On 2 July 2015, the left engine of a Bombarier CRJ 700A exiting the runway after landing at Denver caught fire and continued burning after the aircraft had been stopped on the taxiway and the engine shut down. The Investigation found that the fuel supply to the fuel-operated engine performance valve had failed and the quantity of fuel which then leaked had overwhelmed the engine cowl drain capacity and ignited. A history of similar failures was found and this one resulted in the introduction of additional mandatory in-serviced checks pending the replacement of the valve concerned with an improved design.