Airborne early warning moves the radar horizon outward

A ship's radar cannot see beyond the horizon, whereas an aircraft can carry the sensor higher and farther forward. An attacker travelling at 800 miles per hour instead of 400 halves the warning time over the same distance. More warning allows combat air patrols to engage a smaller number of launch aircraft before each releases several missiles. The Falklands provides a later warning about abandoning carrier airborne early warning and assuming allied land or carrier aircraft would always provide it. Without that warning, Sea Harriers often chased departing attackers instead of breaking up raids before weapons reached the fleet. Airborne radar therefore changes detection range and the entire geometry and timing of fleet defence.