What are ACS codes on a Part 107 test report?

They identify the knowledge elements you answered incorrectly. The Airman Knowledge Test Report does not list the questions — it lists a code per deficient element, and each code resolves to a sentence in the Airman Certification Standards.

How do I read an ACS code?

UA.I.B.K21b breaks into four parts: UA is the unmanned aircraft standards, I is the area of operation (Regulations), B is the task within it (Operating Rules), and K21b is the knowledge element — “Altitude limitations”.

How many ACS codes are there for Part 107?

176 knowledge elements across five areas of operation and seventeen tasks, in FAA-S-ACS-10B. Every one is listed on this page with the FAA’s own wording.

Which ACS revision should I be looking at?

FAA-S-ACS-10B, effective 6 April 2021. The earlier ACS-10A has different codes — it lacks Task E (Operations Over People), Task F (Remote Identification) and a number of elements added in 2021 — so a code list built on it will hand you codes that no longer exist.

Part 107 ACS codes

When you fail a question on the real test you are not told which question. You are given a code — one per knowledge element the test found you deficient in — and that list is the entire diagnostic. Here is what all 176 of them mean.

How to read one

UA.I.B.K21b

UA: The Unmanned Aircraft Systems certification standards
I: Area of operation — here, Regulations
B: Task within the area — here, Operating Rules
K21b: Knowledge element — here, “Altitude limitations”

The practice tests on this site report the same codes, for the same reason. A score tells you how much you missed; a code tells you what.

I. Regulations

15–25% of the test

What part 107 permits, forbids and requires of the person in command

Practise this area →

UA.I.A Task A. General

To determine that the applicant is knowledgeable in the general regulatory requirements of 14 CFR parts 89 and 107.

References: 14 CFR parts 89 and 107, subpart A · AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.I.A.K1	Applicability of 14 CFR part 107 to small unmanned aircraft operations.
UA.I.A.K2	Definitions used in 14 CFR part 107.
UA.I.A.K3	The ramifications of falsification, reproduction, or alteration of a certificate, rating, authorization, record, or report.
UA.I.A.K4	Accident reporting.
UA.I.A.K5	Inspection, testing, and demonstration of compliance.
UA.I.A.K6	Multiple category sUAS.
UA.I.A.K7	Record retention.
UA.I.A.K8	Previously manufactured sUAS.

UA.I.B Task B. Operating Rules

To determine that the applicant is knowledgeable of the operating rules of 14 CFR parts 89 and 107, the registration rules of 14 CFR parts 47 and 48, and other associated operating requirements.

References: 14 CFR parts 47, 48, 89, and 107, subpart B · AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.I.B.K1	Registration requirements for sUAS.
UA.I.B.K2	Requirement for the sUAS to be in a condition for safe operation.
UA.I.B.K3	Medical condition(s) that would interfere with safe operation of an sUAS.
UA.I.B.K4	Responsibility and authority of the remote PIC.
UA.I.B.K4a	Allowing a person other than the remote PIC to manipulate the flight controls.
UA.I.B.K5	Regulatory deviation and reporting requirements for in-flight emergencies.
UA.I.B.K6	Hazardous operations.
UA.I.B.K6a	Careless or reckless.
UA.I.B.K6b	Dropping an object.
UA.I.B.K7	Operating from a moving aircraft or moving land- or water-borne vehicle.
UA.I.B.K8	Alcohol or drugs and the provisions on prohibition of use.
UA.I.B.K9	Daylight operations.
UA.I.B.K10	Visual line of sight (VLOS) aircraft operations.
UA.I.B.K11	Requirements when a visual observer is used.
UA.I.B.K12	Prohibition of operating multiple sUAS.
UA.I.B.K13	Prohibition of carrying hazardous material.
UA.I.B.K14	Staying safely away from other aircraft and right-of-way rules.
UA.I.B.K14a	See and avoid other aircraft and other potential hazard considerations of the remote PIC.
UA.I.B.K15	Operations over human beings.
UA.I.B.K16	Prior authorization required for operation in certain airspace.
UA.I.B.K17	Operating in the vicinity of airports.
UA.I.B.K18	Operating in prohibited or restricted areas.
UA.I.B.K19	Flight restrictions in the proximity of certain areas designated by notice to airmen (NOTAM).
UA.I.B.K20	Preflight familiarization, inspection, and actions for aircraft operations.
UA.I.B.K21	Operating limitations for sUAS.
UA.I.B.K21a	Maximum groundspeed.
UA.I.B.K21b	Altitude limitations.
UA.I.B.K21c	Minimum visibility.
UA.I.B.K21d	Cloud clearance requirements.
UA.I.B.K22	Requirements for a Remote Pilot Certificate with an sUAS rating.
UA.I.B.K23	Automated operations.
UA.I.B.K24	Civil twilight operations.
UA.I.B.K25	Night operations.
UA.I.B.K26	Transportation of property.
UA.I.B.K27	ATC transponder equipment prohibition.
UA.I.B.K28	ADS-B Out prohibition.

