AC 61-83J: FSTD Logging, Credit Limits, and Currency

Logging FSTD time is governed by 14 CFR 61.51, and the rules are strict on two fronts: the entry itself must contain specific information signed by an authorized instructor, and only a capped portion of the hours you accumulate in a device will actually count toward a certificate or rating. Getting either half wrong means hours in your logbook that do nothing for you when you apply for a checkride.

Before working through the mechanics, one boundary: AC 61-83J is sometimes searched alongside this topic, but it addresses nationally scheduled flight instructor refresher courses under 14 CFR 61.197(a)(2)(iii) and has nothing to do with simulator logging.¹ The logging rules come from Part 61 itself and, for aviation training devices, from AC 61-136B.

Know Which Device You Trained In

Credit depends on the device tier, so the first thing every entry needs to identify is what you actually used. The FAA recognizes three categories:

A Full Flight Simulator (FFS) is a full-size replica of a specific aircraft type, make, model, or series, with a visual system and a motion system providing at least three degrees of freedom.²
A Flight Training Device (FTD) is a replica of an aircraft’s instruments, equipment, panels, and controls in either an open flight deck area or an enclosed cockpit replica. It does not require a motion system and may represent a set of aircraft rather than a single make and model.²
An Aviation Training Device (ATD) is a lower-fidelity device outside Part 60’s qualification standards, governed by AC 61-136B and issued a Letter of Authorization by the FAA. ATDs come in two levels: Basic (BATD) and Advanced (AATD).³

A logbook line that says only “simulator” is incomplete. The specific tier and identification of the device belong in the entry.

When the Time Is Loggable

Training time in any of these devices counts only when you are receiving instruction from an authorized instructor. Solo practice in an FTD or ATD, even with a clear training objective, is not loggable time under 14 CFR 61.51.⁴

How you categorize the hours matters too. FSTD time is training received, not pilot-in-command or second-in-command time. For ATDs specifically, columns that refer to “flight time” should stay blank; ATD time is logged only as instruction received (dual), instrument time, or total time on FAA Form 8710-1.³ Simulated instrument time in an ATD only counts when the visual display is configured for instrument meteorological conditions and you are flying solely by reference to instruments.

What Each Entry Must Contain

14 CFR 61.51(b) requires every training entry to include the date, the total lesson duration, the location (not a departure-and-arrival pair the way a flight would be logged), the type and specific identification of the device, and whether simulated instrument conditions were used.⁴

On top of that, 14 CFR 61.51(h) requires the instructor’s endorsement to describe the training given, state the length of the lesson, and include the instructor’s signature, certificate number, and certificate expiration date or recent experience end date.⁴ A designated pilot examiner reviewing your logbook will notice a missing certificate number or an illegible endorsement, and either can hold up a checkride.

Credit Limits by Certificate and Rating

You can spend as many hours in a device as you want. What Part 61 caps is how many of those hours count toward the minimum aeronautical experience for each certificate or rating. The caps vary by device tier, by the certificate being pursued, and by whether the training happens under Part 142.

Private Pilot Certificate

Up to 2.5 hours of FFS or FTD training can be credited toward the flight training time required for a private pilot certificate. That cap rises to 5 hours if training is completed through a Part 142 training center.⁵ For most students under Part 61, simulation plays only a small part in meeting private pilot minimums.

Instrument Rating

The instrument rating requires 40 hours of actual or simulated instrument time, and this is where FSTD credit gets both generous and complicated. The per-device caps under 14 CFR 61.65 are:⁶

FFS or FTD in a Part 142 training center: up to 30 hours.
FFS or FTD outside Part 142: up to 20 hours.
Advanced ATD: up to 20 hours.
Basic ATD: up to 10 hours.

An overall cap sits on top of these: outside Part 142, no more than 20 total hours of instrument time from any combination of FFS, FTD, and ATD can be credited toward the instrument rating.⁶ Stacking 20 hours of FTD time with 10 hours of BATD time to claim 30 hours does not work unless the training was conducted under Part 142.

