MD-11. Too high pitch on take off.

[mburkhard 23]

With high pitch values during take-off (>~20up) LSAS pitch hold function quits working when you want to set a lower pitch angle (eg. from 24 up to 21 up).To solve this, manual trim has to be applied, a method very uncommen to the MD11 in this fase of flight.

Thanks Harry, it does.I guess you're up to something. So you say that LSAS has pitch hold issues as soon as above 20

[3-2-1-Now 126]

LSAS seems to lose the plot when you stall her, too. It's either full nose up or nose down, until you're clear of the stall warning and you're approx. 3 degrees below the alpha birdie.Best regards,Robin.

[Ourgas2 3]

Hi all!Sadly the problem still exists ! It helps of course entering 60 C into the Flex box and it made me having no problem taking off from a specific airport I made take off tests. (LSGG, rwy 05, SID Balsi 6N, about 30 t of fuel, 2/3 passengers/freight).But on other airports the problem is back again.It seems that the critical moment is when engaging not the AP but the VNAV.Can it be that the VNAV path is too steep causing the aircraft into a over the normal pitch up, then loosing speed and causing it to make a sudden correction pitch down?At this point FMC magenta speeds in the upper left PFD's corner turn white and the indications appear: protection and pitch.My proceedure is as follows: (maybe I am doing something wrong here with the procedures)Flex 60 C, trims as per take off page, green box appearing.AP pressed once to engage AT.Apply throttles, rotate at V2, smoothly, keeping needles centered.At 400-500 ft press again / activate AP.Press NAV.No problem until now...At 1500 ft engage Prof.After some seconds pitch goes 20 degr. +, airspeed goes slightly back and the problem occurs...Help as always welcome.Thanks,Christos

[Cuddly1956 1]

Try pressing PROF and NAV (or select heading) before taking off. I suspect, for some reason it's still in toga mode instead of climb thrust mode and pitches up in toga, engages climb thrust, then the speed bleeds off causing the lo speed protection.I know it shouldn't as I usually hand fly the takeoff myself with no problem, just making sure it trims nicely in the climb before engaging the AP.Maybe a screenshot of your panel before takeoff might help here.John Ellison

[Ourgas2 3]

Try pressing PROF and NAV (or select heading) before taking off. I suspect, for some reason it's still in toga mode instead of climb thrust mode and pitches up in toga, engages climb thrust, then the speed bleeds off causing the lo speed protection.I know it shouldn't as I usually hand fly the takeoff myself with no problem, just making sure it trims nicely in the climb before engaging the AP.Maybe a screenshot of your panel before takeoff might help here.John Ellison

John,It seems that you are right here. Works fine with a few take offs I made. (Flex 60 C)I will test more and revert.Christos

[Guest sunbear]

I always thought that the AutoFlight button was pressed to arm the autothrust system along with the Nav button to arm the FMS Nav-mode before engaging the throttles for T.O., then activating the AP at a minimum height of 400 ft followed by climb thrust engagement (Prof Mode) at 1500' AGL, wherein acceleration and flap retraction would then commence at ~3000 feet or whatever the FMC dictates. My question is: "Is it proper procedure to engage both the Nav & the Prof before take-off roll"??? Regards,jack

[mburkhard 23]

I always thought that the AutoFlight button was pressed to arm the autothrust system along with the Nav button to arm the FMS Nav-mode before engaging the throttles for T.O., then activating the AP at a minimum height of 400 ft followed by climb thrust engagement (Prof Mode) at 1500' AGL, wherein acceleration and flap retraction would then commence at ~3000 feet or whatever the FMC dictates. My question is: "Is it proper procedure to engage both the Nav & the Prof before take-off roll"???

Jack,this depends on the airline's SOPs. Your procedure is just fine as well.Markus

[theace6 0]

Jack,this depends on the airline's SOPs. Your procedure is just fine as well.Markus

When I fly I use the AAL manuals and am able to do a perfect takeoff everytime, on the first page of this forum I put the takeoff profile that AAL uses for domestic (takeoff in the US) and if you follow it you will have a nice smotth climb out every time. Kevin W.

[Ourgas2 3]

When I fly I use the AAL manuals and am able to do a perfect takeoff everytime, on the first page of this forum I put the takeoff profile that AAL uses for domestic (takeoff in the US) and if you follow it you will have a nice smotth climb out every time. Kevin W.

Kevin,Where is this AAL manual of yours? Can not find it.Christos

[theace6 0]

Kevin,Where is this AAL manual of yours? Can not find it.Christos

Christos,The AAL manuals are the american airlines manuals that I have for the MD11. But for the takeoff profile it's 5 segments, I'll rewrite for you. So you should have a smooth climb everytime.1st seg/ SPD V2+10 Max Deck Angle 25deg./ 2nd seg/ 400ft AFL Pull HDG select knob or select NAV/ 3rd seg/ 800ft AFL Pull speed knob observe spd change in FMA speed control window to SR/V3. Pull alt knob to engage lvl change. Reduce pitch and accelerate at FR SPD flaps up, at SR/V3 slats retract.4th seg/ 1500ft AFL observe CLB THRUST in FMA altitude control window and maintain V35th seg/ 2500ft AFL press FMC SPD button and reduce pitch to accelerate to 250kts or Clean Min. maneuvering speed.Kevin W.

[KCA9304 0]

Thanks Harry, it does.I guess you're up to something. So you say that LSAS has pitch hold issues as soon as above 20

[KCA9304 0]

When I fly I use the AAL manuals and am able to do a perfect takeoff everytime, on the first page of this forum I put the takeoff profile that AAL uses for domestic (takeoff in the US) and if you follow it you will have a nice smotth climb out every time. Kevin W.

Kevin W.I'am interested in the AAL International take-off procedure as well.Would it be possible to give that procedure also?Thanks in advance.Regards,Harry

[theace6 0]

Kevin W.I'am interested in the AAL International take-off procedure as well.Would it be possible to give that procedure also?Thanks in advance.Regards,Harry

No Problem the AAL international procedure is pretty much the same as the domestic (written a few posts above this one) except for the speed, and also that it is used when taking off when outside of the US.1st seg/ SPD V2+10 Max Deck Angle 25deg./ 2nd seg/ 400ft AFL Pull HDG select knob or select NAV/ 3rd seg/ 800ft AFL Pull alt knob to engage lvl change. Maintain V2+104th seg/ 1500ft AFL observe CLB THRUST in FMA altitude control window and reduce pitch to maintain V2+105th seg/ 3000ft AFL press FMC SPD button and reduce pitch to accelerate to 250kts or Clean Min. maneuvering speed. At FR speed- flaps up. At SR/V3- slats retract.Kevin W.

[KCA9304 0]

No Problem ........Kevin W.

Thanks Kevin.Regards,Harry

[Ourgas2 3]

No Problem the AAL international procedure is pretty much the same as the domestic (written a few posts above this one) except for the speed, and also that it is used when taking off when outside of the US.1st seg/ SPD V2+10 Max Deck Angle 25deg./ 2nd seg/ 400ft AFL Pull HDG select knob or select NAV/ 3rd seg/ 800ft AFL Pull alt knob to engage lvl change. Maintain V2+104th seg/ 1500ft AFL observe CLB THRUST in FMA altitude control window and reduce pitch to maintain V2+105th seg/ 3000ft AFL press FMC SPD button and reduce pitch to accelerate to 250kts or Clean Min. maneuvering speed. At FR speed- flaps up. At SR/V3- slats retract.Kevin W.

Hi Kevin,Thanks a lot.I have been experimenting with your AAL settings.Christos