Earlier today in Puget Sound, a Asiana Airlines Boeing 777-200ER (HL7700) lost an engine after taking off from Seattle-Tacoma Airport. The aircraft was spotted with the engine engulfed in flames, which the pilots extinguished, dumped fuel, and returned safely to SEA-TAC.
Upon hearing of the incident, I was immediately reminded of a feature built into the 777 fly-by-wire system that automatically that provides added stability and reduces pilot workload in the event of an engine emergency. The system, called Thrust Asymmetry Compensation (TAC), automatically applies rudder if one engine is producing more thrust than the other, as would be the case in the event of a shutdown.
The system doesn't fully eliminate all aircraft yaw, and requires the pilot to compensate manually with additional rudder inputs to ensure they're aware which engine has failed.
Here's a video from a 777 simulator that demonstrates the functionality of TAC.
Upon hearing of the incident, I was immediately reminded of a feature built into the 777 fly-by-wire system that automatically that provides added stability and reduces pilot workload in the event of an engine emergency. The system, called Thrust Asymmetry Compensation (TAC), automatically applies rudder if one engine is producing more thrust than the other, as would be the case in the event of a shutdown.
The system doesn't fully eliminate all aircraft yaw, and requires the pilot to compensate manually with additional rudder inputs to ensure they're aware which engine has failed.
Here's a video from a 777 simulator that demonstrates the functionality of TAC.
on April 30, 2009 3:44 PM | Reply
Good post relating one incident to a good video about the layers of safety built into modern aircrafts. Just a small note about TAC: The Primary Flight Computers limit the TAC authority to 60 percent of available rudder travel (as per Boeing 777 maintenance manuals).