词汇与结构 If the ailerons or spoilers are _________, force applied to the Captain’s and the First Officer’s control wheels will identify which system, ailerons or spoilers, is usable.

All ground spoilers are powered by hydraulic system _____ through a control valve and a bypass valve.

词汇与结构 The roll control surfaces consist of hydraulically powered ailerons and flight spoilers which are controlled by _________ either control wheel.