quote:

Originally posted by hrcjon:

I will bet real money that this is a depressurization event and the pilot was not complying with the relevant regulations on oxygen 14CFR135.89, oxygen mask requirements.

The airplane was owned by a company that is owned by relatives of two of the passengers on board, so odds are that this was a Part 91 flight, not Part 135, but 91 also has applicable mask requirements.