Definition
A 2,000-foot wide protected airspace corridor centered between the final approach courses of two parallel instrument runways during simultaneous independent parallel approaches. Controllers continuously monitor both approach paths, and any aircraft observed penetrating the NTZ triggers an immediate breakout instruction to the threatened aircraft on the adjacent approach.
Plain English
A safety buffer between two parallel approach paths that no aircraft is allowed to enter. If a plane drifts into it, controllers immediately turn the aircraft on the next approach away to keep them apart.
Context Anchor
You may see NTZ in procedures or controller instructions for airports that use simultaneous approaches to closely spaced parallel runways.
Derivation
Transgression' comes from the Latin transgredi, meaning 'to step across.' The NTZ is literally the zone you must not step across — a line in the sky between two streams of arriving traffic.
Why Pilots Care
Entering the NTZ during parallel approaches triggers immediate controller intervention and usually requires a missed approach to restore safe separation.
Intuition Check
Do not read “transgression” as a general rule violation here. In this FAA use, it means crossing into a specific protected airspace area between parallel approach paths.
Example Sentence 1
During the simultaneous approach to runways 28L and 28R, the controller monitored both aircraft to ensure neither crossed into the NTZ.
Example Sentence 2
Radar monitoring confirmed both aircraft stayed outside the No Transgression Zone throughout the parallel approaches.