Originally Posted by
teddybear99
I would assume that during an ID check, most airlines would not let you board if your passport was expired. You would most likely be sent to your country's Embassy to renew or at least get a waiver to travel back to your home country.
Agreed. An Emergency Travel Document is what we call it in the UK and can be applied for if:
"your passport has been lost, stolen, damaged, is full, has recently expired or is with HM Passport Office or a foreign embassy"
plus a few other conditions.