The air control tower at Norwood Memorial Airport will be one of the five Massachusetts airport towers closing after April 7, when the FAA will begin a four-week, phased closure of 149 air control towers throughout the country. The closures are the result of across-the-board budget cuts known as sequestration. Christopher R. Donovan of Boston Executive Helicopters, headquartered at Norwood Airport, predicts the tower closing will “have no effect” on his work. The towers in most airports in the US are unmanned, and licensed pilots are trained to work without them. Pilots will still be able to turn runway lights on and off and coordinate takeoffs and landings from their cockpits.