Posters discouraging Delta staff from joining a union prompt a significant backlash on social media.Read more
Southwest, Delta, and United airlines took to Twitter this morning to apologise for system-wide outages.
Southwest told fed-up passengers: "We're working through some technical difficulties".
Delta had a similar message for tired travellers: "Our team is working diligently to get this resolved and hope to have you on your way shortly".
United Airlines said: "It appears that we are experiencing an outage that is impacting our ability to create release paperwork".
However it looks as if the situation may have been been resolved, though it's not clear how many flights have been delayed - or cancelled - because of the outage.
Southwest just tweeted:
The shut down of the US government is having an impact on all sorts of industries.
Delta Air Lines will lose revenue of $25m this month as fewer government contractors are flying.
That's according to the airline's chief executive Phil LeBeau who was speaking to CNBC.
A woman who took a flight from Paris to the United States faces a $500 fine from U.S. Customs for failing to notify them she had an apple in her bag. She faces the penalty for failing to declare an agricultural item. Crystal Tadlock says cabin crew on a Delta Airlines flight gave passengers a free snack and she saved the apple to eat later on a connecting flight. Travel expert Simon Calder tells us many countries have strict rules on importing food to protect farming crops. (Picture: Apples on display in France. AFP/Getty Images.)
Georgia lawmakers have passed a bill fulfilling a Republican threat to deny Delta Air Lines a tax break after the firm cut ties with the US gun lobby.
Delta Air Lines ended its discount for members of the National Rifle Association (NRA) after a Florida school shooting left 17 people dead.
Georgia Republicans vowed to strip a bill of a jet fuel tax exemption that would benefit the carrier as a result.
Delta is one of several firms to end relations with the NRA in recent days.