While the government still suggests against non-essential travel, flights are still leaving airports across the country. In order to make it as safe as possible and follow CDC as best as possible inside an aircraft, the list of airlines requiring passengers to wear masks is growing.

Delta and United have joined JetBlue and Frontier on the list of American carriers, and Lufthansa made its policy public Thursday night as well.

United began requiring employees to wear face masks on April 24, calling it and other precautions “a new way of life for us all.”

Those include boarding fewer customers at a time and starting from the back of the plane to avoid crowding in the gate area, on the jet bridge and in the aisle, blocking middle seats and, in May, making the masks mandatory and offering them to passengers who don’t have them.

Frontier’s requirement of all passengers to wear a face-covering over their nose and mouth at the airline’s ticket counters, gate areas and onboard aircraft goes into effect May 8. Very young children, for whom a face covering is inadvisable, will be exempt from the policy. Face coverings have been required for Frontier flight crews since April 13.

Earlier this month Frontier implemented a program that required passengers to accept a health acknowledgment before completing check-in via the Frontier’s website or mobile app.

Passengers are required to certify that:

  • Neither they nor anyone in their household has exhibited Covid-19 related symptoms in the last 14 days
  • They will check their temperature before heading to the airport and not travel if they have a fever
  • They will wash their hands/sanitize before boarding the flight

To support social distancing during flights, Frontier has blocked every other row on its planes and allows customers to change seats once onboard.