Airworthiness Directives; Boeing Model 737 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 737 series airplanes. This action requires revising the Airplane Flight Manual to prohibit extended dry operation of the center tank fuel pumps (with no fuel passing through the pumps). This action is necessary to prevent ignition of fuel vapors due to the generation of sparks and a potential ignition source inside the center tank caused by metal-to-metal contact during dry fuel pump operation, which could result in a fire or explosion of the fuel tank. This action is intended to address the identified unsafe condition.