82 FR 57687 - Special Conditions: Bell Helicopter Textron, Inc. (BHTI), Model 525 Helicopter; Mode Annunciation

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 234 (December 7, 2017)

We propose special conditions for the BHTI Model 525 helicopter. This helicopter will have a novel or unusual design feature associated with fly-by-wire flight control system (FBW FCS) functions that affect the pilot awareness of the flight control modes while operating the helicopter. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

[Federal Register Volume 82, Number 234 (Thursday, December 7, 2017)]
[Proposed Rules]
[Pages 57687-57688]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-26418]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 29

[Docket No. FAA-2017-1129; Notice No. 29-042-SC]


Special Conditions: Bell Helicopter Textron, Inc. (BHTI), Model 
525 Helicopter; Mode Annunciation

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: We propose special conditions for the BHTI Model 525 
helicopter. This helicopter will have a novel or unusual design feature 
associated with fly-by-wire flight control system (FBW FCS) functions 
that affect the pilot awareness of the flight control modes while 
operating the helicopter. The applicable airworthiness regulations do 
not contain adequate or appropriate safety standards for this design 
feature. These proposed special conditions contain the additional 
safety standards that the Administrator considers necessary to 
establish a level of safety equivalent to that established by the 
existing airworthiness standards.

DATES: Send your comments on or before January 22, 2018.

ADDRESSES: Send comments identified by docket number [FAA-2017-XXXX] 
using any of the following methods:
    [square] Federal eRegulations Portal: Go to http://www.regulations.gov and follow the online instructions for sending your 
comments electronically.
    [square] Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC, 20590-0001.
    [square] Hand Delivery of Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 8 a.m., and 5 p.m., 
Monday through Friday, except Federal holidays.
    [square] Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://www.regulations.gov, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov.
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov at any time. Follow the online instructions 
for accessing the docket or go to the Docket Operations in Room W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m., and 5 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: George Harrum, Aerospace Engineer, 
Rotorcraft Standards Branch, Policy and Innovation Division, FAA, 10101 
Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-4087; email 
[email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive on or before the closing 
date for comments. We will consider comments filed late if it is 
possible to do so without incurring expense or delay. We may change 
these special conditions based on the comments we receive.

Background

    On December 15, 2011, BHTI applied for a type certificate for a new 
transport category helicopter designated as the Model 525. The aircraft 
is a medium twin-engine rotorcraft. The design maximum takeoff weight 
is 20,500 pounds, with a maximum capacity of 19 passengers and a crew 
of 2.
    The BHTI Model 525 helicopter will be equipped with a four-axis 
full authority digital FBW FCS that provides for aircraft control 
through pilot input and coupled flight director modes. Current 
regulations are inadequate in the area of pilot awareness of the flight 
control modes while operating the helicopter. The proposed special 
condition will require that suitable mode annunciation be provided to 
the flight crew for events that significantly change the operating mode 
of the system but do not merit the traditional warnings, cautions, and 
advisories.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, BHTI must show that the Model 
525 helicopter meets the applicable provisions of part 29, as amended 
by Amendment 29-1 through 29-55 thereto. The BHTI Model 525 
certification basis date is December 31, 2013, the effective date of 
application to the FAA.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 29) do not contain adequate or 
appropriate safety standards for the BHTI Model 525 because of a novel 
or unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the BHTI Model 525 helicopter must comply with the noise 
certification requirements of 14 CFR part 36, and the FAA must issue a 
finding of regulatory adequacy under Sec.  611 of Public Law 92-574, 
the ``Noise Control Act of 1972.''
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type-
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The BHTI Model 525 helicopter will incorporate the following novel 
or unusual design features: A four-axis full authority digital FBW FCS. 
Pilot control inputs, through the mechanically linked cockpit controls 
(cyclic, collective, directional pedals), are transmitted electrically 
to each of the three Flight Control Computers (FCCs). The pilot control 
input signals are then processed and transmitted to the hydraulic 
flight control actuators which affect control of

[[Page 57688]]

the main and tail rotors. The FCCs process the pilot control input 
signals depending on the flight control mode in affect.

Discussion

    The current 14 CFR 29 standards do not provide adequate standards 
for pilot awareness of the flight control modes while operating the 
helicopter. The proposed special condition will require that suitable 
mode annunciation be provided to the flight crew for events that 
significantly change the operating mode of the system but do not merit 
the traditional warnings, cautions, and advisories.

Applicability

    As discussed above, these special conditions are applicable to the 
BHTI Model 525 helicopter. Should BHTI apply at a later date for a 
change to the type certificate to include another model incorporating 
the same novel or unusual design feature, the special conditions would 
apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on one model of rotorcraft. It is not a rule of general applicability.

List of Subjects in 14 CFR Part 29

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for Bell Helicopter Textron, Inc., Model 525 helicopters:
    Mode Annunciation: A means must be provided to indicate to the crew 
any mode that significantly changes or degrades the handling or 
operational characteristics of the rotorcraft.

    Issued in Fort Worth, Texas on November 16, 2017.
Larry M. Kelly,
Manager, Rotorcraft Standards Branch, Policy and Innovation Division 
Aircraft Certification Service.
[FR Doc. 2017-26418 Filed 12-6-17; 8:45 am]
 BILLING CODE 4910-13-P