The government says delays in drawing up regulations and a lack of scientific knowledge are behind today's decision.
The final carbon auction of the year has resulted in a clearing price of $68.
Some industry players believe commercial electric flights could be just five years away, and the move to electric may help to improve connectivity with the regions.
A select committee report on RMA reform proposals says tighter definitions and greater clarity needed on contentious issues or there will be years of uncertainty and legal argument.