Archived

This topic is now archived and is closed to further replies.

Drumcode

747X - Violent mid air behavior

Recommended Posts

I just recently purchased the boxed edition of the Queen and decided to take it for a spin from ORD to VHHH for the first time. All of the normal ground procedures were ok and I noticed no problems at all. I took the bird up and made sure it reached it's altitude of 30,000 ft. and went to bed since it's a loooong flight. I wake up this morning and I see the 747 about 150nm east of the Alaska's coast banking from the left to the right about 60 miles south of the flight plan. It was also losing altitude, vertical speeds going up and down. I decided to turn off LNAV and applied HDG SEL but it wouldn't react to that selection, same applies to MCD controlled V/S. I turned off A/P but the plane wouldn't react and was completely unstable. I've also noticed that the FSX menus are not working, I can open the menus and scroll over them but once I click on map view for example, FSX will just freeze until I press ALT+Tab, the FSX will minimize and the map view will open on my desktop. If I close the map view and maximize the FSX, it'll be fine and operational but the 747X still behaves the same way.Here's a little bit more info on my system:i7920 @ 3.8Ghz6Gb DDR3GTX260Windows 7 Ultimate 64-bitFSX SP1, SP2Applications running during the flightFSPassengersRadar ContactAISmoothREX2.0Any suggestions would be greatly appreciated.Jacek GaweckiEdit: FSX is not installed in the system's Program Files but on a separate drive.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

I just recently purchased the boxed edition of the Queen and decided to take it for a spin from ORD to VHHH for the first time. All of the normal ground procedures were ok and I noticed no problems at all. I took the bird up and made sure it reached it's altitude of 30,000 ft. and went to bed since it's a loooong flight. I wake up this morning and I see the 747 about 150nm east of the Alaska's coast banking from the left to the right about 60 miles south of the flight plan. It was also losing altitude, vertical speeds going up and down. I decided to turn off LNAV and applied HDG SEL but it wouldn't react to that selection, same applies to MCD controlled V/S. I turned off A/P but the plane wouldn't react and was completely unstable. I've also noticed that the FSX menus are not working, I can open the menus and scroll over them but once I click on map view for example, FSX will just freeze until I press ALT+Tab, the FSX will minimize and the map view will open on my desktop. If I close the map view and maximize the FSX, it'll be fine and operational but the 747X still behaves the same way.Here's a little bit more info on my system:i7920 @ 3.8Ghz6Gb DDR3GTX260Windows 7 Ultimate 64-bitFSX SP1, SP2Applications running during the flightFSPassengersRadar ContactAISmoothREX2.0Any suggestions would be greatly appreciated.Jacek GaweckiEdit: FSX is not installed in the system's Program Files but on a separate drive.
Jacek - Were you using realtime weather through REX 2.0? I've had instances where the upper level winds in cruise go crazy (150+ kts) and start making the plane bank wildly and show major fluctuations in the airspeed - so much so that I've had to pause the sim and reload the weather... that usually alleviates the problem.I don't think its a problem with the 747-400, per se... I think it has more to do with the weather being generated. I've had it happen using REX 2.0, ASA, and even the FSX real weather downloads.Next time it happens (if it happens again) try pausing the sim and reloading the weather to see if that helps. :( - Alex Edmonds

Share this post


Link to post
Share on other sites

Thanks Alex, I'll give it a shot and yes, I do use the real time weather. Would the weather also have effect on how the bird is behaving? I mean, even if I turn off the autopilot to control it by hand it went totally nuts and I'm a little concerned by the FSX menus not working within the sim during this time. I'll try anything, as long as I can make a use of this fantastic aircraft.

Share this post


Link to post
Share on other sites
Thanks Alex, I'll give it a shot and yes, I do use the real time weather. Would the weather also have effect on how the bird is behaving? I mean, even if I turn off the autopilot to control it by hand it went totally nuts and I'm a little concerned by the FSX menus not working within the sim during this time. I'll try anything, as long as I can make a use of this fantastic aircraft.
There are a bunch of posts about how real time weather can be really messy, especially for the long trans-oceanic flights a 744 will make. The wind reported at LA might be radically different than the winds aloft over Hawaii and without anything in between (as an example, I have no idea whether that's actually true) to provide reporting, the weather can change violently aloft instantly and fry everything. I think most people recommend the payware FSUIPC to smooth this. I personally just use the weather "themes" in FSX with some tinkering around the destination and/or origin, and haven't had any problems. The menus not working is strange. Did you check CPU use? I have a system similar to yours, and the 744 is a big hog of resources even still. Maybe some radical change in weather caused the CPU to freak.

