IFR flight in the United States requires a specific set of instruments and equipment beyond what you need for visual flight. The requirements come from 14 CFR 91.205, and pilots commonly use the mnemonic “GRABCARD” to remember the IFR-specific additions. But the full picture includes everything required for day VFR, night VFR, and then the IFR layer on top.
The GRABCARD Instruments for IFR
These nine items are the IFR-specific requirements under 14 CFR 91.205(d). They’re in addition to everything already required for day and night VFR flight:
- Generator or alternator of adequate capacity to power all electrical and radio equipment
- Rate-of-turn indicator (gyroscopic), unless the aircraft has a third attitude instrument usable through 360 degrees of pitch and roll
- Attitude indicator (artificial horizon), gyroscopic
- Ball (slip-skid indicator), the inclinometer that shows coordinated flight
- Clock displaying hours, minutes, and seconds, either with a sweep-second hand or digital display
- Adjustable altimeter, sensitive and adjustable for barometric pressure
- Radios for two-way communication and navigation equipment suitable for the route
- Directional gyro (heading indicator or equivalent), gyroscopic
The clock requirement is more specific than many pilots realize. It must show seconds, not just hours and minutes. Digital clocks are acceptable as long as seconds can be displayed, either simultaneously with hours and minutes or individually selectable.
Day and Night VFR Equipment You Also Need
Because IFR requirements build on VFR requirements, your aircraft must also carry everything mandated for day VFR under 91.205(b). That list includes an airspeed indicator, altimeter, magnetic compass, tachometer for each engine, oil pressure gauge, oil temperature gauge for air-cooled engines, fuel quantity gauges for each tank, and a landing gear position indicator if the gear is retractable. Manifold pressure gauges are required on altitude engines, and temperature gauges are needed for liquid-cooled engines.
For night operations (which most IFR flights involve or could involve), you also need position lights, an anticollision light system, an adequate electrical energy source, and spare fuses accessible to the pilot. Aircraft operated for hire need an electric landing light as well.
Gyroscopic Instrument Power Sources
Three of the GRABCARD instruments are gyroscopic: the attitude indicator, the heading indicator, and the rate-of-turn indicator. These run on either vacuum (suction) or electrical power, and losing that power source means losing the instruments. For Part 91 operations in most single-engine aircraft, there’s no regulatory requirement for a backup vacuum pump, though many pilots add one voluntarily.
Larger aircraft operating under Part 125 must have two independent sources of energy for gyroscopic instruments, each on a different engine, with a power failure warning device. This redundancy ensures that a single failure won’t wipe out all gyro-driven instruments at once.
Navigation Equipment Requirements
The regulation calls for “navigation equipment suitable for the route to be flown,” which is intentionally flexible. What counts as suitable depends on where you’re going. If your route is built on VOR airways, you need a working VOR receiver. If you’re flying GPS-based routes or approaches, you need an IFR-approved GPS.
For GPS to qualify as IFR navigation equipment, it must meet specific FAA technical standards. Older standalone GPS units certified under TSO-C129 can be used for IFR en route and approach operations but require a backup navigation source onboard. Newer GPS/WAAS units certified under TSO-C145 or TSO-C146 have no such limitation and can serve as the sole means of navigation.
If you’re using VOR for navigation, the receiver must be operationally checked within the preceding 30 days and found within allowable bearing error limits. Each check must be logged with the date, place, bearing error, and a signature.
DME Above Flight Level 240
At or above 24,000 feet MSL, you need Distance Measuring Equipment or a suitable RNAV system (GPS counts) if VOR navigation is required for your route. If your DME or RNAV fails while above FL 240, you must notify ATC immediately but can continue to your next intended landing for repairs.
Transponder and ADS-B Requirements
While not listed in the GRABCARD mnemonic, a Mode C transponder with altitude reporting and ADS-B Out equipment are effectively required for most IFR flying. Class B and Class C airspace both mandate a transponder with automatic altitude reporting and operable ADS-B Out. In Class E airspace, the same equipment is required at and above 10,000 feet MSL within the contiguous 48 states (excluding airspace at or below 2,500 feet AGL).
Since IFR flights routinely pass through controlled airspace, flying without a transponder and ADS-B Out would severely limit where you could go.
Altimeter and Static System Inspections
Having the right instruments installed isn’t enough. Your altimeter, static pressure system, and automatic altitude reporting system must be tested and inspected within the preceding 24 calendar months. This inspection verifies that your altimeter reads accurately at various pressure settings and that your static system has no leaks. Without a current inspection, the aircraft is not legal for IFR flight, even if every instrument appears to work perfectly.
Glass Cockpit Considerations
Modern aircraft with electronic primary flight displays meet the same regulatory requirements but handle redundancy differently. If an aircraft has a single PFD, standby instruments must be installed to provide attitude, airspeed, and altitude information in case the screen fails. These standby instruments need to be at least 2 inches in diameter individually or 3 inches if combined into one display.
Aircraft with dual PFDs powered by independent attitude and air data systems, each on separate power sources, can meet the requirement without dedicated standby instruments. The idea is that no single failure should leave you without primary flight information. A reversionary display mode that pulls data from an independent source is another acceptable method, as long as it provides consistent formatting with the primary display and is powered independently.
Putting It All Together
The total instrument list for IFR flight is longer than GRABCARD alone. You need every day VFR instrument, every night VFR instrument and light, plus the nine GRABCARD items, a transponder with Mode C, ADS-B Out for most airspace, and navigation equipment appropriate to your route. On top of that, your altimeter system needs a current 24-month inspection, and your VOR (if used) needs a 30-day operational check. Missing any single item grounds you for IFR operations until it’s corrected.