Document ID: FAA-2018-0229-0001
Agency: faa
Document Type: Rule
Title: Special Conditions: Bombardier Inc. BD-700-2A12 and BD-700-2A13 Airplane; Flight Envelope Protection: Normal Load Factor (g) Limiting
Posted Date: 2018-03-21T04:00Z

[Federal Register Volume 83, Number 55 (Wednesday, March 21, 2018)]
[Rules and Regulations]
[Pages 12247-12249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-05663]

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 Rules and Regulations
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  Federal Register / Vol. 83, No. 55 / Wednesday, March 21, 2018 / 
Rules and Regulations  

[[Page 12247]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2018-0229; Special Conditions No. 25-720-SC]

Special Conditions: Bombardier Inc. BD-700-2A12 and BD-700-2A13 
Airplane; Flight Envelope Protection: Normal Load Factor (g) Limiting

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 Bombardier Inc. 
(Bombardier) Model BD-700-2A12 and BD-700-2A13 airplanes. These 
airplanes 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 will use a fly-by-
wire electronic flight control system (EFCS) that will prevent the 
flight crew from inadvertently or intentionally exceeding the positive 
or negative airplane limit-load-factor. 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 Bombardier Inc. on March 21, 2018. 
Send your comments by May 7, 2018.

ADDRESSES: Send comments identified by docket number FAA-2018-0229 
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 website, 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 Flight 
Crew Interface Section, AIR-671, Transport Standards Branch, Policy and 
Innovation Division, Aircraft Certification Service, 2200 S. 216th St., 
Des Moines, Washington 98198-6547; telephone 206-231-3158; facsimile 
425-231-3398.

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been published in the Federal Register for public comment in 
several prior instances with no substantive comments received. 
Therefore, the FAA has determined that prior public notice and comment 
are unnecessary, and finds that, for the same reason, good cause exists 
for adopting these special conditions upon publication in the Federal 
Register.

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 May 30, 2012, Bombardier applied for an amendment to Type 
Certificate No. T00003NY to include the new Models BD-700-2A12 and BD-
700-2A13 airplanes. The Model BD-700-2A12 and BD-700-2A13 airplanes, 
which are derivatives of the BD-700 series currently approved under 
Type Certificate No. T00003NY. The Model BD-700-2A12 and BD-700-2A13 
airplanes augment the existing BD-700 family of airplane and are 
marketed as the Bombardier Global 7000 and Global 8000 airplanes, 
respectively. These are business jets with a maximum certified 
passenger capacity of 19. The Model BD-700-2A12 and BD-700-2A13 
airplanes will have a maximum takeoff weight of 106,250 lbs. and 
104,800 lbs., respectively.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Bombardier must show that the Model BD-700-2A12 and BD-
700-2A13 airplanes meet the applicable provisions of the regulations 
listed in Type Certificate No. T00003NY or the applicable regulations 
in effect on the date of application for the change except for earlier 
amendments as agreed upon by the FAA.
    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 Model BD-700-2A12 and BD-700-2A13 
airplanes 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

[[Page 12248]]

include any other model that incorporates the same novel or unusual 
design feature, or should any other model already included on the same 
type certificate be modified to incorporate 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 BD-700-2A12 and BD-700-2A13 airplanes 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 21.101.

Novel or Unusual Design Features

    The Model BD-700-2A12 and BD-700-2A13 airplanes will incorporate 
the following novel or unusual design feature:
    The Model BD-700-2A12 and BD-700-2A13 airplanes will use a fly-by-
wire electronic flight control system (EFCS) that will prevent the 
flight crew from inadvertently or intentionally exceeding the positive 
or negative airplane limit-load-factor. This feature is considered 
novel or unusual because the current regulations do not provide 
standards for maneuverability and controllability evaluations for such 
systems. Therefore, special conditions are needed to ensure adequate 
maneuverability and controllability when using this design feature.

