Early in the development of flying machines, engineers realised the importance of making some form of directional control available to pilots. Without it, pilots were hardly “pilots” at all. Traditionally the pilot’s inputs were transmitted mechanically via a system of pushrods and metal wires which, as well as being the only practical solution at the time, had the considerable bonus of allowing the driver to “feel” the aerodynamic forces at work and get a sense of the performance of the aircraft. Seat-of-the-pants stuff. More recently it has been possible to build computers to interpret these control inputs, replacing the metal wires with lighter electrical ones that transmit signals to servo units located in the wings and tail. Manufacturers have coined the phrase “fly-by-wire” to describe this technology.
A highly developed example of the traditional mechanical system is the beautifully crafted arrangement fitted to the Cloudmaster DC-6, considered by some to be the finest manual flight control system ever devised. Pictured here, Mr Thomas Muigg, Cloudmaster Limited head of engineering and all-round good pair of hands, is holding what ergonomists call the “man-machine interface”, or steering wheel. If he pulls this control back (gently Thomas – remember last time), the aircraft will adopt a nose-up attitude and climb, assisted by the 10,000 brake horsepower available from its four glorious Pratt & Whitney 18-cylinder radial engines. Returning the controls to a neutral position will allow the aircraft to fly level at its new cruising altitude, and pushing forward will cause it to descend. Similarly, turning the wheel smoothly to one side will roll the wings and cause a graceful change of direction until the wheel is centred once more.
And at all times the mechanical connection between the controls and the flying surfaces will provide Mr Muigg with direct and informative feedback, or “feel”. Pilots speak of the simple joy of flying this legendary 50-tonne airliner by hand.
It’s all very straightforward.
It’s all done with, well, wires.
So here at Cloudmaster we’re left wondering: isn’t this the real fly-by-wire?