Instrument Rating key terms

A request filed with air traffic control stating the intended departure point, route, altitude, destination, and alternate, which lets controllers plan traffic flow and starts search-and-rescue if the flight becomes overdue.

A coded observation of current weather at an airport, listing wind, visibility, clouds, temperature, dew point, and altimeter setting, issued at scheduled times and used to judge conditions before flight.

A coded forecast for a specific airport describing expected wind, visibility, clouds, and significant weather changes over a stated period, used to decide whether an alternate airport must be listed.

The altitude in the atmosphere where the temperature is at or below zero degrees Celsius; above it, visible moisture can freeze on the airframe, so it is compared with planned altitudes.

A report from a pilot describing weather actually encountered, such as icing, turbulence, or cloud tops, passed to ATC or flight service to update forecasts and warn other crews.

The minimum instruments and equipment an aircraft must carry to fly under IFR, commonly remembered as GRABCARD: generator, radios, attitude indicator, banking instrument, clock, altimeter, rate of turn, and direction indicator.

The rules that require naming a backup airport on an IFR flight plan when destination weather is forecast to be marginal, and that set the forecast and approach minimums the alternate must satisfy.

A required accuracy check of the aircraft's VOR receiver using a ground checkpoint, airborne checkpoint, test signal, or a second receiver, with the result logged showing date, place, bearing error, and signature.

A required inspection, every 24 calendar months, of the static pressure system and altimeter for IFR flight, confirming there are no leaks or blockages that would make the instruments read falsely.

The full departure clearance received and read back before taxiing, commonly organized as CRAFT: clearance limit, route, altitude, frequency, and transponder code.

The fix, airport, or point to which an IFR clearance is valid; the pilot may not fly beyond it without receiving a further clearance from air traffic control.

The time ATC states in a holding clearance by which the pilot should expect additional instructions; if radio contact is lost, the aircraft leaves the hold and proceeds at that time.

A racetrack-shaped maneuver flown within protected airspace while waiting for further clearance, using right-hand turns unless the charted pattern specifies left turns.

A heading, altitude, or both assigned by a radar controller to guide an aircraft; when vectored to final, the pilot holds the assigned heading until intercepting the approach course.

A four-digit octal number assigned by ATC that identifies the aircraft on radar; 7500, 7600, and 7700 are reserved for hijack, radio failure, and general emergency.

The organized pattern of eye movements a pilot uses to cross-check attitude, airspeed, altitude, and heading instruments so that no single indication is over-relied upon.

A gyroscopic instrument that shows the aircraft's pitch and bank relative to the horizon, and serves as the main reference for control when outside visual cues are unavailable.

An instrument that shows altitude by sensing static pressure; it reads correctly only when set to the current local setting or to standard pressure above the transition altitude.

A false sensation of the aircraft's attitude or motion produced by conflicting inner-ear and visual cues, which a pilot counters by trusting the instruments rather than body feelings.

The deliberate sequence of control inputs used to return the aircraft to level flight after an unintended steep bank or pitch, usually reducing power, leveling the wings, then correcting pitch.

Flying with one or more key gyroscopic instruments failed or covered, using the remaining instruments such as the turn coordinator, airspeed indicator, altimeter, and vertical speed indicator.

A ground station that transmits navigation signals outward along magnetic radials, allowing an aircraft with a suitable receiver to determine and track its position relative to the station.

A magnetic bearing extending outward from a VOR station, identified by its three-digit degree value; tracking inbound to the station means flying the reciprocal of that radial.

The needle on a navigation display that shows left or right deviation from a selected course, together with a TO or FROM flag indicating direction to or from the station.

The part of an instrument landing system that gives left-right course guidance aligned with the runway centerline, usable only within a limited corridor extending outward from the threshold.

The part of an instrument landing system that provides vertical guidance along a descent path, typically about three degrees, toward a point near the runway threshold.

A method of navigation permitting flight along any desired path without relying on a particular ground station, using onboard computing, defined waypoints, and satellite or ground-based signals.

A receiver function in which the GPS unit checks its own satellite solutions for consistency and alerts the pilot when the signal is not reliable enough for the intended approach.

A published set of maneuvers, fixes, altitudes, and radio aids that guides an aircraft from the en route structure to a point where the runway can be seen for landing.

The lowest altitude a pilot may descend to on an approach without vertical guidance; the aircraft must remain at or above it until the required visual references are in sight.

The altitude or height on a vertically guided approach at which the pilot must either see the required references and continue to land or begin the missed approach.

The published route and instructions to be flown when an approach cannot be completed, starting at a defined point and altitude and usually climbing to a holding fix.

The fix or point that marks the beginning of the final approach segment, from which the aircraft is established on course and descends toward the published minimums.

An approach in which the final course is not aligned with the landing runway, so the pilot maneuvers visually within a protected area to land on another runway.

The situation of being unable to communicate with ATC, handled by squawking 7600 and following published procedures for route, altitude, and timing based on the last clearance received.

The rule allowing the pilot in command to deviate from any regulation to the extent required to handle an emergency, with a report of the deviation if ATC asks for one.

Loss of the engine-driven pump that spins the attitude and heading gyros, leaving the electric turn coordinator and the pitot-static instruments as the remaining attitude references.

The recent-experience requirement to log six approaches, holding procedures, and course intercepting and tracking within the preceding six calendar months to act as pilot in command under IFR.

A practical check with an authorized instructor or examiner that restores instrument privileges after the pilot's recent instrument experience has lapsed beyond the allowed grace period.

Notifying ATC or flight service that an IFR flight has ended, either by radio or by telephone after landing, so that search-and-rescue is not started.