You won’t receive compensation in case of delayed flight if the reasons for delay appeared because of force majeure or other disruptions not related to airline actions, such as strikes, political unrest, bad weather conditions, airport operation failures, airplane manufacturing errors, birds flying into the engine etc. Also, your compensation may be reduced if you received other facilities from airlines in form of compensation, for example, discount and gift vouchers. In fact, the flight must be delayed for more than 3 hours in order to receive compensation. You will find more information in Air Passenger Rights.