Definition
A NOTAM contraction used to report that ice is present on the surface of one or more runways at an airport, indicating reduced braking action and degraded directional control during takeoff and landing.
Plain English
A short code in airport notices that tells pilots there is ice on the runway.
Context Anchor
Seen in airport notices and runway condition information before departure, arrival, or taxi operations.
Why Pilots Care
Ice on the runway dramatically reduces tire grip. It lengthens stopping distance, makes crosswind handling harder, and can lead to loss of directional control. Knowing a runway is iced over directly affects go/no-go decisions, runway choice, and required landing distance calculations.
Grounding Statement
If a runway is marked IR, picture an aircraft trying to move on a hard surface that may not give the tires normal grip.
Intuition Check
IR does not mean instrument rating in this notice context. Here it means ice on runway or runways.
Example Sentence 1
The NOTAM included 'IR' for runway 27, so the crew calculated landing performance using a contaminated runway assumption.
Example Sentence 2
Ground control confirmed IR conditions and closed the runway until cleared.