Pilot/Controller Glossary 

3/21/24 

GLOBAL NAVIGATION SATELLITE SYSTEM MINIMUM EN ROUTE IFR ALTITUDE (GNSS MEA)

−

 

The minimum en route IFR altitude on a published ATS route or route segment which assures acceptable Global 

Navigation Satellite System reception and meets obstacle clearance requirements. 

(Refer to 14 CFR Part 91.) 
(Refer to 14 CFR Part 95.) 

GLOBAL POSITIONING SYSTEM (GPS)

−

 GPS refers to the worldwide positioning, navigation and timing 

determination capability available from the U.S. satellite constellation.  The service provided by GPS for civil 

use is defined in the GPS Standard Positioning System Performance Standard. GPS is composed of space, 

control, and user elements. 
GNSS [ICAO]

−

 

(See GLOBAL NAVIGATION SATELLITE SYSTEM.) 

GNSS MEA

−

 

(See GLOBAL NAVIGATION SATELLITE SYSTEM MINIMUM EN ROUTE IFR ALTITUDE.) 

GO AHEAD

−

 

Proceed with your message. Not to be used for any other purpose. 

GO AROUND

−

 

Instructions for a pilot to abandon his/her approach to landing. Additional instructions may 

follow. Unless otherwise advised by ATC, a VFR aircraft or an aircraft conducting visual approach should 

overfly the runway while climbing to traffic pattern altitude and enter the traffic pattern via the crosswind leg. 

A pilot on an IFR flight plan making an instrument approach should execute the published missed approach 

procedure or proceed as instructed by ATC; e.g., “Go around” (additional instructions if required). 

(See LOW APPROACH.) 
(See MISSED APPROACH.) 

GPD

−

 

(See GRAPHIC PLAN DISPLAY.) 

GPS

−

 

(See GLOBAL POSITIONING SYSTEM.) 

GRAPHICAL AIRMEN’S METEOROLOGICAL INFORMATION

−

 A graphical depiction of weather that 

may be hazardous to aircraft, but are less severe than SIGMETs. G

−

AIRMETS are issued 3 hours apart for a 

period of up to 12 hours into the future for the lower 48 states and coastal waters. The weather hazards depicted 

can be: 

a. 

Moderate turbulence 

b. 

Low-level windshear 

c. 

Strong surface winds greater than 30 knots 

d. 

Moderate icing 

e. 

Freezing level 

f. 

Mountain obscuration 

g. 

IFR 

(See AIRMET.) 
(See CONVECTIVE SIGMET.) 
(See CWA.) 
(See SAW.) 
(See SIGMET.) 
(Refer to AIM.) 

GRAPHIC PLAN DISPLAY (GPD)

−

 A view available with EDST that provides a graphic display of aircraft, 

traffic, and notification of predicted conflicts. Graphic routes for Current Plans and Trial Plans are displayed 

upon controller request. 

(See EN ROUTE DECISION SUPPORT TOOL.) 

PCG G

−

2