Fell out of the sky!

[Gryphon 0]

Flying EGKK to MMUN in a BA T7 300ER at FL410 out over the Atlantic, all automated flight functions set and computer running at 4x acceleration.Had been absolutely fine for 10 mins and just fell out of the sky. Went completely unstable and fell to FL200 before I could recover b(via Pause). Violent turns, overspeed, violent pitch changes.Pitch changes can only be avoided by flying with no external scenery visible. If flying Heads Up, the plane nods violently in an increasingly vicious feedback loop until breakup - unless you catch it quick. But we lareasdy know about the 'nodding problem' and the advice in the sticky post makes no difference on this system.Having recovered and climbed back to FL410 in normal time the AT stops responding and a stall results. Fell out of the sky again. etc etcThis model is a bit flaky and certainly not stable. Perhaps withdrawing it for a while until a patch comes out might not be a bad idea? Those that have it will do everything we can to help out and make the bird work as beautifully as you expected, but................System is XP SP2 with all patches and drivers up to date running on a Sony PCV-RZ504 P4 3.4GHz HT, 2GB RAM, 256 NVidia 6600, 23" Monitor running 1920 x 1200.Richard

[Guest Phoenix_7]

so it does this every flight? were you using any addon weather program?JohnPSS SUPPORTsupport@phoenix-simulation.co.ukhttp://www.avsim.com/pss/phoenix.jpg

[Triple7 1]

Hello,Might be a silly question but what was your MAX FL as per the VNAV page of the CDU?I don't have a plan for CUN but a similar length plan (EGKK-KIAH) the flight cruises mid Atlantic FL360 and never actually gets to FL410 - maybe a tad high with the weight of the aircraft?http://i31.photobucket.com/albums/c390/BTr.../phxbanner2.jpg

[Gryphon 0]

CDU showed FL410 as the service ceiling available.I don't have any add-ons other than some major UK airfields and PSS aircraft products.I have saved the flight as of last night and upon reloading the non-VC panel now has the row of additional function buttons to access other panels missing. VC panel is fine.I have also reduced the ceiling to FL360 in case that was the problem and am now continuing with the experiments.Any use of accelerated modes even 2x causes the model to go inverted and head for the sea. I'm going to go on playing with this to see what causes the upsets. BTW the default flight is the MSFS norm, no changes.EDIT 0900Z - Reloaded flight had no flight plan waypoints recorded after the SAM2P departure, the CDU had to have the route reloaded and then the YQX waypoint moved up the list via the scratchpad. Otherwise stable at FL310 (was at FL360 when saved). Aslo had the exit and restart MSFS as the first attempt called up the flight (with the FP missing, and would not allow selection of AP or AT. Switches moved, lights flashed and then immediately dropped out again.Richard

[Triple7 1]

Hello Richard,Just to confirm what was the MAX and OPT flight levels as shown on te VNAV page.The service ceiling is the maximum density altitude where the best rate-of climb airspeed will produce a 100 feet-per-minute climb at maximum weight while in a clean configuration with maximum continuous power.Unless the aircraft is light it will be unable to cruise at the service ceiling.Apologies if you already realise this and it was just a misunderstanding of the term you used.http://i31.photobucket.com/albums/c390/BTr.../phxbanner2.jpg

[Gryphon 0]

Following the reload and reload of the FP as well I know have the Opt showing at FL333 and Max as FL370 (see edit above).I can't remember what the figures were last night and as the FP did not save properly I'll go with what I have at present and proceed from this point.Richard

[Gryphon 0]

Looks like changes in the MSFS real world weather seems to cause an upset at anything faster than 4x acceleration. Sudden changes in wind direction or speed send the whole thing haywiire and can only be fixed by hitting Pause, slowing the accel rate back to normal, wait until it settles again and then increase the accel rate in steps up to 4 or 8.Sp far this morning it hasn't actually fallen out of the sky completely, but has tried to three times. Wind conditions at the times were headwinds +/- 10deg off the nose at 107kts max but varying from 90kts on the guage at FL350. 70,000lbs of fuel on board ZFW 456.1Nodding feedback loop is common to all flights and gets worse until a 'heads down' viewing angle is adopted. NVidia driver set is the latest one available for the 6600 series cards. I reverted the machine to the X600 card I uyed to use and this was the same, but with only 128MB RAM the overall performance suffered. Use of accel rates is impossible in a 'heads up' VC mode and similar in the IFR panel mode - just takes longer to happen (by a few seconds though).Richard

