What is the purpose of the Canadian Runway Friction Index?

• A. To calibrate radar altimeters.
• B. To quantify runway surface conditions for pilots on approach to a runway that is not dry or bare pavement.
• C. To measure air temperature on the runway.
• D. To determine optimum fuel load for landing.

Answer: (B)

The Canadian Runway Friction Index is a single-number gauge of how slippery a runway surface is, reflecting the braking action available on that surface. It’s specifically used when the runway isn’t dry or bare pavement—think wet, icy, snow-covered, or contaminated conditions—so pilots can gauge what braking performance to expect on approach and during landing. This information helps crews plan landing distance, speed management, and braking technique, and it supports safe operations when surface conditions aren’t ideal. It’s not about calibrating radar altimeters, measuring runway temperature, or determining fuel load, which are separate concerns.