Washington (CNN) -- Two days after a Federal Aviation Administration official told contractors that steps were being taken to shut down 168 air traffic control towers on April 1, the agency gave the towers an unexpected reprieve Friday, saying the official's comments were "unauthorized."
In a telephone conference call on Wednesday, an FAA official told contractors who operate the towers they would soon be receiving a letter giving notice that 168 towers would be closed on the first day of April because of government-wide spending cuts that were set in motion on Friday night.
Another 16 towers would be closed on September 30, the end of the fiscal year, the official said.
But the news -- devastating to the three companies and hundreds of employees who staff the towers -- was short-lived.
On Friday, the FAA arranged a second conference call, retracting without explanation the earlier call, according to Spencer Dickerson, head of the U.S. Control Tower Association.
The contractors were told that the first call "was not an authorized call," Dickerson said.
But Dickerson questioned that.
The Wednesday conference call "wasn't just some coffee break conversation at the water cooler," he said, saying it included FAA officials and representatives of all three contractors who operate FAA control towers in the United States.
The move prolongs operation of the contract towers at least a couple of weeks, said Shane Cordes, head of Midwest ATC Service, who called the change "good news."
"It is my understanding that we will hear official news from the FAA in the coming days and coming weeks, and until such time we won't have any definitive guidance on whether or not our towers will face closure," Cordes said.
Said Dickerson, "Quite frankly, I don't think it changes the outcome. I think they'll still be closing all these towers. It just may be on a different schedule."
While the FAA has said it may have to close more than 100 control towers, it has given few specifics.
It has released a list of towers on a list of potential closings, targeting those with fewer than 150,000 aircraft operations (take-offs and landings) or 10,000 commercial operations a year.
Tower closures would not necessarily result in airport closures, because some aircraft can land without ATC help, and those that need controller help can communicate with more distant FAA facilities.
Contract controllers are a widely used but little-known part of the FAA's air traffic control system. About 250 of the nation's 374 towers are staffed by contactors, though they must meet FAA standards and are overseen by FAA managers. Restricted to lower-volume airports, contract towers nonetheless handle 28 percent of all domestic airport operations.
A 2011 report by the Department of Transportation's Office of Inspector General said contract towers cost on average $537,000 a year to operate, compared to $2 million for comparably busy FAA-staffed towers.
The lower costs were chiefly due to lower staffing and salary levels at contract towers. Contract towers had an average of six controllers, while FAA towers had 16. And a typical contract controller near Tampa received a base pay of $56,000 per year compared to a base pay ranging from $63,000 to $85,000 a year for an FAA controller in Sarasota, Florida, the study said.
Dickerson said contract towers are carrying the brunt of the cuts, despite having comparable safety records and being more cost efficient.
But the forced government spending cuts, known as sequestration, are also impacting FAA staff.
Most of the agency's 47,000 workers, including its 14,700 controllers, have been told to expect one- or two-furlough days every two-week pay period. And 49 FAA-staffed towers are on the list of those facing possible closure.