Thank you, OG, for your contribution.
There's one helluva difference between speed stability and longitudinal static/dynamic stability in the FBW jets that emphasize gee compared to what many of us learned back when the Earth was still cooling.
The 'bus does not change the center of aero pressure using the control surfaces or the FBW system. The crew can change the cee gee by transferring fuel or having all the SLF's run back and forth, but the aero remains the same. Maybe the F-111. F-14 and Tornado could actually change the center of aero.
The big deal is that one can reduce the downward lift from the elevators/THS in order to gain fuel efficiency and such by moving the cee gee aft. The jet does not come anywhere close to the tiny one I flew in the dark ages of FBW. As an example, we manually transferred fuel once the deep stall phenomena was verified. This gave us a forward cee gee and supposedly help keep us outta test pilot land. Unfortunately, we would forget to re-position the fuel transfer switch back to "normal" when coming home after initially placing it in "aft fuel transfer". Hell, we were joining up and changing IFF codes and all that stuff. The procedure was not in our checklists, either. So we would have an unbelieveable aft cee gee. I only weighed about 135 - 140 pounds naked, and maybe 150 pounds with survival gear on. Our nose gear WOW would intermittently disconnect our nose wheel steering. So one day I stepped off the ladder and the jet started to tilt back on the engine exhaust nozzles!!! Crew chief and I grabbed the nose and I stepped back on the boarding ladder!!! Still laugh about that. But my point is that no jet ever built could have been flown with that combination of cee gee and center of aero pressure.
Gotta go, and some good discussion here. I'll address PJ's point paper later, maybe a separate thread.
Last edited by gums; 20th Jul 2012 at 23:17.