Commercial Pilot Certificate

For airplane and powered-lift ratings, up to 50 hours of FFS or FTD time can be credited outside a Part 142 training center, and up to 100 hours through a Part 142 program. Helicopter ratings allow 25 hours outside Part 142 and 50 hours through Part 142.⁷

Airline Transport Pilot Certificate

For an ATP in the airplane category, up to 25 hours in an FFS representing the class of airplane sought may be credited toward the 1,500-hour flight time requirement, and only if the training is part of an approved course under Parts 121, 135, 141, or 142. An FTD or ATD cannot be used to satisfy this credit allowance.⁸

Why Part 142 Training Raises the Ceiling

Nearly every certificate level allows more FSTD credit if the training happens through a Part 142 certificated training center. For the instrument rating, that’s 30 hours of allowable FFS/FTD credit instead of 20. For the commercial certificate in an airplane, it’s 100 hours instead of 50. If your plan is to lean on simulator time to build experience, confirm your provider’s Part 142 certificate before you start logging. Hours logged above the Part 61 caps at a provider that does not hold the appropriate Part 142 approval will not count.

Using an FSTD to Maintain Instrument Currency

FSTDs also cover the recency requirements of 14 CFR 61.57(c). You can meet those requirements entirely in an FFS, FTD, or ATD, provided the device represents the category of aircraft for the instrument privileges you want to maintain and you perform the required tasks in simulated instrument conditions.⁹

If instrument currency lapses for more than six calendar months, an instrument proficiency check is required. For airplanes, that check can be completed in an FFS or FTD representative of the aircraft category, but not in an ATD.⁹

Verifying an ATD’s Letter of Authorization

ATDs carry an extra verification step. Every ATD must have a current Letter of Authorization from the FAA’s Flight Standards Service, valid for five years, that specifies exactly what training credit the device is approved for.³

The LOA and the device’s qualifying acceptance guide must accompany the ATD and be available for viewing whenever it is used for training. Confirming that the device is currently qualified before logging any time is the pilot’s and instructor’s responsibility. Designated pilot examiners are instructed to ask applicants for a copy of the LOA when ATD time appears in a logbook, so keeping a copy with your records is a practical safeguard.³

What Falsification Costs You

Logging simulator time you did not complete, inflating session durations, or misrepresenting the device used are all falsification. As of November 2025, the FAA consolidated its falsification rules into 14 CFR Part 3, Subpart D, replacing the former 14 CFR 61.59. Under 14 CFR 3.403, no person may make any fraudulent or intentionally false statement in any record used to show compliance with FAA requirements, and no person may knowingly omit a material fact from such records.¹⁰

A falsification finding gives the FAA grounds to revoke every certificate the pilot holds, not just the one being pursued, and can also produce civil penalties. The most common triggers are small: rounding a 1.3-hour session up to 1.5, or logging time in an ATD whose LOA had already expired. Neither is worth the exposure.¹⁰

1
Federal Aviation Administration. AC 61-83J – Nationally Scheduled, FAA-Approved, Industry-Conducted Flight Instructor Refresher Course
2
Legal Information Institute (Cornell Law School). 14 CFR Appendix F to Part 60 – Definitions and Abbreviations for Flight Simulation Training Devices
3
Federal Aviation Administration. AC 61-136B – FAA Approval of Aviation Training Devices and Their Use for Training and Experience
4
eCFR. 14 CFR 61.51 – Pilot Logbooks
5
eCFR. 14 CFR 61.109 – Aeronautical Experience
6
eCFR. 14 CFR 61.65 – Instrument Rating Requirements
7
eCFR. 14 CFR 61.129 – Aeronautical Experience – Commercial Pilot Certificate
8
eCFR. 14 CFR 61.159 – Aeronautical Experience Airplane Category Rating
9
eCFR. 14 CFR 61.57 – Recent Experience Pilot in Command
10
eCFR. 14 CFR 3.403 – Falsification, Reproduction, Alteration, or Omission