"RST Engineering" wrote in message
...
I won't argue what RF technology would be best for remote signalling. I
argue that small current loops (on the order of microamperes) is much more
efficient of power AND money than optics. I'm not really sure how you
"scrape off the insulation" when the "wire" can be the chain (or better
yet, cable) itself.

I think the point is that with a regular conductor, the signal can simply be
rerouted very easily, assuming someone knows that there's a signal to be
rerouted. Fiber optic makes the job a LOT harder (and probably out of the
skillset of the random person looking to steal an airplane).

You could try to address signal rerouting by monitoring not just its
presence, but other characteristics (voltage or current, for example), and
assume that minor changes are evidence of someone rerouting the signal. But
then the alarm is much more sensitive to things that aren't related to
someone trying to break the lock.

Certainly if you were going to use a physical restraint to conduct a signal,
you'd want cable, not chain. Too much likelihood of one chain link becoming
briefly out of contact with another and breaking the signal, resulting in a
false alarm.

It seems to me that there are enough issues with a electrical conductor,
that fiber optic isn't a bad way to go at all.

Of course, all of this assumes that applying additional locks to an airplane
satisfies a basic cost/benefit analysis, which I think is far from being a
foregone conclusion.

Pete