Narrative:

This report concerns an incident involving our helicopter and another passing too close to one another. I am reluctant to call this a near miss since we were never in any danger of colliding. However; we did pass too close for comfort! This happened while we were in level cruise flight at 5500 MSL enroute back to base. We had just completed a patient transport; having dropped off our patient at the medical center. We were on a southeasterly course back to base. I was actively scanning for aircraft; looking forward when someone announced on [the frequency]; 'hello; there!' in that instant; an aircraft flashed by our left side; approximately one quarter mile away; on a parallel but opposite direction course; a few hundred feet below our altitude. The bright red and white bell 407 immediately caught my attention as our competitor. The 407 was just barely visible to me above the lower edge of the windows out the left side of our aircraft. Shocked by the sudden encounter; I acknowledged the radio transmission by saying; 'nice paint job!' my impression was that the other pilot failed to see us; as well; until only a moment before our passing by. If he had seen us any earlier; I believe they would have turned away to increase separation and made some sort of position report to us. It was evident by their comment that they were also taken by surprise. We did not get a TCAS alert since we were outside a radar environment in this remote area. As I processed what happened; I tried to understand why I had failed to see the other aircraft in time to avoid this encounter. While I cannot excuse myself from responsibility; I identified several factors that made the other aircraft difficult to spot: 1. The nearly head on approach angle meant that there was very little change in relative position; of the other aircraft; in my field of view. The other aircraft was probably nearly stationary; from my vantage point; until the actual passing. 2. The closure rate was very fast: approximately 260 knots; allowing little time to see and avoid. 3. The other aircraft was lower; difficult to spot against the ground clutter. From my position; in the right seat; my view looking ahead; to the left and lower is partially blocked by the instrument panel. 4. Smoke from a large wildfire reduced visibility somewhat to approximately 10 miles. After landing; I discussed what happened with my crew. The medic was sitting on the left side of the aircraft [and] reports that she was actively scanning for aircraft but also failed to see the other aircraft until our passing. The nurse; was sitting behind me was scanning out the right side of the aircraft and did not see the aircraft on our left. We were not talking in the minute or so before the incident; there were no distractions from the task of scanning. I shared my observations about the contributing factors; as listed above; with my crew. We felt better after our discussion but we were all still a little unnerved by thoughts of what could have happened.for my part; I'm considering making periodic radio calls while enroute; position reports in the blind; similar to what we now do near landing zones. This might help to prevent a re occurrence of this problem during the non ATC enroute phase of flight.

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Original NASA ASRS Text

Title: Medevac helicopter pilot reports airborne conflict with another opposite direction helicopter at 5500 feet.

Narrative: This report concerns an incident involving our helicopter and another passing too close to one another. I am reluctant to call this a near miss since we were never in any danger of colliding. However; we did pass too close for comfort! This happened while we were in level cruise flight at 5500 MSL enroute back to base. We had just completed a patient transport; having dropped off our patient at the Medical Center. We were on a southeasterly course back to base. I was actively scanning for aircraft; looking forward when someone announced on [the frequency]; 'Hello; there!' In that instant; an aircraft flashed by our left side; approximately one quarter mile away; on a parallel but opposite direction course; a few hundred feet below our altitude. The bright red and white Bell 407 immediately caught my attention as our competitor. The 407 was just barely visible to me above the lower edge of the windows out the left side of our aircraft. Shocked by the sudden encounter; I acknowledged the radio transmission by saying; 'Nice paint job!' My impression was that the other pilot failed to see us; as well; until only a moment before our passing by. If he had seen us any earlier; I believe they would have turned away to increase separation and made some sort of position report to us. It was evident by their comment that they were also taken by surprise. We did not get a TCAS alert since we were outside a radar environment in this remote area. As I processed what happened; I tried to understand why I had failed to see the other aircraft in time to avoid this encounter. While I cannot excuse myself from responsibility; I identified several factors that made the other aircraft difficult to spot: 1. The nearly head on approach angle meant that there was very little change in relative position; of the other aircraft; in my field of view. The other aircraft was probably nearly stationary; from my vantage point; until the actual passing. 2. The closure rate was very fast: approximately 260 knots; allowing little time to see and avoid. 3. The other aircraft was lower; difficult to spot against the ground clutter. From my position; in the right seat; my view looking ahead; to the left and lower is partially blocked by the instrument panel. 4. Smoke from a large wildfire reduced visibility somewhat to approximately 10 miles. After landing; I discussed what happened with my crew. The medic was sitting on the left side of the aircraft [and] reports that she was actively scanning for aircraft but also failed to see the other aircraft until our passing. The nurse; was sitting behind me was scanning out the right side of the aircraft and did not see the aircraft on our left. We were not talking in the minute or so before the incident; there were no distractions from the task of scanning. I shared my observations about the contributing factors; as listed above; with my crew. We felt better after our discussion but we were all still a little unnerved by thoughts of what could have happened.For my part; I'm considering making periodic radio calls while enroute; position reports in the blind; similar to what we now do near landing zones. This might help to prevent a re occurrence of this problem during the non ATC enroute phase of flight.

Data retrieved from NASA's ASRS site as of April 2012 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.