Share this post


Link to post
Share on other sites

A registered copy of FSUIPC is hightly recommended to smooth weather variations, it works on winds, pressure and temperatures.

Share this post


Link to post
Share on other sites

Thank you guys. I will purchase the FSUIPC license today, I've read similar opinions on REX' message board. I'll report back when I'm able to complete the flight.

Share this post


Link to post
Share on other sites
A registered copy of FSUIPC is hightly recommended to smooth weather variations, it works on winds, pressure and temperatures.
I use a registered copy of FSUIPC, but still.. the winds aloft can can get ridiculously out of control and throw off the autopilot. Example, a couple day sago, I was flying the 747-400X in Japan from Sapporo to Fukuoka.. after reaching cruise at FL370, the winds steadily increased from 40kt to almost 190kt! And it was a crosswind to boot! The autopilot was having a very tough time holding course against that wind! It kept doing small "S" turns to try and stay on course and, eventually, the wind got so ridiculously strong that I had to pause the sim, re-download the weather and then continue. Once the weather was updated manually, the winds were calmer and more steady at around 52kts, things smoothed out and the autopilot had no trouble maintaining the flight path (albeit with almost a 45 degree crab angle) It was NUTS! My weather was coming through ASA, but I seriously doubt that the winds at FL370 were nearly 190kt. I think there's something in FSX that gets confused with winds aloft and computes them as being faster than they really are.Anyway... the 744 performed like a champ and I ultimately landed in Fukuoka without incident!- Alex

Share this post


Link to post
Share on other sites

The default wind smoothing sets up x deg/kts of change per second, many have found that the setting needs to be set up for x seconds per 1 deg/kt of change. I use 8 seconds.The problem really is the MSFS wx engine, not ASA or ASX. In fact, turn off the smoothing in those when using FSUIPC to solve the problem. The HiFi Forum in AVSIM should have plenty of info on this since it bothers everyone using advanced add-ons.The 747 will fly smoothly in 190 kt crosswind, the problem is a changing wind. In the real world the winds change all the time but it happens gradually across an entire pressure gradiant not suddenly as MSFS would have you believe.

Share this post


Link to post
Share on other sites

Gentlemen,I read somewhere in this forum a few months ago about this very problem. My recollection is that one of the PMDG people commented that it is indeed a problem with the FSX weather engine. Currently there is no workaround except to turn off all wind/turbulence in FSX and REX (if that is what you use). Even the smoothing function of a fully registered copy of FSUIPC will not completely remove this problem. The modelling of the autopilot functions in the 747-400 is so complex that the extremes in variation of the winds aloft data just play havoc with the simulation. I believe the guys at REX are "considering" trying to work on a workaround for this THRU their product but I have not heard of any news lately.Alex C

Share this post


Link to post
Share on other sites

How very rude and sexist of me! I apologize, my greeting above should read:Ladies and Gentlemen!sincerest apologies :( Alex C

Share this post


Link to post
Share on other sites
Gentlemen,I read somewhere in this forum a few months ago about this very problem. My recollection is that one of the PMDG people commented that it is indeed a problem with the FSX weather engine. Currently there is no workaround except to turn off all wind/turbulence in FSX and REX (if that is what you use). Even the smoothing function of a fully registered copy of FSUIPC will not completely remove this problem. The modelling of the autopilot functions in the 747-400 is so complex that the extremes in variation of the winds aloft data just play havoc with the simulation. I believe the guys at REX are "considering" trying to work on a workaround for this THRU their product but I have not heard of any news lately.Alex C
Well, I took Dan's advice and bought FSUIPC, I'll be testing in the overnight flight, we'll see how that goes.

