Results 1 to 3 of 3

Thread: Default Boeing 737-800 autopilot problem in flight with loss of control of aircraft

  1. #1
    Join Date
    Mar 2005
    Location
    San Francisco, California
    Posts
    31

    Unhappy Default Boeing 737-800 autopilot problem in flight with loss of control of aircraft

    I have taken a few years off from flight simming, but never encountered this problem before. I love flying the default Boeing 737-800. I even have the Go Flight MCPPRO for my auto pilot. When ascending at 250 KIAS, right about when I reach FL 240 I lose airspeed which rapidly drops to zero. I disengage the autopilot and every time the aircraft goes into an unrecoverable spin and dive which becomes unrecoverable. At this point I usually exit flight sim before hitting the ground. This seems to happen almost every flight and was not a problem when I was flying for a virtual airline years ago and logging many hours. Why FL 240, why nearly every flight. I am getting ready to take another long break from this if I can't figure this out. I am flying with the FS Real WX weather program. Could it be severe weather causing this to happen because of the weather program? Is this autopilot related or just the aircraft always going out of control at this altitude. Also, before this happens airspeed jumps up and down. Please help. This makes no sense to me. I have not programmed in any emergency situations to happen in flight. I should also mention that I am using Windows 10, but haven't had any issues around using it.
    Last edited by MsThang; Yesterday at 12:54 AM.
    Ms. Dale Carlson

    It's The Music That Matters

  2. Default

    Hi Dale,

    Perhaps your Autothrottle Systems (Arm) Toggle switch needs to be set along with an appropriate IAS MACH speed then the Speed Button pressed, otherwise the Autothrottle will not work. You will notice that your Throttle position levers will roll back to idle, and your plane will fall from the sky. It has only a little to do with the Autopilot function CMD switch.

    The N1 Take off thrust can only be set in 2D view via the N1 Rotary knob (N1 rotary does not function in VC), when set along with A/T toggle switch you will see the throttle position levers and thrust increase/decrease to the percentage set using the rotary knob. If you clicked the SPEED button or N1 Button without setting an IAS MACH speed value, or no N1 percentage set you would see the throttles immediately rollback to idle and the aircraft would stall and begin an unrecoverable drop from the sky.
    Once you are at Cruise altitude you can switch to the IAS MACH SPEED setup. You can even use this in the approach phase where you wish to maintain set speed throughout your decent. You will see the throttle position levers roll back continually even to idle, or roll forward to match conditions/ configuration and set speed, to maintain the set speed. (A/T ARM = Autothrottle armed) not active unless SPEED or N1 buttons are pressed.
    I would switch off A/T while in the Approach/landing phase just so that you have full control of throttle levers / Engine thrust.

    Also remember that if your PITOT tubes are iced or blocked these systems will malfunction.

    Click image for larger version. 

Name:	AT-set-N1-Set-IAS-MACH-Set-2-D-737.jpg 
Views:	11 
Size:	118.5 KB 
ID:	209281

    Click image for larger version. 

Name:	AT-set-N1-Set-IAS-MACH-Set-VC-737.jpg 
Views:	12 
Size:	118.7 KB 
ID:	209282
    Last edited by jethrom; Yesterday at 03:46 AM.

  3. Default

    Got a AlphaSim SR-71 that flies along at mach 3.5 then all of a sudden just starts a...

    "unrecoverable spin and dive which becomes unrecoverable"
    HMMM... icing pitot tube, that could have been it thanks for sharing the tip jethrom

    ...or maybe the wings became blocks of ice
    Gigabyte GA-X99 Gaming G1, i7-5960X, Noctua NH-D14, Crucial Ballistix Elite 64gb 2666, Nvidia GTX Titan X, Creative ZxR, WD VelociRaptor 250gb and 1000gb, Sony BDU-X10S BD-ROM, PC Power & Cooling 1200w, CM Cosmos S, Logitech M570/K800 Wireless Trackball/Keyboard, Windows 7 64 Ultimate

Similar Threads

  1. Replies: 10
    Last Post: 09-23-2017, 01:56 AM
  2. Replies: 24
    Last Post: 02-04-2013, 06:27 PM
  3. SmartAir 737-800's first 737-800 FIRST EVER departure!
    By SmartAir_CEO in forum MSFS Screen Shot Forum
    Replies: 3
    Last Post: 06-12-2003, 01:13 PM
  4. Loss of aircraft control at 250 KIAS
    By lplus11 in forum FS2002
    Replies: 29
    Last Post: 07-15-2002, 11:08 AM
  5. Replies: 0
    Last Post: 01-10-2002, 08:31 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •