## EAS- 

(See EN ROUTE AUTOMATION SYSTEM.) 

## EDCT- 

(See EXPECT DEPARTURE CLEARANCE TIME.) 

## EDST- 

(See EN ROUTE DECISION SUPPORT TOOL) 

## EFC- 

(See EXPECT FURTHER CLEARANCE (TIME).) 

## ELT- 

(See EMERGENCY LOCATOR TRANSMITTER.) 

EMERGENCY- A distress or an urgency condition. 

EMERGENCY AUTOLAND SYSTEM- This system, if activated, will determine an optimal airport, plot a course, broadcast the aircraft's intentions, fly to the airport, land, and (depending on the model) shut down the engines. Though the system will broadcast the aircraft's intentions, the controller should assume that transmissions to the aircraft will not be acknowledged. 

EMERGENCY DESCENT MODE- This automated system senses conditions conducive to hypoxia (cabin depressurization). If an aircraft is equipped and the system is activated, it is designed to turn the aircraft up to 90 degrees, then descend to a lower altitude and level off, giving the pilot(s) time to recover. 

EMERGENCY LOCATOR TRANSMITTER (ELT)- A radio transmitter attached to the aircraft structure which operates from its own power source on 121.5 MHz and 243.0 MHz. It aids in locating downed aircraft by radiating a downward sweeping audio tone, 2-4 times per second. It is designed to function without human action after an accident. 

(Refer to 14 CFR Part 91.) 

(Refer to AIM.) 

## E-MSAW- 

(See EN ROUTE MINIMUM SAFE ALTITUDE WARNING.) 

ENHANCED FLIGHT VISION SYSTEM (EFVS)- An EFVS is an installed aircraft system which uses 

## E 

an electronic means to provide a display of the forward external scene topography (the natural or man-made features of a place or region especially in a way to show their relative positions and elevation) through the use of imaging sensors, including but not limited to forward-looking infrared, millimeter wave radiometry, millimeter wave radar, or low-light level image intensification. An EFVS includes the display element, sensors, computers and power supplies, indications, and controls. An operator's authoriza- tion to conduct an EFVS operation may have provisions which allow pilots to conduct IAPs when the reported weather is below minimums prescribed on the IAP to be flown. 

EN ROUTE AIR TRAFFIC CONTROL SER- VICES- Air traffic control service provided aircraft on IFR flight plans, generally by centers, when these aircraft are operating between departure and destination terminal areas. When equipment, capa- bilities, and controller workload permit, certain advisory/assistance services may be provided to VFR aircraft. 

EN ROUTE AUTOMATION SYSTEM (EAS)- The complex integrated environment consisting of situation display systems, surveillance systems and flight data processing, remote devices, decision support tools, and the related communications equipment that form the heart of the automated IFR air traffic control system. It interfaces with automated terminal systems and is used in the control of en route IFR aircraft. 

EN ROUTE CHARTS- 

EN ROUTE DECISION SUPPORT TOOL (EDST)- An automated tool provided at each Radar Associate position in selected En Route facilities. This tool utilizes flight and radar data to determine present and future trajectories for all active and proposal aircraft and provides enhanced automated flight data management. 

(See AIR ROUTE TRAFFIC CONTROL CENTER.) 

(Refer to AIM.) 

(Refer to AIM.) 

(See AERONAUTICAL CHART.) 

