Westover Air Reserve Base aircraft maintainers were out Thursday in 4-degree weather working on the base’s massive C-5M Super Galaxy cargo jets. But more of that work will happen inside once a $46.2 million hangar is built, probably by the year 2022. The new hangar, to be called the Regional ISO Maintenance Hangar, was announced at a Thursday news conference. It will be the size of two football fields and more than 90 feet tall inside, said Col. David C. Post, commander of the of the 439th Maintenance Group at Westover. That’s big enough to fit the tail section of a C-5M, the largest aircraft in the U.S. Air Force fleet.