ASTM F3298-19

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F3298 −19
Standard Specification for
Design, Construction, and Verification of Lightweight
Unmanned Aircraft Systems (UAS)
This standard is issued under the fixed designation F3298; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 Thisspecificationcoverstheairworthinessrequirements
ization established in the Decision on Principles for the
for the design of light unmanned aircraft systems. This
Development of International Standards, Guides and Recom-
specification defines the baseline design, construction, and
mendations issued by the World Trade Organization Technical
verification requirements for an unmanned aircraft system
Barriers to Trade (TBT) Committee.
(UAS).
1.2 As a minimum, a UAS is defined as a system composed
2. Referenced Documents
oftheunmannedaircraftandallrequiredon-boardsubsystems,
2.1 ASTM Standards:
payload, control station, other required off-board subsystems,
F2245Specification for Design and Performance of a Light
any required launch and recovery equipment, all required crew
Sport Airplane
members, and command and control (C2) links between UA
F2908Specification for Unmanned Aircraft Flight Manual
and the control station.
(UFM) for an Unmanned Aircraft System (UAS)
1.3 The intent is for this standard of practice for CAA, self-
F2909Practice for Maintenance and Continued Airworthi-
or third-party determinations of airworthiness for UAS. This
ness of Small Unmanned Aircraft Systems (sUAS)
specification provides the core requirements for airworthiness
F2911Practice for Production Acceptance of Small Un-
certification of lightweight (UAS) (not necessarily limited to
manned Aircraft System (sUAS)
UAs under 55 lb GTOW) or for certain CAA operational
F3002Specification for Design of the Command and Con-
approvalsusingrisk-basedcategories.Additionalrequirements
trolSystemforSmallUnmannedAircraftSystems(sUAS)
are envisioned to address the requirements for expanded
F3003Specification for Quality Assurance of a Small Un-
operations and characteristics not addressed by this specifica-
manned Aircraft System (sUAS)
tion.
F3005Specification for Batteries for Use in Small Un-
manned Aircraft Systems (sUAS)
1.4 This specification is intended to support UAS opera-
tions. It is assumed that the risk of UAS will vary based on F3120/F3120MSpecification for Ice Protection for General
Aviation Aircraft
concept of operations, environment, and other variables. The
F3178Practice for Operational Risk Assessment of Small
fact that there are no human beings onboard the UAS may
Unmanned Aircraft Systems (sUAS)
reduce or eliminate some hazards and risks. However, at the
F3201Practice for Ensuring Dependability of Software
discretion of the CAA, this specification may be applied to
Used in Unmanned Aircraft Systems (UAS)
other UAS operations.
2.2 ANSI Standard:
1.5 The values in Imperial units are to be regarded as the
ANSI Z535.1-1998American National Standard for Safety
standard. The values in SI are for information only.
Colors
1.6 This standard does not purport to address all of the
2.3 FAA Standard:
safety concerns, if any, associated with its use. It is the
Order 8130.34DAirworthiness Certification of Unmanned
responsibility of the user of this standard to establish appro-
Aircraft Systems and Optionally Piloted Aircraft
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1 2
This specification is under the jurisdiction of ASTM Committee F38 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
UnmannedAircraftSystemsandisthedirectresponsibilityofSubcommitteeF38.01 contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
on Airworthiness. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Feb. 1, 2019. Published March 2019. Originally the ASTM website.
approved in 2018. Last previous edition approved in 2018 as F3298–18. DOI: Available from Federal Aviation Administration (FAA), 800 Independence
10.1520/F3298–19. Ave., SW, Washington, DC 20591, http://www.faa.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3298−19
2.4 Federal Standard: 3.1.6.1 manufacturer, n—the person or organization who
14 CFR Part 107Small Unmanned Aircraft Systems causes production of a product or article.Amanufacturer may
also be an operator.
2.5 Joint Authorities for Rulemaking of Unmanned Sys-
3.1.6.2 operator, n—the person or organization that applies
tems:
CS-LURSCertification Specification for Light Unmanned for CAAapproval to operate a UAS or who seeks operational
approvalfortypesofflightoperationsprohibitedbyaCAAfor
Rotorcraft Systems
CS-LUASRecommendations for Certification Specification that UAS.
for Light Unmanned Aeroplane Systems
3.1.6.3 original equipment manufacturer, n—the person or
organization who first produced that product or article. An
2.6 Unmanned Systems Canada Best Practices:
OEM may also be an operator.
Small Remotely Piloted Aircraft System (UAS) Best Prac-
tices for BVLOS Operations
3.1.7 automatic flight control system, n—a system which
includes all equipment to control automatically the flight of an
3. Terminology
aircrafttoapathoraltitudedescribedbyreferences,internalor
external, to the aircraft.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 abstain, v—prior to starting a particular test method,
3.1.8 conflict point, n—the time of a predicted collision or
the UA manufacturer or designated operator shall choose to
point of closest approach that is within the collision volume.
enterthetestorabstain.Anyabstentionshallbegrantedbefore
3.1.9 continued safe flight, n—a condition whereby a UAis
the test begins. The test form shall be clearly marked as such,
capableofcontinuedcontrolledflight,andlandingatasuitable
indicating that the manufacturer acknowledges the omission of
location, possibly using emergency or abnormal procedures,
theperformancedatawhilethetestmethodwasavailableatthe
butwithoutrequiringexceptionalpilotskill.SomeUAdamage
test time.
maybeassociatedwithafailureconditionduringflightorupon
3.1.2 airframe, n—airframe means the fuselage, booms,
landing.
nacelles, cowlings, fairings, airfoil surfaces (including rotors
3.1.10 Control and Non-Payload Communications (CNPC),
but excluding propellers and rotating airfoils of engines), and
n—radio frequency (RF) link(s) between the control station
landing gear of an aircraft and their accessories and controls.