UA.I.C Task C. Remote Pilot Certification with an sUAS Rating

To determine that the applicant is knowledgeable in the requirements associated with remote pilot certification with an sUAS rating.

References: 14 CFR part 107, subpart C · AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.I.C.K1	Offenses involving alcohol or drugs.
UA.I.C.K2	The consequences of refusing to submit to a drug or alcohol test or to furnish test results.
UA.I.C.K3	The eligibility requirements for a Remote Pilot Certificate with an sUAS rating.
UA.I.C.K4	Aeronautical knowledge recency.

UA.I.D Task D. Waivers

To determine that the applicant is knowledgeable of the FAA waiver policy and requirements.

References: 14 CFR part 107, subpart D · AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.I.D.K1

Waiver policy and requirements.

UA.I.E Task E. Operations Over People

To determine that the applicant is knowledgeable of the operating rules of 14 CFR parts 89 and 107, and the associated operating requirements when operating over people.

References: 14 CFR parts 89 and 107 · AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.I.E.K1	Remote pilot responsibilities when operating over people.
UA.I.E.K2	Operations over people at night.
UA.I.E.K3	Category of operations.
UA.I.E.K3a	Category 1.
UA.I.E.K3b	Category 2.
UA.I.E.K3c	Category 3.
UA.I.E.K3d	Category 4.
UA.I.E.K4	Selecting an operational area.
UA.I.E.K5	Minimum distances from a person.
UA.I.E.K6	Operations over moving vehicles.
UA.I.E.K7	Modifications to an sUAS.
UA.I.E.K8	Closed and restricted access sites.
UA.I.E.K9	Remote Pilot operating instructions.
UA.I.E.K10	Required components and Category declaration.
UA.I.E.K11	Optional components.
UA.I.E.K12	Applicant produced, designed, or modified sUAS for operations over people.
UA.I.E.K13	Declaration of Compliance (DoC).
UA.I.E.K14	Maintenance of an sUAS that is eligible for operations over people.
UA.I.E.K15	Means of Compliance (MoC).
UA.I.E.K16	Impact kinetic energy.
UA.I.E.K17	Exposed rotating parts.

UA.I.F Task F. Remote Identification (RID)

To determine the applicant exhibits satisfactory knowledge associated with operating rules of 14 CFR part 89 and their associated operating requirements.

References: 14 CFR part 89 · AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.I.F.K1	Standard remote identification.
UA.I.F.K2	Alternative remote identification.
UA.I.F.K3	Operations for aeronautical research.
UA.I.F.K4	ADS-B Out.
UA.I.F.K5	Confirmation of identification.
UA.I.F.K6	Minimum message elements broadcast for remote identification.
UA.I.F.K7	Product labeling.

