Ashlee Rezin/Chicago Sun-Times, The Chicago Transit Authority’s planned Red Line extension has made a “significant” step toward securing about $1 billion in federal funds, the transit agency announced Monday. Without the Federal Transportation Administration’s preliminary approval of the CTA’s plans, the project likely would have hit a dead-end, CTA officials said. But officials also said train service on the 5.6-mile extension — if the federal money is approved — is set to begin in 2029, three years later than originally planned. The earlier date was a preliminary estimate and based on “limited information,” according to the CTA. The CTA now has two years to complete the next phase, which includes finalizing the project’s environmental impact statement and drawing up preliminary engineering documents.