8900.1 CHG 510



Section 2  Definitions and Acronyms

16-1-2-1    DEFINITIONS. The following definitions are used by the Federal Aviation Administration (FAA) and many Unmanned Aircraft Systems (UAS) organizations to describe relevant differences between UAS operations and those of manned aircraft. Other organizations, such as the International Civil Aviation Organization (ICAO) and RTCA, Inc., have also developed acronyms and definitions that may differ from those used by the FAA.

A.    Aircraft. A device that is used or intended to be used for flight in the air.

Indicates new/changed information.

B.    Airworthy/Airworthiness. Means that the UAS conforms to its type certificate (TC), if applicable, and has been determined to be in a condition for safe operation (Title 49 of the United States Code (49 U.S.C.)  44704(d)(1)).

C.    Airworthiness Statement. Letter from a public UAS applicant specifying self-certification of a UAS in compliance with the criteria of the public entity.

D.    Beyond Visual Line of Sight (BVLOS). Means flightcrew members (i.e., remote pilot in command (PIC), the person manipulating the controls, and visual observer (VO), if used) are not capable of seeing the aircraft with vision unaided by any device other than corrective lenses (spectacles and contact lenses).

E.    Certificate of Waiver (CoW); Certificate of Authorization (CoA). The terms “certificate of waiver” and “certificate of authorization” mean a FAA grant of approval for a specific flight operation.

F.    Chase Aircraft. A manned aircraft that carries its own PIC and a separate qualified VO flying in proximity to an unmanned aircraft (UA).

Indicates new/changed information.

G.    Civil Aircraft. Aircraft other than public aircraft (Title 14 of the Code of Federal Regulations (14 CFR) part 1, 1.1; 49 U.S.C. 40102(a)(16)).

H.    Civil Twilight. The period of time that begins 30 minutes before official sunrise and ends at official sunrise; and the period of time that begins at official sunset and ends 30 minutes after official sunset. In Alaska, the period of civil twilight is defined in the Air Almanac.

I.    Control Station. An interface used by the remote pilot to control the flightpath of the small UA. The structure or system (ground, ship, or air-based) that controls the UAS and its interface to the aircraft and external systems.

J.    Cooperative Aircraft. Aircraft that have an electronic means of identification (i.e., a transponder or Automatic Dependent Surveillance—Broadcast (ADS-B) transceiver) aboard in operation.

K.    Corrective Lenses. Means spectacles or contact lenses.

L.    Crewmember (UAS). A person assigned to perform an operational duty during operations. A UAS crewmember includes the remote PIC, person manipulating the controls, and VOs, but may include other persons as appropriate or required to ensure safe operation of the UAS.

M.    Crew Resource Management (CRM). The effective use of all available resources including human, hardware, software, and information resources.

N.    Daisy-Chaining. The use of multiple, successive VOs to extend the flight of a UA beyond the direct Visual Line of Sight (VLOS) of the PIC or VO.

O.    Data Link. A wireless communication channel between one control station and one UA. Its utility may include, but is not limited to, uplink Command and Control (C2) data, downlink telemetry, and payload data. A data link may consist of the following types:

1)    Uplink: The transmittal of data from the control station to the UA.
2)    Downlink: The transmittal of data from the UA to the control station.

P.    Direct Control. The capability of a remote pilot to manipulate the flight control surfaces of the aircraft in a direct fashion using, for example, a radio control box with joystick or a ground control station using conventional type aircraft controls (such as a yoke/stick, rudder pedals, power levers, and other ancillary controls). This infers a one-to-one correspondence between control input and flight control surface deflection.

Q.    External Pilot. A remote pilot who controls the UA from outside of an enclosure.

R.    FAA-Recognized Equivalent. FAA recognition that a public agency may exercise its own internal processes regarding airworthiness and pilot, aircrew, and maintenance personnel certification and training, and the agency has determined that its UAS are capable of safe operation in the National Airspace System (NAS) when conducting public aircraft operations under 49 U.S.C. 40102(a)(41) and 40125.

S.    Flight Termination. The intentional and deliberate process of terminating the flight in the event of lost link, loss of control, or other failure that compromises the safety of flight.

T.    Flyaway. An interruption or loss of the control link, or when the pilot is unable to effect control of the aircraft and, as a result, the UA is not operating in a predicable or planned manner because lost link procedures are not established or are not being executed by the UA.

U.    Formation Flight. Formation flying is the disciplined flight of two or more aircraft under the command of a flight leader in either standard or nonstandard formation.

V.    Indirect Control. The capability of a remote pilot to affect the trajectory of the aircraft through computer input to an onboard flight control system.

W.    Internal Pilot. A remote PIC who flies from inside an enclosure and does not have VLOS with the aircraft.

X.    Lost Link. An interruption or loss of positive control between the control station and UA. or when the pilot is unable to effect control of the aircraft. Lost link is not considered a flyaway.

Y.    Lost Link Procedures. Preprogrammed or predetermined mitigations to ensure the continued safe operations of the UA in the event of lost link. In the event positive link cannot be achieved, flight termination must be implemented.

Z.    Model Aircraft. Means a UA that is: (i) Capable of sustained flight in the atmosphere; (ii) Flown within VLOS of the person operating the aircraft; and (iii) Flown exclusively for hobby or recreational purposes.

AA.    Nationwide Community-Based Organization. Means, in part, a “membership based association that represents the aeromodeling community within the Unites States; [and] provides its members a comprehensive set of safety guidelines that underscores safe aeromodeling operations within the NAS and the protection and safety of the general public on the ground.”

