As350b3 helicopter pilot reported two nmacs with crop dusters during flight.

Attributes
ACN	1286321
Time
Date	201508
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Eurocopter AS 350/355/EC130 - Astar/Twinstar/Ecureuil
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	VFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Instrument
Experience	Flight Crew Last 90 Days 41 Flight Crew Total 4300 Flight Crew Type 300
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 0 Vertical 200

Narrative:

I am an EMS helicopter pilot. While flying with a patient from a scene call [to the medical center]; I encountered two crop dusting aircraft in close proximity to my aircraft. I was at 500 feet AGL (med crew requested lowest altitude due to patients severe head injury) a crop duster aircraft flew 200 feet below me perpendicular to my flight path. I do not believe the pilot of the other aircraft saw me at all. After this incident I climbed to 1000 feet AGL and [a few minutes later]; I had a second crop duster aircraft fly under me; again perpendicular to my flight path. As with the previous incident; I do not believe this pilot saw my aircraft either. Because of my increased altitude; there was at least 700 feet of separation between us and much less of a factor. Our current flight path flies right through an area of high crop dusting activity. Because they do not have a common frequency; there is no way to make advisory calls or communicate with the crop dusting aircraft.

Original NASA ASRS Text

Title: AS350B3 helicopter pilot reported two NMACs with crop dusters during flight.

Narrative: I am an EMS helicopter pilot. While flying with a patient from a scene call [to the medical center]; I encountered two crop dusting aircraft in close proximity to my aircraft. I was at 500 feet AGL (Med crew requested lowest altitude due to patients severe head injury) a crop duster aircraft flew 200 feet below me perpendicular to my flight path. I do not believe the pilot of the other aircraft saw me at all. After this incident I climbed to 1000 feet AGL and [a few minutes later]; I had a second crop duster aircraft fly under me; again perpendicular to my flight path. As with the previous incident; I do not believe this pilot saw my aircraft either. Because of my increased altitude; there was at least 700 feet of separation between us and much less of a factor. Our current flight path flies right through an area of high crop dusting activity. Because they do not have a common frequency; there is no way to make advisory calls or communicate with the crop dusting 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.