This glossary defines common aviation safety, flight data, crew scheduling, and operations terms in plain language. Definitions follow ICAO, FAA, EASA, and Air Safety Support International wording where an official definition exists, and say so where a term is industry usage only.
Safety management
Safety management system (SMS)
A systematic, organization-wide approach to managing safety risk. The ICAO framework has four components: safety policy and objectives, safety risk management, safety assurance, and safety promotion.
Read what an aviation SMS is and the requirements under ICAO, FAA, and EASA rules.
Quality management system (QMS)
A system that monitors conformity with procedures and standards through audits, findings, and corrective actions. Many operators run it alongside the SMS so that audit findings, risk records, and corrective actions share one workflow.
Aurora is FlightAtom's standalone SMS and QMS.
State safety programme (SSP)
ICAO defines a State safety programme as an integrated set of regulations and activities aimed at improving safety. It is the State-level counterpart of an operator's SMS.
ICAO Annex 19
The ICAO annex on safety management. It sets the SMS framework that States apply to service providers. Amendment 2 becomes applicable on 26 November 2026.
14 CFR Part 5
The United States regulation that sets SMS requirements for Part 121 and Part 135 operators, section 91.147 air tour operators, and certain Part 21 certificate holders.
See the FAA Part 135 SMS requirements guide.
Aviation Safety Action Program (ASAP)
An FAA programme that encourages employees of certain certificate holders to report safety issues and events voluntarily.
Flight data
Flight data monitoring (FDM)
EASA defines flight data monitoring as the proactive and non-punitive use of digital flight data from routine operations to improve aviation safety.
Read what flight data monitoring is and who must have a programme.
Flight data analysis (FDA)
ICAO defines flight data analysis as a process of analysing recorded flight data in order to improve the safety of flight operations. It is ICAO's term for flight data monitoring.
Flight operational quality assurance (FOQA)
The FAA term for flight data monitoring: an FAA-approved program for the routine collection and analysis of digital flight data gathered during aircraft operations. FOQA is voluntary in the United States.
Exceedance detection
Searching recorded flight data for deviations from aircraft flight manual limits and standard operating procedures.
Gatekeeper
The member of a flight data monitoring team who protects crew identity. EASA guidance describes the gatekeeper as the only person permitted to connect identifying data with an event.
Aircraft communications addressing and reporting system (ACARS)
The FAA describes ACARS as a digital data link system for transmission of short messages between aircraft and ground stations via airband radio or satellite.
Out, off, on, in times (OOOI)
Industry term for the four movement times of a flight: out of the gate, off the ground, on the ground, and in at the gate. Block time runs from out to in.
Crew and training
Crew pairing
In ICAO's fatigue management manual, a scheduling expression describing the time from when a flight crew member initially reports for duty until they return home from the sequence of flights and are released from duty. A pairing is also called a trip.
Read how crew scheduling works from pairing to recovery.
Roster
In ICAO's fatigue management manual, a list of planned shifts or work periods within a defined period of time. To roster is to assign individuals to a schedule or pattern of work.
Flight time limitations (FTL)
Regulatory limits on flight time, duty periods, and rest for crew members. Examples are FAA Part 117, EASA Subpart FTL, and Appendix F to OTAR Parts 121 and 135.
Fatigue risk management system (FRMS)
ICAO defines an FRMS as a data-driven means of continuously monitoring and managing fatigue-related safety risks, based upon scientific principles and knowledge as well as operational experience, that aims to ensure relevant personnel are performing at adequate levels of alertness.
Competency-based training and assessment (CBTA)
ICAO describes CBTA as training and assessment characterized by a performance orientation, emphasis on standards of performance and their measurement, and the development of training to the specified performance standards.
Evidence-based training (EBT)
EASA defines evidence-based training as assessment and training based on operational data that is characterised by developing and assessing the overall capability of a pilot across a range of competencies.
Operations
Operational control
ICAO defines operational control as the exercise of authority over the initiation, continuation, diversion or termination of a flight in the interest of the safety of the aircraft and the regularity and efficiency of the flight.
Operations control centre (OCC)
The airline department responsible for operational control of ongoing flights, with authority to originate, delay, divert, and cancel them. It is also called an airline operational control center (AOCC) or systems operations control (SOC).
Read what an operations control centre does.
Flight operations officer or flight dispatcher
ICAO defines a flight operations officer or flight dispatcher as a person designated by the operator to engage in the control and supervision of flight operations, whether licensed or not, suitably qualified in accordance with Annex 1, who supports, briefs or assists the pilot in command in the safe conduct of the flight.
Irregular operations (IROPS)
Industry term with no regulatory definition. IATA guidance describes an irregular operation as one that may be, but is not limited to, a flight delay, cancellation, or diversion due to weather or a mechanical problem.
Minimum equipment list (MEL)
ICAO defines the MEL as a list which provides for the operation of aircraft, subject to specified conditions, with particular equipment inoperative, prepared by an operator in conformity with, or more restrictive than, the master minimum equipment list for the aircraft type.
Air operator certificate (AOC)
ICAO defines an air operator certificate as a certificate authorizing an operator to carry out specified commercial air transport operations. The abbreviation AOC is also used for airline operational control.
On-time performance (OTP)
Industry measure of punctuality: the share of flights that depart or arrive within a set threshold of schedule, commonly 15 minutes. The departure and arrival measures are often written D15 and A15.
Rules and regulators
International Civil Aviation Organization (ICAO)
The United Nations agency that sets international standards and recommended practices for civil aviation in the annexes to the Chicago Convention. States implement them through national rules.
Federal Aviation Administration (FAA)
The civil aviation authority of the United States. Its regulations are published in Title 14 of the Code of Federal Regulations.
European Union Aviation Safety Agency (EASA)
The aviation safety agency of the European Union. Air operations rules are set in Regulation (EU) No 965/2012, with acceptable means of compliance and guidance material published by EASA.
Overseas Territories Aviation Requirements (OTAR)
The requirements for aviation in the UK Overseas Territories, published by Air Safety Support International. They describe the means by which aircraft operators, aviation personnel and service providers can gain approvals, licences and certificates and the requirements they need to meet to maintain them.
Official references and scope
Definitions that cite a regulator follow the wording of these sources. Terms marked as industry usage have no official definition.
- ICAO Safety Management: Annex 19 context and the State safety programme and SMS framework.
- EASA Easy Access Rules for Air Operations: definitions in Annex I to Regulation (EU) No 965/2012, flight data monitoring rules, and Subpart FTL.
- 14 CFR 13.401: the FAA definition of a flight operational quality assurance program.
- 14 CFR 1.1: FAA general definitions, including operational control.
- FAA Aviation Safety Action Program: FAA description of the voluntary reporting programme.
- Overseas Territories Aviation Requirements: Air Safety Support International's description and index of the OTARs.
See the terms in a working product
Each FlightAtom product page shows the workflow behind these terms with real interface screenshots and demonstration data. Compare the products or read the guides.