Increasing efficiency Available to Purchase

On take‐off at sea level conditions, the burner section of the JT9D‐7 and‐15 engines reaches 2,350°F. In the Boeing 747 and McDonnell Douglas DC‐10, developing 45,500lb of thrust, the turbine blades need to be kept at some 500° cooler at 1,850°F, to preserve the metal. Two per cent of the total engine airflow streams at a rate of 51b/scc through 2,900 needle thin holes which have to be bored in the baffles.