CEDAR RAPIDS — United Technologies Corp. announced the completion of its acquisition of Rockwell Collins late Monday, more than a year after it declared its plans to buy Cedar Rapids’ largest employer.Rockwell will combine with Charlotte, N.C.-based UTC Aerospace Systems to form Collins Aerospace Systems. Collins Aerospace spokeswoman Pam Tvrdy-Cleary said there are no immediate changes planned as to how many employees will be based in Cedar Rapids or Collins Aerospace’s other locations in Eastern Iowa.It will have some 70,000 employees, and Kelly Ortberg, Rockwell Collins chief executive officer and president, will be CEO of Collins Aerospace.