Following on from the undercarriage/ramp interaction discussion, another area where the F-35B designers have to be pretty savvy is how the flight control laws cope with finding themselves suddenly in the sky but in a situation where sustained flight is not instantaneously possible. We never did ski-jump take-offs with the VAAC Harrier's experimental FCS engaged (for real that is to say. We did do lots in simulation), because the margins for recovery from a yaw channel (read as nose-wheel steering in this context) runaway of VAAC's simplex (and sometimes just plain wrong!) control laws were just too small for comfort. However, prior to that assessment we did all the other work to allow for ski-jumps including letting the FCS know what was going on in this "special case", so that it would not try to fly straight away on leaving the ramp but instead get the correct priorisation and blending of accelerations. In our case the logic to let the monitoring software back-off temporarily to let the control laws get on with it was triggered by a combination of weight-on-wheels and airframe movement that could only happen on the ramp during a ski-jump. As I said, we never got to try it for real, so it will be truly a "great leap forward" for STOVL technology when an F-35B does it for the first time.
For what TJSF and the ITF have achieved so far
