Air Methods Vice President Craig Yale said the hospital's helicopter, an MBBK 117, was "a very reliable aircraft" and a "workhorse in our industry." He could not discuss the crash because of the ongoing investigation.
He also said that Olesen was an experienced pilot who had worked for the company for 19 years, after flying for the U.S. Army for 23 years.
"We are trying to recognize his professionalism," Yale said. "(Olesen) was a seasoned and professional pilot."
Rockford Memorial said Hollis was a critical care nurse who had worked at the hospital for more than 25 years. Dillow had worked there for 20 years with experience in critical care and in the emergency room.
Air Methods pledged its "full cooperation" with investigators.
"We extend our heartfelt sympathy to the family, colleagues and friends of those who perished in Illinois while on duty," Air Methods CEO Aaron Todd said in a written statement.
Yale said Air Methods is the world's largest medical air transport company. He said the company provides services to hospitals all over the country, and it was unusual for a hospital to own its own helicopter rather than contracting with the company for an aircraft.