An American Airlines MD-80’s safety was jeopardized, according to the NTSB, due to an “unapproved and improper procedure used by mechanics to manually start one of the engines.” The accident, which resulted in an engine fire on departure followed by a go-around then an emergency landing, occurred on Sept. 28, 2007, in St. Louis. During the 13 days before the accident flight, the NTSB said, mechanics replaced the left engine’s turbine starter valve six times, although the valve replacement never solved the engine’s problem with starting using normal procedures. A mechanic’s use of an unapproved tool to initiate the start of the left engine damaged a component in the manual start mechanism, which “led to a sequence of events that resulted in the engine fire…” The NTSB faulted the airline’s continuing analysis and surveillance system for not recognizing “repeated failures to address the issue…” An American Airlines spokesman told AIN that the airline has already implemented most of the NTSB’s recommendations, including “installing a solution to the push-button [manual start valve] design that is prone to causing failures.”