(CS) and the unmanned aircraft (UA), also known as the
3.1.3 airworthiness, n—condition in which the unmanned
Command and Control Link(s).
aircraft systems (UAS) (including the aircraft, airframe,
3.1.11 control station, n—apparatus for hosting the remote
engine, propeller, accessories, appliances, firmware, software,
pilot and her/his device to teleoperate the UAS.
and control station elements) conforms to its design intent,
3.1.12 controlled flight, n—a condition whereby the remote
including as defined by the type certificate (TC), if applicable,
pilot or onboard systems or both, have the ability to perform
and is in condition for safe operation.
functions to the extent necessary to continue safe flight and
3.1.4 alert, n—a generic term used to describe a control
landing, but not necessarily full functional performance.
station indication meant to attract the attention of and identify
3.1.13 demonstration, n—technique used to demonstrate
to the flightcrew a non-normal operational or airplane system
correct operation of the submitted element against operational
condition. Alerts are classified at levels or categories corre-
andobservablecharacteristicswithoutusingphysicalmeasure-
sponding to Warnings, Cautions, andAdvisories.Alert indica-
ments (no or minimal instrumentation or test equipment). It
tions also include non-normal range markings (for example,
generally consists of a set of tests selected by the supplier to
exceedances on instruments and gauges).
showthattheelementresponsetostimuliissuitableortoshow
3.1.5 analysis, n—technique based on analytical evidence
that operators can perform their assigned tasks when using the
obtained without any intervention on the submitted element
element. Observations are made and compared with
usingmathematicalorprobabilisticcalculation,logicalreason-
predetermined/expected responses.
ing (including the theory of predicates), modeling or
3.1.14 design maximum aircraft weight, W ,n—aircraft
MAX
simulation, or combinations thereof, under defined conditions
design maximum weight for unmanned aircraft shall be the
to show theoretical compliance.
highest weight at which compliance with each applicable
3.1.6 applicant/proponent, n—the person or organization
structural loading condition and all requirements for flight
responsibleforseekingtheapprovaltooperateandoperatinga
regimes is shown.
UA. The applicant/proponent may be one of the following
3.1.15 Electric Propulsion Unit, EPU, n—any electric mo-
entities: manufacturer, operator, or original equipment manu-
tor and all associated devices used to provide thrust for an
facturer.
electric aircraft.
3.1.16 Energy Storage Device, ESD, n—used to store en-
ergy as part of an Electric Propulsion Unit (EPU). Typical
Available from U.S. Government Publishing Office, 732 N. Capitol St., NW,
energy storage devices include but are not limited to batteries,
Washington, DC 20401, http://www.gpo.gov.
Available from Joint Authorities for Rulemaking of Unmanned Systems
fuel cells, or capacitors.
(JARUS), http://www.jarus-rpas.org.
3.1.17 envelope protection, n—the human-machine inter-
Available from Unmanned Systems Canada, PO Box 81055, Ottawa, Ontario,
K1P 1B1, https://www.unmannedsystems.ca. face extension of an automatic flight control system that
F3298−19
prevents the remote pilot from making control commands that aircraft)oratthepointoflaunch(forexample,viahand-launch
would force the aircraft to exceed its structural and aerody- or catapult system). Alternatively referred to as “departure
namic operating limits. UAS with envelope protection are roll.”
intended for non-acrobatic operation. Non-acrobatic operation
3.1.30 improbable, n—a probability no greater than one
–2
includes:anymaneuverincidenttonormalflying;stalls(except
occurrence every 100 flight hours (10 ).
whip stalls); and lazy eights, chandelles, and steep turns, in
3.1.31 inspection, n—technique based on visual or dimen-
which the angle of bank is not more than 60°.
sional examination of an element; inspection is generally
3.1.18 expanded operations, n—UAS operations that typi-
non-destructive, and typically includes the use of sight,
cally require authorization from the CAA (for example, Op-
hearing, smell, touch, and taste, simple physical manipulation,
erations Authorization for Specific Category UAS or Part 107
mechanical and electrical gauging, and measurement. No
Certificate of Waiver/Authorization) with specific limitations
stimuli (tests) are necessary. The technique is used to check
adapted to the operation.
properties or characteristics best determined by observation
(for example, paint color, weight, documentation, listing of
3.1.19 extremely improbable, n—a probability no greater
–6
code, etc.).
than one occurrence every 1000000 (10 ) flight hours.
3.1.32 lightweightUAS,n—unmannedsmallaircraftthatare
3.1.20 extremely remote probability, n—a probability no
–5
approved for operation under the authority of a CAA (for
greater than one occurrence every 100000 (10 ) flight hours.
example, UAS approved to operate by the FAAunder 14 CFR
3.1.21 flight-critical system, n—a system that, should it fail,
Part 107, UAS approved to operate by EASA as Open and
will cause loss of control of the UA, or the UAwill no longer
SpecificCategoryUA,andUASapprovedtooperatebyCASA
stay capable of continued safe flight.
as Small, Medium, or Large RPA, or combinations thereof).
