
[Federal Register Volume 80, Number 210 (Friday, October 30, 2015)]
[Rules and Regulations]
[Pages 66788-66789]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-27700]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 23

[Docket No. FAA-2015-3880; Special Conditions No. 23-271-SC]


Special Conditions: Honda Aircraft Company (Honda) Model HA-420, 
HondaJet; Cruise Speed Control System

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions.

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SUMMARY: These special conditions are issued for the Honda Aircraft 
Company HA-420 airplane. This airplane will have a novel or unusual 
design feature(s) associated with the use of a cruise speed control 
system. The applicable airworthiness regulations do not contain 
adequate or appropriate safety standards for this design feature. These 
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: These special conditions are effective October 30, 2015 and are 
applicable on October 26, 2015.

FOR FURTHER INFORMATION CONTACT: Jeff Pretz, Federal Aviation 
Administration, Small Airplane Directorate, Aircraft Certification 
Service, 901 Locust, Room 301, Kansas City, MO 64106; telephone (816) 
329-3239; facsimile (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Background

    On October 11, 2006, Honda Aircraft Company applied for a type 
certificate for their new Model HA-420. On October 10, 2013, Honda 
Aircraft Company requested an extension with an effective application 
date of October 1, 2013. This extension changed the type certification 
basis to amendment 23-62.
    The HA-420 is a four to five passenger (depending on 
configuration), two crew, lightweight business jet with a 43,000-foot 
service ceiling and a maximum takeoff weight of 9963 pounds. The 
airplane is powered by two GE-Honda Aero Engines (GHAE) HF-120 turbofan 
engines.
    The HA-420 airplane will use a cruise speed control system (CSC), 
which is part of the automatic flight control system (AFCS), to reduce 
pilot workload during cruise flight only. The intended function is 
automatic airplane speed control during altitude hold AFCS mode by 
adjustment of the engine thrust within a narrow authority band 
utilizing the existing engine synchronization control. The CSC system 
does not back drive the throttles. The command authority is limited to 
values used for engine synchronization and can only be engaged when the 
throttle is positioned in a pre-determined range typically used for 
cruise power. This significantly reduces the CSC authority such that 
failure modes of the system should be minor. The proposed CSC system 
functions in a manner similar to an auto-throttle system, but has 
significantly less authority when compared to a traditional auto-
throttle system.

Type Certification Basis

    Under the provisions of 14 CFR 21.17, Honda Aircraft Company must 
show that the HA-420 meets the applicable provisions of part 23, as 
amended by amendments 23-1 through 23-62, thereto.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 23) do not contain adequate or 
appropriate safety standards for the HA-420 because of a novel or 
unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the HA-420 must comply with the fuel vent and exhaust 
emission requirements of 14 CFR part 34 and the noise certification 
requirements of 14 CFR part 36. In addition, the FAA must issue a 
finding of regulatory adequacy pursuant to 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). 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.

Novel or Unusual Design Features

    The HA-420 will incorporate the following novel or unusual design 
features: Cruise Speed Control system

Discussion

    As defined in the summary section, this airplane makes use of a CSC 
system, which is a novel design for this type of airplane. The 
applicable airworthiness

[[Page 66789]]

regulations do not contain adequate or appropriate safety standards for 
this design feature. Mandating additional requirements, developed in 
part by adapting relevant portions of 14 CFR 25.1329, Automatic pilot 
systems, applicable to auto-throttle systems along with FAA experience 
with similar autothrust systems, mitigates the concerns associated with 
installation of the proposed CSC system.

Discussion of Comments

    Notice of proposed special conditions No. 23-15-05-SC for the Honda 
Aircraft Company model HA-420 airplanes was published in the Federal 
Register on September 23, 2015 (80 FR 57312). No comments were 
received; therefore, the special conditions are adopted as proposed.

Applicability

    As discussed above, these special conditions are applicable to the 
HA-420. Should Honda Aircraft Company apply at a later date for a 
change to the type certificate to include another model on the same 
type certificate incorporating the same novel or unusual design 
feature, the special conditions would apply to that model as well.
    Under standard practice, the effective date of final special 
conditions would be 30 days after the date of publication in the 
Federal Register; however, as the certification date for the Honda 
Aircraft Company model HA-420 airplane is imminent, the FAA finds that 
good cause exists to make these special conditions effective upon 
issuance.

