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