3.1.22 flight manual, FM, n—manual describing the opera-
3.1.33 loads:
tion of the aircraft and includes any limitations; normal,
3.1.33.1 flight load, n—those loads experienced within the
abnormal, and emergency procedures; and provides specific
operational flight envelope.
facts, information, or instructions, or combinations thereof,
3.1.33.2 ground handling load, n—those loads experienced
aboutaparticularaircraftandtheoperationofthataircraft. F44
during regular operation while the aircraft is not in flight (for
3.1.22.1 Discussion—For airplanes, this is identified as an
example, assembly, flight preparation, taxi, and maintenance).
airplaneflightmanual(AFM).ForUAS,thisisidentifiedasan
unmanned aircraft flight manual (UFM). 3.1.33.3 launch and recovery load, n—those loads experi-
enced during normal launch and recovery.
3.1.23 flight manual supplement, FMS, n—document that
3.1.33.4 landing loads, n—the load exerted upon an aircraft
provides supplemental information, usually for equipment that
is not part of the basic aircraft and included in the main flight at touchdown or upon a runway by an airplane during
touchdown and in the landing roll.
manual.
3.1.33.5 limit load, n—the maximum load experienced in
3.1.24 flightterminationsystem,n—asystemthatterminates
the normal operation and maintenance of the UA.
the flight of a UAS in the event that all other contingencies
have been exhausted and further flight of the aircraft cannot be
3.1.33.6 load factor, n—the ratio of a specified load to the
safely achieved, or other potential hazards exists that immedi-
total weight of the aircraft. The specified load is expressed in
ate discontinuation of flight.
terms of any of the following: aerodynamic forces, inertia
forces, or ground or water reactions.
3.1.25 flight training supplement, FTS, n—document pro-
viding guidance for training for unmanned aircraft.
3.1.33.7 ultimate load—limit load multiplied by the factor
of safety (as determined by the CAA, but heuristically 1.5).
3.1.26 fly-away, n—flight outside of operational boundaries
(altitude/airspeed/lateral limits) as the result of a failure,
3.1.34 loss of tailrotor effectiveness, n—an unanticipated
interruption, or degradation of the control station or onboard
yaw is defined as an uncommanded, rapid yaw towards the
systems, or both.
advancing blade that does not subside of it’s own accord.
3.1.27 fly-away protection system, n—system that will
3.1.35 maneuver time, T, n—the maneuver time, T, should
safely recover the sUA, or keep the sUA within the intended
be the time required for the specific UAto execute a maneuver
operationalarea,intheeventofafly-awayasdefinedin3.1.26.
that ensures the point of closest approach of a conflicting
aircraft remains outside the collision volume. The manufac-
3.1.28 geo-fence—a virtual geographic boundary, defined
turer of the UAS should determine and document this value or
by location-based services, that enables software to trigger a
the means of how it is determined in real time.
response when a mobile device enters or leaves a particular
area.
3.1.36 operational envelope, n—the subset which bounds
the full set of operational cases by all associated variables (for
3.1.29 ground roll distance, n—the horizontal distance be-
example, speed, altitude, attitude, etc.).
tween start of takeoff or at a low height above ground (as used
in rail-assisted launch), or both, and should be of sufficient 3.1.37 out of ground effect, n—condition where the down-
distance to allow the UA to gain the manufacture’s published wash of air from the main rotor (or propellers of a vertical
climb-out speed (that is, the point when V is reached). This flight aircraft) is unable to react with a hard surface (the
T
may begin at the release of brakes (that is, with traditional ground), and commonly begins at altitude above ground level
F3298−19
ofapproximately0.5to1.0timesthediameterofthemainrotor 3.1.47 test, n—designed collection of methods that are used
(or propellers of a vertical flight aircraft). collectively to evaluate the performance of or to identify the
capability of a UAS’ particular subsystem or functionality.
3.1.38 payload, n—any instrument, mechanism, equipment,
part, apparatus, appurtenance, or accessory, including commu- 3.1.48 test form, n—form corresponding to a test method
nications equipment, that is installed in or attached to the that contains fields for recording the testing results and the
associated information.
aircraft, is not used or intended to be used in operating or
controlling an aircraft in flight, and is not part of an airframe,
3.1.49 testing task or task, n—activities well defined and
engine, or propeller.
specified according to an identified metric or an identified set
3.1.39 permanent deformation, n—a condition whereby a of metrics for the testing UAS and operators to perform in
order for the UAS’ capabilities to be evaluated.
UAstructure is altered such that it does not return to the shape
required for normal flight upon removal of external loads.
3.1.50 tethered aircraft, n—a configuration where the un-
3.1.40 propeller, n—a device for propelling an aircraft that manned aircraft remains securely attached (tethered) via a
physical link to a person, the ground or an object at all times
has blades on an engine-driven shaft and that, when rotated,
produces by its action on the air, a thrust approximately while it is flying.
perpendicular to its plane of rotation. It includes control
3.1.51 trial, n—numbered used to identify a series of
components normally supplied by its manufacturer, but does
repetitions that a UAS is required to succeed in a standard
not include main and auxiliary rotors or rotating airfoils of
verification method for the results to meet the required statis-
engines.
tical significance.
