Definition
The straight-in landing minimums line published on an LDA approach chart when the procedure includes a glide slope. It specifies the lowest decision altitude (DA) and visibility a pilot may use to fly the LDA approach as a precision-style approach to a straight-in landing on the associated runway, provided the LDA course alignment with the runway is within prescribed limits.
Plain English
The lowest altitude and visibility you can use when flying an LDA approach that has a glide slope and is lined up well enough with the runway to land straight ahead.
Context Anchor
Seen in the minimums section of an instrument approach chart for an LDA approach that includes a glide slope.
Derivation
S = Straight-in; LDA = Localizer-type Directional Aid (a localizer-style course not aligned closely enough with the runway to be called an ILS); GS = Glide Slope. Read together: straight-in minimums for an LDA approach that has vertical guidance.
Why Pilots Care
Allows precision-like vertical guidance on approaches where a full ILS is not installed, improving safety and minimums.
Intuition Check
Do not read the S as standard; here it means straight-in. Do not use the /GS line unless the glide slope is available and being used.
Example Sentence 1
With the glide slope alive and the weather above minimums, we briefed the S-LDA/GS line for the approach into Roanoke.
Example Sentence 2
Flying the S-LDA/GS gave the crew vertical guidance down to decision altitude.