Conclusion

    This action affects only certain novel or unusual design features 
on one model of HA-420 airplane. It is not a rule of general 
applicability and affects only the applicant who applied to the FAA for 
approval of these features on the airplane.

List of Subjects in 14 CFR Part 23

    Aircraft, Aviation safety, Signs and symbols.

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 14 CFR 21.16 and 
21.17; and 14 CFR 11.38 and 11.19.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Honda Aircraft Company HA-420 
airplanes.
    1. Cruise Speed Control.
    In addition to the requirements of Sec. Sec.  23.143, 
Controllability and Maneuverability--General; 23.1309, Equipment, 
systems, and installations; and 23.1329, Automatic pilot system; auto 
throttle systems of limited authority that do not back drive the 
throttles and for which all failure modes are shown to be no greater 
than minor, the following requirements apply:
    (a) Quick disengagement controls for the autothrust functions must 
be provided for each pilot. Quick disengagement controls must be 
readily accessible to each pilot while operating the thrust control 
levers.
    (b) The effects of a failure of the system to disengage the 
autothrust functions when manually commanded by the pilot must be 
assessed in accordance with the requirements of Sec.  23.1309.
    (c) Engagement or switching of the flight guidance system, a mode, 
or a sensor may not cause the autothrust system to effect a transient 
response that alters the airplane's flight path any greater than a 
minor transient, as defined in paragraph (l)(1) of this section.
    (d) Under normal conditions, the disengagement of any automatic 
control function of a flight guidance system may not cause a transient 
response of the airplane's flight path any greater than a minor 
transient.
    (e) Under rare normal and non-normal conditions, disengagement of 
any automatic control function of a flight guidance system may not 
result in a transient any greater than a significant transient, as 
defined in paragraph (l)(2) of this section.
    (f) The function and direction of motion of each command reference 
control (such as CSC) must be plainly indicated on, or adjacent to, 
each control, if necessary to prevent inappropriate use or confusion.
    (g) Under any condition of flight appropriate to its use, the 
flight guidance system may not produce hazardous loads on the airplane, 
nor create hazardous deviations in the flight path. This applies to 
both fault-free operation and in the event of a malfunction, and 
assumes that the pilot begins corrective action within a reasonable 
period of time.
    (h) When the flight guidance system is in use, a means must be 
provided to avoid excursions beyond an acceptable margin from the speed 
range of the normal flight envelope. If the airplane experiences an 
excursion outside this range, a means must be provided to prevent the 
flight guidance system from providing guidance or control to an unsafe 
speed.
    (i) The flight guidance system functions, controls, indications, 
and alerts must be designed to minimize flightcrew errors and confusion 
concerning the behavior and operation of the flight guidance system. 
Means must be provided to indicate the current mode of operation, 
including any armed modes, transitions, and reversions. Selector switch 
position is not an acceptable means of indication. The controls and 
indications must be grouped and presented in a logical and consistent 
manner. The indications must be visible to each pilot under all 
expected lighting conditions.
    (j) Following disengagement of the autothrust function, a caution 
(visual and, unless there are no misleading or hazardous consequences 
associated with its absence, auditory) must be provided to each pilot.
    (k) During autothrust operation, it must be possible for the 
flightcrew to move the thrust levers without requiring excessive force. 
The autothrust may not create a potential hazard when the flightcrew 
applies an override force to the thrust levers.
    (l) For purposes of this section, a transient is a disturbance in 
the control or flight path of the airplane that is not consistent with 
response to flightcrew inputs or environmental conditions.
    (1) A minor transient would not significantly reduce safety margins 
and would involve flightcrew actions that are well within their 
capabilities. A minor transient may involve a slight increase in 
flightcrew workload or some physical discomfort to passengers or cabin 
crew.
    (2) A significant transient may lead to a significant reduction in 
safety margins, an increase in flightcrew workload, discomfort to the 
flightcrew, or physical distress to the passengers or cabin crew, 
possibly including non-fatal injuries. Significant transients do not 
require, in order to remain within or recover to the normal flight 
envelope, any of the following:
    (i) Exceptional piloting skill, alertness, or strength.
    (ii) Forces applied by the pilot which are greater than those 
specified in Sec.  23.143(c).
    (iii) Accelerations or attitudes in the airplane that might result 
in further hazard to secured or non-secured occupants.

    Issued in Kansas City, Missouri, on October 26, 2015.
Mel Johnson
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-27700 Filed 10-29-15; 8:45 am]
BILLING CODE 4910-13-P


