Christopher Cline, founder of Foresight Energy, died with six others in a chaotic helicopter flight in 2019.
The mask requirement takes effect “immediately,” or as soon as agencies can enact it, the order said.
People have incrementally returned to the skies, but in far fewer numbers than normal.
The move could result in some locations being served by only one airline.
For the first time, the FAA has given approval for a commercial drone delivery service in some areas.
The delays may also have forced agreement on a possible temporary re-opening of the federal government.
But there were others that struggled as well.
Get ready for longer airport security lines as consequences of the government shutdown grow.
Despite bipartisan enthusiasm for the idea, several recent efforts to reach agreement on a major bill have faltered.
The technology would provide a quicker way to verify the identities of passengers.