Re: Interresting thread in comp.lang.eiffel

["Ken Garlington" <Ken.Garlington@computer.org>]

"Robert I. Eachus" <rieachus@earthlink.net> wrote in message
news:396CA5AD.EE955F7A@earthlink.net...
>    As I remember it, there was planned to be a relationship as part of
> the full-up
> simulation of the flight control system.  When the decision was made not
> to use the
> SRIs in the simulation, that part of the contract was cut back or
> cancelled.  I think
> they still had the SRI hardware supplier on contract, but not the
> software developers.

Actually, I posted the AW&ST articles on my website. They indicate that
Sextant was a full partner in Ariane 5, and in fact that the Ariane 4 SRI
was *not* used "as is". See

http://www.flash.net/~kennieg/ariane5_awst.html

>
>    Incidently, I was just looking at your YF-22 crash data.  The cause
> may be called Pilot Induced Oscillation, but the real culprit was lack
> of feedback to the pilot.  There was no
> direct relationship between the position of the stick and the position
> of the stabilators
> in the later part of the event due to the rate-limited nature of the
> stabilator controls.
> I hope that this is fixed in the production F-22.  (The nasty effect of
> the change in flight
> control mode when the gear went up seems to have been key.

The gains changed abruptly when the aircraft transitioned from
takeoff-and-landing to up-and-away mode. This produced a sudden transient,
triggering the start of the PIO. The transition now occurs more gradually.