The emergency helicopter used by Wiltshire Air Ambulance has been grounded after failing a safety test and its operator going bust.
Since 2014, Heli Charter has run the charity's Bell 429 but the firm went into voluntary liquidation on Monday.
Emergency calls will be dealt with by using its two rapid response cars, as the Swindon Advertiser reported.
The charity said it was trying to secure its own helicopter to run rather than rely on a third party operator.
A spokesman for Wiltshire Air Ambulance, which is based in Semington, said it had its own "contingency plan in place and its implementation has already begun".
"For some time we have been looking to secure our own AOC [Air Operator Certificate] and those preparations are well advanced and its issuance imminent."
He added that if the need arose for an air ambulance, protocols were in place with neighbouring air ambulance charities to use their helicopters.
The charity said it had also grounded the helicopter due to technical problems which were noted on 2 January.
A spokesman said that during routine checks of the engines, "the helicopter systems did not perform as expected and as such the decision was made to ground the aircraft".
The pilot did not lose control of the aircraft, he added.
It is waiting for the results of the flight data for analysis, but the demise of Heli Charter has prevented the charity from using the helicopter for the time being.
The charity's new headquarters were opened in December by the Duchess of Cornwall.