3.1.41 propulsion system, n—consists of one or more power
3.1.52 vertical flight aircraft, n—also referred to as
plants (for example, a combustion engine or an electric motor
“VTOL” or “vertical takeoff and landing aircraft,” aircraft
and, if used, a propeller or rotor) together with the associated
capable of vertical or near-vertical takeoffs and landings.
installation of fuel system, control and electrical power supply
Vertical-lift aircraft include:
(for example, batteries, electronic speed controls, fuel cells, or
3.1.52.1 fan-in-wing aircraft—fixed-wingaircraftwithrotor
other energy supply).
fans in the wing to permit vertical or hover operations.
3.1.42 Remote Pilot-In-Command, RPIC, n—person who is
3.1.52.2 powered-lift aircraft, n—heavier-than-air aircraft
directly responsible for and is the final authority as to the
capable of vertical takeoff, vertical landing, and low-speed
operation of the UAS; has been designated as remote pilot in
flight that depends principally on engine-driven lift devices or
command before or during the flight of a UAS; and holds the
engine thrust for lift during these flight regimes and on
appropriate CAA certificate for the conduct of the flight.
nonrotating airfoil for lift during horizontal flight.
3.1.43 remote probability, n—a probability no greater than
–4
3.1.52.3 rotorcraft, n—rotary-winged aircraft that lift verti-
one occurrence every 10000 flight hours (10 ).
cally (to hover) and principally sustained in forward flight by
3.1.44 rotor, n—a propeller that is positioned to provide
power-driven rotor blades turning on a vertical axis.
principle lift/vertical thrust and is capable of being driven
3.1.52.4 tiltrotor aircraft, n—rotorcraft with the axes of the
entirelybyactionoftheairwhentherotorcraftisinmotion(for
power-driven proprotor blades capable of pivoting from verti-
example, autorotative state).
cal for vertical takeoff, landing, and hover operations to
3.1.45 shall versus should versus may, v—use of the word
horizontal to derive lift from the wing in cruise.
“shall” means that a procedure or statement is mandatory and
3.1.52.5 tilt-wing aircraft, n—rotorcraft with both the wing
must be followed to comply with this specification, “should”
chord and the axes of the power-driven proprotor blades
means recommended, and “may” means optional at the discre-
capable of pivoting from vertical for vertical takeoff, landing,
tion of the applicant/proponent.
and hover operations to horizontal to derive lift from the wing
in cruise.
3.1.45.1 Discussion—“Shall” statements are requirements
and they include sufficient detail needed to define compliance
3.1.52.6 vertical lift aircraft, n—heavier-than-air aircraft
(for example, threshold values, test methods, oversight, and
capable of vertical takeoff, vertical landing, and flight that
referencetootherstandards).“Should”statementsareprovided
depends principally on engine-driven lift devices or engine
as guidance towards the overall goal of improving safety and
thrust for lift during these flight regimes.
could include only subjective statements. “Should” statements
3.1.52.7 vortex ring state, n—also referred to as “settling
also represent parameters that could be used in safety evalua-
with power,” an aerodynamic condition when a vortex ring
tions or could lead to development of future requirements, or
system engulfs the rotor (or propellers of a vertical flight
both. “May” statements are provided to clarify acceptability of
aircraft) causing severe loss of lift. Vertical lift aircraft with
a specific item or practice and offer options for satisfying
higher disk loading and increased blade twist are more suscep-
requirements.
tible to vortex ring state.
3.1.46 supplier, n—any entity engaged in the design and
production of components (other than a payload which is not
3.1.53 warning, n—a condition that requires immediate
required for safe operation of the UAS) used on a UAS. flight crew awareness and immediate flight crew response.
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3.1.54 The terms “engine” referring to internal combustion 3.2.35 V —design speed for maximum gust intensity
B
enginesand“motor”referringtoelectricmotorsforpropulsion
3.2.36 V —design cruising speed
C
are used interchangeably within this specification.
3.2.37 V —design diving speed
D
3.1.55 The term “engine idle” or “throttle closed,” when in
3.2.38 V —demonstrated flight diving speed
DF
reference to electric propulsion units, shall mean the minimum
power or propeller rotational speed condition for the electric
3.2.39 V —design flap speed
F
motor as defined without electronic braking of the propeller
3.2.40 V —maximum flap extended speed
FE
rotational speed.
