Definition
An air traffic control approach procedure that allows two aircraft to fly Instrument Landing System (ILS) approaches at the same time to parallel runways whose centerlines are separated by at least 4,300 feet. Radar monitoring is provided to ensure aircraft remain within their assigned final approach courses, and standard separation is maintained until the aircraft are established inbound on the localizer.
Plain English
Two aircraft are allowed to land at the same time on side-by-side runways at the same airport, each using their own ILS guidance, while controllers watch on radar to make sure neither one drifts toward the other.
Context Anchor
You may encounter this term in instrument approach briefings, ATC procedures, and airport information for larger airports with parallel runways.
Derivation
Simultaneous comes from the Latin simul, meaning at the same time. Parallel runways far enough apart let two ILS approaches happen at once instead of one after another, which is where the name comes from.
Why Pilots Care
Increases the number of landings an airport can handle during busy periods or poor weather without reducing safety, provided the required runway spacing and monitoring are in place.
Grounding Statement
Picture two aircraft lined up with two side-by-side runways, each following its own electronic landing path while ATC keeps the operation organized and separated.
Intuition Check
“Simultaneous” does not mean aircraft are approaching the same runway or that normal separation no longer matters. It means approved ATC procedures allow aircraft to fly instrument approaches to separate parallel runways at the same time.
Example Sentence 1
Approach control advised that simultaneous ILS approaches were in progress to runways 28L and 28R, so we kept the localizer needle centered through the entire descent.
Example Sentence 2
Simultaneous ILS approaches at this airport are suspended when the required radar monitoring is unavailable.