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Classic airliner mechanical question

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Say a Constellation or DC-6. The pilots moved all the controls (throttle, yoke, cowl, rudder, etc). How?


I mean were they simply moving hydraulic control valves then oil psi moved all the actual plane parts with rams? Where there actual cables used?


I tried Google searching but come up pretty empty for any good pictures that show how old airliners worked or put together for flight control systems?

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Here is a link to a PDF I found about the flight controls for the Electra. 27 pages of it with lots of diagrams and pictures of the flight controls.


Lots of cables and hydraulic booster pumps used in the Electra.


Take the time to download it as it really explains the workings of the Electra rather well.


If you want to know how an aircraft works it is always worth a search for the aircraft name + "illustrated parts". If you are lucky someone will have uploaded a PDF of the Illustrated parts catalog for the aircraft which really goes into the nuts and bolts of all the parts that put a particular aircraft together.

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Yes lots of the old planes would have super long cables to connect controls. Even now a days, general aviation planes have cables.

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I trained as a Flight Engineer on the P-3 many years ago and the P-3 was based on the Electra. Control movement  operated cables that then moved selector (control) valves which operated boost packs containing the actuators  and these moved the flight controls. The Autopilot (AFCS) could electrically signal the control valves giving a kind of analogue FBW.


The boost packs could also be reconfigured in an emergency by pulling the Boost Out handles at the FE's feet. This reconfigured the geometry of the boost pack 'cage' and gave limited manual reversion. Quite ingenious!


On mechanical (cables and pulleys) DC-4/6 type aircraft, the cables operated servo tabs which then gave aerodynamic assistance (like a crude power steering system) and made the controls lighter to move. The control movement initiated the tab first and the tab moved in opposite sense to the control surface giving this assistance.


Does that help?



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