II. Airspace Classification and Operating Requirements

15–25% of the test

Which airspace you are standing under, and what it costs you to fly there

Practise this area →

UA.II.A Task A. Airspace Classification

To determine that the applicant is knowledgeable in airspace classification.

References: 14 CFR part 71 · AC 107-2 · AIM · FAA-H-8083-25 · FAA-G-8082-22

UA.II.A.K1	General airspace.
UA.II.A.K1a	Class B controlled airspace.
UA.II.A.K1b	Class C controlled airspace.
UA.II.A.K1c	Class D controlled airspace.
UA.II.A.K1d	Class E controlled airspace.
UA.II.A.K1e	Class G uncontrolled airspace.
UA.II.A.K2	Special-use airspace, such as prohibited, restricted, warning areas, military operation areas, alert areas, and controlled firing areas.
UA.II.A.K3	Other airspace areas, such as Airport Advisory Services, Military Training Routes (MTRs), Temporary Flight Restrictions (TFRs), Parachute Jump Operations, Terminal Radar Service Areas (TRSAs), National Security Areas (NSA) and Visual Flight Rules (VFR) routes.
UA.II.A.K4	Air Traffic Control (ATC) and the NAS.

UA.II.B Task B. Airspace Operational Requirements

To determine that the applicant is knowledgeable of airspace operational requirements.

References: 14 CFR part 71 · AC 107-2 · AIM · FAA-H-8083-25 · FAA-G-8082-22 · SAFO 10015

UA.II.B.K1	Basic weather minimums.
UA.II.B.K2	ATC authorizations and related operating limitations.
UA.II.B.K3	Operations near airports.
UA.II.B.K4	Potential flight hazards.
UA.II.B.K4a	Common aircraft accident causal factors.
UA.II.B.K4b	Avoid flight beneath unmanned balloons.
UA.II.B.K4c	Emergency airborne inspection of other aircraft.
UA.II.B.K4d	Precipitation static.
UA.II.B.K4e	Light amplification by stimulated emission of radiation (laser) operations and reporting illumination of aircraft.
UA.II.B.K4f	Avoiding flight in the vicinity of thermal plumes such as smoke stacks and cooling towers.
UA.II.B.K4g	Flying in the wire environment.
UA.II.B.K5	The NOTAM system, including how to obtain an established NOTAM through Flight Service.
UA.II.B.K6	Operator equipment for night flight.
UA.II.B.K7	Ground structures and ground structure lighting.
UA.II.B.K8	Hazards on the ground that do not have lighting.
UA.II.B.K9	Manned aircraft lighting.
UA.II.B.K10	sUAS lighting requirements.

III. Weather

11–16% of the test

Reading a METAR and a TAF, and what the air does to a small aircraft

Practise this area →

UA.III.A Task A. Sources of Weather

To determine that the applicant is knowledgeable in sources of weather information.

References: AC 107-2 · AIM · FAA-H-8083-25 · FAA-G-8082-22

UA.III.A.K1	Internet weather briefing and sources of weather available for flight planning purposes.
UA.III.A.K2	Aviation routine weather reports (METAR).
UA.III.A.K3	Terminal aerodrome forecasts (TAF).
UA.III.A.K4	Weather charts.
UA.III.A.K5	Automated surface observing systems (ASOS) and automated weather observing systems (AWOS).

UA.III.B Task B. Effects of Weather on Performance

To determine that the applicant is knowledgeable of the effects of weather on performance.

References: AC 107-2 · AIM · FAA-H-8083-25 · FAA-G-8082-22

UA.III.B.K1	Weather factors and their effects on performance.
UA.III.B.K1a	Density altitude.
UA.III.B.K1b	Wind and currents.
UA.III.B.K1c	Atmospheric stability, pressure, and temperature.
UA.III.B.K1d	Air masses and fronts.
UA.III.B.K1e	Thunderstorms and microbursts.
UA.III.B.K1f	Tornadoes.
UA.III.B.K1g	Icing.
UA.III.B.K1h	Hail.
UA.III.B.K1i	Fog.
UA.III.B.K1j	Ceiling and visibility.
UA.III.B.K1k	Lightning.

