Definition
The plural form of Glide Slope. A Glide Slope is the electronic vertical guidance component of an Instrument Landing System (ILS), transmitting a narrow radio beam angled upward from the runway touchdown zone (typically 3 degrees) that aircraft follow downward to the runway during an instrument approach. GSs refers to more than one such facility or signal.
Plain English
GSs means Glide Slopes — more than one of the radio beams that tell a pilot whether they are flying the correct downward path to the runway during an instrument approach.
Context Anchor
Seen in air traffic control delay information, traffic management notices, and pilot/controller discussions about departure delays.
Derivation
‘Glide’ comes from Old English glīdan, meaning to move smoothly downward. ‘Slope’ refers to a slanted line or angle. Together, ‘glide slope’ describes the angled descent path the aircraft glides down. The lowercase ‘s’ simply makes it plural.
Why Pilots Care
Used to calculate time en route, fuel burn, and arrival times independent of wind effects.
Grounding Statement
If your flight is covered by a GS, you wait on the ground until air traffic control allows departure.
Intuition Check
In this Pilot/Controller Glossary context, GSs means ground stops, not ground speeds or glide slopes.
Example Sentence 1
The airport’s two parallel runways each have their own GSs, providing independent vertical guidance for simultaneous approaches.
Example Sentence 2
Strong headwinds reduced the GSs well below the planned cruise speed.