Share this post


Link to post
Share on other sites
Gentlemen,I read somewhere in this forum a few months ago about this very problem. My recollection is that one of the PMDG people commented that it is indeed a problem with the FSX weather engine. Currently there is no workaround except to turn off all wind/turbulence in FSX and REX (if that is what you use). Even the smoothing function of a fully registered copy of FSUIPC will not completely remove this problem. The modelling of the autopilot functions in the 747-400 is so complex that the extremes in variation of the winds aloft data just play havoc with the simulation. I believe the guys at REX are "considering" trying to work on a workaround for this THRU their product but I have not heard of any news lately.Alex C
I am using latest version of ASA and registered FSUIPC. I have turned on all weather smoothing functions and disabled wake turb. I am not encountering any weather related issues.

Share this post


Link to post
Share on other sites

Ok, I've purchased the FSUIPC license and flying the same route again. So far, so good!!!! Those sudden wind changes surely are different now! Thanks to everyone who helped me addressing this.I did notice a few weird issues in the VC during this flight so far:- EFIS gets suck, I believe this happens only when I leave the VC and change views to spot or wing. I come back to VC and EFIS is stuck and does not respond to any EFIS/MCD changes. It gets back to normal when I switch to 2D panel and back to VC. - A few minutes after take-off I've accessed FMC via FMC1 view to make a change. None of the FMC buttons worked and on top of it I couldn't get out of the view by right clicking the mouse and selecting VC. I had to go to the FSX views menu and select it from there.- Also during cold & dark cockpit setup, PFD, EFIS (F/O side) and EICAS went totally dark after engines were started and I was ready to taxi, I had to restart FSX to make them work again.

Share this post


Link to post
Share on other sites
EFIS gets suck
This is a MSFS problem, when the active window (your cockpit) looses focus such as when you look at the default map. Easy fix is to change VC camera view away from and back to the active camera. In FSX this is a quick A Shift+A.Other problems are odd.. don't know what to suggest.

Share this post


Link to post
Share on other sites

Update. as soon as I've reached the eastern coast of Japan, it all went nuts again , I refreshed REX weather and still the same. Before I reached the coast the winds were steady 344/80 but when REX updated the weather (I guess to local metars) winds were all over the place destabilizing the 747's autopilot. I turned off REX weather and set FSX' default real time weather with winds and everything is fine. I will contact REX about this, even though I might not get anywhere with this.Which one of the Hifi's products works with REX textures? ASA or ASX?

Share this post


Link to post
Share on other sites
Update. as soon as I've reached the eastern coast of Japan, it all went nuts again , I refreshed REX weather and still the same. Before I reached the coast the winds were steady 344/80 but when REX updated the weather (I guess to local metars) winds were all over the place destabilizing the 747's autopilot. I turned off REX weather and set FSX' default real time weather with winds and everything is fine. I will contact REX about this, even though I might not get anywhere with this.Which one of the Hifi's products works with REX textures? ASA or ASX?
I use ASA and it seems to work OK with the REX graphics. Funny that you and I both experienced wind problems over Japan... I think there's something screwy with the weather reporting over Japan in FSX because I always seem to get exceedingly violent winds over Japan... sometimes reaching as much as 200kt :( Any other country I fly in, I have no problems. :( - Alex

Share this post


Link to post
Share on other sites

The Japanese were to first to discover jet winds. Our B-29's failed miserably at high altitude precision bombing and Curtis LeMay finally had to resort to low level tactics. Their winds are truly significant.

Share this post


Link to post
Share on other sites
The Japanese were to first to discover jet winds. Our B-29's failed miserably at high altitude precision bombing and Curtis LeMay finally had to resort to low level tactics. Their winds are truly significant.
On March 5, 1966 after taking off from Tokio, BOAC Flight 911, a Boeing 707, disintegrated while transiting the mountain wave in the lee of Mount Fuji. Witnesses on the ground reported seeing the aircraft in a flat spin trailing white atomized jet fuel escaping from the fuel tanks prior to breaking up in flight.Shortly after the accident, a U.S. Navy A-4 Skyhawk sent up to measure the CAT - Clear Air Turbulence recorded +9/-4 G on its accelerometer.See: http://en.wikipedia.org/wiki/BOAC_Flight_911Cheers,-jahman.

Share this post


Link to post
Share on other sites