Definition
A specified altitude or height on a precision approach or approach with vertical guidance at which the pilot must initiate a missed approach if the required visual reference to continue the approach has not been established. Decision Altitude (DA) is referenced to mean sea level. Decision Height (DH) is referenced to the threshold elevation. This is the ICAO definition of the term.
Plain English
On a precision approach, this is the point on the way down where you must look up and decide: if you can see the runway environment, you keep going and land; if you cannot, you go around. DA is read off your altimeter (height above sea level). DH is how high you are above the runway threshold.
Context Anchor
Seen in instrument approach procedures, approach briefings, and ICAO-based definitions for precision approaches and approaches with vertical guidance.
Derivation
‘Decision’ comes from Latin decidere, meaning ‘to cut off’ or ‘to settle.’ At this altitude or height, the pilot literally cuts off the descent unless the runway is in sight — the moment of settlement between landing and going around.
Why Pilots Care
It is the last safe point to decide whether to land or go around, directly affecting safety and compliance with approach minima.
Grounding Statement
As the aircraft descends on final approach, this is the pre-set point where the pilot must already have the needed visual cues or go around.
Intuition Check
Do not read “decision” as “start thinking about what to do here.” The decision point is the latest point where the required condition must already be met; if it is not, the missed approach begins.
Example Sentence 1
At decision altitude, the captain saw the approach lights and continued the approach to landing.
Example Sentence 2
The pilot called decision height at 200 feet AGL and immediately initiated the go-around when the approach lights remained obscured by fog.