[Triple7 1]

Hello Richard,That could be one reason that it fell out of the sky then as it was unable to maintain FL410. With figures you've produced FL360 seems a sensible FL.Do you have a registered version of FSUIPC? As that has the option to tone down the refresh rate of the weather to have smooth changes which we can try :).http://i31.photobucket.com/albums/c390/BTr.../phxbanner2.jpg

[Gryphon 0]

It tried to fall out of the sky at FL330 too, even though that was below optimum. I managed to get all the way across without any more upsets, providing you don't make any other changes. Altering the time of day (Night to Day) also sends it haywire at 4x accel!!I don't have a registered copy of FSUIPC but may be I need one. I've not seen any advantages to having it registered and have no idea what that will give me that I don't have or need.Richard

[Gryphon 0]

Retunr flight from MMUN to EGKK.Perfectly stable at FL320 - OPT is FL320, MAX FL358, PC accel at 4x, happy for about 10mins. Weather change brought in by MSFS in line with the every 15 min live updates and it just falls out of the sky again. It doesn't stall. The first warning is a rapid increase in the 'nodding' rate and then the yoke just disappears into a blur swinging violently fully left and right (no pitch change). Throttles also go berserk (full power to idle and back). Revert to normal time , all auto functions disconnected and model just would not recover. Stall to overspeed to inverted to right side up to falling leaf etc etc. Into the ocean tail first at 350kts indicated.I also noted that the frame rate plummeted to one or two per second even though its set to target 25 and all other PC programs switched off except firewall and AV.This one stays in the hangar until you guys issue the patch - very soon I hope!Richard

[Guest NormanB]

* Departed Barbados @ 1900z yesterday using Active Sky 5.* Flown over (well as over as FS will let you) the North Pole.* FL310 initially* FL330 just before the polar cap.* FL370 over Shanghai* FL410 now* ETA Perth, Australia 1700zNo issues. Currently online. A customer flew Perth to Barbados yesterday and reported no issues either.

[Triple7 1]

Hello Richard,Sounds like the weather change is doing something which the simulator can't cope with at 4x.I know I had this problem with various addon and default aircraft in that they are all set up to cope with a 50kt tail wind, then all of a sudden the wind changes to 0 and then becomes a 20kt cross wind.The reason I asked if you had a registered version of FSUIPC is because it allows you to set the weather to change at a much slower rate rather than changing instantly, thus letting the simulator adapt progressivly to the change rather than shocking it.This is how I cured my problem... Not sure if there is a freeware addon which can do the same thing.Next time you fly every 15 mins or so note the winds, and see if the fall occurs when the winds change significantly in a weather update.Cheershttp://i31.photobucket.com/albums/c390/BTr.../phxbanner2.jpg

[Guest Hawkeyeted]

Could this be a CG% issue? I found that she flys quite well with a CG between 14-18%. If its pushed out to 20%, that is where the porpoising begins at cruise levels and gets worse as the fuel burns (presumable because the CG moves aft with fuel burn).Just a thought.

[Guest NormanB]

Update:Departed Barbados 1908zTouched down Perth, Australia 1704zLanding Fuel 21,368KG (Gate Fuel 20,994KG)We left Barbados with 161,336KG fuel and travelled 10774nm.CoG was 20%. All in real time, no porpoising. And it captured the loc/glide with no issues.The only difference between my 200LR and the release is a newer FDE we are testing.

[Gryphon 0]

OK trying again.Departed MMUN with 95T excess fuel (to get the coG to 17.2 and for test). I've saved the loadsheet too just in case.Weather rate changed within MSFS to 'Mild'. So far so good. Still nodding. Wind mainly from 180 to 305deg at 102kts at FL330.Following the VNAV FL recommended for OPT as the FL used.After all the help from you guys I have to persevere really don't I Richard:-wave :-wave