IV. Loading and Performance

7–11% of the test

Weight, centre of gravity, load factor and what the air will actually lift

Practise this area →

UA.IV.A Task A. Loading and Performance

To determine that the applicant is knowledgeable in the loading and performance of an sUAS.

References: AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.IV.A.K1	General loading and performance.
UA.IV.A.K1a	Effects of loading changes.
UA.IV.A.K1b	Balance, stability, and center of gravity.
UA.IV.A.K2	Importance and use of performance data to calculate the effect on the aircraft’s performance of an sUAS.

V. Operations

35–45% of the test

Radio, airports, emergencies, decision-making, physiology and maintenance

Practise this area →

UA.V.A Task A. Radio Communications Procedures

To determine that the applicant is knowledgeable in radio communication procedures.

References: AC 107-2 · AIM · FAA-H-8083-25 · FAA-G-8082-22

UA.V.A.K1	Airport operations with and without an operating control tower.
UA.V.A.K2	The description and use of a Common Traffic Advisory Frequency (CTAF) to monitor manned aircraft communications.
UA.V.A.K3	Recommended traffic advisory procedures used by manned aircraft pilots such as self-announcing of position and intentions.
UA.V.A.K4	Aeronautical advisory communication station (UNICOM) and associated communication procedures used by manned aircraft pilots.
UA.V.A.K5	Automatic Terminal Information Service (ATIS).
UA.V.A.K6	Aircraft call signs and registration numbers.
UA.V.A.K7	The phonetic alphabet.
UA.V.A.K8	Phraseology: altitudes, directions, speed, and time.

UA.V.B Task B. Airport Operations

To determine that the applicant is knowledgeable in airport operations.

References: AC 107-2, 150/5200-32 · AIM · FAA-H-8083-25 · FAA-G-8082-22

UA.V.B.K1	Types of airports such as towered, uncontrolled towered, heliport, and seaplane bases.
UA.V.B.K2	ATC towers, such as ensuring the remote pilot can monitor and interpret ATC communications to improve situational awareness.
UA.V.B.K3	Runway markings and signage.
UA.V.B.K4	Traffic patterns used by manned aircraft pilots.
UA.V.B.K5	Security Identification Display Areas (SIDA).
UA.V.B.K6	Sources for airport data.
UA.V.B.K6a	Aeronautical charts.
UA.V.B.K6b	Chart Supplements.
UA.V.B.K7	Avoiding bird and wildlife hazards and reporting collisions between aircraft and wildlife.
UA.V.B.K8	Airport and seaplane base lighting.

UA.V.C Task C. Emergency Procedures

To determine that the applicant is knowledgeable in sUAS emergency procedures.

References: AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22 · SAFOs 09013, 10017, 15010

UA.V.C.K1	Emergency planning and communication.
UA.V.C.K2	Characteristics and potential hazards of lithium batteries.
UA.V.C.K2a	Safe transportation such as proper inspection and handling.
UA.V.C.K2b	Safe charging.
UA.V.C.K2c	Safe usage.
UA.V.C.K2d	Risks of fires involving lithium batteries.
UA.V.C.K3	Loss of aircraft control link and fly-aways.
UA.V.C.K4	Loss of Global Positioning System (GPS) signal during flight and potential consequences.
UA.V.C.K5	Frequency spectrums and associated limitations.
UA.V.C.K6	Procedures for operations over people.
UA.V.C.K7	Procedures for operations at night.

UA.V.D Task D. Aeronautical Decision-Making

To determine that the applicant is knowledgeable in aeronautical decision-making.

