Definition
The Landing Threshold Point (LTP) is a specific three-dimensional point at the runway threshold, defined by latitude, longitude, and elevation, that anchors the final approach path of an instrument approach procedure. For RNAV (GPS) and LPV approaches, the LTP sits on the runway centerline at the threshold and serves as the origin from which the glidepath angle is measured.
Plain English
It is an exact point at the start of the landing runway that the approach is built around. The descent path the aircraft follows on an instrument approach is aimed at this point.
Context Anchor
Seen in instrument approach procedure data and runway threshold references.
Derivation
The term is built from plain English: 'landing threshold' is the beginning of the runway available for landing, and 'point' specifies that it is a precise, surveyed location rather than an area. The word 'threshold' comes from Old English meaning the entry point of a doorway — here, the entry point of the usable runway.
Why Pilots Care
It fixes the precise touchdown reference so the calculated glidepath brings the airplane to the correct landing point on the runway.
Intuition Check
Do not read “threshold” as a general boundary or decision point. Here it means the beginning of the runway surface that is available for landing.
Example Sentence 1
The published glidepath angle for the RNAV approach is measured from the LTP at the approach end of Runway 27.
Example Sentence 2
During the final approach segment the navigation system references the LTP to keep the aircraft on the proper vertical path.