Rule2022-03026
Special Conditions: Dassault Aviation Model Falcon 6X Airplane; Electronic Flight-Control System: Lateral-Directional and Longitudinal Stability and Low-Energy Awareness
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
February 14, 2022
Effective
February 14, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
These special conditions are issued for the Dassault Aviation (Dassault) Model Falcon 6X 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 electronic flight-control system (EFCS) associated with lateral-directional and longitudinal stability, and low-energy awareness. 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.
Full Text
<html>
<head>
<title>Federal Register, Volume 87 Issue 30 (Monday, February 14, 2022)</title>
</head>
<body><pre>
[Federal Register Volume 87, Number 30 (Monday, February 14, 2022)]
[Rules and Regulations]
[Pages 8145-8147]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-03026]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2020-1039; Special Conditions No. 25-807-SC]
Special Conditions: Dassault Aviation Model Falcon 6X Airplane;
Electronic Flight-Control System: Lateral-Directional and Longitudinal
Stability and Low-Energy Awareness
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for the Dassault Aviation
(Dassault) Model Falcon 6X 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 electronic flight-control system
(EFCS) associated with lateral-directional and longitudinal stability,
and low-energy awareness. 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 Dassault on February 14, 2022. Send
comments on or before March 31, 2022.
ADDRESSES: Send comments identified by Docket No. FAA-2020-1039 using
any of the following methods:
<bullet> Federal eRegulations Portal: Go to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a> and follow the online instructions for sending
your comments electronically.
<bullet> 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.
<bullet> 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.
<bullet> Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: Except for Confidential Business Information (CBI) as
described in the following paragraph, and other information as
described in title 14, Code of Federal Regulations (14 CFR) 11.35, the
FAA will post all comments received without change to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact received about these special conditions.
Confidential Business Information: Confidential Business
Information (CBI) is commercial or financial information that is both
customarily and actually treated as private by its owner. Under the
Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from
public disclosure. If your comments responsive to these special
conditions contain commercial or financial information that is
customarily treated as private, that you actually treat as private, and
that is relevant or responsive to these special conditions, it is
important that you clearly designate the submitted comments as CBI.
Please mark each page of your submission containing CBI as ``PROPIN.''
The FAA will treat such marked submissions as confidential under the
FOIA, and the indicated comments will not be placed in the public
docket of these special conditions. Send submissions containing CBI to
the Information Contact below. Comments the FAA receives, which are not
specifically designated as CBI, will be placed in the public docket for
this rulemaking.
Docket: Background documents or comments received may be read at
<a href="https://www.regulations.gov/">https://www.regulations.gov/</a> 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: Troy Brown, Performance and
Environment Section, AIR-625, Technical Innovation Policy Branch,
Policy and Innovation Division, Aircraft Certification Service,
[[Page 8146]]
Federal Aviation Administration, 1801 S Airport Rd., Wichita, KS 67209-
2190; telephone and fax 405-666-1050; email <a href="/cdn-cgi/l/email-protection#cabeb8a5b3e4abe4a8b8a5bda48aacababe4ada5bc"><span class="__cf_email__" data-cfemail="a7d3d5c8de89c689c5d5c8d0c9e7c1c6c689c0c8d1">[email protected]</span></a>.
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 finds, pursuant to Sec. 11.38(b), that new comments
are unlikely, and notice and comment prior to this publication are
unnecessary.
Comments Invited
The FAA invites 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.
The FAA will consider all comments received by the closing date for
comments. The FAA may change these special conditions based on the
comments received.
Background
On July 1, 2012, Dassault applied for a type certificate for its
new Model Falcon 5X airplane. However, Dassault has decided not to
release an airplane under the model designation Falcon 5X, instead
choosing to change that model designation to Falcon 6X.
In February of 2018, due to engine supplier issues, Dassault
extended the type certificate application date for its Model Falcon 5X
airplane under new Model Falcon 6X. This airplane is a twin-engine
business jet with seating for 19 passengers, and has a maximum takeoff
weight of 77,460 pounds.
Type Certification Basis
Under the provisions of 14 CFR 21.17, Dassault must show that the
Model Falcon 6X airplane meets the applicable provisions of part 25, as
amended by amendments 25-1 through 25-146.
If the Administrator finds that the applicable airworthiness
regulations (e.g., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Dassault Model Falcon 6X 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 Dassault Model Falcon 6X 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 Dassault Model Falcon 6X airplane will incorporate the
following novel or unusual design features:
Lateral-directional and longitudinal stability, and low-energy
awareness, functions of the EFCS.
Discussion
Lateral-directional Static Stability: The Dassault Model 6X
airplane includes a flight-control design feature within the normal
operational envelope in which side-stick deflection in the roll axis
commands roll rate; and stick force in the roll axis will be zero
(neutral stability) during the straight, steady sideslip flight
maneuver required by Sec. 25.177(c), which will not be ``substantially
proportional to the angle of sideslip'' as required by the rule.
Longitudinal Static Stability: The longitudinal flight control laws
for the Model Falcon 6X airplane provide neutral static stability
within the normal operational envelope; therefore, the airplane design
does not comply with the static longitudinal stability requirements of
Sec. Sec. 25.171, 25.173, and 25.175.
