MONTGOMERY, Ala. (AP) — Federal officials say a Delta Air Lines flight has made an unplanned landing in Montgomery, Ala. because the crew said they smelled smoke in the cockpit area. Federal Aviation Administration spokeswoman Kathleen Bergen says a Boeing 757 was flying from Cancun, Mexico when the crew reported the odor Sunday afternoon. Delta Air Lines spokesman Russell Cason says a fluorescent bulb ballast burned out and caused the smell. It wasn't immediately clear if the piece of equipment was inside the cockpit area. Cason says 184 passengers and six crew members deplaned at the Montgomery Regional Airport. A replacement aircraft is scheduled to get passengers and crew members to Atlanta about four hours later than originally scheduled. Bergen says the FAA is investigating.