Ok tried again some more takeoff, looks like the only way to get off the ground with a good thrust is with a TO or D-TO setting with a max 30° assumed temp, almost I can fly this baby, I will forget about D-TO 1 or 2 till the next update that I hope will solve the issue wherever it could be.

For what concern D-TO or not is all about the company policy as far as I know, in Europe I know 1 is used by some operators, on the 777 as well.

400kts wrote on Jul 24^th, 2020 at 4:21pm:


I got some interesting data for you:

First, are you using any type of performance calculator?

Because according to mine: the ONLY way to be able to use a TO2 takeoff for example on a perfect weather day, (ISA and 0/0 wind) on an 11,350ft runway with no obstables is if your takeoff weight is under 330,050lb. Which means on a fully (pax) loaded semi-low density 767 (take Delta Air Lines' 30/184 config), and in my case 21k lb of cargo, the max fuel would be as low as 80,000lb. Higher density planes would be nearly impossible even with less fuel.

As far as actual data I got from the CS767, on my perfomance calculator I put in for a forced TO2 takeoff, it made me remove about 50k of fuel! So I did that and brought my weight down to 317,500lb and took-off. It estimated I'd have about 2400ft of stop margin at V1. Looking at the video and measuring on google earth, I had about 2900ft. You can also see the climb, it had no issue with that either! (I was also only at flaps 5).

In conclusion, I'd say their thrust model on the 767 (unlike the 757) is pretty good! It seems simmers are either derating when they shouldn't be, or using way too high assumed temperatures. I was actually surprised to see the results and how close they were to an actual performance calculator. For reference, I also used the exact same engine type on my calculator (PW4060), to ensure a fair test.

https://www.youtube.com/watch?v=FkubBzG9SKA&feature=youtu.be

400kts wrote on Jul 25^th, 2020 at 10:34am:


Good point, I seem to have forgotten to test a TO1.

I just did one and my data was:

KBOS 251354Z 12005KT 10SM FEW030 FEW070 SCT250 25/20 A3008

TO1
TOW:306,000lb (185pax and 14k cargo)
KBOS Runway 09 (7000ft)
Flaps 15
Packs on  Engines
Estimated stop margin: 943ft
Actual stop margin: ~2000-3000ft^

https://www.youtube.com/watch?v=khQXsvxtdJE&feature=youtu.be

So it looks like again the thrust is perfect? I'm sorry you're having issues Maybe you can send me your exact parameters (maybe save flight files?) and I can see how they compare?

400kts wrote on Jul 26^th, 2020 at 2:40pm:


I found your problem: First: did you realize in the saved flight files you posted, you're not doing a TO1, you're doing a D-TO? And yes! They are different things. Like I said, it's impossible to do a hard derate plus an assumed temp, it's either one or the other.

In this pic, it would look like you're doing a D-TO1 + 40* right? Actually no, the fact that the "1" next to D-TO is white, signifies that it is armed for the CLB thrust only, and not active:



This picture I removed the TO1 and you can still see the same EPR?



Make sure on TOPCAT on the aircraft editor you uncheck the option for "Allow combination of both"

I threw this flight situation and exact weight into TOPCAT and with flaps 15, this takeoff is over 5000lb overweight. Even bringing the weight down to the climb / field limited max, it's only possible to do it with full thrust!

Hi Alex,

good point, so on the 767 it's not allowed to combine D-TO + ATM, didn't know that, I was misleaded by some info you can find for example at the link below, if you see there you have both D-TO1 setting and all green coloured with an assumed temp of 53, maybe is available on some models of 767 only, I have read it with more attention and it might be that these "another company" version could have this feature, frankly I don't know, I rely on what you wrote, for me is enough to solve my "thrust mistery"  I thank you for that : 

https://fdx.alpa.org/Portals/26/docs/120115_training%20PR.pdf

I removed the combination of both Derated and ATM from topcat for this aircraft, what is strange is that for the save flight it wasn't saying I was overweight for a D-TO, maybe some parameters were wrong or my mistake typing the zfw when transfering the flight plan from PFPX to TOPCAT.

Thanks for all your effort and help with this, very happy is not a bug of the aircraft as I don't have to hope for a new update and I can fly it!
In the past days I've flown two long haul routes (One with TO and one with an assumed temp of 35 deg) and was happy with it, it's indeed a much more mature aircraft then the CS 757, if only we could have FS2CREW with it, MCE is not bad, at all, but not smooth as the first one.