The flight is scheduled to land at 5:00PM.
此句中的动词不定式短语to land at 5:00PM 是主语补足语。又如:
Meetings are scheduled to take place all over the country. 会议安排在全国各地举行。(摘自《朗文当代高级英语辞典》第六版)
He is scheduled to visit the U.S.A. next year. 他预定于明年访问美国。(摘自《外研社英汉多功能词典》2008年7月第1版)