The Different Kinds of Simulators Explained: BATD, AATD, FFS, FTD

Simulation Classification The FAA categorizes aviation ground trainers into three main categories: full flight simulators, flight training devices, and aviation training devices.

  1. FFS: We’ll start first with the heavy hitters: flight simulators — or more accurately — full flight simulator (FFS). These more capable (and more expensive) training devices are required to have motion and visual capabilities. FFSs are sub-categorized into four levels, A through D, with Level D being the most sophisticated and having the most requirements, including six degrees of motion and realistic cockpit sounds. All levels of FFSs are objectively evaluated against airplane specific validation data (typically aircraft flight test data) to ensure that the FFS’s aerodynamics, flight controls characteristics, and ground handling characteristics represent a specific make, model, and series of aircraft. An FFS is often a “type” specific platform. It’s because of this that pilots can use a FFS to earn a type-rating without flying the actual aircraft. Many FAA-approved part 142 training centers use FFSs to train professional pilots for type ratings and to deliver the recurrency training required by regulation and insurance companies.


  1. FTD: The next category is flight training devices, or FTDs. These devices are designed to represent a specific aircraft configuration and, depending upon the FTD’s qualification level, may include an enclosed cockpit and realistic visual references. They are not always motion capable but are sophisticated enough to provide training in preparation for commercial and airline transport pilot certificates, as well as other ratings. You can find specifics on these allowances in figure 1. FTDs are very popular with aviation-oriented universities and colleges. The airline industry also uses these devices extensively to train new hires or provide for upgrades (First Officer to Captain) and transition training (e.g., B-737 to B-747 aircraft), or for recurrency training. FTDs are sub-categorized into Levels 4 through 7. Levels 4, 5, and 6 apply to fixed wing devices, while Level 7 applies to helicopters. Incidentally, Levels 1 through 3 apply to older devices that are either no longer supported, grandfathered, or were recategorized elsewhere.


FS-430/530 ATD Simulator located at KMJX – Ocean Aire FBO

The Next Generation of ATDs

The Aviation Training Device or ATD, which is by far the most common option for GA flight training. In 2008, the FAA adopted Advisory Circular (AC) 61-136, FAA Approval of Aviation Training Devices and their use for Training and Experience, which helped reclassify and redefine standards for what were previously Level 1-3 FTDs and personal computer ATDs (PCATDs). The AC did so by introducing two new terms, the Basic ATD (BATD) and the Advanced ATD (AATD), along with providing corresponding performance standards and user guidelines. The AC also describes that policy and approvals for ATDs resides with the FAA’s General Aviation and Commercial Division and provides a clear outline of how these devices are to be evaluated and approved.

  1. BATD: But let’s start by first understanding the difference between BATDs and AATDs. A BATD generally has more enhanced hardware and software features that allow the FAA to authorize it for certain training and proficiency “credits.” These credits are limited to private pilot certification as well as instrument rating and currency requirements.

Maintain IFR Currency of 6 approaches in 6 months, up to one year – All In a BATD!


In a nutshell, then, all displays and controls in the BATD must reflect the dynamic behavior of an actual aircraft. For example, if you change the flap setting, or the cyclic control, the appropriate changes in flight dynamics must be registered and reflected on all of the applicable displays and indicators in the BATD similar to how that actual aircraft would respond. Even the aircraft performance parameters (e.g., cruise speed, stall speed, max climb rate, etc.,) must be comparable to the representative aircraft. It may seem like a tall order to meet these requirements, but the good news is that today’s high-end and relatively low-cost computer options are usually more than capable of providing the processing horsepower needed to meet these demands.


  1. AATD: As its name implies, you’ll notice that there are higher standards for Advanced ATDs, along with design criteria that call for a more realistic aircraft look-and-feel. First off, an AATD must meet all BATD-approval criteria, as well as incorporate additional features and systems fidelity that significantly exceed that of a BATD. Among those provisions include incorporating ergonomics “representative” of a category and class of aircraft flight deck, a GPS system with moving map display, a two-axis autopilot (if standard equipment), an independent visual system capable of rendering realistic VFR and IFR conditions, a separate instructor station, and the ability to simulate all emergency procedures that have a checklist in the POH or flight manual.

FS-G1000 ATD Simulator located at KMJX - Ocean Aire FBO

Approved Simulators

It’s important to note that before a pilot can use an ATD for flight training credit, specific to a certificate or rating, the device must first be issued an FAA letter of authorization (LOA). LOAs are valid for five years and specify the amount of credit a pilot may earn for training and experience requirements. This is important because the regulations do not specifically address airplane ATD allowances for all pilot certification requirements. The LOA will provide for this. (See 14 CFR section 61.4 (c)) To receive this LOA, all ATDs must go through a rigorous approval process. It starts with developing what’s known as an approved Qualification and Approval Guide or QAG. This QAG document serves as the basis for approval and includes a detailed description of all components, functions, capabilities, and possible configurations for the training device. A manufacturer requesting an ATD approval will send this QAG along with a request letter to the FAA. If both are found acceptable and pass an initial audit, the FAA will then schedule and conduct an onsite operational evaluation of the device. If the ATD passes, the FAA will issue the LOA and an approved QAG to the manufacturer. If a manufacturer later modifies an approved ATD, a revised QAG must be resubmitted for approval.