Listen to how loud these engines are on this comercial jet. this is just one engine!! I think. Now how come when you/I are onboard the jet plane we barely hear the engines running?
What is Boeing and Airbus using for soundproofing for the cabin areas?
http://www.youtube.com/watch?v=OzMXj_3-p8o
I found this link while researching APU’s. When the main engine/s are not running the APU provides electric power to the plane, and compressed air, etc. I’m thinking some of the electrical cables you see hanging off the plane to the truck is electric power to the plane since the APU was dead.