3.2.41 V —maximum speed in level flight with maximum
H
3.2 Abbreviations:
continuous power (corrected for sea level standard conditions)
3.2.1 ADS-B—Automatic Dependent Surveillance Broad-
3.2.42 V —minimum controllable airspeed
cast MC
3.2.43 V —never exceed speed
3.2.2 AR—aspect ratio NE
3.2.44 V —operating maneuvering speed
O
3.2.3 AFCS—Automated Flight Control System
3.2.45 V —ground gust speed
3.2.4 b—wing span (m) R
3.2.46 V —stallingspeedorminimumsteadyflightspeedat
S
3.2.5 c—chord (m)
which the fixed-wing UA is controllable (flaps retracted)
3.2.6 CASA—Civil Aviation Safety Authority (Australia)
3.2.47 V —stalling speed or minimum steady flight speed
S0
3.2.7 CAS—calibrated air speed (m/s, kts)
at which the aircraft is controllable in a landing configuration
3.2.8 C —lift coefficient of the fixed-wing UA
L
3.2.48 V —stalling speed or minimum steady flight speed
S1
3.2.9 C —drag coefficient of the fixed-wing UA
at which the aircraft is controllable in a specific configuration
D
3.2.10 CG—center of gravity
3.2.49 V —for multiengine UA, the airspeed at which the
SE
aircraft remains capable of controlled flight the minimum
3.2.11 C —moment coefficient (C is with respect to c/4
m m
number of required operational propulsion systems
point, positive nose up)
3.2.50 V —speed for best angle of climb
X
3.2.12 C —zero lift moment coefficient
MO
3.2.51 V —speed for best rate of climb
Y
3.2.13 C —normal coefficient
n
3.2.52 w—average design surface load (N/m )
3.2.14 C —fixed-wing UA normal force coefficient
nA
3.2.53 W—maximum takeoff or maximum design weight
3.2.15 EASA—European Aviation Safety Agency
(N)
3.2.16 FAA—Federal Aviation Administration (FAA)
3.2.54 W —maximum empty fixed-wing UA weight (N)
2 E
3.2.17 g—acceleration as a result of gravity = 9.81 m/s
3.2.55 W —minimum useful load (N)
U
3.2.18 IAS—indicated air speed (m/s, kts)
3.2.56 W —maximum zero wing fuel weight (N)
ZWF
3.2.19 ICAO—International Civil Aviation Organization
3.2.57 W/S—wing loading (p.s.f.) due to the applicable
3.2.20 MAC—mean aerodynamic chord (m)
weight of the fixed-wing aircraft in the particular load case.
3.2.21 n—load factor
4. Significance and Use/Applicability
3.2.22 n —fixed-wing UA positive maneuvering limit load
factor
4.1 This specification is intended for lightweight UAS
permitted to operate over a defined area and in airspace
3.2.23 n —fixed-wing UAnegative maneuvering limit load
authorized by a nation’s civil aviation authority (CAA) with a
factor
fully interactive ground based person as “Remote Pilot in
3.2.24 n —load factor on wheels
Command.”
3.2.25 NIST—National Institute for Standards and Technol-
4.2 The baseline covered by this specification should not
ogy
require an authorization by a Civil Aviation Authority for the
3.2.26 P—power, (kW)
flight but stay within defined boundaries for the operation (for
3.2.27 ρ—air density (kg/m ) = 1.225 at sea level standard
example, distance from airports, from people, maximum
conditions weight, altitude, airspeed and operational envelope). However,
unless otherwise allowed by a nation’s CAA or subject to
3.2.28 POH—Pilot Operating Handbook
voluntarily compliance by an applicant, this specification
3.2.29 q—dynamic pressure
applies to UA that:
3.2.30 RC—climb rate (m/S)
4.2.1 Have a maximum takeoff gross weight of less than 55
lb (25 kg), including everything that is on board or otherwise
3.2.31 S—wing area (m )
attached to the aircraft, and
3.2.32 TCAS—Traffic Collision Avoidance System
4.2.2 Are remotely piloted (that is, flown without the
3.2.33 V—airspeed (m/s)
possibility of direct human intervention from within or on the
3.2.34 V —design maneuvering speed aircraft), and
A
F3298−19
4.2.3 Conduct Expanded Operations that typically require (that is, maximum takeoff RPM during takeoff and 110% of
authorization from the CAA (for example, Operations Autho- maximum continuous RPM at closed throttle and V .
NE
rization for Specific Category UAS or Part 107 Certificate of
5.5 Flight Characteristics:
Waiver/Authorization) with specific limitations adapted to the
5.5.1 Controllability and Maneuverability:
operation.
5.5.1.1 The aircraft shall be safely controllable and maneu-
4.3 These requirements apply to unmanned aircraft systems verable during takeoff, climb, level flight (cruise), dive to V
DF
that are: or the maximum allowable speed for the configuration being
4.3.1 Fixed-Wing—Heavier than air and supported in flight investigated, approach, and landing (power off and on, flaps
retractedandextended,etc.)throughthenormaluseofprimary
by the dynamic reaction of the air against its wings. The UA
may be powered or unpowered; the UA may have rigid, controls.
5.5.1.2 The aircraft shall be safely controllable and maneu-
semi-rigid, or flexible wings.
4.3.2 VTOL—Heavier than air and capable of vertical or verable during all flight phases including, where applicable:
(1)Taxi or Hover Taxi;
near-vertical takeoffs and landings. The rotor system may be
powered or unpowered; Rotors may be either fixed collective (2)Takeoff or Launch;
(3)Climb;
pitchorcollectivepitchcontrolthatarenotadjustableinflight.
Reference 3.1.52 for characteristics by category of vertical (4)Level flight;
(5)Descent;
flight aircraft.
(6)Go-around;
4.3.3 Hybrid UAS (that is, incorporating gyrodyne or
(7)Landing or Recovery; and
powered-liftflightmodes)arerecommendedtofollowthemost
(8)At all permissible aircraft speeds and in all permissible
restrictive aspects of this specification.
aircraft configurations.
