Could not reach TOC

I was in MD-11F. Climbing to 430. Airspeed 250. VS 4500. As I passed through FL340ish I started loosing airspeed. It went Down to 150. Could not recover. Even lowered VS to zero. Could I have been over weight?

Could you send the replay link at

Yes, if you traveled with lots of cargo, going to high will cause you to loose airspeed. You should probably step climb next time.

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Also FL430 is about high, as well as being 250kts sounds a bit slow


4500 fpm is way too fast. Try something like 2000-2500ish.


Take a look at this a second.

Don’t climb with your v/s at +4500! That’s your issue. Also you would need to step climb with an MD11 to get all the way up to FL430.


Woah, A Normally loaded 787 wouldn’t even do that. Step climb.


Also I’d recommend FL380 or FL400 in a MD-11.

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To my knowledge, the service ceiling of the MD-11F is FL430. VS 4500fpm is quite high. If you ever have any trouble in deciding the altitude or VS of an aircraft, you can always use :)


It appears your climb rate if 4500 FPM is high for that altitude and phase of flight …checking real world MD11 series and DC10 the rate of climb would be typically lower. Please feel free to look that up yourself. This is a general statement obviously the weight and wind components are key factors in the equation and IF AC performance may vary from real world data

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Deer’s “Guide to Step Climbing” is definitely something you need to read.

However; here are some quick tips -

  • Cruise Altitude is determined by weight. The heavier the plane, the lower the altitude. The lighter the plane, the higher the altitude

    • Keep in mind (When flying West, fly even FLs (ex. FL360), when flying East, fly odd FLs (ex. FL370)
  • Every plane has unique characteristics that make a generalization difficult across the board, BUT:

    • VS can be constant from Surface to 10,000ft. Around 2,500fpm will work for most aircraft at most weights - this can be too high for some heavies, and there are definitely conditions where more can be supported, but 2,500fpm should keep your N1% in a normal range. (Pay attention to your N1% - it should never really pass around 95% during a climb - and that’s already in the high range, I personally like to keep it below 90% until reaching the higher parts of the climb)

    • After crossing 10,000ft, most planes should accelerate to ~300kts IAS. And from there the VS will continually drop from ~2,500fpm down to ~500fpm as you near your TOC. Judging when to lower your VS can be done by watching your N1% - as it creeps up, lower your VS to maintain a suitable N1% around 90%… 95% if you’re looking for max performance, or nearing the very top of your climb… where sometimes it’s neccessary (ex. 78X)

    • After crossing FL280 you’ll switch to Mach numbers, look for something suitable for your aircraft - typically in the .78-.84 range (easily searchable on google, wiki, etc.). During your climb above FL280 to TOC, stay around .02 below your cruise speed until reaching/nearing your TOC and then accelerate to your cruise speed as you begin to level off.

  • Cruise Altitudes

    • Early in a ULH - FL320-340

    • Late in a ULH - FL380-420 (aircraft dependant)

    • For shorter flights - look to start in that ~FL360 range - watch you N1% - that’s a great “on-the-fly” gauge for how hard your aircraft is having to work to continue to climb and/or maintain the current speed/altitude


Very high climb rate. How did you not stall on high altitude?!?! Oh you did stall. Obvious.

Climb 2-3k after initial take off, around FL180 bring it down 1.6-2k. Check flight radar24 for more realism

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Thank you all for the responses. FP to IF gave me the climb rate and altitude. I turn off step climb when computing my FP. I will now use. Everyday better than the last!

You have the option to choose a cruise level. The service ceiling isn’t the best for all flights (or most, even).

Thanks for you time

It was great wow

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