EN ROUTE DESCENT- Descent from the en route cruising altitude which takes place along the route of flight. 

## EN ROUTE HIGH ALTITUDE CHARTS- 

(See AERONAUTICAL CHART.) 

## EN ROUTE LOW ALTITUDE CHARTS- 

(See AERONAUTICAL CHART.) 

EN ROUTE MINIMUM SAFE ALTITUDE WARN- ING (E-MSAW)- A function of the EAS that aids the controller by providing an alert when a tracked aircraft is below or predicted by the computer to go below a predetermined minimum IFR altitude (MIA). 

EN ROUTE SPACING PROGRAM (ESP)- A program designed to assist the exit sector in achieving the required in-trail spacing. 

## EN ROUTE TRANSITION- 

a. Conventional STARs/SIDs. The portion of a SID/STAR that connects to one or more en route airway/jet route. 

b. RNAV STARs/SIDs. The portion of a STAR preceding the common route or point, or for a SID the portion following, that is coded for a specific en route fix, airway or jet route. 

## ESP- 

(See EN ROUTE SPACING PROGRAM.) 

## EST- 

(See ESTIMATED.) 

ESTABLISHED- To be stable or fixed at an altitude or on a course, route, route segment, heading, instrument approach or departure procedure, etc. 

ESTABLISHED ON RNP (EoR) CONCEPT– A system of authorized instrument approaches, ATC procedures, surveillance, and communication re- quirements that allow aircraft operations to be safely conducted with approved reduced separation criteria once aircraft are established on a PBN segment of a published instrument flight procedure. 

ESTIMATED (EST)-When used in NOTAMs “EST” is a contraction that is used by the issuing authority only when the condition is expected to return to service prior to the expiration time. Using “EST” lets the user know that this NOTAM has the possibility of returning to service earlier than the 

expiration time. Any NOTAM which includes an “EST” will be auto-expired at the designated expiration time. 

ESTIMATED ELAPSED TIME [ICAO]- The estimated time required to proceed from one significant point to another. 

(See ICAO Term TOTAL ESTIMATED ELAPSED TIME.) 

ESTIMATED OFF-BLOCK TIME [ICAO]- The estimated time at which the aircraft will commence movement associated with departure. 

## ESTIMATED POSITION ERROR (EPE)- 

(See Required Navigation Performance) 

ESTIMATED TIME OF ARRIVAL- The time the flight is estimated to arrive at the gate (scheduled operators) or the actual runway on times for nonscheduled operators. 

ESTIMATED TIME EN ROUTE- The estimated flying time from departure point to destination (lift-off to touchdown). 

## ETA- 

(See ESTIMATED TIME OF ARRIVAL.) 

## ETE- 

(See ESTIMATED TIME EN ROUTE.) 

EXECUTE MISSED APPROACH- Instructions issued to a pilot making an instrument approach which means continue inbound to the missed approach point and execute the missed approach procedure as described on the Instrument Approach Procedure Chart or as previously assigned by ATC. The pilot may climb immediately to the altitude specified in the missed approach procedure upon making a missed approach. No turns should be initiated prior to reaching the missed approach point. When conducting an ASR or PAR approach, execute the assigned missed approach procedure immediately upon receiving instructions to “execute missed approach.” 

(Refer to AIM.) 

EXPECT (ALTITUDE) AT (TIME) or (FIX)- Used under certain conditions to provide a pilot with an altitude to be used in the event of two-way communications failure. It also provides altitude information to assist the pilot in planning. 

(Refer to AIM.) 

