Airlines are canceling hundreds of flights to comply with the FAA's order. But there are still questions about the plan, which the agency says will keep the skies safe during the government shutdown.

Flight delays linked to the ongoing federal government shutdown continue, with this past weekend marking the worst for air traffic control staffing shortages since the shutdown began, according to a CNN analysis of Federal Aviation Administration operations plans.

Delays of nearly 1½ hours were anticipated for flights heading to LAX between 8 and 10 p.m. In San Diego, delays of 1 hour, 20 minutes were expected between 9 and 10 p.m.

The Federal Aviation Administration will reduce air traffic at many busy airports to maintain safety during the government shutdown, which has led to staffing shortages of air traffic controllers.

According to the FAA, it is highly competitive to become an air traffic controller, as candidates must be under 31 years old and pass yearly medical evaluations and multiple specialized tests, among other requirements. Controllers are also forced to retire at age 56.

For the second consecutive day, flights into Austin-Bergstrom International Airport are likely to experience widespread delays due to air traffic control staffing shortages as controllers at the airport continue to work without pay.