NTSB Urges Windshield Fixes

The National Transportation Safety Board (NTSB), critical of years of delays, is urging Boeing to issue a service bulletin (SB) and the Federal Aviation Administration (FAA) to issue airworthiness directives (ADs) to fix hazardous cockpit windshields that have caused fires on at least nine Boeing commercial transports. In January 2004, there were two incidents in which electrical fires started near the windshields of Boeing 757-200s. Boeing then informed the Safety Board and the FAA that there were at least four other events on 747s, 757s, 767s and 777s, and three other 757 incidents between May 2004 and April 2006. Boeing determined that the cause of the electrical fires was cross-threading of screws that attach the power wire to the windshield heat terminal block. The terminal block was redesigned to incorporate a pin/socket connector, instead of the screw. The redesigned terminal block went into new production aircraft starting in mid-2004. Boeing issued a series of SBs calling for fixes to pre-2004 model airplanes, and the FAA said ADs making the Boeing service bulletins mandatory would follow. But disagreements between Boeing and the FAA regarding the 767’s SB and the FAA’s ADs have kept all the installations from being completed, prompting the Sept. 4, 2007 NTSB recommendation letter. “The Board considers any kind of fire and/or smoke in the cockpit to be a serious issue.”