies an alternate means of 
compliance (AMOC) approved by the FAA for AD 2015-04-04 (80 FR 9594, 
February 24, 2015). Instead of the flight limitations mandated by AD 
2015-04-04, ASB 412-15-164 limits allow operation under instrument 
flight rules (IFR) and night operations with two pilots.
    We also reviewed Bell ASB 412-16-171, dated March 22, 2016 (ASB 
412-16-171), which specifies replacing certain serial-numbered 
inverters P/N 412-375-079-101 and 412-375-079-103 with inverter P/N 
412-375-079-105 as a direct replacement or with a retrofit kit. Bell 
specifies that completing the actions specified by the ASB constitute 
terminating action for Bell ASB 412-15-164.
    Lastly, we reviewed Bell Service Instruction for Inverter Retrofit 
Kit BHT-412-SI-93, dated February 15, 2016, which provides instructions 
for installing retrofit kit P/N 412-704-058-103.

Proposed AD Requirements

    The proposed AD would require, within 25 hours time-in-service 
(TIS), replacing the inverter with inverter P/N 412-375-079-105 and, 
for some helicopters, installing retrofit kit P/N 412-704-058-103.
    After accomplishing the previous actions, the proposed AD would 
allow removing the placard and Rotorcraft Flight Manual limitations 
that prohibit night operations and restrict flights to visual flight 
rules.
    After the effective date of this AD, this proposed AD would 
prohibit installing an inverter P/N 412-375-079-101 or 412-375-079-103 
on any helicopter.

Differences Between This Proposed AD and the Service Information

    Bell ASB 412-16-171 requires compliance no later than January 1, 
2017, while this proposed AD would require compliance within 25 hours 
TIS. Bell ASB 412-16-171 makes an electrical load analysis a 
determining factor for corrective actions. This proposed AD would make 
no such requirement. Bell ASB 412-16-171 provides instructions for 
helicopters with serial numbers 36649, 36658, 36659, 36673, 36681 
through 36684, 36686, 36688, 36690, 36692, 36694, and 36696 through 
36704, and this proposed AD would not. Bell has notified us of errors 
in the S/Ns listed for Part B of ASB 412-16-171. Accordingly, this 
proposed AD would only be applicable to those serial-numbered 
helicopters subject to the unsafe condition.

Costs of Compliance

    We estimate that this proposed AD would affect 73 helicopters of 
U.S. Registry and that labor costs average $85 per work-hour. Based on 
these estimates, we expect that installing a new inverter or retrofit 
kit would require about 3 work-hours and a parts cost of $15,749, for a 
total cost of $16,004 per helicopter and $1,168,292 for the U.S. fleet.

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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the 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 proposed 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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 Airworthiness Directive (AD) 
2015-04-04, Amendment 39-18106 (80 FR 9594, February 24, 2015), and 
adding the following new AD:

Bell Helicopter Textron Inc.: Docket No. FAA-2017-0052; Product 
Identifier 2016-SW-081-AD.

(a) Applicability

    This AD applies to Model 412 and 412EP helicopters with a serial 
number (S/N) 33001 through 33213, 34001 through 34036, 36001 through 
36648, 36650 through 36657, 36660 through 36672, 36674 through 
36680, 36685, 36687, 36689, 36691, 36693, 36695, and 37002 through 
37012, certificated in any category, with a static inverter 
(inverter) part number (P/N) 412-375-079-101 or 412-375-079-103 
installed.

(b) Unsafe Condition

    This AD defines the unsafe condition as the failure of an 
inverter under instrument meteorological conditions or night flight. 
This condition could result in smoke in the cockpit, increased pilot 
workload due to the loss of primary flight and navigation displays, 
alternating current powered engine and transmission indicators, and 
autopilot, and subsequent loss of control of the helicopter.

(c) Affected ADs

    This AD replaces AD 2015-04-04, Amendment 39-18106 (80 FR 9594, 
February 24, 2015).

(d) Comments Due Date

    We must receive comments by October 1, 2018.

(e) Compliance

    You are responsible for performing each action required by this 
AD within the

[[Page 37766]]

specified compliance time unless it has already been accomplished 
prior to that time.

 (f) Required Actions

    (1) Within 25 hours time-in-service:
    (i) For helicopters with a S/N 33001 through 33213, 34001 
through 34036, and 36001 through 36086, replace the inverter with 
inverter P/N 412-375-079-105.
    (ii) For helicopters with a S/N 36087 through 36648, 36650 
through 36657, 36660 through 36672, 36674 through 36680, 36685, 
36687, 36689, 36691, 36693, 36695, and 37002 through 37012, install 
retrofit kit P/N 412-704-058-103 and replace the inverter with 
inverter P/N 412-375-079-105.
    (2) After accomplishing the actions required by paragraph (f)(1) 
of this AD, you may remove the placard and Rotorcraft Flight Manual 
limitations, required by AD 2015-04-04, prohibiting night operations 
and restricting flights to visual flight rules.
    (3) After the effective date of this AD, do not install an 
inverter P/N 412-375-079-101 or 412-375-079-103 on any helicopter.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, DSCO, FAA, may approve AMOCs for this AD. Send 
your proposal to: Tim Beauregard, Aviation Safety Engineer, DSCO 
Branch, AIR-7J0, FAA, 10101 Hillwood Pkwy, Fort Worth, TX 76177; 
telephone 817-222-5190; 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.

(h) Additional Information

    Bell Alert Service Bulletin 412-15-164, dated March 13, 2015, 
and Bell Alert Service Bulletin 412-16-171, dated March 22, 2016, 
which are not incorporated by reference, contain additional 
information about the subject of this AD. For service information 
identified in this AD, contact Bell Helicopter Textron, Inc., P.O. 
Box 482, Fort Worth, TX 76101; telephone (817) 280-3391; fax (817) 
280-6466; or at http://www.bellcustomer.com/files/. You may review 
this service information at the FAA, Office of the Regional Counsel, 
Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 
76177.

(i) Subject

    Joint Aircraft Service Component (JASC) Code: 2422, AC Inverter.

    Issued in Fort Worth, Texas, on June 19, 2018.
Scott A. Horn,
Deputy Director for Regulatory Operations, Compliance and Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2018-16495 Filed 8-1-18; 8:45 am]
 BILLING CODE 4910-13-P