"Did your colleague help you out by taking a shift today? Flew somewhere all of a sudden?"
"Whether he flew today or not, he still covered a shift for me. Definitely have to pay it back as soon as possible."
"That's not something you need to hurry over right away, is it?"
"I have to pay it back before my next scheduling, otherwise, if it gets delayed and I'm supposed to fly, it won't qualify as a temp backup anymore."
"Sounds complicated."
"It's not really, same as car drivers can't drive when they're too tired. Pilots have duty time limitations. Sometimes, if a flight is delayed for too long and the crew's working hours exceed the daily limit, it's necessary to switch out the entire crew."
"They have to switch even after boarding the plane?"
"Yes, if it's over time, that situation can arise."
"All the passengers have boarded the plane already, and because of weather or some other reason, they wait on the plane, does that count as time?"