References: AC 107-2 · FAA-H-8083-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.V.D.K1	Aeronautical decision-making (ADM).
UA.V.D.K1a	Effective team communication.
UA.V.D.K1b	Task management.
UA.V.D.K2	Crew Resource Management (CRM).
UA.V.D.K3	Situational awareness.
UA.V.D.K4	Hazardous attitudes.
UA.V.D.K5	Hazard identification and risk assessment.

UA.V.E Task E. Physiology

To determine that the applicant is knowledgeable in the physiological factors affecting remote pilot performance.

References: AC 107-2 · FAA-H-8083-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.V.E.K1	Physiological considerations and their effects on safety such as dehydration and heatstroke.
UA.V.E.K2	Drug and alcohol use.
UA.V.E.K3	Prescription and over-the-counter medication.
UA.V.E.K4	Hyperventilation.
UA.V.E.K5	Stress and fatigue.
UA.V.E.K6	Factors affecting vision.
UA.V.E.K7	Fitness for flight.
UA.V.E.K8	Physiological aspects of night operation.
UA.V.E.K9	Night illusions.

UA.V.F Task F. Maintenance and Inspection Procedures

To determine that the applicant is knowledgeable in sUAS maintenance and inspection procedures.

References: AC 107-2 · FAA-H-8083-25 · FAA-G-8082-22

UA.V.F.K1	Basic maintenance.
UA.V.F.K2	Preflight inspection.
UA.V.F.K3	Techniques to mitigate mechanical failures of all elements used in sUAS operations such as the battery and any device(s) used to operate the sUAS.
UA.V.F.K4	Appropriate record keeping.
UA.V.F.K5	Persons that may perform maintenance on an sUAS.
UA.V.F.K6	Preflight inspection for night operations.
UA.V.F.K7	Manufacturer’s Declaration of Compliance for Category 2 and 3 operations.

What this site covers

176 of the 176 elements above have at least one question behind them on this site — 100%. The remaining 0 do not yet, and that number is printed rather than rounded away because a coverage claim without its gap is not a claim.

Frequently asked

What are ACS codes on a Part 107 test report?: They identify the knowledge elements you answered incorrectly. The Airman Knowledge Test Report does not list the questions — it lists a code per deficient element, and each code resolves to a sentence in the Airman Certification Standards.
How do I read an ACS code?: UA.I.B.K21b breaks into four parts: UA is the unmanned aircraft standards, I is the area of operation (Regulations), B is the task within it (Operating Rules), and K21b is the knowledge element — “Altitude limitations”.
How many ACS codes are there for Part 107?: 176 knowledge elements across five areas of operation and seventeen tasks, in FAA-S-ACS-10B. Every one is listed on this page with the FAA’s own wording.
Which ACS revision should I be looking at?: FAA-S-ACS-10B, effective 6 April 2021. The earlier ACS-10A has different codes — it lacks Task E (Operations Over People), Task F (Remote Identification) and a number of elements added in 2021 — so a code list built on it will hand you codes that no longer exist.

Sources

Every figure on this page comes from one of the documents below, with the date it was read and what the document says about its own currency. Regulations change by amendment; where a source has moved on since the date shown, the source is right and this page is out of date.

FAA-S-ACS-10B — Remote Pilot – Small Unmanned Aircraft Systems Airman Certification Standards Read August 27, 2026· Material in FAA-S-ACS-10B is effective April 6, 2021 The shape of the test and the ACS codes. Appendix 1 publishes the 60-question length, the two-hour limit, the 70% passing score and the share of the test each area of operation gets. Appendix 3 publishes that a passing test report is valid for 24 calendar months.

Page facts last verified August 27, 2026.

Part 107 Drills is independent practice material. It is not affiliated with, endorsed by, or authorized by the Federal Aviation Administration, PSI Services LLC, or any knowledge testing centre. Every question here is original and none is taken from any actual FAA knowledge test. Regulatory text and FAA publications are works of the United States Government and are in the public domain; where this site states a rule, it cites the section it came from and the date that section was read.