Re: DC-9 Flight Control

From:         Patrick Ware <>
Organization: SmartWare
Date:         21 May 96 11:10:50 
References:   1
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billie durso wrote:
> I am new to this subscription so please bear with me.  I was wondering
> about the recent crash of the Valujet DC-9, and arrived at the
> following question.  This question applies to all of the elder
> transports 727, 737, DC-9, DC-10...
>     I am pretty sure that all of these earlier aircraft had mechanical
> linkages to all of the primary flight control surfaces.  I also am
> pretty sure that these mechanical linkages were hydraulically boosted
> to easy in control of the aircraft.  Assuming a total power failure in
> the aircraft, are these hydraulic boosters shutdown?  If so the flight
> surfaces would become excessively hard to control.

As long as the cables are still attached and operating, no hydraulic
assist is needed. Pull out the manual reversion checklist and get a good
hold of the yoke. The rudder is usually operated by a seperate standby
hydraulic system so it will be very useful in turns. Pitch can be
controlled by an electric trim motor. Roll is controlled by cables and
tabs on the ailerons. This is for the 737. I am not qualified to speak
on the DC-9.

Patrick Ware