How to Log Simulator Time: AATD, BATD and FFS Rules

Simulator time is not flight time, and the regulations are blunt about it. 14 CFR 1.1 defines flight time as "pilot time that commences when an aircraft moves under its own power for the purpose of flight and ends when the aircraft comes to rest after landing." A training device never moves. The hours go in their own column. They still count, in capped amounts, toward the private, the instrument rating, the commercial and instrument currency. Getting the column right is what keeps a DPE from pulling out a calculator at your checkride.

The device hierarchy in plain terms

The FAA recognizes three tiers of ground trainer, and the credit you can claim depends on which one you sat in.

A full flight simulator (FFS) is, under 14 CFR 1.1, "a replica of a specific type; or make, model, and series aircraft cockpit" with an out-the-window visual system and motion cues, qualified under Part 60 to a specific level. These are the airline and training-center boxes. The Instrument ACS refers to them by level ("Level B, C, or D").

A flight training device (FTD) is, in the same section, "a replica of aircraft instruments, equipment, panels, and controls in an open flight deck area or an enclosed aircraft cockpit replica," also qualified under Part 60, without the motion requirement.

An aviation training device (ATD) is anything else the FAA has approved: 61.1 defines it as a training device, other than an FFS or FTD, "that has been evaluated, qualified, and approved by the Administrator". The approval runs through 61.4(c), which lets the Administrator approve a device other than a simulator or FTD "for specific purposes". The paperwork is a letter of authorization (LOA) issued to the manufacturer for each model. AC 61-136B (September 12, 2018) splits ATDs into a basic aviation training device (BATD), which meets its Appendix B, and an advanced aviation training device (AATD), which meets Appendix B and the stricter Appendix C. A flight school trainer is approved as one or the other, and the FAA list below says which.

The FAA publishes the approved models in a single PDF, FAA Approved Aviation Training Devices (the edition read for this article is dated July 15, 2026). It says LOAs "are valid for 60 calendar months, and must contain an expiration date to be valid," and it carries a note worth taping to the device: "ATD's are not Flight Training Devices (FTD) or Full Flight Simulators (FSS) qualified under 14 CFR part 60." A school calling its AATD "the sim" is fine in conversation and wrong in a logbook.

How many hours count toward each certificate and rating

The caps live in three sections of Part 61, and they are not interchangeable. The table collects them; the paragraphs under it carry the conditions.

The figures come from 61.109(k), 61.65(h) to (j), 61.129(i), 61.57(c)(2) and Appendix 1 of FAA-S-ACS-8C; Part 141 schools use their own appendices and are not covered here.

Two of those rows need a closer look. For the private certificate, 61.109(k) names only "a full flight simulator or flight training device," 2.5 hours, or 5 hours "in a course conducted by a training center certificated under part 142." ATDs are not in the paragraph; their private pilot credit comes through the LOA, which AC 61-136B says "will specify the allowable credit ... for private pilot" for both BATDs and AATDs. The same is true of the commercial: 61.129(i) names simulators and FTDs, and the AC says an AATD's LOA covers "commercial pilot, and ATP." Read the LOA for the number.

For the instrument rating, the arithmetic is tighter than schools sometimes advertise. 61.65(i) allows "a maximum of 10 hours of instrument time received in a basic aviation training device or a maximum of 20 hours of instrument time received in an advanced aviation training device," and 61.65(j) caps every device combined at 20 hours "except as provided in paragraph (h)(1)," the Part 142 case. Ten in a BATD plus 20 in an AATD is still 20. Against the 40 hours of instrument time 61.65(d)(2) requires, that means at least half must be in an airplane for anyone training outside a Part 142 center.

When an instructor has to be present

For hours toward a certificate or rating, an authorized instructor must be present in the device and must sign for the session; for instrument currency alone, no instructor is required, only a record of device, time and content (14 CFR 61.51(g)(4) and (g)(5)).

The two paragraphs sit next to each other and say opposite things on purpose. Paragraph (g)(4) permits device time "for acquiring instrument aeronautical experience for a pilot certificate or rating provided an authorized instructor is present to observe that time and signs the person's logbook or training record to verify the time and the content of the training session." Paragraph (g)(5) permits device time "for satisfying instrument recency experience requirements provided a logbook or training record is maintained to specify the training device, time, and the content." The certificate-specific paragraphs repeat the instructor condition. 61.109(k) counts device training only "if received from an authorized instructor." 61.65(i)(2) requires that "an authorized instructor provides the instrument time in the device." 61.129(i) requires experience "obtained from an authorized instructor."

