The National Air Traffic Controllers Association also filed a lawsuit against the administration on Friday to force the government to pay its members for the hours they’ve worked since the shutdown began.

Besides the essential workers, a nearly equal number of federal workers are not deemed “essential” and have been placed on temporary leave. Their absence is affecting some functions ranging from FAA inspections of aircraft to CBP interviews with applicants for Global Entry status.

For example, about 3,300 safety inspectors under Federal Aviation Administration (FAA) have not been working. These are regulatory workers who certify the inspections done by the airlines and companies that repair aircraft. To offset this, the FAA has recalled a small number of inspectors to work, and has reassured travelers that their safety is not being compromised. Yet.