The Federal Aviation Administration (FAA) has ordered airlines to shut off fuel pumps on Boeing 737s when there is a low level of fuel remaining in the center tank.
Fuel tanks have been blamed for an explosion last month aboard a Thai Airways Boeing 737 and for the 1996 destruction of TWA Flight 800.
The FAA's action on Friday comes four years after the National Transportation Safety Board made a similar recommendation following the TWA Flight 800 crash.
Under the new rules, pilots must turn off the center fuel pump if there is less than 1,000 pounds of fuel in the tank. In addition, the pump must be turned off when the low fuel pressure lights are lit. Otherwise, the pump could overheat, increasing the chance of a fire.
The pump is used to move fuel from the center tank to the engines. Boeing spokesman Tim Neale said the Thai Airways' pump was running when there was very little fuel in the center tank.
The Thai Airways plane exploded on the tarmac in Bangkok, Thailand, last month. One crew member was killed and seven other airline staff were injured.
Flight 800, a Boeing 747 airplane, crashed on July 17, 1996, shortly after taking off from John F. Kennedy Airport in New York en route to Paris, killing all 230 people aboard.
Unlike similar guidelines issued earlier this month by Boeing, the FAA's directives must be followed, Neale said.
The FAA estimates that 1,501 737s would be affected in the U.S. The FAA also sends its rules to aviation regulatory agencies in other countries.
Besides requiring a certain amount of fuel in the tank before turning on the pump, the NTSB also recommended that installing insulation between the fuel tanks and heat-generating equipment, and pumping in gases that don't ignite in order to reduce the amount of air in a fuel tank. The NTSB has listed its fuel tank recommendations among its most-wanted safety improvements.
The FAA also has proposed new rules to change the way manufacturers and operators and airlines design, maintain and operate fuel tanks.