Colombian carrier Aces will return eight ATR 42 turboprops to leasing companies as part of a reorganization plan by parent group Alianza Summa. Last month Summa announced a 30-percent cut in both its fleet and its workforce of some 7,500 employees as its flagship airline, Avianca, struggled to emerge from bankruptcy. Alianza Summa was formed last year by a merger of Avianca, Aces and Sam but has been hit hard by rising fuel and insurance costs, the war in Iraq and depreciation of the peso.