Comment from David Foster


Firstly, congratulations on a great Russian aircraft website! As a big fan of Russian iron (and having even been there for tours of the space facilities and launch of Mir-18), I find your website great!!!!!

I noticed, however, that on the T-4 page, it is mentioned that way back in 1967 it was the first aircraft in the world to fly with a "fly-by-wire" system.

I may just be making an issue of nothing, but I wonder if you have ever heard of the Avro CF-105 Arrow? As a brief bit of background, the Arrow was developed in the late fifties to fulfil an Royal Canadian Air Force requirement for a high speed interceptor. Unfortunately, the aircraft was cancelled (the reasons are many) but not before five prototypes amassed a total of 66 flights and just over that number in hours of flight time. It was a very advanced aircraft designed by people that were cream-of-the-crop at the time and who went on to illustrious careers afterwards with other companies including NASA. Unfortunately, the aircraft is shrowded in a lot of mystic and fanaticism to the point of almost being a cult icon whose attributes have grown out of the realm of the possible.

Cutting away the chaff, however, this aircraft was spectacular! Which FINALLY brings me to the point of my email! I'll include the reference at the end, but in short, the Arrow possessed a fly-by-wire system.

The control stick contained transducers that measured the force being applied by the pilot. The autopilot then moved the control surfaces according to data from the stick, sensors, and other inputs, to maneuver the aircraft in the desired manner. The autopilot then moved the control stick in the direction the controls were moved giving the pilot feedback. Granted, this system did not have the pilot entirely disconnected from the feedback loop like in an Airbus, for instance, but the fact remains that except in emergency operation, the aircraft was flown by the autopilot and not the pilot. The autopilot could also take input from the automatic fire control system and/or ground control guidance. In theory, the pilot could line an Arrow up for take-off and the entire mission could then be flown - take-off, intercept, attack, and landing - all automatically.

The only argument against this being a true fly-by-wire system that I can think of is that there was a mechanical backup in case of emergency. Other than that, it sure seems to fulfill the criteria. Often, the chase-plane observers would report the control surfaces moving to compensate for engine-out flight, changes in trim with gear extension, or whatever, with not noticeable difference to the pilot in the control characteristics. The reference supplied below also gives a basic schematic of the system.

Even without the hype and the extravagant claims, the Arrow remains one of the most technologically advanced aircraft ever built, certainly in its time. And to top it off, the entire aircraft, engines included, were Canadian.

I'm not really suggesting you change your webpage (and I would hope you didn't until you found other supporting sources and made up your own mind to the validity of my argument), I hope you enjoyed at least hearing about the Arrow as much as I have enjoyed zooming through your website!! Thanks for your time and energy! Rest assured, it is MOST appreciated!


David Foster

Ref: The Avro Arrow, authors: "The Arrowheads", pub: 1980, The Bostin Mills Press. ISBN: 0-919822-35-5