US Boeing 737 operators are being ordered to retrofit their fleets with four newly developed rudder-system components, following the formal issue by the US Federal Aviation Administration of two airworthiness directives (ADs). The announcement follows a US National Transportation Safety Board report, urging the FAA to make its proposed AD mandatory as soon as possible (Flight International, 5-11 March, P10). The AD will affect an estimated 2,800 aircraft if the US rule is made mandatory worldwide. The changes have been prompted by two unexplained 737 fatal crashes where an uncommanded rudder hard-over is suspected.
Source: Flight International
