Definition
A condition on certain instrument approach charts where the published landing minimums are split into two separate values: one that applies when the full approach procedure is flown with all required navigation aids and components operative, and another, higher set that applies when a component is inoperative, the procedure is flown without a procedure turn, or some other charted condition exists. The pilot must determine which set applies before beginning the approach and use those minimums for the descent and missed approach decision.
Plain English
Some approach charts list two different minimum altitudes and visibilities for landing. Which one you must use depends on the equipment that's working and how you're flying the approach. You pick the correct set before you start, and that's the minimum you fly to.
Context Anchor
Seen in the minimums area and notes on an instrument approach chart, especially when the missed approach requires a certain climb performance.
Derivation
Minimum comes from the Latin minimus, meaning “smallest.” In aviation, minimums are the lowest allowed limits, not suggested targets. That matters here because each set is a different legal and safety floor for using the approach.
Why Pilots Care
Knowing which set applies prevents a pilot from descending below a safe altitude while attempting a missed approach that has its own, often higher, requirements.
Intuition Check
Do not read two sets of minimums as two equal choices. They are conditional: the lower set is only for the aircraft and conditions that meet the stated requirement.
Example Sentence 1
During the approach briefing, the captain noted that the chart had two sets of minimums and confirmed they would use the higher set because the approach lighting system was reported out of service.
Example Sentence 2
Because the procedure lists two sets of minimums, the crew briefed the higher altitude required if they had to go around.