82 FR 37811 - Special Conditions: Textron Aviation Inc. Model 700 Airplanes; Use of Automatic Power Reserve for Go-Around Performance Credit

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 155 (August 14, 2017)

These special conditions are issued for the Textron Aviation Inc. (Textron) Model 700 airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is an Automatic Takeoff Thrust Control System (ATTCS), referred to as an Automatic Power Reserve (APR), to set the performance level for approach-climb operation after an engine failure. 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.

[Federal Register Volume 82, Number 155 (Monday, August 14, 2017)]
[Rules and Regulations]
[Pages 37811-37814]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-17073]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2017-0484; Special Conditions No. 25-700-SC]


Special Conditions: Textron Aviation Inc. Model 700 Airplanes; 
Use of Automatic Power Reserve for Go-Around Performance Credit

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Textron Aviation 
Inc. (Textron) Model 700 airplane. This airplane will have a novel or 
unusual design feature when compared to the state of technology 
envisioned in the airworthiness standards for transport-category 
airplanes. This design feature is an Automatic Takeoff Thrust Control 
System (ATTCS), referred to as an Automatic Power Reserve (APR), to set 
the performance level for approach-climb operation after an engine 
failure. 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: This action is effective on Textron on August 14, 2017. Send 
your comments by September 28, 2017.

[[Page 37812]]


ADDRESSES: Send comments identified by docket number FAA-2017-0484 
using any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov/and follow the online instructions for sending your 
comments electronically.
     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.
     Hand Delivery or 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 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
     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).
    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 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: Joe Jacobsen, FAA, Airplane and 
Flightcrew Interface, ANM-111, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2011; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been subject to the notice and comment period in several prior 
instances and has been derived without substantive change from those 
previously issued. It is unlikely that prior public comment would 
result in a significant change from the substance contained herein. 
Therefore, because a delay would significantly affect the certification 
of the airplane, the FAA has determined that prior public notice and 
comment are unnecessary and impracticable.
    In addition, since the substance of these special conditions has 
been subject to the public comment process in several prior instances 
with no substantive comments received, the FAA finds it unnecessary to 
delay the effective date and finds that good cause exists for adopting 
these special conditions upon publication in the Federal Register.
    The FAA is requesting comments to allow interested persons to 
submit views that may not have been submitted in response to the prior 
opportunities for comment described above.

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 by the closing date for 
comments. We may change these special conditions based on the comments 
we receive.

Background

    On November 20, 2014, Textron applied for a type certificate for 
their new Model 700 airplane. The Model 700 airplane is a turbofan-
powered executive-jet airplane with seating for two crewmembers and 12 
passengers. This airplane will have a maximum takeoff weight of 38,514 
pounds.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Textron must show that the Model 700 airplane meets the 
applicable provisions of part 25, as amended by Amendments 25-1 through 
25-139, 25-141, and 25-143.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Textron Model 700 airplane 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 novel or 
unusual design feature, these special conditions would also apply to 
the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model 700 airplane 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.
    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 Model 700 airplane will incorporate the following novel or 
unusual design feature: An Automatic Takeoff Thrust Control System, 
referred to as an Automatic Power Reserve, to set the performance level 
for approach-climb operation after an engine failure.

Discussion

    Textron proposes using the ATTCS function of the Model 700 airplane 
during go-around and requests approach-climb performance credit for the 
use of the additional power. The Model 700 powerplant control system 
comprises a Full Authority Digital Electronic Control (FADEC) for the 
AS907-2-1S engine. The control system includes an ATTCS feature, 
referred to as Maximum Takeoff Thrust (MTO), and in the airplane flight 
manual (AFM), Automatic Power Reserve.
    Section 25.904 and part 25, appendix I, limit the application of 
performance credit for ATTCS to takeoff only. Because the airworthiness 
regulations do not contain appropriate safety standards for approach-
climb performance using ATTCS, special conditions are required to 
ensure a level of safety equivalent to that established in the 
regulations.
    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.

Applicability

    As discussed above, these special conditions are applicable to the 
Textron Model 700 airplane. Should Textron apply at a later date for a 
change to the type certificate to include another model incorporating 
the same novel or unusual design feature, these special conditions 
would apply to that model as well.

Conclusion

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

[[Page 37813]]

