Be mindful about keeping an adequate amount of fuel in tanks, especially on 74s. A newfound phenomena about Hydro-Aire (Burbank) fuel pumps capable of reaching temperatures of 1,100 degrees Fahrenheit has triggered an FAA/Boeing Airworthiness Directive: Ordering additional quantities than previously thought of minimum fuel to be maintained in tanks. Only 900 degrees Fahrenheit is necessary to initiate spontaneous combustion of fuel vapors.
Emergency Airworthiness Directive