But paramedics say the service was understaffed from the outset, with only five paramedics at each base at Tamworth, Orange and Lismore. A 24-hour service could only be achieved if those staff worked significant overtime. Fairfax Media is aware of a paramedic who recently worked longer than 20 hours in order to keep the helicopter service online, while another performed a 17-hour shift. In both cases, urgent cases were still pending when the paramedics clocked off because they were too exhausted to keep working. "Ethically this is a horrible situation to be in," a paramedic said.

"At some point we have to stop because it is just too dangerous to continue, but it's pretty hard knowing someone's treatment and standard of care is being compromised because we're declining the job. Alternatively, if we accepted the job and made a fatigue-induced error, we would be held responsible." Doctors have written to NSW Ambulance with concerns about paramedic welfare and patient safety. A Tamworth doctor detailed the case of a paramedic who worked 16 hours and was then woken at 4am, only five hours after the previous shift had ended, to do another mission. At some point we have to stop because it is just too dangerous to continue, but it's pretty hard knowing someone's treatment ... is being compromised. Paramedic The Australian Paramedics Association wants paramedics to be brought under Civil Aviation Safety Authority regulations, which require flight crew to have at least eight consecutive hours at suitable sleeping accommodation between shifts. The association also wants two extra paramedics per base.

"If the minister wants 24-hour helicopter coverage in regional areas there needs to be adequate rosters to operate the bases," APA NSW assistant secretary Wayne Flint said. A 36-year-old man died in May after his evacuation to a tertiary hospital was delayed at least four hours when the Tamworth service was grounded due to paramedic fatigue. The patient was suffering a severe traumatic brain injury and hypothermia when he was admitted to Armidale Hospital after a fall from his bike. A helicopter had to be dispatched from Newcastle to transfer him to John Hunter Hospital. The case was made the subject of an incident report, which noted: "If the Tamworth helicopter had responded and not been offline because of fatigue ... the patient would have been intubated and ventilated earlier and delivered to the neurosurgical service at least four hours earlier."

Nine instances of fatigue had been reported within the Tamworth service over a 37-day period, which meant the helicopter was grounded for 63 hours, the report said. NSW Ambulance said in a statement that across all bases - which includes Sydney, Newcastle and Wollongong - less than 0.1 per cent of whole shifts had been lost. Senior clinicians who reviewed the case of the 36-year-old patient concluded he would have died regardless of any delays. "NSW Ambulance is not aware of any patients who have died due to a delayed response due to medical team fatigue," the statement said. "NSW Ambulance uses a range of strategies to manage unplanned paramedic absences, including shift swaps between staff. In the event one service cannot respond for any reason, another service or vehicle type is used to ensure timely access to care for patients across NSW."