MADISON, Miss. (AP) — An aerospace company spun off from a larger conglomerate will make its headquarters in central Mississippi. Vertex Aerospace announced Friday that it will invest $1.4 million and hire 70 front-office workers over the next two years at its Madison office. The company currently employs 340 there, and 856 more statewide. Private equity firm American Industrial Partners of New York bought Vertex in July from L3 Technologies for $540 million....