FAR 91.205: Day VFR, Night VFR, and IFR Equipment

FAR 91.205 lists the instruments and equipment that must be installed and working on a powered civil aircraft with a standard U.S. airworthiness certificate before it can legally fly. The list stacks: day visual flight has a baseline, night visual flight adds items on top of that baseline, and instrument flight adds more on top of both. If anything on the list that applies to your flight isn’t working, the aircraft is unairworthy, and federal law prohibits operating an aircraft that isn’t in airworthy condition.¹

Work from the flight you’re planning. Day VFR needs the shortest list. Night VFR requires everything on the day list plus lighting and electrical items. IFR requires everything on the night list plus navigation and gyroscopic instruments. A landing light burned out during a preflight might mean nothing, or it might ground you, depending on when and why you’re flying.

Day VFR Equipment

For daytime VFR flight, the following instruments and equipment must be in working order:²

Airspeed indicator.
Altimeter.
Magnetic direction indicator (magnetic compass).
Tachometer for each engine.
Oil pressure gauge for each engine using a pressure-fed oil system.
Coolant temperature gauge for each liquid-cooled engine, or an oil temperature gauge for each air-cooled engine.
Manifold pressure gauge for each altitude engine (a reciprocating engine rated to produce its takeoff power from sea level up to a specified higher altitude, which in practice means supercharged or turbocharged engines).³
Fuel gauge for each tank.
Landing gear position indicator, if the aircraft has retractable gear.
An approved emergency locator transmitter if required by 14 CFR 91.207.

Small civil airplanes certified after March 11, 1996, under Part 23 must have an approved red or white anti-collision light system. If one of those anti-collision lights fails in flight, the pilot may continue to an airport where repairs can be made.²

Flights operated for hire over water and beyond power-off gliding distance from shore add two items: approved flotation gear readily available for each occupant, and at least one pyrotechnic signaling device. This does not apply to operations under Part 121.

Every occupant two years old or older needs an approved safety belt with a metal-to-metal latching device. Small civil airplanes manufactured after July 18, 1978, need an approved shoulder harness for each front seat. Airplanes manufactured after December 12, 1986, need shoulder harnesses for all seats.²

Night VFR Equipment

Night VFR flight requires everything on the day VFR list, plus:²

Approved position lights (the red, green, and white navigation lights).
An approved anti-collision light system. At night this applies to all U.S.-registered civil aircraft, regardless of the airplane’s manufacture or certification date. If any light in the system fails, the aircraft may continue to a stop where repairs can be made.
An adequate source of electrical energy for all installed electrical and radio equipment.
Spare fuses: one spare set, or three spare fuses of each kind, accessible during flight, if the aircraft uses fuses for circuit protection.
One electric landing light, but only if the aircraft is operated for hire.

The landing light requirement is worth reading carefully. If you’re flying at night for personal purposes, 91.205 does not require a landing light. If you’re flying for hire, it does. Position lights and the anti-collision system, however, are required for every night flight, and a bulb that no one noticed was out during the day becomes a grounding item after sunset.

IFR Equipment

IFR flight requires everything from the day and night VFR lists, plus the instruments needed to fly and navigate without outside visual references:²

A two-way radio communication system capable of reaching ATC on the frequencies needed for the route.
Navigation equipment appropriate to the ground facilities used along the planned route.
A gyroscopic rate-of-turn indicator.
A slip-skid indicator (the ball).
A sensitive altimeter adjustable for barometric pressure.
A clock displaying hours, minutes, and seconds, with either a sweep-second pointer or a digital readout.
A generator or alternator of adequate capacity.
An attitude indicator (the gyroscopic pitch-and-bank instrument).
A directional gyro or equivalent heading indicator independent of the magnetic compass.

High Altitude: DME or Suitable RNAV

At and above Flight Level 240, aircraft required to have VOR navigation equipment must also carry Distance Measuring Equipment or a suitable area navigation (RNAV) system. An IFR-approved GPS satisfies the DME requirement at these altitudes, and an aircraft using GPS in place of DME is not required to carry separate DME hardware.²

If the DME or RNAV system fails at altitude, the pilot must notify ATC immediately. The flight can generally continue to the next intended airport after notifying ATC, but the aircraft cannot depart again until the equipment is repaired.

What To Do When Something Is Inoperative

Finding a broken instrument during preflight doesn’t automatically cancel the flight. 14 CFR 91.213 gives two paths.⁴

Some operators hold an FAA-approved Minimum Equipment List and an associated Letter of Authorization. The MEL is tailored to the specific aircraft and lists which items may be inoperative and under what conditions. Airlines and larger operators almost always have MELs; most private owners do not.

For an aircraft without a MEL, the inoperative item has to clear three gates before the flight can go:

It is not required by the aircraft’s type certificate or equipment list for the kind of operation being conducted.
It is not required by 14 CFR 91.205 or any other Part 91 rule for the specific flight.
It is not required to be operational by an airworthiness directive.

If the item passes all three, the pilot has two options: physically remove the equipment and update the maintenance record, or deactivate the item and placard it “Inoperative.” A certificated pilot can handle the deactivation and placarding as long as no maintenance work is involved. Either way, the maintenance record needs an entry.⁴

If the broken item is on the 91.205 list that applies to your flight, the aircraft doesn’t fly until it’s fixed. There is no workaround for a dead airspeed indicator on a VFR flight or a dead attitude indicator on an IFR flight. This is where knowing the exact requirements for each type of flight matters. A burned-out landing light grounds a charter aircraft at night but not a privately flown one, because the landing light appears on the night VFR list only for aircraft operated for hire.

Other Equipment Rules 91.205 Doesn’t Cover

The 91.205 checklist is not the whole picture. Three other regulations add equipment that must be installed and working depending on where and how you fly, and they can catch pilots who treated the 91.205 walk-through as sufficient.

Under 14 CFR 91.207, every U.S.-registered civil airplane must carry an approved emergency locator transmitter in operable condition, with several exceptions for training, testing, ferry, and other specific operations.⁵

Under 14 CFR 91.215, a Mode C transponder with automatic altitude reporting is required in Class A, B, and C airspace; within 30 nautical miles of a Class B primary airport from the surface to 10,000 feet MSL (the “Mode C veil”); above the ceiling of Class B or C airspace up to 10,000 feet MSL; and at and above 10,000 feet MSL in the contiguous 48 states and D.C., except when at or below 2,500 feet AGL.⁶

Under 14 CFR 91.225, ADS-B Out has been required since January 1, 2020, in essentially the same airspace as the Mode C transponder, plus Class E airspace at and above 3,000 feet MSL over the Gulf of Mexico from the U.S. coastline out to 12 nautical miles.⁷ The Gulf of Mexico requirement is unique to ADS-B and has no transponder equivalent.