While we are in midst of massive thread creep....
The arming of floats concept predates the immersion switches technology. I'm not sure it does, as I remember several Royal Navy beasties returning with inflated floats which were of an "Armed" and then automatic Salt Water Activation system back in 60s and 70s.
Obviously there have been improvements over the years and as Geoffers says with the AW139 we should have total confidence in its electical system which
never goes wrong, goes wrong, goes bong!
