It is one of about 16 fixed-wing air ambulances in New Zealand, operated by about 10 providers including Life Flight and Flying Doctors.
The service aimed to transport patients who needed a non-pressurised plane between hospitals in Taranaki, Rotorua, Taupo, Bay of Plenty, Waikato and Gisborne while saving taxpayers' money. Previously, pressurised and non-pressurised flights were outsourced.
Six months after its inauguration, the service was $700,000 over budget and had provided 40 per cent fewer flights than expected.
Green told the Herald on Sunday the service failed to reduce costs because of an increase in demand for pressurised flights. Almost half of patients required a pressurised flight compared to just 10 per cent when the service went for tender last year. This was a phenomenon happening around the country.
The full service also struggled due to a four-month delay in receiving an aircraft, he said.
"Some of those delays were around equipment arriving, fitting out the plane and getting Civil Aviation Authority approval. So we had to use other providers in the initial period of time."
Green said the service had not reached financial objectives but it had improved its clinical care.
However, minutes obtained from a meeting in October revealed he told the board patients were not getting the benefit of a faster service.
"This is not a satisfactory situation either clinically or financially as patients are not getting the benefit of the faster service provided locally," he said. "We are unlikely to reach the target volumes for the local service and to minimise this effect we are carrying out an urgent review of the options going forward as the current situation is untenable."