Low Energy Awareness: Static longitudinal stability provides
awareness to the flight crew when they have deviated from a trimmed
state. This could also be an important factor in their awareness of a
low energy state (low speed and thrust at low altitude) if they are
flying at low speeds. Entry into a low energy state may be less
noticeable due to this lack of static stability and recovery may become
more hazardous when associated with a low altitude and performance
limiting conditions. These low energy situations must therefore be
avoided, and pilots must be given adequate cues when approaching such
situations.
The EFCS affects the following stability and energy-awareness
features of the airplane:
1. Lateral-Directional Static Stability
The EFCS on the Dassault Model Falcon 6X contains fly-by-wire
control laws that can result in neutral lateral-directional static
stability. Therefore, the airplane does not meet the conventional
requirements in the regulations.
Positive static directional stability is defined as the tendency to
recover from a skid with the rudder free. Positive static lateral
stability is defined as the tendency to raise the low wing in a
sideslip with the aileron controls free. These control criteria are
intended to accomplish the following:
a. Provide additional cues of inadvertent sideslips and skids
through control-force changes.
b. Ensure that short periods of unattended operation do not result
in any significant changes in yaw or bank angle.
c. Provide predictable roll and yaw response.
d. Provide an acceptable level of pilot attention (workload) to
attain and maintain a coordinated turn.
2. Static Longitudinal Stability
Static longitudinal stability on airplanes with mechanical links to
the pitch-control surface means that a pull force on the controller
results in a reduction in speed relative to the trim speed, and a push
force results in higher than trim speed. Longitudinal stability is
required by the regulations for the following reasons:
a. Speed-change cues are provided to the pilot through increased
and decreased forces on the controller.
b. Short periods of unattended control of the airplane do not
result in significant changes in attitude, airspeed, or load factor.
c. A predictable pitch response is provided to the pilot.
d. An acceptable level of pilot attention (workload) to attain and
maintain trim speed and altitude is provided to the pilot.
e. Longitudinal stability provides gust stability.
The pitch-control movement of the side stick on the Model Falcon 6X
airplane is designed to be a normal load factor, or ``g'' command, that
results in an initial movement of the elevator surface to attain the
commanded load factor that is then followed by integrated movement of
the stabilizer and elevator to automatically trim the airplane to a
neutral, 1g, stick-free stability. The flight path commanded by the
initial side-stick input will remain, stick-free, until the pilot
provides another command. This control function is
[[Page 8147]]
applied during ``normal'' control law within the speed range, from
initiation of the angle-of-attack protection limit, V<INF>prot</INF>,
to V<INF>MO</INF>/M<INF>MO</INF>. Once outside this speed range, the
control laws introduce the conventional longitudinal static stability
as described above.
As a result of neutral static stability, the Model Falcon 6X
airplane does not meet the regulatory requirements for static
longitudinal stability.
3. Low Energy Awareness
Past experience on airplanes fitted with a flight-control system
providing neutral longitudinal stability reveals insufficient feedback
cues to the pilot of excursion below normal operational speeds. The
maximum angle-of-attack protection system limits the airplane angle of
attack and prevents stall during normal operating speeds, but this
system is not sufficient to prevent stall at low-speed excursions below
normal operational speeds. Until intervention, there are no stability
cues because the aircraft remains trimmed. Additionally, feedback from
the pitching moment due to thrust variation is reduced by the flight-
control laws. Low-speed excursions may become more hazardous without
the typical longitudinal stability, and recovery is more difficult when
the low-speed situation is associated with a low altitude, and with the
engines at low thrust or with performance-limiting conditions.
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
Dassault Model Falcon 6X airplane. Should Dassault 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 a certain novel or unusual design feature
on one model of airplane. It is not a rule of general applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
Authority Citation
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 the Dassault Aviation Model Falcon 6X
airplane.
In lieu of the requirements of Sec. Sec. 25.171, 25.173, 25.175,
and 25.177(c), the following special conditions apply:
1. The airplane must be shown to have suitable static lateral,
directional, and longitudinal stability in any condition normally
encountered in service, including the effects of atmospheric
disturbance. The showing of suitable static lateral, directional, and
longitudinal stability must be based on the airplane handling
qualities, including pilot workload and pilot compensation, for
specific test procedures during the flight-test evaluations.
2. The airplane must provide adequate awareness to the pilot of a
low energy (low speed, low thrust, low height) state when fitted with
flight-control laws presenting neutral longitudinal stability
significantly below the normal operating speeds. ``Adequate awareness''
means warning information must be provided to alert the crew of unsafe
operating conditions, and to enable them to take appropriate corrective
action.
3. The following requirement must be met for the configurations and
speed specified in paragraph (a) of Sec. 25.177. In straight, steady
sideslips over the range of sideslip angles appropriate to the
operation of the airplane, the rudder-control movements and forces must
be substantially proportional to the angle of sideslip in a stable
sense. This factor of proportionality must lie between limits found
necessary for safe operation. The range of sideslip angles evaluated
must include those sideslip angles resulting from the lesser of:
a. One-half of the available rudder control input; and
b. A rudder control force of 180 pounds.
Issued in Kansas City, Missouri, on February 8, 2022.
Patrick R. Mullen,
Manager, Technical Innovation Policy Branch, Policy and Innovation
Division, Aircraft Certification Service.
[FR Doc. 2022-03026 Filed 2-11-22; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on February 14, 2022.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.