It's really simple.
If Ryans aircraft and more specifically the sale of seats on it are NOT available to the public generally it is a private operation and does not require an AOC.
You may operate a B747 in private on a PPL if you wish. The moment you charge a "public" even unto a token dollar the regulatory for hire or reward the roof falls in. Company staff, parts and equipment on company business or jollies yet do not fall into the net. The Tax man might have something to say about the jollies but the regulator is not interested.
Standards are an entirely separate issue. However in most countries the 'standards' for Part 25 type aircraft maintenance are similar whether private or "airline" crew training and SMS is another story.
I have operated (now retired) four Part 25 AOC's the most recent with Challenger and Gulfstream. So I know of what I speak.
And yes the "private" jets illegally operated in charter are a danger to everyone, dumb owners and complicit and even dumber pilots don't seem to understand the seriously negative financial consequences if it goes pear shaped.
Edit: for dumb pilot, add idiot.
Last edited by gaunty; 1st Nov 2012 at 10:40.