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Guest Applebe

747-400 Autopilot

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Guest Applebe

Hi guys and girls, First off i would like to say thanks to the pmdg team for a wonderfull aircraft it truly makes flightsim "AS REAL AS IT GETS".My problem is with the autopilot when selecting a desired altitude in the autopilot box and a good vertical speed the autopilot completely ignores the command to capture an altitude with the disered vertical speed and goes past the altitude with erratic vert speed commands.Its alomst like the autopilot is turned off, check my screen shot of the problem note the red boxes.Apart from that i havent tested anything else so will post anmore problems if i find any.PaulNew Zealand

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Guest brettdonahue

Glad that I am not a passenger on your flight Out of curiosity, when are the conditions when you turn autopilot on? I personally have never had this happen. For me I turn F/D on, A/T on and have the correct values set before taking off. Then roughly between 500' - 1000' I hit the Autpilot CMD which illuminates the ALT Hold and the SPD, then I hit the V/S button and adjust accordingly since when you hit the V/S button it will pick up the current rate of climb. This seems to be good for me.http://forums.avsim.net/user_files/137729.jpgBretthttp://www.precisionmanuals.com/images/forum/800driver.jpg

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LOLWhat is it with 744 pilots and early AP engagement? When I fly the 767, I do a bit of manual flying first.Just giving some trouble...Paul

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Guest D17S

First, pitch mode is in V/S something in the MCP V/S window.Deck angle at 20+ degrees as pitch dutifully tries to comply with the V/S commanded. MCP set to 250IAS at 210Autothrottle

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Paul,Go to PMDG Menu/Options/AFDS.See whether your AP Elevator/Aileron/Rudder control override box is ticked. If YES then make sure your joystick is well calibrated and an adequate null zone is defined. Else the AP will release control to the pilot (you) and allow override if control column (joystick) is deflected from centre position. An erratic joystick calibration will have exactly the same effect. There is NO warning/message for this happening. On the other hand if you do not care about this feature then simply untick this option's box.Vangelis===================================== E. M. Vaos Precision Manuals Development Group www.precisionmanuals.com=====================================


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E M V

Precision Manuals Development Group

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Guest jgreth123

I'm with ya on this one Paul ;)I hand fly both planes a lot. My 763 I fly from the gate to cruise and initial descent back down to the gate. My 744 I fly from gate to about 18,000 and about 10,000 back down to the gate. In all honesty the 744 doesn't quite fly as smooth with my yoke as the 763, but just personal preference.And for anyone that's going to bash me for stating that the 744 isn't the ULTIMATE plane in EVERY aspect... please don't post ;) I love both planes, but the 763 just feels smoother to me in flight.

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and i thought i was the only one!!!i also have this problem *sometimes* (note that it is not always happening) - even with VNAV! the other day i was departing and activated VNAV and a little later i got a stick shaker and almost stalled. the pitch was excessive at some 25 degrees (nose up) and i had to disable the a/p and recover by hand. that is only one example.and yes, sometimes i get a similar situation with v/s mode. the plane just won't follow the F/D bars (pitch anyways). i have the override box checked and my yoke calibration is fine.does anybody have an idea? should we reinstall the queen?edit: or could it even be an elevator null zone problem?regards,


Denis Kosbeck

KPHX

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This thread serves as a reminder of one important rule. You fly the airplane, not the other way around! No-one is paying the autopilot a salary or giving it a nice spiffy hat to wear, you're the boss here!Under no circumstances should an autopilot or autoflight system be allowed to 'get away' with behaviour like that. As soon as things start to look as though they're going bad, either take action to correct the autopilot behaviour, or better still, disengage the sucker, HAND fly the aircraft and trim it out once you're flying the correct profile, then reengage the autopilot in an approriate mode.As for the original poster, welcome to the forum mate, nice to see another kiwi on board. :-)I won't make any assumptions about your experience either in the real world or in flightsim, but use of V/S in the climb is something that requires a fair bit of caution and understanding of your airplane. It's also a common sim-flying habit due to the simplified MS autopilot we all started out with in the sim.My advise would be to limit your use of Vertical Speed mode to the descent portion of the flight ONLY, as it serves a good purpose there. Want to be at a given height by a given point? Set the desired altitude on the MCP, then go to V/S mode and tinker with the rate of descent until the green arc on the NAV display intersects with the desired point.For the climbout, either use VNAV (preferred) or FLCH mode. FLCH allows you to set a safe speed on the MCP and the airplane then maintains a pitch attitude to achieve and hold that airspeed, the airplane will climb at whatever rate it is capable of.CheersMark


Mark Adeane - NZWN
Boeing777_Banner_BetaTeam.jpg

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Guest D17S

Here, Here.These really sound like autothrottle disconnects though. Watch that far left FMA. That's really the only way the AT can talk to you. If it's blank and you have ANY pitch mode engaged, well . . . that would be a bad time for a nap. If you're totally conked out, at least make the flight mechanic stay awake . . . that's what they usually did to me. Don't know how may times I was the only one awake on a flight deck. (Don't freak out . . . mostly on cargo trips over Africa.)

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hey Paul,i did some testing and i found that my yoke does not always go all the way back to the center when releasing back pressure after departure, meaning the elevator was in an up position. not much, but a notch.and the autopilot does not override that control input. so the next time you get this problem check your secondary EICAS screen (status page) and look at your elevator position. it might not be in the neutral position. you will see that if you move it to neutral the autopilot will assume positive control.my yoke is 5 years old now, so i guess it is worn out a bit. no big deal though, because all it takes to fix this problem is to UNcheck the box for elevator/aileron override in the PMDG settings menu. yes, uncheck.hope this helps you.regards,


Denis Kosbeck

KPHX

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