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Guest danowat

Any soloution for the aggresive pitch up on AP?, A320

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Hi,I am still having this problem, and I am pretty sure it has not been cured yet.The A320 works very well, apart from the first AP activation.Now when I first engage the AP, I get MASSIVE amounts of pitch up, around 5500fpm, then the AP will "settle" down, and reduce the pitch to a more satisfactory level.How can I stop this big pitching?CheersDan.

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The pitch up is usually caused by the aircraft having shot through V2+10 after rotation, then when you engage the autopilot the computers try to get the speed back down to V2+10 until you reach acceleration altitude (as I'm sure you know V2+10 is shown by the magenta triangle on the speed tape of the PFD).One thing to try is to change the trim to -2.0UP on the F/CTL page of the lower ECAM. You do this with keypad 1 (with numlock off) and reduce trim with keypad 7. This adjusts the trim sufficiently that it will hold V2+10 and you are less likely to shoot through to a faster speed and then when the auopilot is engaged you won't experience the sharp pitch up.

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Yeah, I did wonder if it had something to do with the SRS.Now, does this mean the FDE is a little off?, because to hold V2+10 on TOGA thrust you need a hell of a lot of pitch up?I will try the trim and see if I can "tone" it down a little, would using a "fake" FLX thrust to derate the power on takeoff make it a little better?CheersDan.

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No I don't think the FDE is off, but the trim on the A320 under FS9 is which is why using a trim setting of -2.0UP will solve this particular problem.What is a "fake" flex thrust? You either have a flex setting of x degrees C up to a usual max of 60 deg C or you are using TOGA thrust. The default PSS setting is 42 deg C but depending on the conditions I have it going from anywhere from about 30 to the max of 60 (I know the MCDU allows it to 99 but no airline permits that). There is no such thing as fake flex. I will shortly be publishing an excel spreadsheet for calculating the flex to use, just a few issues with ISA temperatures at the moment.

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Hi,Thanks for taking the time to help, I really appreciate it.What I meant by the flex was, is it possible to lie by entering and different temp and derate the engines so I didnt have to pitch up so much, way over 17 deg, to keep it under control.Maybe I am wrong in thinking this, BUT, it does not matter now, as last night I flew V-Bird A320 from Niederrhein to Manchester, using your pitch -2.0UP "trick" and the take-off was excellent, it held V2+10 all the way to accel alt, with no excessive pitching, looked and felt absouloutly great, it was an extremely good flight all round, thanks very much for your helpCheersDan.

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Changing the flex temp won't really have any diference on the pitch on the initial climbout prior to a/p engage. I'm glad the trim adjustment worked for you as successfully as it does for me.

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Make sure that the speed button on the glareshield is set to V2+10. Left click the speed, heading and altitude buttons prior to take-off, on take-off follow the flight director bars untill the aircraft settles to V2+10, then connect the auto-pilot. There should be no pitch deviation, it works fine for me. The pitch is usually around 22deg which I believe is normal on initial take-off. The problem you are having is that you are allowing the speed to go much higher than V2+10, then if you connect the a/p the a/c tries to slow down by pitching up untill speed is achieved, then it will slowly pitch down again to maintain v2+10 untill flap accelleration altitude is reached. At tis point, "climb thrust" will flash on the PFD-you should then start your flap clean-up which automatically pitches down to achieve each new flap speed in turn. When you are clean, 250 kts will be commanded, when that is reached, the a/c goes into a normal climb, or whatever v/s you dial in.Hope this helps.

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Sory to bring up an old thread but I have a related problem. Whatever I do, I cannot get the aircraft (even at pitch -2.0up and yoke all the way back) to rotate until its going much faster then v2+10. Consequently, I have a huge pitch up on autopiliot activation. My fuel and payload setting are set properly in FS and in the MCDU (usually around 48.0 for ZFW and 9.0 for fuel). What am I doing wrong?

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