Which of the following is not a valid maximum holding speed above 14,000 feet MSL?

The maximum holding speeds above 14,000 feet Mean Sea Level (MSL) are dictated by aviation regulations to ensure safe and efficient procedures during holding patterns. The limits are set to minimize the risk of stall while maintaining appropriate separation from other air traffic.

For aircraft operating in this altitude range, the maximum holding speed is generally 265 knots indicated airspeed (KIAS). Therefore, speeds such as 200 KIAS, 230 KIAS, and 180 KIAS fall within the permissible limits for holding above 14,000 feet.

While holding at 180 KIAS is a rate that may be acceptable for lower altitudes, it does not reach the designated thresholds for maximum speeds above 14,000 feet. Hence, 180 KIAS is recognized as not a valid maximum holding speed in these circumstances, making it the correct answer.