EC135
Flight Crew Air Transport Pilot (ATP); Flight Crew Rotorcraft
Situational Awareness
Conflict Airborne Conflict
Flight Crew Took Evasive Action
Human Factors
During our return trip to our base from the Medical Center we had a near mid-air collision that required evasive action on our part...Approach Control warned us of an unidentified aircraft; but before she could say more; the TCAD went off showing aircraft just off our 9 o'clock position; 100 plus feet above us. Simultaneously; I looked and saw two white lights at what looked like less than a mile abeam heading right for us. I started a descending right turn and told Approach Control what I was doing and what just happened. She said she had no idea of who the aircraft was. The aircraft appeared to make no course change or altitude change. My Nurse thought it was a helicopter. My Medic up front thought he heard the TCAD say; 'Traffic less than one mile.' I thanked the Controller for the heads up; returned to my altitude and landed uneventfully. I...contacted [the State] and there were no State Police aircraft in the area but [they said] it might have been a [Company] Air Ambulance [helicopter]... I [contacted the Company] pilot and asked him if it was him. He stated that it was and his TCAD was fed from ATC and stated he was no closer than two miles according to his TCAD. I ended the conversation at that point.There was no doubt this was less than one mile to me and my entire crew. My crew remained very professional and reacted appropriately to the ATC warning and the TCAD warning with immediate visual scanning in the appropriate direction. ATC did an incredible job looking out for us like always and that is why I prefer to flight follow when ever possible. It seemed the other aircraft was not looking out the window at all. I had all my night lights on plus my high visibility strobe lights; which makes [the aircraft] difficult to miss. Not sure what the other aircraft was doing; but see and avoid was not one of the tasks.
EC-135 pilot on night flight took evasive action to avoid another helicopter that was reported by ATC and detected by helicopter's TCAD.