What we know from the news reports so far is that the aircraft was seen floating inverted a few minutes after impact, but soon sank. Doesn't sound like the floats were inflated once they were in the water, but maybe all four were damaged on impact or they were never armed. Good question for the 92 guys on the floats: do you fly with them armed over water (like the AW139), are you supposed to blow them before ditching or just put it in the water and wait for the water sensors to work, and will the sensors work inverted or does the float in the sensor have to go up (towards the belly) to make contact with the switch?