5. Flight
5.6 VTOL:
5.6.1 Rotor Speed and Pitch Limits:
5.1 Proof of Compliance:
5.6.1.1 Main Rotor Speed Limits—A range of main rotor
5.1.1 Each applicant who claims compliance to this speci-
speeds shall be established that:
fication shall be able to show compliance with the applicable
(1)Withpoweron,providesadequatemargintoaccommo-
requirements of this specification.
date the variations in rotor speed occurring in any appropriate
5.1.2 The applicant shall determine and document in the
maneuver, and is consistent with the kind of governor or
aircraft flight manual appropriate operating limitations and
synchronizer used; and
other information necessary for safe operation of the system.
(2)With power off, allows each appropriate auto-rotative
5.1.3 Eachofthefollowingrequirementsshallbemetatthe
maneuver to be performed throughout the ranges of airspeed
most critical weight and CG configuration.
and weight for which certification is requested.
5.1.4 Unless otherwise specified, the speed range from stall
5.6.1.2 NormalMainRotorHighPitchLimits(PowerOn)—
to V or the maximum allowable speed for the configuration
DF
For rotorcraft, except helicopters required to have a main rotor
being investigated shall be considered.
low-speed warning, it shall be shown with power on and
5.1.4.1 V shall be less than or equal to V .
DF D
without exceeding approved engine maximum limitations, that
5.1.4.2 If V chosen is less than V , V shall be less than
DF D NE
main rotor speeds substantially less than the minimum ap-
or equal to 0.9 V and greater than or equal to 1.1 V .
DF C
proved main rotor speed shall not occur under any sustained
5.1.5 The following tolerances are acceptable during flight
flight condition. This shall be met by:
testing:
(1)Appropriate setting of the main rotor high pitch stop;
Weight +5 %, –10 %
(2)Inherent rotorcraft characteristics that make unsafe low
Weight, when critical +5 %, –1 %
CG ±7 % of total travel
main rotor speeds unlikely; or
(3)Adequate means to warn the remote pilot of unsafe
5.2 Load Distribution Limits:
main rotor speeds.
5.2.1 The maximum weight shall be determined so that it is
5.6.1.3 Normal Main Rotor Low Pitch Limits (Power Off)—
not more than:
It shall be shown, with power off, that:
5.2.1.1 The highest weight selected by the applicant,
(1)The normal main rotor low pitch limit provides suffi-
5.2.1.2 The design maximum weight, and
cientrotorspeed,inanyauto-rotativecondition,underthemost
5.2.1.3 HOGE at standard atmosphere conditions (59°F
critical combinations of weight and airspeed; and
(15°C)) and sea level pressure altitude.
(2)It is possible to prevent overspeeding of the rotor
5.2.2 The design empty weight shall be specified by the
without requiring exceptional piloting skill.
applicant.
5.6.1.4 Emergency High Pitch—If the main rotor high pitch
5.3 Empty Weight and Corresponding CG:
stop is set to meet subparagraph (b)(1), and if that stop cannot
5.3.1 Theapplicantshalldeterminethepermissiblerangeof
be exceeded inadvertently, additional pitch may be made
weight and positions of the center of gravity of the UA.
available for emergency use.
5.4 Propeller Speed and Pitch Limits—Propeller speed 5.6.1.5 Main Rotor Low-Speed Warning for Helicopters—
(RPM) and pitch shall not be allowed to exceed safe operating There shall be a main rotor low-speed warning that meets the
limitsestablishedbythemanufacturerundernormalconditions following requirements:
F3298−19
(1)Thewarningshallbefurnishedtotheremotepilotinall 6.5.2 The applicant shall determine the minimum control-
flight conditions, including power-on and power-off flights, lable airspeed (V ) for most critical configuration used in
MC
when the speed of a main rotor approaches a value that can takeoff and landing operations.
jeopardize safe flight. 6.5.3 The applicant shall comply with 6.3 for each possible
(2)The warning shall be furnished by a device. permutation of operational motors.
(3)The warning shall be clear and distinct under all
6.6 VTOL Performance:
conditions, and should be clearly distinguishable from other
6.6.1 Hover Taxi.
warnings. A visual device that requires the attention of the
6.6.2 Takeoff—With takeoff at the maximum weight, full
remote pilot is not acceptable by itself.
throttle, sea level, the distance(s) required from rest to takeoff
(4)The warning device shall automatically deactivate and
and climb to 50 ft (15 m) above the takeoff surface with zero
reset when the low-speed condition is corrected. If the device
wind shall be measured.
has an audible warning, it should also be equipped with a
6.6.3 Climb:
means for the remote pilot to manually silence the audible
6.6.3.1 At maximum takeoff weight and full throttle, the
warning before the low-speed condition is corrected.
minimum rate of climb shall exceed 200 ft/min (1.0 m/s).
5.6.2 Height/Velocity Envelope:
6.6.3.2 Rate of climb at V should exceed 315 ft/min (1.6
Y
5.6.2.1 The applicant shall establish the combinations of
m/s).
height and forward airspeed from which a safe landing cannot 1
6.6.3.3 Climb gradient at V should exceed ⁄12 .
X
be made following engine failure as a limiting height-speed
6.6.4 Landing—The following shall be determined:
envelope (graph) for vertical lift aircraft.
