Glossary

Dynamic stability. The property of an aircraft that causes Encoding altimeter. A special type of pressure altimeter it, when disturbed from straight-and-level flight, to develop used to send a signal to the air traffic controller on the ground, forces or moments that restore the original condition of showing the pressure altitude the aircraft is flying. straight and level. Engine pressure ratio (EPR). The ratio of turbine discharge E pressure divided by compressor inlet pressure, which is used as an indication of the amount of thrust being developed by Eddy currents. Current induced in a metal cup or disc when a turbine engine. it is crossed by lines of flux from a moving magnet. En route facilities ring. Depicted in the plan view of IAP Eddy current damping. The decreased amplitude of charts, a circle which designates NAVAIDs, fixes, and oscillations by the interaction of magnetic fields. In the case intersections that are part of the en route low altitude airway of a vertical card magnetic compass, flux from the oscillating structure. permanent magnet produces eddy currents in a damping disk or cup. The magnetic flux produced by the eddy currents En route high-altitude charts. Aeronautical charts for en opposes the flux from the permanent magnet and decreases route instrument navigation at or above 18,000 feet MSL. the oscillations. En route low-altitude charts. Aeronautical charts for en EFC. See expect-further-clearance. route IFR navigation below 18,000 feet MSL. EFD. See electronic flight display. EPR. See engine pressure ratio. EGT. See exhaust gas temperature. Equilibrium. A condition that exists within a body when the sum of the moments of all of the forces acting on the body Electronic flight display (EFD). For the purpose of is equal to zero. In aerodynamics, equilibrium is when all standardization, any flight instrument display that uses LCD or opposing forces acting on an aircraft are balanced (steady, other image-producing system (cathode ray tube (CRT), etc.) unaccelerated flight conditions). Elevator. The horizontal, movable primary control surface in Equivalent airspeed. Airspeed equivalent to CAS in standard the tail section, or empennage, of an airplane. The elevator is atmosphere at sea level. As the airspeed and pressure altitude hinged to the trailing edge of the fixed horizontal stabilizer. increase, the CAS becomes higher than it should be, and a correction for compression must be subtracted from the CAS. Elevator illusion. The sensation of being in a climb or descent, caused by the kind of abrupt vertical accelerations Evaporation. The transformation of a liquid to a gaseous that result from up- or downdrafts. state, such as the change of water to water vapor. Emergency. A distress or urgent condition. Exhaust gas temperature (EGT). The temperature of the exhaust gases as they leave the cylinders of a reciprocating Empennage. The section of the airplane that consists of the engine or the turbine section of a turbine engine. vertical stabilizer, the horizontal stabilizer, and the associated control surfaces. Expect-further-clearance (EFC). The time a pilot can expect to receive clearance beyond a clearance limit. Emphasis error. The result of giving too much attention to a particular instrument during the cross-check, instead of Explosive decompression. A change in cabin pressure faster relying on a combination of instruments necessary for attitude than the lungs can decompress. Lung damage is possible. and performance information. F Empty-field myopia. Induced nearsightedness that is associated with flying at night, in instrument meteorological FA. See area forecast. conditions and/or reduced visibility. With nothing to focus on, the eyes automatically focus on a point just slightly ahead FAA. Federal Aviation Administration. of the airplane. FAF. See final approach fix. EM wave. Electromagnetic wave. G-11