Aerospace Gurus - Can you explain what the fuck this means

[ZeroMinus]

Q) Compare and contrast a fully electrically powered and operated aircraft primary flight control system with its electro-hydraulic counterpart.

Any fellow Aerospace students/engineers be able to shed some light on this, hydraulics is not my strongest subject at this minute in time, any help be appreciated.

[ChristopherB]

I'm an aerospace engineering student but the question is rather poorly worded.

I've never heard of a fully electrically powered control system on aircraft other than RC vehicles that use servos to actuate control surfaces. As far as I know all commercial and military aircraft use hydraulics that are controlled using solenoids.

Assuming they mean that a "fully electrically powered and operated ..." means the aircraft is using servos or electric motors to actuate the control surfaces and that "electro-hydraulic" refers to using hydraulic actuators controlled via electronics, my comparison would be this: [b]An electronically powered flight control system actuates control surfaces directly using electrical power whereas an electro-hydraulic system uses fluids under pressure to perform the work needed to actuate surfaces and the electronics merely control that force.[/b]

[ZeroMinus]

[QUOTE=ChristopherB;28972845]I'm an aerospace engineering student but the question is rather poorly worded.

I've never heard of a fully electrically powered control system on aircraft other than RC vehicles that use servos to actuate control surfaces. As far as I know all commercial and military aircraft use hydraulics that are controlled using solenoids.

Assuming they mean that a "fully electrically powered and operated ..." means the aircraft is using servos or electric motors to actuate the control surfaces and that "electro-hydraulic" refers to using hydraulic actuators controlled via electronics, my comparison would be this: [b]An electronically powered flight control system actuates control surfaces directly using electrical power whereas an electro-hydraulic system uses fluids under pressure to perform the work needed to actuate surfaces and the electronics merely control that force.[/b][/QUOTE]

Yeah that's why I seem to be struggling with the question, it is worded poorly, I will have a double check through my notes and files to see if I have a copy of the assignment rather than hand written copy of the question.

[editline]3rd April 2011[/editline]

I'm assuming its related to Fly by Wire systems.