Salute!
Thank you Garage, thank you, thank you, thank you!!!
The "Direct Law" in the 'bus is not much different than the basic Viper control laws. Closest relation is on the ground and with WOW switch depressed.
- There was no direct relationship between control stick input and control surface deflection or rate of deflection.
Here's the roll command function:
But wait!!!! There's more!!! That was only the "command". Between the "command" and actual control surface movement the computers blended AoA, body rates, etc. The end result was still the same - the jet tried to achieve your command.
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So we roll back the clock to late 40's and early 50's. Hydraulic augmentation or even direct control of the ailerons, elevator, rudder. No direct feedback from cables or pushrods. Wow! The dinosaurs bitched. We new kids on the block didn't know any better. I, personally, learned in Champs, Luscombes and Taylorcraft taildraggers. But when I went to USAF pilot training our first plane had mechanical controls!! I could "feel" the burble and lack of response at the edge of the envelope. And then on to the fighters.
Wow! No direct mechanical connection to the elevons in the F-102. Then same for the F-101B. We had springs and dampening gizmos to keep us from commanding full deflection at any speed. Elevator in the VooDoo and Phantom had a pneumatic bellows that "stiffened" the stick the faster we went. VooDoo even had AoA protection that included rate limits - this was back in mid-60's.
Biggest change in flight controls was in 1973. You guessed it. Lightweight Fighter program. GD introduced us to the "electric jet".
The initial impression to all of us was that we didn't move a hydraulic valve with the stick or rudder. Hell, we just sent a signal to the actuators on the wing or tail and voila!!! NOPE!!!! And nope big time.
The designers tried to make the jet "feel" like the ones from the old days. They also figured we didn't need to pull hard at slow speed to 60 degrees AoA, then recover from the stall or whatever. Hornet violates this design consideration, BTW. Then they added gee protection, blended AoA and gee command and pitch rate when landing gear was down. And the beat went on......
The electronics did not simply convert stick deflection to surface movement. Along the way, the computers applied all kindsa functions and limits. To be honest, the jet felt like all the others except the relics that had mechanical connections ( pre-60's except for the big jets most here have flown or heard about). The engineers did a great job on the Viper, but that same team did not work on the Airbus. We also did not have much of an autopilot connection to the flight control system. It was not quad-redundant and had limited functions. More like a pilot's stick input.
more later, as I wanted to "set the stage".