Tina Swail, spokeswoman for U.S. Airways, said the flight bound for Charlotte, N.C., was supposed to leave at 7 a.m. but was delayed for two hours because the inbound plane with the flight's crew had been late and rules state they must receive at least two hours of rest before their next flight, The Des Moines Register reported Monday.
Swail confirmed the plane was further delayed until just after 1 p.m. because of a passenger's comment about crew drinking led officials to administer drug tests, which all crew members passed.
"Any accusation of this sort is taken very seriously and out of an abundance of caution the crew was administered a drug test," Swail said.
Passenger Glenn Clark, who was traveling with his wife, said he heard a passenger boarding the plane ask the crew if they had partied too much last night. He said the man and other passengers laughed at the comment.
"He said it jokingly, and I didn't really think much of it, personally," he said.