Why arab leagues wants a no-fly zone over libya?

Colonel Gaddafi has always been a lose cannon, and an embarrment for more moderate Arab leaders. They want to remove him from power, firstly to remove an annoyance. Secondly a full blown civil war could lead to further instability within their own states, and you must remember majority of Arab states are oppressive regimes. Finally I see it as an appeasement to the West in return of investment and arms contracts, as well as to secure their support in the the event that Iran attack Bahrain which although unlikely would lead a multi-state conflict on the Arab peninsular.