Definition
A spacing technique used during simultaneous dependent approaches to closely spaced parallel runways, in which aircraft on adjacent final approach courses are sequenced so that they are not abeam (side-by-side) at the same point in space. A required minimum diagonal distance is maintained between an aircraft on one final approach course and the aircraft ahead on the adjacent final approach course, typically 1.0, 1.5, or 2.0 nautical miles depending on runway centerline spacing.
Plain English
Aircraft landing on two parallel runways are arranged so they are not flying right next to each other. Instead, one is always a little ahead of the other, with a set diagonal distance between them.
Context Anchor
Seen in instrument approach procedures and air traffic control instructions for simultaneous dependent approaches to parallel runways.
Derivation
Staggered' comes from an Old Norse word meaning to walk unsteadily, and came to describe things arranged in an offset, zig-zag pattern rather than lined up evenly. That offset arrangement is exactly what controllers create between the two streams of arriving aircraft.
Why Pilots Care
It permits higher arrival rates at busy airports by allowing closer overall spacing while still meeting safety requirements.
Analogy
Think of two cars in side-by-side lanes. Staggered separation is like keeping one car a safe distance ahead of the other, instead of having both cars drive exactly side by side.
Intuition Check
Do not read staggered separation as random or uneven spacing. In this FAA context, it means a planned diagonal spacing between aircraft on nearby approach paths.
Example Sentence 1
Approach control used staggered separation to sequence our arrival behind and to the left of the traffic landing on the parallel runway.
Example Sentence 2
Staggered separation of 1.5 nautical miles allowed both aircraft to continue on their parallel approaches without conflict.