Preferential runway selection
Preferential runway: runway ATC assigns at a controlled airport instead of the one most aligned into the wind, picked "for noise abatement or for other reasons" (TC AIM RAC 4.1.3).
Controllers weigh:
- Runway condition
- Effective crosswind component
- Effective tailwind component
Max effective components:
| Component | Runway | Max |
|---|---|---|
| Crosswind | Dry | 25 kt |
| Crosswind | Wet | 15 kt |
| Tailwind | Any | 5 kt |
Can stay in use once more than 25% contaminated only if ALL four hold:
- Contamination TRACE depth only.
- Crosswind component not over 15 kt.
- CRFI on every segment greater than 0.40.
- No pilot braking-action report less than "good."
Any one fails: ATC must switch to the runway most nearly aligned into the wind.
Trap: "for noise abatement or for other reasons": preferential-runway questions are not always about noise.
References
- TC AIM RAC 4.1.3