So a solo evening in the school's AATD knocking out six approaches keeps you current under 61.57(c)(2), which asks only that the device represent the category and that you fly the tasks in simulated instrument conditions. The same evening adds nothing to the 40 hours for the rating. Build device time alone expecting it to count toward the rating, and the hole shows up in your totals the week before the checkride.

How to record the session

A device entry has to carry what 61.51(b) asks of every entry, adapted for the ground: the date; "total flight time or lesson time"; for FFS and FTD lessons, "the location where the lesson occurred"; and the type and identification of the aircraft or device used. The experience type is "training received in a full flight simulator, flight training device, or aviation training device from an authorized instructor" (61.51(b)(2)(v)), and the condition of flight is "simulated instrument conditions in flight, a full flight simulator, flight training device, or aviation training device" (61.51(b)(3)(iii)). Because it is training time, 61.51(h) adds the instructor's legible endorsement with a description of the training, the lesson length, signature, certificate number and expiration or recent-experience date.

AC 61-136B, Appendix D, paragraph D.3, turns that into column rules for ATDs. Instructors are told to log the time as dual instruction and as BATD or AATD time. Then the sentence that matters. "Any columns that reference flight time should remain blank when logging ATD time." Simulated instrument time may be logged only while the visual display is set to instrument conditions and the pilot is flying solely by reference to the instruments. The AC also reads 61.51(b)(1)(iv) as requiring the type and identification of the ATD "as described in the letter of authorization," and suggests keeping a copy of the LOA, because examiners "are instructed to request a copy of the LOA from applicants logging ATD pilot time."

One phrase in that paragraph confuses people. The AC says ATD time "can only be logged as Instruction Received (Dual), Instrument Time, or Total Time as reflected on the pilot time section of FAA Form 8710-1," and the FAA's device list repeats it. That "Total Time" is not flight time. Form 8710-1, section III, Record of Pilot Time, has a separate row for each kind of device below the aircraft categories, and the device total goes in that row.

Suppose a 1.5-hour instrument lesson in a school's AATD, written as an example rather than a record of a real session.

The fields follow 61.51(b) and (h) and the column rules in AC 61-136B, D.3. Note what is not there: no PIC, no cross-country, no landings, no night, and nothing in total flight time. If you move a paper logbook or another app's CSV into a digital one, the device rows are where imports go wrong, because "sim" in the remarks does not stop 1.5 landing in total time. FlyFren's import shows every entry for review before it is saved; check those rows there.

The common error, and what it costs

The error is writing device time into the flight-time column, usually because the school's sheet says "1.5" and the student copies it across. The 1.1 definition makes that wrong on its face, and AC 61-136B's "remain blank" instruction removes any ambiguity for ATDs. At a checkride it is not small. The DPE compares the logbook against the totals on the application, and the FAA's ATD list says examiners "should request to see a copy of the LOA, when ATD pilot time is used to meet the minimum pilot time experience requirements." Inflated flight time with device hours is the kind of discrepancy that ends a practical test before the preflight.

An ATD also cannot host a practical test or a 61.58 proficiency check. It cannot host the flight portion of a flight review either, and both documents name only the flight portion. Type rating experience "cannot be accomplished in an ATD" (Appendix 3 of the Instrument ACS and the FAA list).

Before the first session in any device, ask for the LOA and photograph it. Check the expiration date, because the FAA list says the letter "must contain an expiration date to be valid" and InFO 15012 requires "an unexpired letter of authorization" before device approaches count for currency, and check that the LOA's credit lines match what the school told you. Then log the session in its own column, with the device identified exactly as the LOA names it and the total-flight-time box empty. Add the instructor's signature if the hours are headed for a certificate. For what those device approaches do to your instrument currency, the counting is the same as in an airplane.

This article is educational and is not a substitute for the current regulations, the AIM, official weather briefings, or instruction from a CFI. Check the current text at the linked sources before you rely on any detail.