Not every air traffic control tower slated for shutdown will stop operating at once, according to an FAA list posted online by AOPA on Monday. The first group of 24 towers will close on April 7, another 46 on April 21, and 79 on May 5. The Lakeland, Fla., tower will remain open until April 21, giving the Sun ‘n Fun organizers a respite from having to hire their own ATC staff for the event, which runs April 9 to 14. AOPA said the closing dates were based on activity levels, with the towers that handle the fewest commercial operations closing first. FAA spokesperson Laura Brown told AVweb on Tuesday the posted lists are “pre-decisional.” She added, “We should have a final official list in the next day or so.”