摘要 |
Spoilers on the forward top and bottom elevator tail surface of large aircraft offer an independent backup for pitch control. The placement of spoilers in a line along the forward portion of an aircraft pitch-control structure offers direct upward or downward "lift" from a spoiler-induced unbalance of Bernoulli forces on a near-symmetrical airfoil. Combined with a temporary bypass valve and channels between the "up" and "down" hydraulic actuators, a spoiler's forward-mounted torsion force on the elevator surfaces can also rotate the elevators in a controlled fashion. Preparation for hi-risk aircraft missions would install gate-spoiler surfaces into spoiler-actuating subsystems as a temporary safety-of-flight hedge against the loss of hydraulic elevator control.
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