Frequently Asked Questions
The most-asked questions about flight instruments and avionics.
What exactly are 'flight instruments and avionics'?
Flight instruments are the gauges, sensors, and displays that give a pilot real-time information about attitude, speed, altitude, heading, and systems status. Avionics is the broader umbrella covering every electronic system in the cockpit — navigation, communication, autopilot, and display hardware — that supports safe operation of the aircraft.
What are the 'six basic flight instruments' every pilot learns first?
The classic sextet is the airspeed indicator, altimeter, attitude indicator, heading indicator, vertical-speed indicator, and turn coordinator. These were the minimum set a pilot needed to fly under instrument rules before glass cockpits folded them into integrated screens.
What is a 'glass cockpit' and how does it differ from a traditional one?
A glass cockpit replaces most or all analog dials with large LCD or LED screens, typically a Primary Flight Display plus one or more Multi-Function Displays. The underlying data sources are the same; the difference is that the pilot reads synthesized, reconfigurable information rather than individual mechanical gauges.
Who are the major avionics manufacturers fans and pilots talk about?
The leading names in commercial and general aviation include Honeywell, Collins Aerospace (RTX), Thales, and Garmin, while Avidyne and Aspen serve much of the light-aircraft segment. Enthusiast communities frequently compare the display logic, reliability, and update cycles of each vendor's systems.
What is an ATC transponder and why does every aircraft carry one?
A transponder is a small radio transceiver that, when interrogated by ground radar or a nearby aircraft, replies with a four-digit squawk code and often an altitude report. It lets air-traffic controllers identify and track the aircraft, and in Mode S or ADS-B configurations it also broadcasts position to other traffic.
What do VOR, ILS, and DME stand for, and why do they still matter with GPS everywhere?
VOR (VHF Omnidirectional Range) provides a radial bearing to a ground station, ILS (Instrument Landing System) gives a precise localizer and glideslope for a runway approach, and DME (Distance Measuring Equipment) outputs slant-range distance. Even with satellite navigation ubiquitous, these ground-based aids remain required backups in most controlled airspace.
How does an autopilot actually work under the hood?
An autopilot is a closed-loop controller that continuously compares the aircraft's actual state, read from the flight instruments, against a commanded trajectory and then drives the control surfaces or thrust to close the gap. Modern systems scale from simple heading-hold to fully automated approach-and-land sequences.
What is the difference between a PFD and an MFD?
The Primary Flight Display shows the core 'fly-the-airplane' data — attitude, airspeed, altitude, heading — in a fixed layout the pilot can read at a glance. The Multi-Function Display is reconfigurable and carries navigation maps, engine or ECAM pages, weather radar, and other secondary information.
Why do pilots distinguish between IAS, TAS, and EAS, and which one is on the gauge?
Indicated Airspeed is the raw pitot-static reading, True Airspeed corrects for altitude and temperature, and Equivalent Airspeed further accounts for compressibility at high speed. The traditional airspeed indicator shows IAS, though modern PFDs can be configured to display any of the three.
Where should a newcomer start if they want to understand cockpit avionics?
A solid path is to learn the six basic instruments and the pitot-static and gyroscopic principles behind them, then move to navigation aids such as VOR, DME, ILS, and GPS, and finally study how a modern integrated cockpit (PFD, MFD, FMS, autopilot) stitches everything together. Most general-aviation flight schools and FAA or EASA manuals offer free introductory chapters that walk through exactly this sequence.