After two crashes with many casualties, the aircraft type Boeing 737 Max 8 is currently grounded worldwide, including Austria. The investigation about the causes of the crashes and the rectification of the problems by the aircraft company Boeing will probably take several months.
What are my rights as a consumer if my flight is affected?
If your flight was cancelled due to the ban, the airline is obligated to transport you to your final destination. It has to rebook you to a new flight at the earliest possible date without any further costs for you (e.g. for meals or accommodation).
When the affected flight is part of a package travel, the tour operator is responsible for your rebooking.
Compensation questionable
It is not yet clear if you are also entitled to a compensation - it depends on whether the flying ban is considered as "extraordinary circumstances" which would free the airlines of their obligation to pay compensation.
As it is a new situation, there is no clear jurisdiction so far. There are arguments in both directions. The decision will have to be made by a court.
For more information please read our article Problems during air travel.