The Federal Aviation Administration, after finding several takeoff alarm systems not working properly, on Thursday ordered the warning devices tested on nearly 1,800 Boeing 727 and Boeing 737 jetliners.
The action, prompted in part by two fatal airline crashes, requires the tests to be conducted within 200 flight hours and repeated every 200 flight hours to make certain that pilots are warned if their planes are not properly configured to take off.
The takeoff alarms on the two model Boeing planes--two of the most widely used jet aircraft in commercial operation--sound a horn if the crew has forgotten to set, or has set improperly, a variety of control and operational devices in the cockpit.
The alarm failed to sound last year on a McDonnell Douglas MD-80 jet after the flight crew forgot to set the plane’s flaps, keeping it from gaining proper lift. The jet crashed seconds after taking off from Detroit Metropolitan Airport, killing 156 people.
Investigators have said the possibility remains that the pilots of a Delta Air Lines Boeing 727 may not have set the flaps on their plane Aug. 31 while taking off from Dallas-Ft. Worth International Airport, resulting in a crash that killed 14 people.