But the model has some serious issues: fuel consumption is way too low - fixed that (fuel_flow_scalar set to default 1.0, instead of .75). There's pitch oscillations around Mach 0.70 when in autopilot and level flight. And the engines are very underpowered, nowhere near able to get a cruise of Mach 0.88. Changing the inlet_area value from 94 to 55 helps it match its published specs, and fly with more "realistic" N1/N2 performance during climb and cruise. Without these modifications, this mythical Boeing climbs pretty much like a lead balloon at higher flight levels.
I've tried some different values with pitch_stability and elevator_effectiveness, and almost eliminated the porpoising pitch, bumped up both values, which has always worked fine on other planes with that problem. But a new side effect resulted: it can no longer accurately track an ILS glide path, with slow and exaggerated pitch down, then it pulls up into a stall.
Has anyone else had a go with this very big flying wing?
