jbirdsal wrote on Apr 2nd, 2020 at 12:45pm:| This system works in the actual airplane because the autothrottle physically moves the throttle, so that when the AT mode transitions to THR HOLD the throttle is already in the appropriate position and there is no change to thrust unless the throttles are moved. In the simulator, however, this obviously is not so -- the AT does not physically move the throttles on your desktop -- and any amount of throttle "noise" is interpreted by the sim as a throttle command. I would imagine that you left your throttle at 50%, and when the AT system went to THR HOLD some noise or spike directed the sim to reset the throttles to where your throttles physically were -- i.e. 50%. |
Interesting observation, and analysis, of the problem. When I take off, I often use F3 to increase the throttle, eventually increasing it up to 100% (there are times when I simply press the EPR button right at the start of the takeoff run). When doing this, my joystick throttle (a VKBSim Gladiator MKII) is in the stop position (because I have pulled it all the way back after taxiing on to the runway so the 757 stops). Using this method, I have never had the 757 pull up/fail to gain enough speed to take off (V2) - VNAV and LNAV are always armed. Maybe I'm just lucky that there are no spikes from the joystick to cause it to go into an aborted takeoff. Those spikes are known to cause problems with the throttles, so increasing the null zone can help fixing the problem.
jbirdsal wrote on Apr 2nd, 2020 at 12:45pm:| I have no idea why it would only let you turn to the right. Was the autopilot on and trying to join a course or something? |
This happens, or at least used to happen, with the 757 v4.x, but I only had this problem upon landing, so I was using Approach mode on the A/P. I don't recall it ever happening with the 757 III. Could it be that the A/P has locked onto the ILS? However. If that was the case, I would have thought that you wouldn't be able to turn left, or right, as happens with the 757 v4.x.