I've heard of level A, B, C, and D simulators, (as well as FTD and AATDs) but know nothing about them.

What criteria is used to certify a sim as a particular level?


3 Answers 3


Here there is a nice tabular representation of the requirements for each level.

Wiki provides a handy summary:

Full Flight Simulators (FFS)

  • FAA FFS Level A - A motion system is required with at least three degrees of freedom. Airplanes only.

  • FAA FFS Level B - Requires three axis motion and a higher-fidelity aerodynamic model than does Level A. The lowest level of helicopter flight simulator.

  • FAA FFS Level C - Requires a motion platform with all six degrees of freedom. Also lower transport delay (latency) over levels A & B. The visual system must have an outside-world horizontal field of view of at least 75 degrees for each pilot.

  • FAA FFS Level D - The highest level of FFS qualification currently available. Requirements are for Level C with additions. The motion platform must have all six degrees of freedom, and the visual system must have an outside-world horizontal field of view of at least 150 degrees, with a Collimated (distant focus) display. Realistic sounds in the cockpit are required, as well as a number of special motion and visual effects.

  • 1
    $\begingroup$ These requirements are a bit dated, FAA 14 CFR part 60 requires a horizontal field of view of 200 degrees. $\endgroup$
    – Koyovis
    Apr 26, 2017 at 4:14
  • 1
    $\begingroup$ @Koyovis I will try to update the values asap $\endgroup$
    – Federico
    Apr 26, 2017 at 8:51

It's a complicated system based on the past. It started with FAA classification of Full Flight simulators (FFS), with visual and motion, and Flight Training Devices (FTD) without visual and motion. The letter system A,B,C,D is still used by FAA and EASA, the number system is replaced with acronyms such as MCC and FNPTII.

FFS for fixed wing:

  • Level D is the highest level, zero hours machines (meaning all type training can be carried out in them, including landings & everything). Visual system: uninterrupted field of view of 200 x 40 degree, on top of a 6 DegreeOfFreedom motion base with 1.5m stroke actuators. Aerodynamic modelling to match actual aircraft measurements to a very high degree.
  • Level C is almost as good, but some requirements that used to be hard to achieve are relaxed. Sound for instance does not have to be frequency matched, only OK-ed by a test pilot. Aerodynamics have less stringent requirements: no ground effect, mach effects, icing etc. Same motion requirements as Level D.
  • Level B and Level A could use three Degree-Of-Freedom motion, great in the olden days when the software did not exist yet to control the complicated motion of a 6-DoF system. As far as I know no-one builds them anymore.

FTD for fixed wing: old system

  • Level 7 was the highest level, stringent requirements on instrumentation and model fidelity - but no visual and motion required.
  • Levels 5 and 6 are reasonably high fidelity cockpits with aerodynamic models from a similar class of aircraft. For instance a Level 5 FTD for a B737 could use the aero model for an A320 because they are both medium size wing mounted twin jets.
  • Levels 2-4 were devices for novice pilots where they learn how to operate switches and see live effects. Very limited aero modelling required.
  • Level 1 was such a low level that to my knowledge it was never built.

FTD new system:

  • FTD. The highest level, akin to a Level &, with visual, no motion. Visual can be direct projection, non collimated.
  • MCC. Multi Crew Cooperation, a setup where 2 pilots can train how to share tasks in the cockpit. Reasonably stringent requirements, no motion required. Some old flight sims have been re-classified as MCC or FNPT II
  • FNPT and FNPTII: Navigation trainers, focused on the task how to find your way from beacon to beacon and to the landing airport.

Helicopters follow grosso modo the same requirements. A Level D has a huge field of view to enable to look down and see the runway for landing. For helicopters Level B is an attractive option: full motion and visual allows you to train in the dark art of hell hovering. Main difference with Level D is in the data collection: instruments can be read from a video instead of having to be downloaded from the aircraft internal data bus and measured with external transducers.


You will find a perfect description for each kind of simulator in the FAA Part 60 Change 2, the EASA CS-FSTD(a) 2012, the ICAO 9625 Edition 4, the CCAR 60 and many others.

Some authorities based their need on EASA or FAA or ICAO documents like CAAS (Singapore) is using the ICAO document.

FSTD EASA Level explanation

For example, EASA is describing each level of Flight Training Devices in that table. And you will see a checkmark when the device will need to respect that requirement. And a small description for each level: FFS Level description

The goal behind that is to be able to fulfill the training requirement for pilots. And on which kind of device we can train the pilot as a necessary level to the license needs.



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