. . . Swiss Challengers
I would assume most, if not all, medical services offering flights, have access to larger aircraft. If not their own aircraft, any flight can be sub-contracted out.
As for staff required for flights, I'm unfamiliar with any legal requirements, but it appears from reading website info from medical flight operators - it is up to whomever is paying for the flight what services and staff are requested.
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Contact AirMD Air Ambulance Services
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AirMD Clearwater, Florida