Difference between "Accident" and "Incident"

[Stubenfliege 2]

Hello.

For a study, I need some advice for a study: According to the ICAO Annex 13 an occurence is an "accident" when "The aircraft sustains damage or structural failure". An "Incident" is "assoiacted with the operation which affect the safety of operation".

Now, where in the real live is the difference, "Incident" a "Accident" which ended with a "substantial damage", but no "hull loss"?

My problem is for instance: Is the double engine failure of the Qatar A330 back in 2006 an "Incident" or a "Accident" which has to be investigated by the official bodies in accordance to ICAO Annex 13?

Could somebody give me an advice or some example?

Thanks,