On October 31, 2016, about 1530 central daylight time, a Cirrus SR22 airplane, N454RK, experienced an engine fire while at the Baton Rouge Metropolitan Airport, Ryan Field, (KBTR), Baton Rouge, Louisiana. The airline transport rated pilot was not injured, and the airplane was substantially damaged during the accident. The airplane was registered to and operated by Johnnie Burrow, LLC, Longview, Texas, under the provisions of 14 Code of Federal Regulations Part 91 cross country flight. Day visual meteorological conditions prevailed at the time of the accident. The pilot reported that she had flown into the airport about 2.5 hours earlier, and then parked at the airport. Before departing for a return cross-country flight, the pilot conducted a normal preflight and engine start. About a minute after engine start, she heard a loud "pop", followed by the smell of smoke, an erratic engine sound, and the oil light illuminating. She shut down the engine and evacuated the airplane. Ground and fire department personnel responded and extinguished the engine fire. Examination of the engine compartment was conducted by an inspector from the Federal Aviation Administration (FAA) and a technical representative from Continental Motors, Inc. The examination revealed small hole in the fuel drain line near an adel clamp. The examination noted areas where fire/thermal damage was concentrated, such as, the fuel drain line past the hole location. An area on the bottom cowling, located directly under the drain line, and a spot near the bottom of the firewall area, also located just aft of the fuel drain line, had heavier damage. The fuel drain line assembly appeared consistent with the airframe manufacturer's assembly instructions.