Why is the FAA using the runway in good weather when it was described as a runway needed in poor weather?
The third runway was built primarily to address lower visibility conditions surrounding Sea-Tac Airport. However, the third runway was also built to improve operational efficiency during peak periods in any weather condition. Regardless of the weather, during peak periods the third runway, along with the easternmost runway, will be used for arrivals in order to help reduce delays. Therefore, you can expect the third runway to be used during peak periods nearly every day. However, in general, the FAA does not expect the third runway to be needed as often in good weather conditions as it will be when there are lower visibility conditions.
