On March 22, 257 United Airlines passengers aboard their flight from LA heading to Shanghai, China, got a mid-air announcement they weren’t expecting. Two hours into the trip, the airplane would redirect to San Francisco International Airport, where passengers would sit until the airline worked out an unusual problem.

The pilot on United flight 198 forgot his passport.

What’s really strange is that this happened on a different United Airlines flight a week prior

Oddly, another flight on March 14, United 857, also aborted due to the pilot missing their passport.

This flight took off from SFO and also headed to Shanghai before cancelling.

The most recent batch of flyers subjected to the pilot’s error got hit with a 6-hour delay until another crew (wielding passports) arrived at SFO to restart the journey.

United Airlines told multiple outlets that it gave passengers on 198 some meal vouchers and “compensation.” CNN confirmed that one passenger said they’d followed the airline’s instructions to file a claim for “compensation,” but didn’t have a clue what it would lead to. They also said United gave them two meal vouchers totalling $30.

Wait…pilots don’t have to show a passport to board an international flight?

While the TSA doesn’t require pilots to carry passports during international travel (apparently), SFGATE.com reached out to the FAA. A spokesperson there responded that it doesn’t require them, either. The airlines would all have their own requirements and procedures about passports, they said.

Getting stuck at airport customs is far from ideal, of course, but if a passenger doesn’t have their passport, they can’t even board an international flight. Maybe the rules should change so that the crew can’t board before showing theirs, either. In any case, it seems like United Airlines has some pre-flight procedural checks to put into place.