Originally Posted by
Mad (Flt) Scientist
*caveat: except POSSIBLY FBW-envelope protected types *cough*Airbus*cough* - but even those may not be fully immune.
A320s envelope protection through FBW does not extend to yaw/sideslip. And thatīs because, once again,
rudder is not primary control on any transport category aircraft and shouldnīt be used as such. (not pointed at you Mad(flt)Sceintist, i got your point, just for the ones who might say that Airbus should protect their airplanes in yaw too). Of course you can and will use it to roll the plane but only after all of your ailerons and roll spoilers are rendered inoperative and thatīs fairly unlikely event. Rolling with rudder while your roll control channel is operative will most likely lead to PIO (or APC if youīre newspeakīs fan) and PIO leads to... AA587. Just take a look at NTSB animation of cockpit control movements.
Despite JTīs warning to play the ball and not the man, I really, but really have the urge to comment on some posters here. I think it was mid 2002 when we got the letter from mr Caldarelli of ATR, not to use rudder for roll control and warning we might shed a tail if we donīt obey. Soon after that, the yellow FCOM pages arrived and by winter they were replaced by white pages, conveying the same message. Recently Iīve exchanged ATR FCOM for A320īs and there was the message again: donīt roll airplane with rudder and donīt cycle rudder, because when oscillations start, flying below Va does not offer protection. I think that every FCOM (AFM, POH. OM-B...) of the transport category airplane in the world has the same warning nowadays, as a result of AA587 accident. So people who are unable to grasp the significance of the warning, either donīt have the FCOM, or worse, have the FCOM but donīt bother to read it. I hope that no one here falls within bounds of second cathegory.