Narrative:

I was flying a direct route from our base in ZZZ to pick-up a patient at the hospital in ZZZ1. I was at 1;000 feet MSL with autopilot engaged. I had noticed that there was another aircraft on TCAS about 10 NM from me but did not have a visual. Their direction indicated that they were east of us and flying west (we were headed in a generally southern heading). At 5 NM I alerted my crew that there was an aircraft out around the 10-11 o'clock position and that I did not have them in sight yet. There was no response on frequency (a general helicopter frequency for avoidance and awareness). We did finally get a visual confirmation at approximately 1 mile or so of separation (with them at our 10 o'clock position) and it appeared that we had converging vectors. Still; nothing on the radio and they did appear to be maneuvering to avoid us. Turning would not have been sufficient to separate the aircraft so I began a rapid climb (over 500 FPM) and the aircraft passed directly underneath us with about 300 feet or so of vertical separation (we were rapidly climbing past 1;300 feet MSL). Afterwards we still got no communication or acknowledgment from the other aircraft.

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Original NASA ASRS Text

Title: Pilot reported a NAMC with another aircraft.

Narrative: I was flying a direct route from our base in ZZZ to pick-up a patient at the hospital in ZZZ1. I was at 1;000 feet MSL with autopilot engaged. I had noticed that there was another aircraft on TCAS about 10 NM from me but did not have a visual. Their direction indicated that they were east of us and flying west (we were headed in a generally southern heading). At 5 NM I alerted my crew that there was an aircraft out around the 10-11 o'clock position and that I did not have them in sight yet. There was no response on frequency (a general helicopter frequency for avoidance and awareness). We did finally get a visual confirmation at approximately 1 mile or so of separation (with them at our 10 o'clock position) and it appeared that we had converging vectors. Still; nothing on the radio and they did appear to be maneuvering to avoid us. Turning would not have been sufficient to separate the aircraft so I began a rapid climb (over 500 FPM) and the aircraft passed directly underneath us with about 300 feet or so of vertical separation (we were rapidly climbing past 1;300 feet MSL). Afterwards we still got no communication or acknowledgment from the other aircraft.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.