Definition
An instrument approach procedure that uses a Localizer-Type Directional Aid (LDA) for lateral guidance combined with an electronic glideslope for vertical guidance. The LDA provides course guidance comparable in accuracy to a localizer, but its course is not aligned with the runway centerline (typically offset by more than 3 degrees), so the approach is not classified as a precision approach even though it provides both lateral and vertical electronic guidance.
Plain English
An approach that gives you a left-right needle and an up-down needle, like an ILS, but the left-right path is not lined up with the runway. You follow it down to a point where you can see the runway, then maneuver visually to land.
Context Anchor
Seen on instrument approach charts where an LDA approach includes vertical guidance from a glideslope.
Derivation
LDA stands for Localizer-Type Directional Aid. "Glideslope" combines "glide" (a controlled descent without power increase) and "slope" (an inclined path). Together the name tells you what equipment is in use: a localizer-style course that isn't aligned with the runway, plus a glideslope for descent guidance.
Why Pilots Care
Supplies vertical guidance on precision-like approaches where a full ILS is unavailable, reducing the risk of controlled flight into terrain on offset finals.
Intuition Check
Do not assume “glideslope” means the approach is an ILS. Here, the glideslope gives vertical guidance, but the LDA course may still point at the runway from an angle.
Example Sentence 1
Roanoke's LDA/Glideslope Rwy 6 approach is used when terrain prevents an aligned ILS, so we'll fly the offset course down to minimums and then sidestep visually to the runway.
Example Sentence 2
Because the LDA/Glideslope course is offset, the pilot began the circling maneuver after reaching the published minimums.