Project Helga's fully fly-by-wire control system has to keep the vehicle stable across the widest speed envelope any Overby vehicle will fly — from hypersonic reentry at a high angle of attack down to a conventional runway approach at landing speed, with no mechanical linkage anywhere between the pilot input and the control surface actuators.
The blended wing lifting body's double-delta planform doesn't have room for a conventional tail, so pitch, roll, and yaw authority all come from a small set of control surfaces that the flight computer mixes dynamically depending on speed regime — a surface deflection that produces pure roll at subsonic speed produces a coupled roll-yaw response at hypersonic speed, and the control laws compensate for that shift continuously rather than switching between discrete flight modes.
Passive dihedral and the canted trailing edge sweep carry part of the stability burden aerodynamically, so the active control system only has to correct deviations rather than fight the airframe's natural tendencies at every instant.
High-AOA attitude control comes primarily from body-flap deflection and differential thrust vectoring from the MHD-Lorentz nozzle, since conventional control surfaces lose effectiveness in the thin, superheated boundary layer at reentry velocities.
As dynamic pressure builds, control authority shifts progressively onto the trailing-edge elevons, with the flight computer blending thrust vectoring and aerodynamic control smoothly rather than switching abruptly between the two.
Full aerodynamic control authority is available — elevons handle pitch and roll, a split rudder on the aft body provides yaw authority, all commanded through the triple-redundant fly-by-wire actuator loop.
At low speed the control laws increase control surface gain to compensate for reduced dynamic pressure, while the landing gear and speed brake deployment sequences are handled as scheduled, computer-managed events rather than raw pilot input.
Every actuator on the airframe sits in the same thermal environment as the structure it moves, so actuation hardware is designed around reentry heating from the start, not adapted from a subsonic aircraft baseline.
Each control surface is driven by paired electromechanical actuators rather than hydraulics, eliminating hydraulic fluid lines that would need thermal protection across the full length of the wing.
Each actuator pair takes commands from all three flight computers independently, with a local voting circuit resolving disagreements without waiting for a full flight computer re-sync.
Actuator housings near the leading edge share the ionic liquid thermal management loop with the airframe skin, keeping electromechanical components within operating temperature through peak reentry heating.
If an actuator pair fails outright, the control laws automatically redistribute authority to adjacent surfaces and flag the loss for the fault-handling layer, rather than requiring a hard failover event.