Ever wondered what EFIS means? What’s the difference between a nautical mile and a statute mile? This glossary, the first in a multi-part series, will attempt to define and answer basic questions about aviation terms. Come back each Friday for new posts! Visit Fairway Aviation to learn more.

AILERONS An aircraft control surface hinged to the rear, outer section of the wing for banking (“tilting”) the aircraft. A bank causes an aircraft to turn. Controlled by right or left movement of the control yoke or stick.

AIRFOIL The shape of any flying surface, but principally a wing, as seen in side-view (cross section).

ALTIMETER A highly sensitive barometer that shows an aircraft’s altitude above mean sea level by measuring atmospheric pressure.

AVIONICS The electronic control systems airplanes use for flight such as communications, autopilots, and navigation.

EFIS (Electronic Flight Information Systems) Glass cockpit avionics that integrate all flight parameters into one optimized instrument. These modern systems offer enhanced reliability, reduced weight, simplified installation and overall cost savings.

EGPWS (Enhanced Ground Proximity Warning System) Uses aircraft inputs such as position, attitude, air speed and glide slope, which along with internal terrain, obstacles, and airport databases predict a potential conflict between the aircraft’s flight path and terrain or an obstacle.

ELEVATOR An aircraft control surface hinged to the rear of the left and right horizontal stabilizer of the aircraft tail. Changes the aircraft pitch attitude nose-up or nose-down, as during climb or descent. Controlled by pushing or pulling on control yoke or stick.

ELT (Emergency Locator Transmitter) A radio transmitter activated automatically by the impact of an accident. Emits a warbling tone on the international emergency frequencies of 121.5 MHz, 243 MHz and (newer models) 406 MHz. ELT signals can be received by nearby FAA facilities, aircraft overhead, and search and rescue (SARSAT) satellites.

FLAPS Hinged surfaces on the inboard rear of wings, deployed to increase wing curvature (and thus, lift), primarily used to control angle of descent and to decrease landing touchdown speeds.

FMS (Flight Management System) A computerized avionics component found on commercial and business aircraft. Consists of the Flight Management Computer (FMC), the Auto Flight System (AFS) and the Navigation System, which includes the Inertial Reference System (IRS) and the Global Positioning System (GPS).

FUSELAGE An aircraft’s main body structure housing the flight crew, passengers, and cargo.

GPS (Global Positioning System) Satellite-based navigation system operated by Department of Defense, providing extremely accurate position, time, and speed information to civilian and military users. Based on a “constellation” of 24 satellites.

GPWS (Ground Proximity Warning System) System designed to alert pilots if their aircraft is in immediate danger of flying into the ground. Also called Ground-Collision Warning System.