FAR 91.205: Required Aircraft Equipment Guide

FAR 91.205 sets the essential instrument and equipment standards for powered civil aircraft in the U.S., ensuring safety and legal compliance.

Whether you're a student pilot prepping for a checkride or an experienced aviator planning your next flight, mastering these requirements is crucial. Dive in to learn everything you need to know about FAR 91.205.

Overview of FAR 91.205 and When It Applies

FAR 91.205 tells you the absolute minimum when it comes to instruments and equipment that's required on all powered civil aircraft that have those standard U.S. airworthiness certificates. All this falls under Title 14 of the Code of Federal Regulations, specifically 14 CFR Part 91.

Essentially the feds check to make sure you've got the right gear on your aircraft for the conditions you're flying in. The rule gets progressively tougher as the weather gets worse or you're flying further into the night.

Here is what you need to know at a glance

• This rule affects any Civil aircraft with standard U.S. airworthiness that's flying under Part 91 within the U.S.

• These are the minimum requirements by law other companies or insurance companies might have their own stricter rules.

• FAR 91.205 is part of Subpart C, which also covers inoperative equipment, transponder mandates, and ADS-B rules.

• All required instruments must be in operable condition according to FAR 91.205 before the aircraft departs.

• These are minimum standards for flight operations, not recommendations.

FAR 91.205 Structure: Paragraphs (a) Through (d)

Knowing the structure of this regulation really helps you find what you're looking for in a hurry - it's all laid out neatly in paragraphs that build on top of each other.

• (a) General applicability. The rule states that any aircraft with standard U.S airworthiness has to have the right instruments and gear for the job and they have to be working properly.

The instruments also need to be easy for the pilot to see and use while flying the plane.

• (b) Visual flight rules (Day). This one lays out the minimum equipment you need to fly VFR during the day.

• (c) Visual flight rules (Night). Any VFR night flight needs all the stuff from (b) plus some extra gear.(d) Instrument flight rules. If you're flying IFR at night, you need to have everything from (b) and (c) plus some extra instruments to help you fly in the dark.

Each of these paragraphs builds on the ones before it so if you're flying IFR at night, you need to have all the right gear from (b), (c) and (d)

The rule doesn't actually apply to things like gliders or hot air balloons those have their own rules laid out elsewhere in Part 91.

One of the things that sets this rule apart is that it's performance based in some places that means instead of naming specific brands or gadgets, it just says what's required like using "sensible" navigation and comms gear for the route & airspace you're in. This gives operators the freedom to use modern avionics that do the job.

VFR Day Equipment: ATOMATOFLAMES Explained

Aircrew often employ mnemonics like ATOMATOFLAMES to make preflight checklists more manageable, and this particular one covers the gear and equipment as per 91.205(b).

ATOMATOFLAMES is also affectionately known as Tomato Flames; it's a 11 letter acronym that breaks down into eleven required instrument and equipment categories. Daytime VFR flight requires a total of 14 specific bits of equipment and that's not even counting conditional items like emergency flotation gear and pyrotechnic flares.

Here is each element:

• A – Airspeed indicator. A stands for airspeed indicator in ATOMATOFLAMES. VFR Day requires an airspeed indicator and an altimeter as two of the most fundamental flight instruments.

• T – Tachometer. The T in ATOMATOFLAMES represents tachometer for each engine. Multi-engine aircraft need one per engine.

• O – Oil pressure gauge. Required for each engine using a pressure system for lubrication.

• M – Manifold pressure gauge. Only required for altitude engines (turbocharged or supercharged). A naturally aspirated engine does not legally need one under this section.

• A – Altimeter. A standard altimeter suffices for VFR day; IFR demands a more precise version.

• T – Temperature gauge. Required for each liquid cooled engine to monitor coolant temperature.

• O – Oil temperature gauge. Required for each air cooled engine to track engine health.

• F – Fuel gauge indicating the quantity of fuel in each tank.

• L – Landing gear position indicator. Required only for aircraft with retractable landing gear. Fixed-gear airplanes skip this one.

• A – Anticollision light system. Required for small civil airplanes certificated under Part 23 after March 11, 1996.

• M – Magnetic direction indicator. The traditional magnetic compass, required regardless of how advanced your avionics are.

• E – Emergency locator transmitter. An emergency locator transmitter is required for certain operations, per § 91.207, with exceptions for training flights within specified distances and agricultural operations.

• S – Safety belts and shoulder harnesses. You're going to need an approved safety belt with a solid metal-to-metal latch for every single passenger onboard, and where required an approved shoulder harness to tie them down in there. In smaller civilian planes that rolled off the production line after 1978, front seat shoulder harnesses are now a must and if you've got one of those planes that hit the market after 1986, you'll be needing a proper restraint system or other approved restraint system at every seat. And when you're sitting alongside another passenger, you want that system to be up to par. After 1992, any rotorcraft will need a harness at every single seat.

Two conditional VFR day requirements also apply: for operations for hire over water beyond power off gliding distance from shore, approved flotation gear readily available for each occupant is required, along with at least one pyrotechnic signaling device.

ATOMATOFLAMES is required for VFR day flights, and every item must be operative unless relief is provided under 91.213 or a Minimum Equipment List.

VFR Night Equipment: FLAPS and Additional Requirements

VFR Night requires not just day VFR gear, but also some extra safety goodies to help you stay safe in the dark. And it makes sense Night flight is all about reduced visibility and higher collision risk, so a bit more lighting and some basic redundancy in your electrical system can make all the difference.

VFR night is more than just a case of adding a few bits to the VFR day kit, & is neatly summed up by the mnemonic FLAPS that's the magic trick to help you remember the kit you need.

• F – Fuses. Spare fuses, or three of each kind required, accessible to the pilot in flight. Circuit breakers may substitute where applicable.

