Equivalent  Equivalent Airspeed is a direct measure of the 
Airspeed  incompressible.free.stream.of.dynamic.pressure. 
(EAS)  It.is.CAS.corrected.for.compressibility.effects. 
ERPDU  Echo.Reply.Protocol.Data.Unit 
ERA  European.Regional.Airlines.Association 
ERB  Engineering.Review.Board 
ERD  End.Routing.Domain 
ERDI  En.Route.Domain.Infrastructure 
ERE  External.Roll.Extrusion 
ERP  (.1.).Eye.Reference.Point.. 
(.2.).Enterprise.Resource.Planning 
ERPPDU  Echo.Reply.Protocol.Data.Unit 
ERQPDU  Echo Request Protocol Data Unit 
ERU  Engine.Relay.Unit 
ES  (.1.).End.System.. 
( 2 ) Extended Squitter 
ESA  European.Space.Agency 
ESAS  (.1.).Electronic.Situation.Awareness.System. 
(.2.).Enhanced.Situational.Awareness.System 
E-Scan  Electronic.Scanning 
ESD  Electrostatic.Discharge 
ESDS  Electrostatic.Sensitive.Devices..Also.known.as. 
ESSD. 
ESE  COTS Ethernet Switching Equipment 
ESH  End.System.Hello 
ESID  Engine.and.System.Indication.Display 
ESIS  Engine.and.System.Indication.System 
ESR  Energy.Storage/Control 
ESS  (.1.).Electronic.Switching.System.. 
(.2.).Environmental.Stress.Screening 
ESSD  Electro.Static.Sensitive.Devices..See.also.ESDS. 
ESSP  Environmental.Stress.Screen.Procedure 
EST  Estimated 

ESU Environmental.Sensor.Unit ET Elapsed.Time ETA Estimated.Time.of.Arrival:.The.estimated.time.
to.arrive.at.some.navigational.position.based.on. present.position.and.estimated.ground.speed.
ETB  (.1.).End.of.Block.(ASC.II/IA5.character).. (.2.).Engineering.Test.Band
ETD  Estimated.Time.of.Departure
ETI  Elapsed.Time.Indicator
ETM  Elapsed.Time.Measurement
ETMS  Enhanced Traffic Management System
ETOPS  Extended Twin Engine Operations
ETP  Equal Time Point
ETRC  Expected.Taxi.Ramp.Clearances
ETVS  Enhanced.Terminal.Voice.Switch
ETX  (.1.).End.of.Transmission.. (.2.).Entry.Task.Exit
EUAFS  Enhanced.Upper.Air.Forecast.System
EUPS  External.Uninterruptible.Power.Supply
EUR  European
EURATN  European.ATN
EURET  European.Transport