Tucson’s Ryan Airfield and three other Arizona airports remain on a list of small airports that face closure of their contractor-operated air-traffic control towers April 7 as part of automatic federal budget cuts expected to start kicking in next week.

Though aviation officials say the cuts will jeopardize air safety, the closures look more likely after efforts in Congress to stave off the closures failed this week.

The Federal Aviation Administration today sent email updates to small airports, saying that two dozen of the 189 contract towers targeted for closure have been dropped from the list.

Ryan and three other Arizona airports — Glendale Municipal Airport, Phoenix Goodyear Airport and Laughlin-Bullhead International Airport — remain on the planned closure list.

Under the FAA’s original plan to deal with the automatic cuts known as sequestration, contract towers at 173 small airports would close April 7, while 16 others would close by year’s end.

In its update today, the FAA said towers at 24 airports that had appealed their possible closures will remain open “because closing them would have a negative impact on the national interest.” Airports had been allowed to file arguments showing their tower operations were in the national interest.

The Tucson Airport Authority, which runs Ryan as well as Tucson International Airport, had petitioned the FAA to keep the Ryan tower open. Today, the authority issued a statement thanking Arizona's congressional delegation and local officials for supporting its appeal, and noting that flight operations will continue at Ryan without the tower.

A bipartisan amendment pushed this week by Senator Jerry Moran (R-Kan.) would have forestalled the closures by shifting $50 million in FAA research funding to the contract-tower program. But a vote on that amendment was blocked, so it wasn’t included in a stopgap spending measure passed by Congress and signed by President Obama on Thursday.

Even if the control tower is closed, Ryan Airfield and the other affected airports will remain open for flight operations. Without a tower, pilots will have to coordinate takeoffs and landings themselves via radio and visual contact, as they do now at night when the tower isn’t open.