Rotorua's rescue helicopter service will be at risk, as well as Taupo's, if a new proposal goes ahead.
The National Ambulance Sector Office's (NASO) call for air ambulance services proposals does not include Rotorua or Taupo, which are the bases for the BayTrust and Greenlea rescue helicopters respectively.
The list of regions where air ambulances would be based under the new system would come into effect on November 1. Under the proposal, the closest bases would be in Tauranga, Hamilton and Palmerston North.
The Rotorua and Taupo choppers are each called out hundreds of times a year to jobs from medical emergencies to lost trampers and survival situations on the mountains of the Central Plateau.
The Greenlea chopper was called out 10 times during the four-day Easter break alone.
Taupo district mayor David Trewavas said people would die if the service was withdrawn.
Although the Taupo area might in future be serviced from Hamilton, Trewavas said the time difference - it takes at least 55 minutes for a Hamilton helicopter to reach the Central Plateau mountains as opposed to 20 or less from Taupo - would see lives lost.
"It's as simple as that. It's a life or death situation."
Bay of Plenty police operation support manager Inspector Kevin Taylor also had concerns about what was being proposed.
"The trust helicopter service is an essential part of the provision of search and rescue to those lost in what can be a difficult terrain.
"In time critical searches, particularly with weather and daylight challenges, any delay is potentially life threatening."
Taylor said numerous lives would have been saved as a direct result of access to the helicopters. He said while the Bay of Plenty police hadn't formulated a formal response or submission on the proposal, it was likely they would.
The Ministry of Health operates NASO in conjunction with ACC.
In a written statement, its community and ambulance manager Andrew Inder said ambulance helicopter services were a "critical part of how we respond to health emergencies" and communities relied on them.
He said the demand for air ambulance services was rising but the existing model was not sustainable.
Inder said although a decision hadn't been made on where air ambulances would be based, coverage of the Central Plateau would continue.
"The locations will be determined through the current request for proposal process but it is important to note there will be an improved nationwide air ambulance service," he said.
Rotorua mayor Steve Chadwick said the rescue helicopter was valued and vital.
"If the idea is to take a more integrated, co-ordinated approach to air and land ambulance services, in part to address concerns regarding the sustainability of these essential services, that makes sense," she said, in a written statement.
"I would want assurances that our community still has access to a responsive, efficient and effective service."
Rotorua's Ruth Ashby and her three children were in a car crash in Taupo in December 2015.
She remembers four helicopters coming to the rescue and said if they hadn't, the outcome might have been different.
Ashby was "appalled" to hear the Taupo and Rotorua helicopters were at risk.
"I think the damage would have been greater if the helicopters weren't there to help."
Ashby said the helicopters were valuable, particularly in isolated areas.
"It's quite appalling they are thinking about taking away that service.
"It's going to be a huge loss."
David Wickham, secretary of the Philips Search and Rescue Trust, was unable to be reached for comment about the BayTrust helicopter but said the trust was blindsided by Taupo not being included in the request for proposal.
The trust operates rescue helicopters in Tauranga, Rotorua, Taupo, Hamilton and Palmerston North.
Wickham said the trust would develop an evidence-based proposition for the NASO to consider as an alternative.
Local rescue helicopter pilots knew the region intimately and that was of huge benefit, he added.
"They just know that area like the back of their hand and it does count."
Asked if waiting longer for a rescue helicopter from outside the immediate region could mean life or death for somebody needing help, Wickham said: "Without a doubt."
BayTrust did not want to comment on the proposal until they understood it more and had worked through it with other stakeholders.
Callouts in 2017:
Hamilton - 654
Palmerston North -286
Taupo - 237
Rotorua - 229
Tauranga - 203
Philips Search and Rescue Trust
Philips Search and Rescue Trust helicopters:
Palmerston North: Safe
Taupo: At risk
Rotorua: At risk