Definition
The minimum descent altitude (MDA) or decision altitude/height (DA/DH) and visibility values published on an instrument approach chart that authorize a pilot to land on the runway aligned with the final approach course. These minimums apply when the final approach track is within 30 degrees of the runway centerline and a normal descent can be made from the MDA or DA to that runway.
Plain English
The lowest altitude and least visibility a pilot is allowed to use when flying an instrument approach that lines up with the runway directly. If the weather is below these numbers, the pilot cannot land straight ahead from that approach.
Context Anchor
Seen on instrument approach charts in the minimums section for a specific runway.
Derivation
Minimum comes from the Latin word meaning “smallest.” That fits the aviation use: these are the smallest allowed values for altitude or height and visibility before landing may continue.
Why Pilots Care
Using the correct straight-in minimums lets the pilot land with less maneuvering and lower fuel burn when weather permits; choosing them incorrectly can lead to an unsafe descent or a missed approach.
Intuition Check
Do not assume “straight-in” means you are automatically cleared or required to land straight ahead. It only identifies which published landing limits apply if you are using that runway directly from the approach.
Example Sentence 1
The straight-in landing minimums for the ILS approach were 200 feet and half a mile, so the crew briefed the decision altitude before starting the descent.
Example Sentence 2
With the reported visibility at 3/4 mile, the crew could not use the straight-in landing minimums and requested the circling approach instead.