CNN  — 

Delta Airlines’ mask policy is not a suggestion, it’s mandatory. Passengers refusing to abide by the rule to keep masks on at all times (save eating or drinking) don’t get to fly with Delta. It’s just that simple.

As of August 27, Delta said it has banned roughly 240 people from flying with the carrier.

“Although rare, we continue to put passengers who refuse to follow the required face-covering rules on our no-fly list,” says Delta CEO Ed Bastian in an internal memo to employees shared with CNN.

The memo celebrates the opening of Delta’s new Salt Lake City hub and included references to the airline’s current state of affairs, its continued growth and the considerable impact that Covid-19 has had on managing the health and safety of staff and passengers.

“Systemwide, we continue to identify opportunities to speed up our airport projects and position Delta to lead in the recovery with world-class facilities that will help us transform the customer experience,” writes Bastian.

Masked skies

From compulsory mask rules to keeping middle seats empty and the reduction or elimination of food and drink service, struggling airlines are doing what they can to reduce the spread of coronavirus while trying to stay in business.

And make no mistake: Many, like Delta, couldn’t be more serious about following through with their pledges in the time of Covid-19.

Delta Airlines continues to provide service for passengers, provided they wear a mask on board the aircraft.

Since the advent of the policy, which Delta began implementing in June, the number of passengers on the no-fly list has more than doubled in less than a month. Bastian told CNN on August 7, “We’ve had well over 100 people that have refused to keep their mask on during the flight.”

The federal government has not implemented mask-wearing regulations, unlike the enforceable requirements around wearing seatbelts and not smoking on planes. This leaves it up to airlines to police passenger behavior, which has resulted in stringent new policies.

Passengers who decide to break the mask-wearing rules face consequences – like banning those passengers from future flights.

In the employee memo, Bastian said: “As we all work toward the recovery, it’s vital that we continue to stay focused on the drive to provide the safest, cleanest airports, aircraft and workspaces possible.”

No mask? No go

Less than three weeks ago, Delta had banned 100 passengers for refusing to wear masks; that number has now more than doubled.

The Atlanta-based airline requires passengers to wear masks starting at check-in. Last month, Delta began telling passengers who cannot wear a mask because of a health condition to consider staying home.

CNN’s Francesca Street recently wrote of unruly airplane travelers, many of whom could end up banned on Delta or other carriers with strict mask rules — if the unruly behavior involves refusing to wear a face covering.

CNN’s Michael Callahan contributed to this report.