Phoenix Air, the Cartersville company transporting two Ebola patients to Atlanta, is one of hundreds of medical charter operations around the world taking on the role of airborne ambulances.

The companies, with names like Angel MedFlight and Air Ambulance Worldwide, employ jets configured specifically for medical uses, including offering stretchers, hospital beds and life-support equipment. Phoenix Air says on its website that “we now have two emergency rooms to go!”

These air charters are used by patients who cannot be transported by passenger jet because of the accompanying medical equipment, the need for trained medical staff or concerns about the exposure of compromised immune systems to the general public.

It is not known how many such charter businesses specialize in transporting patients involving biomedical-related cases such as Ebola, said Dan Hubbard, spokesman for the National Business Aviation Association.

Phoenix Air, started in Atlanta in the 1970s, has offered “patient evacuation and transfer services for over 20 years,” according to the company’s website. Members of its medical team have at least five years critical care experience and are certified in advanced cardiac life support and basic trauma life support.

The company did not return repeated calls for comment on Friday.

It uses Learjet and Gulfstream planes to transport patients and is accredited by the Commission on Accreditation of Medical Transport Services. Photos on its website show as many as three or four beds on a plane.

Its medical jets are part of a larger fleet that includes planes used to transport cargo such as explosives and other dangerous materials. The company also has a contract with the Department of Defense, providing electronic warfare and weapons training and testing.

Dick Koenig, executive director of the Corporate Angel Network, said the medical air charter business has been around since World War II. The flights are paid for through a variety of means, including insurance and charitable giving.

Koenig’s organization, CAN, helps transport cancer patients by plane. But instead of medically equipped aircraft, CAN patients “hitchhike” on corporate jets already going to cities to which the patients seek to travel. That allows patients to ride free and doesn’t add to a company’s cost, he said.