Definition
An ICAO classification for an instrument approach procedure that uses a non-precision approach aid, such as VOR, NDB, or LOC, providing lateral guidance only with no electronic glide path.
Plain English
A type of instrument approach that helps the pilot line up with the runway side-to-side, but does not give an electronic descent path. The pilot manages the descent using altitudes published on the chart.
Context Anchor
Seen when a glossary entry, chart title, or line break begins a longer term starting with "Standard Instrument."
Derivation
"Standard" comes from older use meaning an official measure or accepted model. In aviation, it points to something established and published, not improvised. The "I" is not meaningful by itself here; it appears to be the start of "Instrument" in a longer term.
Why Pilots Care
Determines the minimum weather and equipment needed to conduct a legal instrument approach and land; misapplying the category can lead to an unstabilized approach or regulatory violation.
Grounding Statement
If only "Standard I" is visible, the full aviation meaning depends on the missing words that follow it.
Intuition Check
"Standard" does not just mean normal or better here; in FAA use it usually means officially established and published. The single letter "I" does not identify a procedure by itself.
Example Sentence 1
The VOR approach into the field was a Standard I procedure, so we briefed step-down altitudes rather than tracking a glide path.
Example Sentence 2
Because the airport only published a Standard I procedure, the crew could not continue the approach once visibility dropped below one-half mile.