Definition
The published set of design criteria and the resulting flight path used by aircraft transitioning from en route flight to a landing, or to a point from which a landing can be made visually. TERPS criteria specify minimum obstacle clearance, descent gradients, course alignment, and minimum altitudes for each segment of an instrument approach.
Plain English
It is the official rulebook the FAA uses to design instrument approaches into airports, and the term is also used loosely to mean the approach itself. The rules make sure the path the aircraft flies stays safely clear of terrain and obstacles all the way down to the runway.
Context Anchor
You encounter this term when studying instrument approach charts, approach design, and IFR arrival planning near an airport.
Derivation
From 'terminal' (the area near the airport where the flight ends), 'instrument' (flown by reference to instruments rather than by sight), and 'procedure' (a defined sequence of steps). Together it names the published procedure used in the terminal area when flying on instruments.
Why Pilots Care
Provides the only reliable path to the runway when visibility is too low for visual flight.
Intuition Check
Do not read terminal as the airport building. Here, terminal means the airport-area part of the flight; the TERP is the approved approach procedure for that area.
Example Sentence 1
The minimum descent altitude on the approach chart was set according to TERPS criteria to keep the aircraft clear of nearby terrain.
Example Sentence 2
Each TERP specifies altitudes, courses, and minimums that must be followed precisely during the approach.