The following Glossary is centric to Flight Simulation Training Devices (FSTDs) and although many terms and abbreviations have similar, or the same meaning in other parts of the aviation industry, the following is specific to FSTDs.  The list has been created from many sources plus the valued input of the colleagues of Training Technology International (Canada) Ltd.  Every effort has been made to make sure it is accurate, but as with all documents of this type it is quite possible that errors exist.  If you find one of those, or have a suggestion for improvement, please contact us here…

Certification Specification – Aeroplane

EASA document – Certification Specification Flight Simulation Training Device – Aeroplane

Certification Specification – Helicopter

EASA document – Certification Specification Flight Simulation Training Device – Helicopter

Certification Specifications

EASA term for a document that defines the specifications a device must meet to receive certification. Certification Specifications (CS) are non-binding technical standards adopted by the EASA to meet the essential requirements of the Basic Regulation. CSs are used to establish the certification basis (CB)

Class I, II & III visual model

A Class of visual model. See 14CFR Part 60 Appendix F for full definition. Also see Generic visual model. See also Generic visual model.

Closed loop testing

‘Closed loop testing’ is a test method for which the input stimuli are generated by controllers which drive the FSTD to follow a pre-defined target response with corrective feedback from instrumentation.

Code of Federal Regulations 

Definition of Code of Federal Regulations: compilation of administrative laws governing federal regulatory agency practice and procedures.


Collimation as used in an FSTD visual display system, it is the optical process of converting a point-source of image (the visual scene) to parallel rays of light thereby giving the pilot the illusion that the scene is located at a distance of greater than 40ft.

Competent Authority

An EASA term defining that a National Aviation Authority (or other organization) is deemed competent and capable of performing aviation related tasks to EASA standards.

Compliance Management Manual

A Compliance Management Manual is a comprehensive document defining full details of an Operators organization, processes, systems and record keeping required to meet the requirements of a FSTD operation. It is a requirement of EASA to obtain a FSTD Qualification.

Compliance Management System

A Compliance Management System is a comprehensive compliance program. A compliance management system is an integrated system comprised of written documents, functions, processes, controls, and tools that help an organization comply with legal requirements and minimize harm to consumers due to violations of law. It is a requirement of EASA to obtain a FSTD Qualification.

Computer Controlled Aircraft

‘Computer controlled aircraft’ means an aircraft where the pilot inputs to the control surfaces are transferred and augmented via computers.

Confined Area (helicopter operations)

An area where the flight of the helicopter is limited in some direction by terrain or the presence of natural or man-made obstructions (e.g., a clearing in the woods, a city street, or a road bordered by trees or power lines are regarded as confined areas). 

Control sweep

‘Control sweep’ means a movement of the appropriate pilot’s primary control from neutral to an extreme limit in one direction (forward, aft, right, or left), a continuous movement back through neutral to the opposite extreme position, and then a return to the neutral position.

Convertible FSTD

‘Convertible FSTD’ means an FSTD in which hardware and software can be changed so that the FSTD becomes a replica of a different model or variant, usually of the same type aircraft. The same FSTD platform, cockpit shell, motion system, visual system, computers, and necessary peripheral equipment can thus be used in more than one simulation.

Correct Trend and Magnitude

A term used when evaluating a FSTD where the parameters of the FSTD are demonstrating the same trend and magnitude of that of the aircraft it is simulating. In some cases tolerances are acceptable as being the Correct Trend and Magnitude, but in these cases it is highly recommended that once the FSTD is considered to meet requirements during an initial Evaluation, the performance of the FSTD is recorded as a footprint for the specific test that is using CT&M.

Critical Decision Speed

A calculated maximum speed at which a pilot may abort a takeoff without causing a runway overrun or, beyond which the pilot can continue the takeoff after suffering the failure of the critical engine and maintain the at least the regulatory minimum climb gradients.

Critical engine parameter

‘Critical engine parameter’ means the engine parameter that is the most appropriate measure of propulsive force, usually that which is visible to the pilot(s) in the cockpit.

Damping (critical)

‘Damping (critical)’: critical damping means that minimum damping of a second order system such that no overshoot occurs in reaching a steady state value after being displaced from a position of equilibrium and released. This corresponds to a relative damping ratio of 1:0.

Damping (over-damped)

‘Damping (over-damped)’: an over-damped response is that damping of a second order system such that it has more damping than is required for critical damping, as described above. This corresponds to a relative damping ratio of more than 1:0.

Damping (under-damped)

‘Damping (under-damped)’: an under-damped response is that damping of a second order system such that a displacement from the equilibrium position and free release results in one or more overshoots or oscillations before reaching a steady state value. This corresponds to a relative damping ratio of less than 1:0.