BB.    Non-Cooperative Aircraft. Aircraft that do not have an electronic means of identification (e.g., a transponder) aboard or that have inoperative equipment because of malfunction or deliberate action.

CC.    Off-Airport. Any location used to launch or recover aircraft that is not considered an airport (e.g., an open field).

DD.    Optionally Piloted Aircraft (OPA). A manned aircraft that can be controlled by a remote pilot from a location not onboard the aircraft. An aircraft having UAS technology and retains the capability of being flown by a Pilot Onboard (PO) using conventional control methods.

EE.    Person Manipulating the Controls. A person who is controlling an sUAS under the direct supervision of a remote PIC.

FF.     Remote Pilot in Command Certification (Remote PIC). A person who holds a remote pilot certificate with a small Unmanned Aircraft Systems (sUAS) rating and has the final authority and responsibility for the operation and safety of an sUAS operation conducted under 14 CFR part 107.

GG.    Public Aircraft. Title 49 U.S.C. 40102(a)(41) provides the definition of “Public Aircraft” and  40125 provides the qualifications for public aircraft status.

HH.    Safety Risk Management (SRM). A formalized, proactive approach to system safety. SRM is a methodology that ensures hazards are identified; risks are analyzed, assessed, and prioritized; and results are documented for decisionmakers to transfer, eliminate, accept, or mitigate risk.

II.    Scheduled Maintenance (Routine). The performance of maintenance tasks at prescribed intervals.

JJ.    Small Unmanned Aircraft. A UA weighing less than 55 pounds on takeoff, including everything that is onboard or otherwise attached to the aircraft.

KK.    Small Unmanned Aircraft System (sUAS). A small UA and its associated elements (including communication links and the components that control the small UA) that are required for the safe and efficient operation of the small UA in the NAS (including launch and recovery systems and equipment).

LL.    Special Airworthiness Certificates. Means a “special airworthiness certificate” used for all aircraft that are certificated in categories other than standard.

MM.    Tethered UAS. A UA that is restrained by a cable and attached to the ground or an object thereon.

NN.    Unmanned Aircraft (UA). Means an aircraft that is operated without the possibility of direct human intervention from within or on the aircraft.

OO.    Unmanned Aircraft System (UAS). A UA and associated elements (including communication links and the components that control the UA) that are required for the remote PIC to operate safely and efficiently in the NAS.

PP.     Unscheduled Maintenance (Nonroutine). The performance of maintenance tasks when mechanical irregularities occur.

QQ.    Visual Line of Sight (VLOS). Means that any flightcrew member (i.e., remote PIC, the person manipulating the controls, and visual observer, if used) is capable of seeing the aircraft with vision unaided by any device other than corrective lenses, spectacles or contact lenses in order to know the UA’s location, determine the UA’s attitude, altitude, and direction of flight, observe the airspace for other air traffic or hazards, and determine that the UA does not endanger the life or property of another.

RR.    Visual Observer (VO). A person who is designated by the PIC to assist the remote PIC and the person manipulating the flight controls of the sUAS to supplement situational awareness and Visual Line of Sight (VLOS), assisting with seeing and avoiding other air traffic or objects aloft or on the ground. The visual observer (VO) must be able to effectively communicate:

1)    The small UA location, attitude, and direction of flight;
2)    The position of other aircraft or hazards in the airspace; and
3)    The determination that the UA does not endanger the life or property of another.

16-1-2-3    ACRONYMS.

Figure 16-1-2A.  UAS Acronym List


Advisory Circular


Air Force Policy Directive


Flight Standards Service


Office of The Chief Counsel


Above Ground Level


Aeronautical Information Manual


Acceptable Level of Safety


Alternative Method of Compliance


Army Regulations


Aviation Safety Inspector


Air Traffic Control


Air Traffic Control Assigned Airspace


Air Traffic Control System Command Center


Air Traffic Organization


Air Traffic Service


Aviation Safety


Command and Control Link


Controlled Flight Into Terrain


Code of Federal Regulations


Certificate of Waiver or Authorization


Crew Resource Management


Control Station


Divert/Contingency Point


Department of Homeland Security


Department of Defense


Detect, Sense, and Avoid System


Federal Aviation Administration


Federal Communications Commission


Fault Hazard Analysis


Flight Information Region


Flight Level

Figure 16-1-2A.  UAS Acronym List (Continued)


Flight Standards Information Management System


Flight Termination Point


Flight Termination System


Ground Control Station




Government Master File


Headquarters (FAA)


Instrument Flight Rules


Lost Link Point


Letter of Agreement


Manufacturing Inspection District Office




Mean Sea Level


National Airspace System


National Aeronautics and Space Administration


Naval Air Systems Command Instruction


Nautical Mile


National Telecommunications and Information Administration


Optionally Piloted Aircraft


Pilot in Command


Point of Contact


Research and Development


Radio Frequency


Risk Management


Area Navigation


Return to Base


Reduced Vertical Separation Minimum


Statute Mile


Safety Risk Management


Safety Risk Management Document


Sensitive Security Information


Special Temporary Authority

Figure 16-1-2A.  UAS Acronym List (Continued)


Traffic Advisory Systems


Type Certificate


Traffic Alert and Collision Avoidance System


Unmanned Aircraft


Unmanned Aircraft System


United States Code


U.S. Customs and Border Protection


U.S. Coast Guard


Visual Flight Rules


Visual Meteorological Conditions


Visual Observer

16-1-2-5 through 16-1-2-19 RESERVED.