Sunwing airlines has threatened to sue a Nova Scotia family for $50,000 after their unruly behaviour forced a flight to make an emergency landing in Bermuda on Friday.

The airline alleges the Cape Breton family -- David McNeil Sr., his wife Donna and their 22-year-old son David Jr -- lit up cigarettes on the plane and verbally abused crew members.

David Sr. and his wife appeared in Bermuda court this week to answer charges related to the mid-air altercation.

David Sr. pleaded guilty to behaving in a disorderly manner and calling one member of the crew a "f---ing a--hole," reports the Royal Gazette newspaper in Bermuda.

Donna pleaded guilty to disobeying a lawful command on the flight from Halifax to the Dominican Republic.

David Jr. was initially charged with smoking on an aircraft, but prosecutors decided not to proceed with the charges when he pleaded not guilty.

A judge fined the mother and father $500 each.

But that's not enough for Sunwing, which says the diversion cost the airline $50.000. The company told the Halifax Chronicle Herald newspaper it would sue the MacNeils.

"That's based on the cost of the landing fees in Bermuda (and) the cost of flying a mechanic to Bermuda to check the aircraft out for stress fractures because it had to land overweight, because of the amount of fuel that was on board," spokesman Daryl McWillians told the paper.