Funny bug on the md11

[Guest mhedbi]

Hi everybody!I was just flying a little trip from EGLL London to Frnkfurt EDDF using the MD11 in FS9 when, all of a sudden, i had this big little bug:As i was approaching the top of descent, the aircraft suddenly banked with no ailerons deflection as you can see on the SD...I will try now to recover this flight...I'll give more news later!'Bye!Please watch your language in the future... no official warning issued but next time for sure, thank you

Edited August 31, 2009 by Staggerwing

[CaptEm1 6]

Don't wory, that's normal.

[Cuddly1956 1]

Blame the F/O... he must've been bored lolJohn E

[KCA9304 0]

Hi everybody!I was just flying a little trip from EGLL London to Frnkfurt EDDF using the MD11 in FS9 when, all of a sudden, i had this big little bug:As i was approaching the top of descent, the aircraft suddenly banked with no ailerons deflection as you can see on the SD...I will try now to recover this goddamn flight...I'll give more news later!'Bye!

Did you monitor the aircraft as she entered this situation?Don't think the AP, that is still on, will resolve this.There are 3 programs running, wonder which one causes the "big little bug".Regards,Harry

[Guest mhedbi]

I recovered that flight and landed succesfully at EDDF.I had a failure with this display: R EMER BUS DC OFF and LSAS OUTBOARD AILERONS OFF. Can this be the reason of that sudden bank?I don't think that the other programs running are the reason of that problem.

[KCA9304 0]

I recovered that flight and landed succesfully at EDDF.I had a failure with this display: R EMER BUS DC OFF and LSAS OUTBOARD AILERONS OFF. Can this be the reason of that sudden bank?I don't think that the other programs running are the reason of that problem.

Mhedbi,With a BUS R EMER DC OFF, Autopilot 2 and Autothrottle 2 will disconnect.LSAS and Ailerons have nothing in common.In case of a Right Emergency DC bus failure, also the Right Inboard LSAS channel that's 'connected' with the Right Inboard Elevator will be OFF. (LSAS R INBD OFF)Both failures are no reason to put a correctly trimmed aircraft upside down.Regards,Harry

[Jason_Peters 16]

I have had this happen to me before also. I belive it is some sort of rare problem with the autopilot. Both times it has happened to me, the only way I could regain control of the aircraft was to disconnect the autopilot entirely via the AFS OVRD OFF switches on the glareshield, and also turning off the the LSAS completely on the overhead. This returned some control of the aircraft. I say some, because centering the yoke no longer provides neutral controls. It's like the joystick calibration is suddenly off. However, with the stick centered no flight control deflection is indicated on the synoptic display.In one case I was able to recover (after loss of about 12,000ft and about 10-15 complete rolls, way oversped the aircraft! during the dive), and make an emergency landing, by holding the stick in the new centered position and hand flying the aircraft to a stressful landing. FS Passengers cheered, and I got a parade the likes of which Sulley never even saw! :( In the other, the aircraft went into one of those weird MSFS FDE tumbles where it just flips all over the place, but never hits the ground.. LOL Both flights were long flights in which time compression was used. If I remember correctly the problem occured shortly after coming back to normal time. Everything is fine till you change something with the autopilot and away she goes, departing controlled flight!I think the only reason I found a way to fly out of it is due to my real world training. I kept telling myself "fly the aircraft, fly the aircraft" :( In order to do that, I had to get the autopilot out of the way. First by the standard disconnect, and whren that didn't work by the override. As a an avid simmer I should have said "screw it reset the flight, just reset the dang flight!" :( It seems to just be a weird bug, not sure if its FSX or PMDG. However, it has happened only 2-3 times. I've lost count of how many complete flights I have with the aircraft. It happens so infrequently, that in in no way impact my enjoyment. B)

[3-2-1-Now 126]

Holy cow...I haven't experienced anything like this...yet.I see you're at or very near a waypoint there. Were you flying to that waypoint, or from it?Pleased you recovered it at least.Could be bad navdata.EDIT: Hmm... you're near ToD, and the synoptic is showing full up elevator. Are you sure it didn't loop on you?Best regards,Robin.

[KCA9304 0]

Mhedbi,With a BUS R EMER DC OFF, Autopilot 2 and Autothrottle 2 will disconnect.LSAS and Ailerons have nothing in common.In case of a Right Emergency DC bus failure, also the Right Inboard LSAS channel that's 'connected' with the Right Inboard Elevator will be OFF. (LSAS R INBD OFF)Both failures are no reason to put a correctly trimmed aircraft upside down.Regards,Harry

Update:The only bug I find sofar:The alert tells you to: SEL LSAS RIB OFF (Select LSAS Right Inboard Off)However on the Overhead panel the FAIL light in the Right Outboard switch is on.Taking the wrong switch will trigger an extra alert (as per aircraft), switching the correct button (ie. Right Inboard) will extinguish the wrongly placed FAIL light, and confirm LSAS R INBD OFF.Its also interesting that the aircraft is still flying and behaving normally.Found this on a quick replay of the scenario on FS9 (notebook)Time permitting will check FSX on my main system.

[KCA9304 0]

Mhedbi,With a BUS R EMER DC OFF, Autopilot 2 and Autothrottle 2 will disconnect.LSAS and Ailerons have nothing in common.In case of a Right Emergency DC bus failure, also the Right Inboard LSAS channel that's 'connected' with the Right Inboard Elevator will be OFF. (LSAS R INBD OFF)Both failures are no reason to put a correctly trimmed aircraft upside down.Regards,HarryUpdate:The only bug I find sofar:The alert tells you to: SEL LSAS RIB OFF (Select LSAS Right Inboard Off)However on the Overhead panel the FAIL light in the Right Outboard switch is on.Taking the wrong switch will trigger an extra alert (as per aircraft), switching the correct button (ie. Right Inboard) will extinguish the wrongly placed FAIL light, and confirm LSAS R INBD OFF.Its also interesting that the aircraft is still flying and behaving normally.Found this on a quick replay of the scenario on FS9 (notebook)Time permitting will check FSX on my main system.

Update 2:Checked in FSX as well. Works same as under Update above for FS9.So for both versions:Aircraft control is not impaired by the mentioned scenario!Try to find a reason for that abnormal attitude outside the PMDG MD11 programming.Regards,Harry

[KCA9304 0]

Update 2:Checked in FSX as well. Works same as under Update above for FS9.So for both versions:Aircraft control is not impaired by the mentioned scenario!Try to find a reason for that abnormal attitude outside the PMDG MD11 programming.Regards,Harry

Above Jason hinted 'time compression' or accelerated mode, so I had a third look:IF an AP disconnects AND accelerated mode is ON,Then the A/C will start a quick succession of left / right rolls to about 10 degrees of bank, but will not roll on her back.You don't have to scare your passengers (but miss a chance to become a hero) when you return to normal simulation accelleration mode, BEFORE making any control inputs.OR even better select the other AP in command as long as an AP is available (white FMA AP box)THEN go ahead to solve any failure.Hope it helps,Regards,Harry