Discussion

    Title 14, Code of Federal Regulations, part 25 does not specify 
requirements or policy for demonstrating maneuver control that impose 
any handling qualities requirements beyond the design limit structural 
loads. Nevertheless, some pilots have become accustomed to the 
availability of this excess maneuver capacity in case of extreme 
emergency such as upset recoveries or collision avoidance.
    As with previous fly-by-wire airplanes, the FAA has no regulatory 
or safety reason to prohibit a design for an electronic flight control 
system with load factor limiting. It is possible that pilots accustomed 
to this feature feel more freedom in commanding full-stick displacement 
maneuvers because of the following:
    a. Knowledge that the limit system will protect the structure,
    b. Low stick force/displacement gradients,
    c. Smooth transition from pilot elevator control to limit control.
    These special conditions will ensure adequate maneuverability and 
controllability when using this design feature.
    The normal load factor limit on the Model BD-700-2A12 and BD-700-
2A13 airplanes is unique in that traditional airplanes with 
conventional flight control systems (mechanical linkages) are limited 
in the pitch axis only by the elevator surface area and deflection 
limit. The elevator control power is normally derived for adequate 
controllability and maneuverability at the most critical longitudinal 
pitching moment. The result is that traditional airplanes have a 
significant portion of the flight envelope wherein maneuverability in 
excess of limit structural design values is possible.
    These special conditions for the Model BD-700-2A12 and BD-700-2A13 
airplanes supplement the applicable regulations, including Sec.  
25.143, to accommodate the unique features of the flight envelope 
limiting systems, and establish an equivalent level of safety to the 
existing 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 
Model BD-700-2A12 and BD-700-2A13 airplanes. Should Bombardier 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 Model BD-700-2A12 and BD-700-2A13 airplanes. It is not a rule of 
general applicability.

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(f), 106(g), 40113, 44701, 44702, 44704.

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 Model Bombardier BD-700-2A12 and BD-
700-2A13 airplanes.

Flight Envelope Protection: Normal Load Factor (g) Limiting

    1. To meet the intent of adequate maneuverability and 
controllability required by Sec.  25.143(a), and in addition to the 
requirements of Sec.  25.143(a) and in the absence of other limiting 
factors, the following special conditions based on Sec.  25.333(b) 
apply:
    a. The positive limiting load factor must not be less than:
    (1) 2.5g for the normal state of the electronic flight control 
system with the high lift devices retracted.
    (2) 2.0g for the normal state of the electronic flight control 
system with the high lift devices extended.
    b. The negative limiting load factor must be equal to or more 
negative than:
    (1) Minus 1.0g for the normal state of the electronic flight 
control system with the high lift devices retracted.
    (2) 0.0g for the normal state of the electronic flight control 
system with high lift devices extended.
    c. Maximum reachable positive load factor, wings level, may be 
limited by by the characteristics of the electronic flight control 
system or flight envelope protections (other than load factor 
protection) provided that
    (1) the required values are readily achievable in turns, and
    (2) wings-level pitch up is satisfactory.
    d. Maximum achievable negative load factor may be limited by the 
characteristics of the electronic flight control system or flight 
envelope protections (other than load factor protection) provided:
    (1) Pitch down responsiveness is satisfactory, and
    (2) From level flight, 0g is readily achievable or alternatively, a 
satisfactory trajectory change is readily achievable at operational 
speeds. For the FAA to consider a trajectory change as satisfactory, 
the applicant should propose and justify a pitch rate that provides 
sufficient maneuvering capability in the most critical scenarios.
    e. Compliance demonstration with the above requirements may be 
performed without ice accretion on the airframe.
    These special conditions do not impose an upper bound for the 
normal load factor limit, nor do they require that the limiter exist. 
If the limit is set at a value beyond the structural design limit 
maneuvering load factor ``n'' of Sec. Sec.  25.333(b) and 25.337(b) and 
(c), there should be a very obvious positive tactile feel built into 
the controller so that it serves as a deterrent to inadvertently 
exceeding the structural limit.

[[Page 12249]]

    Issued in Des Moines, Washington, on March 15, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2018-05663 Filed 3-20-18; 8:45 am]
BILLING CODE 4910-13-P