Quote:
Originally Posted by gums
Give me a 'bus and I believe I can duplicate the scenario easily.
DJ77
Not so sure you could.
I think the scenario you describe explains why the “bus” FBW computers calculate a “phase advanced AoA” as mentioned in the A340 zoom climb incident report. Remember the bus has a pitch attitude protection (IIRC: 30 deg NU progressively reduced to 25 deg at low speed). With that limitation and factoring pitch inertial moment and tail effectiveness it must be relatively easy to anticipate and prevent the AoA to become greater than alpha prot. Of course, this works only in normal law.
DJ77, I think we have already seen what can be done with an aircraft when it doesn't have good airspeed information to the computers. I concur with Gums that it would be easy to duplicate this scenario. Wouldn't be that hard to do any number of aerobatic maneuvers that you are not supposed to do with the beast. You would just have to sit down and do the calculations first to avoid breaking things.
Even the direct hydraulic control A-4 Skyhawk and F-4 Phantom could run out of control effectiveness and end up back sliding/falling at higher nose up attitudes.
I would hate to take an F-4 in autopilot Control stick steering mode (which is very much like the mode that AF447 was in when it lost control) and do anything but essentially level flight. (You former F-4 flyers should remember what this was like). It would be too easy to set an unstable attitude and decelerate/accelerate. (basically a pure attitude hold).
The control inputs made by the AF447 crew as presented to date by BEA only seem to make sense WRT seat of the pants flying. I hope BEA has been able to make some sense of the control inputs and their rationale when they give their next interim report.
I'm having trouble believing that there was almost no scan of the instrument panel going on.
JD-EE. That was a very respectable explanation for the problems with Dutch_M's "paper." Newtonian Physics should work properly in any frame of reference and give consistent results. When it doesn't work out that way, then there is a problem with the analysis.