List of Subjects in 14 CFR Part 25

    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 Special Conditions

    The Textron Model 700 airplane must comply with the requirements of 
14 CFR 25.904, and appendix I, and the following requirements for the 
go-around phase of flight:
    1. Definitions
    a. Takeoff/go-around (TOGA): Throttle lever in takeoff or go-around 
position.
    b. Automatic Takeoff Thrust Control System: The ATTCS in Model 700 
airplanes is defined as the entire automatic system available during 
takeoff and in go-around mode, including all devices, both mechanical 
and electrical, that sense engine failure, transmit signals, actuate 
fuel controls or power levers (or increase engine power by other means 
on operating engines to achieve scheduled thrust or power increase), 
and furnish cockpit information on system operation.
    c. Critical time interval:
    (1) When conducting an approach for landing using ATTCS, the 
critical time interval is defined as follows:
    (i) The critical time interval begins at a point on a 2.5-degree 
approach glide path from which, assuming a simultaneous engine and 
ATTCS failure, the resulting approach-climb flight path intersects a 
flight path originating at a later point on the same approach path that 
corresponds to the part 25 one-engine-inoperative approach-climb 
gradient. The period of time from the point of simultaneous engine and 
ATTCS failure, to the intersection of these flight paths, must be no 
shorter than the time interval used in evaluating the critical time 
interval for takeoff, beginning from the point of simultaneous engine 
and ATTCS failure and ending upon reaching a height of 400 feet.
    (ii) The critical time interval ends at the point on a minimum 
performance, all-engines-operating go-around flight path from which, 
assuming a simultaneous engine and ATTCS failure, the resulting minimum 
approach-climb flight path intersects a flight path corresponding to 
the part 25 minimum one-engine-inoperative approach-climb gradient. The 
all-engines-operating go-around flight path, and the part 25 one-
engine-inoperative approach-climb gradient flight path, originate from 
a common point on a 2.5-degree approach path. The period of time from 
the point of simultaneous engine and ATTCS failure, to the intersection 
of these flight paths, must be no shorter than the time interval used 
in evaluating the critical time interval for the takeoff, beginning 
from the point of simultaneous engine and ATTCS failure and ending upon 
reaching a height of 400 feet.
    (2) The critical time interval must be determined at the altitude 
resulting in the longest critical time interval for which one-engine-
inoperative approach-climb performance data are presented in the 
airplane flight manual.
    (3) The critical time interval is illustrated in the following 
figure:
[GRAPHIC] [TIFF OMITTED] TR14AU17.028

    2. Performance and system reliability requirements: The applicant 
must comply with the performance and ATTCS reliability requirements as 
follows:
    a. An ATTCS failure or a combination of failures in the ATTCS 
during the critical time interval:
    (1) Must not prevent the insertion of the maximum approved go-
around thrust or power, or must be shown to be a remote event.
    (2) Must not result in a significant loss or reduction in thrust or 
power, or must be shown to be an extremely improbable event.
    b. The concurrent existence of an ATTCS failure and an engine 
failure during the critical time interval must be shown to be extremely 
improbable.
    c. All applicable performance requirements of part 25 must be met 
with an engine failure occurring at the most critical point during go-
around with the ATTCS functioning.
    d. The probability analysis must include consideration of ATTCS 
failure occurring after the time at which the flightcrew last verifies 
that the ATTCS is in a condition to operate until the beginning of the 
critical time interval.
    e. The propulsive thrust obtained from the operating engine, after 
failure of the critical engine during a go-around used to show 
compliance with the one-engine-inoperative climb requirements of Sec.  
25.121(d), may not be greater than the lesser of:
    (1) The actual propulsive thrust resulting from the initial setting 
of power or thrust controls with the ATTCS functioning, or
    (2) 111 percent of the propulsive thrust resulting from the initial 
setting of power or thrust controls with the ATTCS failing to reset 
thrust or power, and without any action by the flightcrew to reset 
thrust or power.
    3. Thrust setting
    a. The initial go-around thrust setting on each engine at the 
beginning of the go-around phase may not be less than any of the 
following:

[[Page 37814]]

    (1) That required to permit normal operation of all safety-related 
systems and equipment dependent upon engine thrust or power lever 
position; or
    (2) That are shown to be free of hazardous engine-response 
characteristics, and not to result in any unsafe airplane operating or 
handling characteristics when thrust or power is advanced from the 
initial go-around position to the maximum approved power setting.
    b. For approval to use an ATTCS for go-arounds, the thrust-setting 
procedure must be the same for go-arounds initiated with all engines 
operating as for go-around initiated with one engine inoperative.
    4. Powerplant controls
    a. In addition to the requirements of Sec.  25.1141, no single 
failure or malfunction, or probable combination thereof, of the ATTCS, 
including associated systems, may cause the failure of any powerplant 
function necessary for safety.
    b. The ATTCS must be designed to:
    (1) Apply thrust or power to the operating engine(s), following any 
one-engine failure during a go-around, to achieve the maximum approved 
go-around thrust without exceeding the engine operating limits;
    (2) Permit manual decrease or increase in thrust or power up to the 
maximum go-around thrust approved for the airplane, under the existing 
conditions, through the use of the power lever. For airplanes equipped 
with limiters that automatically prevent the engine operating limits 
from being exceeded under existing ambient conditions, other means may 
be used to increase the thrust in the event of an ATTCS failure, 
provided that the means:
    (i) Is located on or forward of the power levers;
    (ii) Is easily identified and operated under all operating 
conditions by a single action of either pilot with the hand that is 
normally used to actuate the power levers; and
    (iii) Meets the requirements of Sec.  25.777(a), (b), and (c).
    (3) Provide a means to verify to the flightcrew, before beginning 
an approach for landing, that the ATTCS is in a condition to operate 
(unless it can be demonstrated that an ATTCS failure, combined with an 
engine failure during an entire flight, is extremely improbable); and
    (4) Provide a means for the flightcrew to deactivate the automatic 
function. This means must be designed to prevent inadvertent 
deactivation.
    5. Powerplant instruments: In addition to the requirements of Sec.  
25.1305:
    a. A means must be provided to indicate when the ATTCS is in the 
OFF or FAILED condition; and
    b. If the inherent flight characteristics of the airplane do not 
provide adequate warning that an engine has failed, a warning system 
that is independent of the ATTCS must be provided to give the pilot a 
clear warning of any engine failure during a go-around.

    Issued in Renton, Washington, on August 8, 2017.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2017-17073 Filed 8-11-17; 8:45 am]
 BILLING CODE 4910-13-P