Clause 8 inserts new clause 8A into the principal order. This will allow the Director-General to, in the future, bring a current levy period to a close, begin a new levy period, and set new levy rates to apply in the new levy period. The Director-General will be able to do so in the same circumstances that apply under clause 8 of the principal order, which permits the resetting of a levy rate in a current levy period. The circumstances must have arisen after a levy rate was last set or reset and not have been anticipated by the Director-General at that time. However, under new clause 8A, the Director-General may set a new rate for both of the levy rates payable under the principal order whether or not the requirements in that clause are met in both cases. This is intended to give greater flexibility, for example, to reflect rapid changes in passenger numbers as a consequence of the effects of COVID-19.