According to avweb, the Seattle Times published that Boeing will rewire the stability control system and avionics of all 800 Boeing 737 Max aircraft and will no longer try to obtain immunity through the FAA. During the overall inspection of the aircraft, Boeing found that the harness of the connecting point did not separate the low-voltage wire from the high-voltage wire. It is worrying that the so-called “thermal short circuit” in the high-voltage wire may send a false signal to the motor through the low-voltage wire, causing the stabilizer to move. It was later found that other areas of the aircraft also had unqualified beam lines.
Boeing said that the previous Boeing 737 model also adopted the same wiring settings. The model accumulated 205 million hours of flight time without any problems. The ng model was certified before the current cabling standard was implemented. In the late 1990s, a Boeing 747 of TWA and a MD-11 of Swiss Airlines crashed due to wiring problems. The FAA then formulated new standards and hoped that all aircraft would meet the new standards. Boeing “must demonstrate compliance with all certification standards,” the company said in a statement last week
Boeing began a repair program over the weekend, starting with its aircraft stored in Seattle and lake mosey in Washington. Those already delivered may be repaired when they get the new flight control software and are ready to return to service. This may cause some delays because it takes about five days to rewire the harness for each aircraft. In addition to the tail work, the avionics box and shelf under the cabin must be removed at 10 to 12 positions. A source told the times: “we will put a protective shell on the wire and install it, and re lay a new harness separate from the power line.”
The FAA has not yet issued an announcement of the repair procedure, but it is likely to give operators some time to comply. The times said that some airlines may insist on rewiring before go around.
Responsible editor; zl