EAD Area
The expression EAD Area describes the combined area of responsibility of the National
Administrations providing Air Navigation Services and participating in the EAD.

EAD Bulk Data
Bulk data is that which is downloaded into Client systems either via a network or a magnetic
medium (e.g. CD_ROM). It includes download of a complete AIP.

EAD Message Distribution
"Distribution" is used to mean the transmission of a message. Where messages are distributed by Aeronautical Fixed Service (AFS) or national X.25 ATC networks the responsibility of the EAD extends only to ensuring that messages are correctly addressed. If other communications means are used the responsibility of the EAD may extend to ensuring correct delivery.
EAD Office
The expression EAD Office describes building(s) or parts thereof where the EAD is to be installed and/or operated
EAD Responsibility
This expression is not intended to imply any legal responsibility but to define functions usually provided by National Administrations providing Air Navigation Services through their participation in the EAD.
Earth Referenced Navigation
Navigation that is dependent on an external navigation source but is not dependent on a single fixed site. ERN may use either time or phase differences from hyperbolic radio navigation systems or satellite sources with earth models (datum’s) to determine position (normally latitude and longitude) on the surface of the earth. Omega, Loran-C, DME and GNSS are different forms of ERN.
Earth-Centred-Earth-Fixed
A right-hand Cartesian co-ordinate system with its origin located at the centre of the Earth - the co-ordinate system used by GPS to describe three-dimensional location. ECEF co-ordinates are centred on the WGS-84 reference ellipsoid, have the "Z" axis aligned with the Earth's spin axis, the "X" axis through the intersection of the Prime Meridian and the Equator and the 'Y' axis is rotated 90 degrees East of the "X" axis about the "Z" axis.
EATCHIP Work Programme Document
Detailed description and programme of the common work to be carried out under the central
management of the Eurocontrol Agency.

Tip: to find a specific term, use the Acrobat search : click E on the binocular icon in the window bar menu
EATMP Users Group of people who use EATMP’s products, systems, services or information, obtain benefits, and may incur costs by doing so. EATMP Validation Project Study project on advanced ATCO roles. Eurocontrol study project tasked to define, develop/evolve and evaluate controller roles, tasks and working methods suited to the introduction of the ATM Decision Support Tools (DST) and datelink communication as planned in ATM2000+. Echoback A method of operational acknowledgement whereby the operational contents of a data link message are echoed back within the operational data link acknowledgement message, to ensure that the message recipient has received exactly what was transmitted. The Echoback differs from the Readback, in that the latter is conducted over R/T and therefore requires that a human operator physically reads the operational contents of the message being readback. The Echoback cannot guarantee this level of understanding. Editing Changing the wording of the free text of a NOTAM to make it clearer or express explicitly ideas that are implicit in that text. Effective Radiated Power It is the Transmitted Power enhanced by the gain of the antenna less the losses of cables, rotary joints etc. Effective/Equivalent Isotropic Radiated Power It is the output power at the transmitter terminal, minus feeder and mismatch losses, plus average antenna gain relative to an isotropic radiator in the horizontal direction, or : where EIRP = Pt - L + Ga (EIRP is power in decibels (dB) relative to one watt, dBW; Pt is transmitter power, in dBw; L is feeder and mismatch losses, in dB; Ga is antenna gain in dBi. Efficiency Measurement Any quantifiable unit resulting from the ratio of output over input. Element A system component which, at a given level of analysis, one does not intend to divide any further. Elevation An angle in the vertical plane through a longitudinal axis; height above mean sea level, usually of terrain. Elevation angle The angle subtended at the radar head between the vertical and the vector joining the radar head to a particular target. Eligibility horizon The lead time (VSP) before the estimated time of arrival at the constraint point. The flight becomes eligible at this time. Eligible (SNET) Those aircraft which are considered to be of interest to the ATS unit under consideration. The precise method of indicating which aircraft are eligible (SNET) is implementation-specific. "Eligible" has its normal English meaning when used without the qualifier "(SNET)". Eligible flight A flight for which a flight plan is available and becomes relevant to be considered for AMAN processing (relevant for planning purposes).