Rates versus gee versus "q" and Ps
Excellent post, Retired. And coming from an old stick-and-rudder-and-AoA dude, heh heh.
- As with the 'bus, our Viper control inputs resulted in close to "absolute" rates and gee, and were not "additive". The 'bus has some attitude and roll values added that we didn't employ. e.g. Pitch gee is biased for pitch attitude up to "x" degrees of pitch in Normal law. Gee is also adjusted for bank angles up to "x", so making a level turn and keeping the jet level is easier than what we had in our little jet. This aspect of the Nz laws helped us enter the dreaded deep stall at extreme pitch attitudes, as relaxing stick pressure resulted in a continuous one gee pitch command and the jet didn't go over the top in a ballistic trajectory at zero AoA or gee.
- The discussion about blending pitch rates with the gee command is a good one. Our laws reflected that, especially in landing configuration when rate dominated gee command. We also biased the AoA curves to provide us the "feel" of a conventional jet where you trimmed/commanded for an AoA. In other words, the neutral speed stability had to be overcome.
- Both of the above made the Viper feel like a much larger jet. Going thru turbulence and thermals at low altitude/high speed was very smooth. Was like an old Cadillac with the "soft" suspension versus the teeth-splintering up and down ride.
- The dynamic and static pressure inputs influence body rates due to the "gains" that are used for control surface deflections in magnitude and rate. As I have pointed out before, the Viper used fixed values for the gains when the air data was deemed unreliable. Seems the 'bus gives up and tells the pilot - "you have the controls". Heh heh.
MM43's input on handling the frozen sensors hits home for this old dinosaur. Had the static ports freeze up once in the SLUF and was descending for the approach in weather. Hmmmmm... I am not going down and speed is building up. Since we had an inertially-derived vertical velocity in the HUD, it was obvious I was going down and I checked groundspeed ( also inertially-derived), Clue light comes on and I realize I had frozen static pressure. BFD and waited for the radar altimiter to kick in at 5,000 feet and then the ice on the ports finally melted, so things were back to normal.