Ok I love the NGX and learning to fly this beauty is a threat. In the tutorial on we are taking off with Derate 2 and reduce temp to 40c, with flap 5. I'm using TOPCAT and I tried to recreate those condition. I have no problem getting exactly that same condition (the V speed are close tough not a match, but it's certainly because the profile is for PMDG old 737). Though if I choose to let the flap setting on "optimum" the 'best' configuration for this take-off is derate 2 reduce temp at 42c and flap 1.Why flaps 5 was choosen in this tutorial instead of 1? Also how do I choose the best climb derate? Thanks for your help, Sincerely,Jeremy

I believe the minimum take off flaps for the 737 is Flaps 5. For some reason TOPCAT gives us the option to select Flaps 1, which I think is unrealistic. Never heard of anyone departing with Flaps 1 on the 737. Well, TOPCAT also gives the option to take off with Flaps 10 on the MD-11, but I also think that no real pilot is crazy enough to take a MD-11 with 250 passengers, even with a low amount of fuel for a short trip, and set Flaps 10 for departure.

We depart with flaps 1 95% of the time. Not unrealistic at all.

F1-F25. Some airlines do F5 most of the time, some do F1 most of the time. It probably came down the guys in the training dept. and what they had experience in before they got the 737.

When I was with Ryanair it was always flaps 5.

Depends on the company I suppose but we dont select a flap setting based on previous experience. We use the ACARS. You input the runway, wind, temp, pressure and fuel. After you send that off the usually within a couple minutes we get the ACARS Takeoff Data and that dictates which flap and derate/assumed temp combination we use.

Jack Thank you for the answer. Do you know why Ryan chose flap 5 for the tutorial then. He said he used Topcat but for me the software is recommending flap 1.Also how do you choose the derate climb is it the same as for TO with ACARS?