Pilot/Controller Glossary

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

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

EN ROUTE HIGH ALTITUDE CHARTS-

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

(See AERONAUTICAL CHART.)

EN ROUTE LOW ALTITUDE CHARTS-
(See AERONAUTICAL CHART.)

(See ICAO Term TOTAL ESTIMATED ELAPSED
TIME.)

EN ROUTE MINIMUM SAFE ALTITUDE WARNING (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).

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

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

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.

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 requirements 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

ESTIMATED POSITION ERROR (EPE)-
(See Required Navigation Performance)

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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.)