Under what conditions is the runway considered contaminated for the CRJ700 during takeoff?

The runway is considered contaminated during takeoff under specific conditions where the presence of moisture can compromise the aircraft's performance and safety. In the case of the CRJ700, one of the critical thresholds for contamination occurs when the Outside Air Temperature (OAT) is 5 degrees Celsius or lower and visible moisture is present. This combination creates an increased risk of the runway being covered in ice, snow, or slush, which can significantly impact traction and aircraft performance during takeoff.

This condition accounts for scenarios where moisture from precipitation, such as rain, sleet, or snow, might freeze upon contact with a cold surface, creating hazardous conditions. Therefore, when the OAT is at or below 5°C and there is visible moisture—such as rain, snow, or fog—pilots must recognize the potential for a contaminated runway and adjust their takeoff procedures accordingly to enhance safety.

The recognition of these landing conditions is crucial for effective performance calculations, speed adjustments, and overall flight safety decisions.