“We are requesting this action not only for the benefit of the traveling public, but also for the thousands of airline employees charged with enforcing a patchwork of now-outdated regulations implemented in response to Covid-19,” the group said.

The Association of Flight Attendants-CWA, the largest union of such workers, didn’t lobby for the recent mask extension, but said it expected the requirement to remain in place. The union couldn’t immediately be reached for comment on the letter.

The Association of Professional Flight Attendants, which represents about 22,000 American Airlines Group Inc. employees, previously said it didn’t oppose an extension of the mask rule, but was “looking forward to the day that it is no longer needed.”