• L – Landing light. One electric landing light is required if the aircraft is operated for hire. Private night flights do not legally require an electric landing light under 91.205(c), though carrying one is good practice.

• A – Anticollision light system. If not already required under day rules, the system must be operable for night operations. Approved aviation red or white strobes and rotating beacons satisfy this requirement depending on type certification.

• P – Position lights. Approved position lights (red, green, and white navigation lights) are mandatory for night operations to make the aircraft visible and identifiable to other traffic.

• S – Source of electrical energy adequate for all installed electrical and radio equipment. The aircraft's battery, alternator, or generator must support the full electrical load during night flight, ensuring position lights, radios, and cockpit lighting remain powered.

From a safety standpoint, these items function as collision avoidance system equipment: position lights and anticollision lights dramatically improve see-and-avoid capability when natural visibility drops to zero.

IFR Equipment Requirements Under 91.205(d)

Instrument flight rules are a whole different ball game you'll need all the VFR day and night gear, plus some additional instruments and equipment to make sure you can fly safely when things get really tough.

Key IFR additions:

• Two way radio communications and radio equipment suitable for the route to be flown.

• Navigation equipment suitable for the route. The 2007 FAA revision to § 91.205(d)(2) replaced rigid references to ground-based navaids with "navigation equipment suitable for the route to be flown," recognizing GPS and RNAV as valid alternatives.

• Gyroscopic rate-of-turn indicator. Required unless the aircraft has a third attitude instrument system that is an attitude instrument system usable through flight attitudes of 360 degrees of pitch and roll, installed per § 121.305(j) or equivalent rotorcraft certification.

• Slip skid indicator (the inclinometer ball) for coordinated flight monitoring.

• Sensitive altimeter adjustable for barometric pressure, providing the accuracy needed for IFR altitude assignments and approach procedures. For IFR operations, pilots should also understand the inspection and testing requirements of FAR 91.411, which ensure the altimeter and static pressure system remain accurate and compliant.

• Clock displaying hours, minutes, and seconds-either a sweep-second analog or digital equivalent-for timed holds, approaches, and logging.

• Generator or alternator of adequate capacity to power all installed electrical and radio equipment throughout the flight.

• Gyroscopic direction indicator (heading indicator or equivalent) and an attitude indicator for pitch and bank reference.

These days you can get a lot of this stuff on glass panels and integrated avionics but make sure they are all FAA-approved and up to spec. The old mechanical backup instruments are still a good idea to have around.

Handling Inoperative Instruments and Equipment (Link to FAR 91.213)

FAR 91.205 tells you what equipment is required. Pilots must follow FAR 91.213 for inoperative equipment, which explains when and how a flight may depart with something broken. An approved Minimum Equipment List (MEL) is required for inoperative equipment deferral in many operations.

To better understand how an MEL is developed, approved, and applied in practice, see Minimum Equipment List FAA. Part 91 operators without an MEL can use the regulatory process under 91.213(d).

Here is the decision flow:

• Identify the inoperative item.

• Determine whether it is required by 91.205 for the intended operation (VFR day, VFR night, IFR).

• Check whether it is required by the aircraft's KOEL, TCDS, or operating limitations.

• Check whether it is required by an airworthiness directive.

• If the item is not required by any of those sources, deactivate or remove it, and placard it. Inoperative equipment must be deactivated and placarded "INOPERATIVE."

• Make an appropriate maintenance record entry.

• If the item is required, the aircraft must be repaired or obtain a special flight permit if required equipment is inoperative.

Failure of an instrument not on the FAR 91.205 list requires consultation of the TCDS and other directives to determine if it is legally required through other channels. Failure to comply with inoperative equipment procedures can lead to FAA violations, certificate action, or both.

The key principle: if it is required and it is broken, you do not fly that type of operation until it is fixed or properly deferred.

Training, Checkrides, and Practical Application of 91.205

Knowledge of FAR 91.205 is routinely tested on private, instrument, and commercial pilot checkrides during both oral questioning and preflight planning scenarios. Examiners frequently ask applicants to:

• Recite or explain ATOMATOFLAMES and VFR night equipment requirements.

• Distinguish VFR and IFR equipment requirements and explain why IFR demands more redundancy.

• Describe what to do when a required instrument is inoperative before flight, walking through the 91.213 decision tree.

Rather than relying purely on rote memorization, focus on quickly locating, reading, and applying the regulation in the FAR/AIM or an electronic reference. Examiners value pilots who can find answers efficiently under pressure.

Practical study methods that work:

• Build a personal checklist mapping each 91.205 paragraph to your specific aircraft.

• Tab relevant FAR sections for fast reference during oral exams.

• Practice equipment-failure scenarios during ground lessons, walking through 91.213 each time.

• Use flashcards pairing each ATOMATOFLAMES letter with the corresponding instrument and any conditional notes (e.g., "M = manifold pressure gauge, only for altitude engines").

Summary and Quick-Reference Approach to 91.205 Compliance

FAR 91.205 defines minimum instruments and equipment for powered civil aircraft. Safe, legal flight operations depend on meeting or exceeding those standards for each type of operation: visual flight rules day, visual flight rules night, or instrument flight rules.

Before every flight, use this workflow:

• Identify the planned operation (VFR day, VFR night, IFR).

• Review aircraft documents (airworthiness certificate, KOEL, AFM/POH).

• Verify required instruments and equipment are installed and operative.

• Consult 91.213 and MEL/KOEL if anything is inoperative.

Treat 91.205 as a living checklist integrated into your routine preflight planning, not a one-time study topic you cram for a checkride and forget. The regulation evolves as technology and safety standards change, and your understanding of it should evolve with it.

Build the habit now, and you will spend less time guessing and more time flying legally and safely.