Definition
The normal operating zone (NOZ) is the airspace of defined width on each side of a final approach course within which an aircraft is expected to remain during a simultaneous independent approach to parallel runways. Each parallel approach has its own NOZ, and between adjacent NOZs lies a no transgression zone (NTZ) that aircraft must not enter.
Plain English
When two airplanes are flying parallel approaches to side-by-side runways at the same time, each one has a lane it is supposed to stay inside. That lane is the normal operating zone. As long as you stay inside your lane, you are clear of the airplane on the parallel approach.
Context Anchor
Seen in instrument approach procedures for simultaneous independent approaches to parallel runways.
Derivation
The abbreviation comes from the first letters of normal operating zones. In this use, a zone is a defined area of airspace, not just a general region.
Why Pilots Care
Keeps aircraft safely separated; leaving the NOZ risks entering the NTZ and triggering a go-around or safety alert.
Analogy
Think of two cars driving side by side in adjacent highway lanes. Each lane is a NOZ. The painted buffer between the lanes is the NTZ. Stay in your lane and everyone is safe.
Grounding Statement
Picture two aircraft flying side by side toward parallel runways, each staying inside its own protected lane of airspace.
Intuition Check
Normal does not mean informal or approximate here. It means the expected, protected area where the aircraft should be during the approach.
Example Sentence 1
During the simultaneous approach to runways 28L and 28R, the captain flew precisely on course to keep the aircraft well inside the NOZ.
Example Sentence 2
Both pilots confirmed they were within their assigned NOZs before continuing the approach.