Narrative:

Upon arriving into the traffic pattern for the active runway; there were 3 aircraft transmitting on CTAF. One on a three mile final; another on left downwind; and myself on a midfield left base for the taxiway parallel to the landing runway. There was another aircraft on the upwind; departing; that had not announced intentions on CTAF and was in sight; no factor. As I rolled out on short final for the taxiway; I suddenly saw another aircraft outside my starboard window taking evasive action to the right; who subsequently departed the traffic pattern. The aircraft had not announced his takeoff; and was camouflaged by other aircraft on the ramp.

Google
 

Original NASA ASRS Text

Title: An EMS helicopter pilot experienced a NMAC on short final to a taxiway paralleling the active runway.

Narrative: Upon arriving into the traffic pattern for the active runway; there were 3 aircraft transmitting on CTAF. One on a three mile final; another on left downwind; and myself on a midfield left base for the taxiway parallel to the landing runway. There was another aircraft on the upwind; departing; that had not announced intentions on CTAF and was in sight; no factor. As I rolled out on short final for the taxiway; I suddenly saw another aircraft outside my starboard window taking evasive action to the right; who subsequently departed the traffic pattern. The aircraft had not announced his takeoff; and was camouflaged by other aircraft on the ramp.

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.