Hi I just wanted to know how much flaps I would need for a particular length of runway. On a 7000ft Runway can I use flap 5? Or I can only use 15 to have enough room to stop in time. What is the minimum length of runway I need before I can use flap 5. I mean I have the runway length chart but I don't understand why they have flap 20 on it when the manual says you only use 5 or 15. This is what I normally do please correct me if I am wrong. Thank You :-)Runway Length7000FT-11000FT =Flaps 1511000FT and higher Flaps 5

Our standard procedure is flaps 5 on all runways.Only time we use flap 15 is if runway limited (depending on weight this basically never happens on runways greater than 2000m), or in reported windshear.I'd say you could change your rule of thumb to runways greater than 7000ft flaps 5, provided you're not too close to MTOW!