Boeing Suggests Tests of Its Rudder System

Boeing Co. recommended that airlines flying its 737 aircraft test the rudder power control units to see if they are at risk of jamming, an event that could cause the planes to roll. Seattle-based Boeing said it discovered the potential for jams during a test of the control unit under extreme temperatures that would never be encountered by an aircraft in commercial service. The 737 rudder system has been under scrutiny because two 737s have crashed without apparent cause in the last five years. Boeing executives said the rudder power controls from those 737s were examined by the National Transportation Safety Board and that no jamming was detected. The company said it is designing a new piece of equipment that it will install in all 737s in service.