6.6.4.1 The distance required to land and come to rest from
5.6.2.2 The height-speed envelope graph must be included
a point 50 ft (15 m) above the landing surface, with zero wind,
in the UFM.
and
6.6.4.2 The approach airspeed to achieve this performance.
6. Performance
6.6.5 Multi-Engine:
6.6.5.1 For UA with multiple motors, the applicant shall
6.1 Fixed-Wing:
determinetheminimumnumberofoperationalmotorsrequired
6.1.1 Stalling Speed:
to maintain normal operation.
6.1.1.1 For UA that does not employ flight envelope
6.6.5.2 The applicant shall determine the minimum control-
protection, 6.1.1.2 and 6.1.1.3 shall be determined.
lable airspeed (V ) for most critical configuration used in
MC
6.1.1.2 Wing level stalling speeds V and V shall be
S0 S
takeoff and landing operations.
determined by the manufacturer for a specific aerodynamic
6.6.5.3 The applicant shall comply with 6.6.3 for each
configuration or as determined by the installed flight envelope
possible permutation of operational motors.
protection (for example, be determined with the engine idling,
6.6.6 Autorotation—If autorotation capability is imple-
propeller in the takeoff position, and the cowl flaps closed).
mentedtofulfilltherequirementsof6.6.5,theminimumrateof
6.1.1.3 Wing level stalling speeds V and V should be
S0 S
descent airspeed and the best angle-of-glide airspeed shall be
determined by flight test at a rate of speed decrease of 1 knot/s
determined in autorotation at:
or less, throttle closed, with maximum takeoff weight, and
6.6.6.1 Maximum weight; and
most unfavorable CG.
6.6.6.2 Rotor speed(s) selected by the applicant.
6.2 Takeoff—With takeoff at the maximum weight, full
7. Design
throttle, sea level, the following shall be measured:
6.2.1 Ground roll distance; and,
7.1 General:
6.2.2 Distance to clear a 50 ft (15.2 m) obstacle at 1.3 V .
S1 7.1.1 Allsystemcomponentsrequiredforthesafeoperation
of the UA shall be designed and constructed to:
6.3 Climb:
7.1.1.1 Be appropriate to their intended function, and
6.3.1 At maximum takeoff weight, flaps in the position
7.1.1.2 Function properly when installed.
specified for climb within the POH, and full throttle, the
7.1.2 The UAS shall be designed and constructed to mini-
minimum rate of climb shall exceed 200 ft/min (1.0 m/s).
mize the likelihood of fire, explosion, or the release of
6.3.2 Rate of climb at V should exceed 315 ft/min (1.6
Y
hazardous chemicals, materials, and flammable liquids or
m/s).
gasses, or a combination thereof, in flight or in the event of a
6.3.3 Climb gradient at V should exceed ⁄2 .
X
crash, hard landing, or ground handling mishap.This includes,
6.4 Landing—The following shall be determined:
but is not limited to: containing the fire if the UAcrashes; use
6.4.1 Landing distance from 50 ft (15 m) above ground
of flame resistant materials; and protection against battery-
when speed at 50 ft (15 m) is 1.3 V ;
S0 induced fires.
6.4.2 Ground rolls distance described in 6.4.1 shall be
7.2 Equipment, Systems, and Installation:
achieved with braking, if so equipped.
7.2.1 General Function:
6.5 Multi-Engine:
7.2.1.1 Each item of equipment, each system, and each
6.5.1 For UA with multiple motors, the applicant shall installation shall be designed and constructed so that, it does
determinetheminimumnumberofoperationalmotorsrequired notadverselyaffecttheresponse,operation,oraccuracyofany
to maintain normal operation. equipment required for the safe operation of the UAS.
F3298−19
FIG. 1ICAO Class 9 Lithium Battery Label
7.2.1.2 Each item of installed equipment in a UA shall: 7.3 Materials and Workmanship:
(1)Be of a kind and design appropriate to its intended 7.3.1 The suitability and durability of materials used for
function; parts, the failure of which could adversely affect safety, shall:
(2)Be labelled as to its identification, function, or operat- 7.3.1.1 Be established based on intrinsic material properties
ing limitations, or any applicable combination of these factors, or tests;
ifappropriate.Smallitemsthatprecludereadablelabelsshould 7.3.1.2 Conform to approved specifications (such as indus-
be easily identified via a schematic/installation drawing which try or military specifications, or Technical Standard Orders)
depicts the item via an illustrated diagram and parts list; that ensure their having the strength and other properties
(3)Be installed according to limitations specified for that assumed in the design data; and
equipment; and 7.3.1.3 Consider the effects of environmental conditions,
(4)Function properly, and as designed, when installed. such as temperature and humidity, expected in service.
7.2.1.3 There shall be a means to assure that, prior to taxi 7.3.2 Design values (strength) shall be chosen so that no
and takeoff or launch, the UAS and its subsystems are structural part is under strength because of material variations
operating correctly. or load concentration, or both.
7.2.2 Installation:
7.4 Airframe:
7.2.2.1 Each item of equipment, each system, and each
7.4.1 The UAshall be designed and constructed so that it is
installation:
possible to determine during preflight that all external doors,
(1)When performing its intended function, shall not ad-
panels, and hatches are in the position for safe flight.
versely affect the response, operation, or accuracy of any
7.5 Structure:
equipment essential to safe operation;
7.5.1 TheUAstructureshallbedesignedandconstructedso
(2)Shall be designed to minimize hazards to the safe
that:
operation of the UAin the event of a probable malfunction or
7.5.1.1 The structure shall not fail at ultimate load. This
failure.
shall be verified either through analysis or testing.
