Federal Register / Vol. 87, No. 30 / Monday, February 14, 2022 / Rules and Regulations 8145 

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 Dassault Aviation 

Model Falcon 6X airplanes. 

General Limiting Requirements 

a. Onset characteristics of each flightenvelope protection feature must be 

smooth, appropriate to the phase of 

flight and type of maneuver, and not in 

conflict with the ability of the pilot to 

satisfactorily change airplane flight 

path, speed, or attitude as needed. 

b. Limit values of protected flight 

parameters (and, if applicable, 

associated warning thresholds) must be 

compatible with the following: 

1. Airplane structural limits, 

2. Required safe and controllable 

maneuvering of the airplane, and 

3. Margins to critical conditions. 

Unsafe flight characteristics/conditions 

must not result if dynamic 

maneuvering, airframe, and system 

tolerances (both manufacturing and 

inservice), and non-steady atmospheric 

conditions, in any appropriate 

combination and phase of flight, can 

produce a limited flight parameter 

beyond the nominal design limit value. 

c. The airplane must be responsive to 

intentional dynamic maneuvering to 

within a suitable range of the parameter 

limit. Dynamic characteristics such as 

damping and overshoot must also be 

appropriate for the flight-maneuver and 

limit parameter in question. 

d. When simultaneous envelope 

limiting is engaged, adverse coupling or 

adverse priority must not result. 

Failure States 

a. Electronic flight-control system 

(EFCS) failures, including sensors, must 

not result in a condition where a 

parameter is limited to such a reduced 

value that safe and controllable 

maneuvering is no longer available. 

b. The crew must be alerted by 

suitable means if any change in 

envelope limiting or maneuverability is 

produced by single or multiple failures 

of the EFCS not shown to be extremely 

improbable. 

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. 2022–03025 Filed 2–11–22; 8:45 am] 

BILLING CODE 4910–13–P 

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: LateralDirectional 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 lateraldirectional 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: 

• Federal eRegulations Portal: Go to 

https://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: 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 https://

www.regulations.gov/, 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 

https://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: Troy 

Brown, Performance and Environment 

Section, AIR–625, Technical Innovation 

Policy Branch, Policy and Innovation 

Division, Aircraft Certification Service, 


jspears on DSK121TN23PROD with RULES1
8146 Federal Register / Vol. 87, No. 30 / Monday, February 14, 2022 / Rules and Regulations 

Federal Aviation Administration, 1801 

S Airport Rd., Wichita, KS 67209–2190; 

telephone and fax 405–666–1050; email 

troy.a.brown@faa.gov. 

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 § 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 

§ 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 § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the Dassault Model Falcon 

6X airplane must comply with the fuelvent and exhaust-emission requirements 

of 14 CFR part 34, and the noisecertification requirements of 14 CFR 

part 36. 

The FAA issues special conditions, as 

defined in 14 CFR 11.19, in accordance 

with § 11.38, and they become part of 

the type certification basis under 

§ 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 

§ 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 §§ 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 lateraldirectional 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 


jspears on DSK121TN23PROD with RULES1
Federal Register / Vol. 87, No. 30 / Monday, February 14, 2022 / Rules and Regulations 8147 

applied during ‘‘normal’’ control law 

within the speed range, from initiation 

of the angle-of-attack protection limit, 

Vprot, to VMO/MMO. 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 

§§ 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 flightcontrol 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 § 25.177. In 

straight, steady sideslips over the range 

of sideslip angles appropriate to the 

operation of the airplane, the ruddercontrol 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 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2021–1023; Special 

Conditions No. 25–811–SC] 

Special Conditions: The Boeing 

Company, Model 737–10 Airplane; 

Dynamic Test Requirements for SingleOccupant, Oblique (Side-Facing) Seats 

Installed at 49 Degrees With Airbag 

Devices and 3-Point Restraints 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final special conditions. 

SUMMARY: These special conditions are 

issued for The Boeing Company 

(Boeing) Model 737–10 airplane. This 

airplane will have a novel or unusual 

design feature when compared to the 

state of technology envisioned in the 

airworthiness standards for transportcategory airplanes. This design feature 

is single-occupant oblique seats with 

airbag devices and 3-point restraints, 

installed at 49 degrees relative to the 

airplane cabin bow-to-stern centerline. 

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: Effective February 14, 2022. 

FOR FURTHER INFORMATION CONTACT: John 

Shelden, Human Machine Interface 

Section, AIR–626, Technical Innovation 

Policy Branch, Policy and Innovation 

Division, Aircraft Certification Service, 

Federal Aviation Administration, 2200 

South 216th Street, Des Moines, 

Washington 98198; telephone and fax 

206–231–3214; email john.shelden@

faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

On January 30, 2019, Boeing applied 

for a change to Type Certificate No. 

A16WE for the installation of singleoccupant oblique seats, with airbag 

devices and 3-point restraints, installed 

at 49 degrees relative to the airplane 

cabin bow-to-stern centerline in the 

Boeing Model 737–10 airplane. The 

Boeing Model 737–10 airplane is a twinengine, transport-category airplane with 

seating for 230 passengers and a 

maximum takeoff weight of 197,900 

pounds. 


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