Originally Posted by
FlyJSH
For those of us unfamiliar with Airbus systems, perhaps someone who knows could describe the hydraulic systems. Thanks."
The A-320 has 3 hydraulic systems. Instead of numbering them 1,2,3... they're called green, yellow, and blue. Green and yellow normally powered by engine driven pumps. Blue has electric motor pump and can also be powered by RAT.
Originally Posted by
teedog
If they lost yellow system hyd they should have landed overweight. The worst case they would have needed was 4400 feet of runway that is with a 1.25 correction @ 170k. One of the reasons they were rocking back and fourth could have been because they were in alt law with the loss of yellow.
But we were not there so we don't know what all the reasons were.
The RUMOR is that it was loss of Green and Yellow systems, which would be a 2.8 correction @170k (10,276') @ sea level/ISA. Some items lost include autopilot, anti-skid, nose wheel steering, both thrust reversers, and 8 out of 10 ground spoiler panels. Additionally, you'd have only 7 applications of the brakes, would have to gravity extend the gear with handcrank, and the airplane would be handling just like a c-172 as opposed to the smoother control of fly-by-wire.
Just my 2 cents.