Hi,I have a question on how to choose the 'correct' take-off configuration in terms of thrust and flap settings. In my opinion this is the captains' choice but I can imagine there are some guidelines... I found some remarks on the thrust setting in the manual (page 1-13, 'reduced takeoff N1 should not be used when....'). Furthermore, I think takeoff weight, runway length, etc influence the desired thrust setting.Regarding flap settings, is it true that this is mainly based on the runway surroundings; when a runway is surrounded by mountains one uses a flap 20 takeoff to make a initial climb with a large vertical speed???Can some confirm my thoughts or if I am mistaking correct me??Thnx!Nielsps. Does the same way of reasoning hold for determining the desired landing configuration??

Hi Niels,For the 747 have a look at a program called TOPCAT http://744.hoppie.nl/pub/node/240 For the 737 I'm not sure if any programs are out there.If a runway is surrounded by mountains a Lower flap setting is more likely to be used due to a higher climb gradient. Flaps 20 will get you of the runway sooner but decrease your climb perfomance.Rob