NOTE 1—“Probable” above refers to malfunctions that have a reason-
7.5.1.2 The UA and systems required for continued safe
able likelihood of occurring, or can be envisioned to occur.
flight shall be designed to be capable of supporting limit loads
7.2.2.2 IfasinglefailureofanUAsystemcouldresultinthe throughouttheoperatingenvelopetoincludeatmosphericgusts
loss of control of the UA trajectory: or maneuvering loads, or both.
(1)The probability of such a failure under all expected 7.5.1.3 The UA and systems required for continued safe
operating conditions shall be extremely remote, or
flight shall be designed to withstand landing loads without
(2)Thereshallbeameansofinitiatingflight-terminationin damage that would affect safety of flight of subsequent flights
the event of such a failure, or
unless it can be maintained, repaired, and inspected as per
(3)There shall be an alternate means of regaining control. procedures that will ensure continued safe operation.
F3298−19
7.5.2 Protection of Structure: 7.9.2.5 The system shall include a means for shutting down
7.5.2.1 Protection of the structure against weathering, the engine on the UA during an emergency.
7.9.2.6 For aircraft using electric propulsion systems, the
corrosion, and wear, as well as suitable ventilation and
drainage, shall be provided as required. system shall include a means to determine the capacity
remaining in the ESD.
7.5.2.2 Design precautions shall be taken to minimize the
7.9.2.7 Performance with One Propulsion System Inopera-
hazards associated with exposed rigid sharp structural objects.
tive:
7.5.2.3 For those systems that might have components
(1)The UA should be designed so that in the event of
capable of causing injury, the UA shall be designed with
propulsion system failure:
appropriate placards alerting the crew to the risk.
(a)The flight path can be controlled, or
7.5.2.4 Energy absorbing structure should be used where
(b)The system defaults to a safe automated recovery
practical.
procedure.
7.5.2.5 Refer to A2.2.1 for additional guidance on energy
(2)For UA with multiple propulsion systems, the UA
absorbing structure.
should be designed and constructed so that in the event of a
7.6 Airspeed Limitations:
singular or multiple propulsion system failure:
7.6.1 All flight speeds shall be stated in terms of indicated
(a)The aircraft remains capable of controlled flight, or
airspeed (IAS).
(b)The descent flight path can be controlled from the
7.6.2 Ground speed displays shall be clearly marked to
control station, or
prevent interpretation as air speeds.
(c)The system defaults to a safe automated recovery
procedure.
7.7 Weight and Center of Gravity:
7.9.3 EPU Wiring:
7.7.1 Weight and center of gravity limitations shall be
7.9.3.1 If the aircraft is provided with a EPU then:
provided, including reference and leveling data.
(1)Wiringmustbeproperlysupportedtopreventexcessive
7.8 Loads and Dynamics:
vibration and withstand loads due to inertial forces during
7.8.1 Factors of Safety—Representative limit load cases
flight.
shall be demonstrated to prove compliance with a 1.5 safety
(2)Wiring carrying the power consumed by the electric
factor.
motor must be supported such that any possibility for wire
7.8.2 Control Surface and System Loads:
chafing, shorting, or adverse contact with the airframe is
7.8.2.1 The applicant shall determine the minimum torque
eliminated.
requirement for the mechanical output of UAcontrol surfaces.
(3)Wiring connected to components of the aircraft, be-
7.8.2.2 Binding, chafing, or jamming of controls, actuators,
tween which relative motion could exist, must have provisions
and control surfaces shall not occur at less than or equal to the
for flexibility.
limit load threshold.
7.9.4 Fuel and Oil System—For UA using a combustion
7.8.2.3 The UAS shall be designed so that the UA can be
propulsion system:
operated within the confines of the defined operational enve-
7.9.4.1 The fuel and oil systems shall be designed and
lope without exceptional pilot skill.
constructed to be capable of supplying adequate fuel and oil to
7.8.3 Stability: the propulsion system throughout the entire flight envelope.
7.8.3.1 The UA shall be designed to be longitudinally, 7.9.4.2 Allitemsthatareintendedtobeexposedtofuel,oil,
directionally, and laterally positively statically able for all and lubricating grease shall be resistant to deterioration.
weight and CG positions in the operational flight envelope. 7.9.4.3 Eachfuelsystemandoilsystemshallbedesignedto
be able to withstand ultimate loads; and
7.9 Propulsion System:
7.9.4.4 Each fuel system shall be designed so that it can be
7.9.1 Installation:
serviced when the aircraft is on the ground.
7.9.1.1 The propulsion system shall be designed to operate
7.9.5 Energy Storage Devices:
throughout the flight envelope.
7.9.5.1 The UA shall be designed with a redundant ESD
7.9.1.2 The propulsion system shall be designed to conform
system with sufficient stored power that the minimal configu-
to the installation instructions.
ration of the ESD packs could safely fly the UA to a safe
7.9.2 Propulsion: Powerplant, Engines, and Motors:
landing area.
7.9.2.1 Powerplant limitations shall be provided.
NO
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