Just 60% of Air New Zealand's trans-Tasman flights jetted off on time last month. 

A report by the Ministry of Transport shows aviation performance for April. 

It reveals 82% of the airline's domestic flights were on time, taking off within 15 minutes of their scheduled time. 

Air New Zealand's highest cancellation rate was on its Rotorua to Auckland route, with just 52 of 65 scheduled flights flown.  

Associate Transport Minister James Meager told Mike Hosking these figures aren't acceptable, but will be helpful. 

He says it will help them focus on the regions that are suffering from poor performance. 

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