Bkdoss
It is not weird. With only Slats out there is increase in body angle which will compromise tail clearance during take off rotation. Flap decreases the body angle. In the air with only slat at1 the body angle is 7 degrees while with flap1+F it is 4 degrees.Also in the case with G+Y fail with zero flap the approach body angle is about 8 degrees instead of normal 3 degrees. All aircraft use some trailing edge and leading edge flap combination for take off but airbus made the change in the air config. to only slat1 thereby reducing drag during manoeuvring for approach. For reverse inop When you select Flap1 Confg. for approach you land only with slat1 and flap zero but as the speed drops below 100kts. it will extend flap as per system design and not because of requirement.
Last edited by vilas; 20th Sep 2015 at 15:11.