RC vs FLY BY WIRE

Profile picture for user pistonrob

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8 years 9 months

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why can a radio controlled model of an Eurofighter fly without "fly by wire" and yet a "real" Eurofighter fall out of the sky if the fly by wire system fails?. as i believe the real aircraft is designed to be unstable and unable to fly without it...
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Profile picture for user Moggy C

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An RC model is generally not 'fly by wire' other than in the sense that wires are used to mechanically connect the servos to the control surfaces Fly by wire in the full scale aircraft means that the control surfaces are connected to the servo (pilot) electronically, not physically, with a computer between the two (Three computers actually - they take a vote in the case of a disagreement) Moggy
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8 years 9 months

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so if you ripped out the fly by wire stuff and you stuck a good old fashioned set of controls in the Eurofighter would it still fly though?. i would have thought so but i suppose its not the kind of thing we would ever find out unless someone made a real good flight sim of it
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I doubt we will ever know. Moggy

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CG position. If you move the CG back as far as the real ones are then you would not be able to fly it RC, when building large scale turbine powered models for competition, marks were lost in static judging because the under cart position has to be further forward on a model because of the forward CG or it would not take off Dave
This. The CG on the real one is moved so far aft that it causes stability problems (this is done to reduce drag as far as possible to get the best speed from the power available). This reduced stability is what generates the need for the "fly by wire" system. On an RC model, the performance is not so critical wheras the stability is (otherwise it would be impossible to fly) so the C of G is moved forward from the prototypical position.
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so if you ripped out the fly by wire stuff and you stuck a good old fashioned set of controls in the Eurofighter would it still fly though?
The Typhoon relies on it's computers to constantly make small adjustments in its control surfaces to keep the aircraft in the air, without them it would simply fall out of the sky. As I understand it the Typhoon is negatively aerodynamically stable, a human pilot would simply be unable to compensate for this in flight, hence the computers. The benefit to this is that it makes the aircraft much more maneuverable.
The benefit to this is that it makes the aircraft much more maneuverable.
A common misconception. Actually it does not make it more manouvreable, it reduces the drag which increases top speed. The impression of increased manouvrebility comes from the fact that as the C of G of an aircraft moves aft, the centre of gravity and the centre of pressure are closer together. Consequently, the size of the control input required to generate a given pitch rate reduces which leads to the impression of the aircraft becoming more pitch sensitive.