Bill Daniels wrote:
I think the system would need three sensors to give a useful warning -
airspeed above a certain value, ring in hook and spoiler open.

If you add a $2 microcontroller to the system (or are clever with
relays) you could use a switch to sense that the release has been
pulled with airspeed above threshold, rather than trying to determine if
there is a ring in the hook...

Marc