Auto Speed Brake MEL Performance question

[rudderrudderrat]

Hi Oilhead,

I think it may be because:
1) Take off flap setting is normally less than landing flaps
2) RTO is conducted with attitude zero.

1 & 2 means there is lots of weight on wheels so brakes will work reasonably well during the time it takes to select ground spoilers manually.

On landing without AGS, there is a greater chance of a skip or bounce. Due nose up attitude and Landing Flap, there is less weight on wheels (even when nose wheel down) and delayed ground spoilers will delay satisfactory braking.

Edit, the landing weight penalties quoted will affect the minimum landing distance required. Normally the landing runway is so long that it won't be a problem.