A helicopter pilot flying a survey mission over an oil spill reported a near midair collision with a...

Narrative:

I was flying east along the coast of louisiana. My passenger and I were conducting a survey of the marsh islands along the gulf coast. While flying to an island I noticed a boeing vertol 107 helicopter approaching me at about my 10 o'clock position at same altitude and opposite direction. I advised my passenger that I was going to turn right to allow more separation between us. As we passed the other helicopter; I noticed that they slowed down and went into a hover over the island that we were originally heading for. I noticed a long line with a grapple on the end of it hanging from the bottom of the helicopter. Our plan was to set up about a 2 mile orbit around the island to keep separation between the two helicopters while they performed their long line operation of picking an oil boom out of the marsh. We were on our second orbit when we noticed the helicopter was still in a 500 ft hover but now the helicopter was doing a pedal turn facing towards us. We made a third orbit and at the end of the third orbit; the vertol nosed over and made a direct path headed straight for us at the same altitude. I immediately started flying straight and level. About 20 seconds later the vertol had pulled up behind us and my passengers screamed out;'he is right behind us and I don't see him anymore!' I caught a glimpse of the helicopter at my 5 o'clock position about 500 ft and closing. I immediately made a hard right turn to reverse course and to put the other helicopter on the same side as me so I could see him. As I made my right turn; so did the other helicopter. I was thinking maybe that he would make a left turn to avoid hitting me but instead he turned into and on the inside of my helicopter. At this point the boeing helicopter was 300 ft directly to my 3 o'clock position. I took up a straight and level course and the boeing helicopter stayed with me for about 10 seconds and then made a gentle right turn and went back to the island and picked up an oil boom with their long line and transported it to an awaiting barge.

Original NASA ASRS Text

Title: A helicopter pilot flying a survey mission over an oil spill reported a NMAC with another helicopter engaged in picking up oil spill booms. The narrative implies purposeful attempts by the other pilot to intimidate the reporter.

Narrative: I was flying east along the coast of Louisiana. My passenger and I were conducting a survey of the Marsh Islands along the Gulf Coast. While flying to an island I noticed a Boeing Vertol 107 helicopter approaching me at about my 10 o'clock position at same altitude and opposite direction. I advised my passenger that I was going to turn right to allow more separation between us. As we passed the other helicopter; I noticed that they slowed down and went into a hover over the island that we were originally heading for. I noticed a long line with a grapple on the end of it hanging from the bottom of the helicopter. Our plan was to set up about a 2 mile orbit around the island to keep separation between the two helicopters while they performed their long line operation of picking an oil boom out of the marsh. We were on our second orbit when we noticed the helicopter was still in a 500 FT hover but now the helicopter was doing a pedal turn facing towards us. We made a third orbit and at the end of the third orbit; the Vertol nosed over and made a direct path headed straight for us at the same altitude. I immediately started flying straight and level. About 20 seconds later the Vertol had pulled up behind us and my passengers screamed out;'he is right behind us and I don't see him anymore!' I caught a glimpse of the helicopter at my 5 o'clock position about 500 FT and closing. I immediately made a hard right turn to reverse course and to put the other helicopter on the same side as me so I could see him. As I made my right turn; so did the other helicopter. I was thinking maybe that he would make a left turn to avoid hitting me but instead he turned into and on the inside of my helicopter. At this point the Boeing helicopter was 300 FT directly to my 3 o'clock position. I took up a straight and level course and the Boeing helicopter stayed with me for about 10 seconds and then made a gentle right turn and went back to the island and picked up an oil boom with their long line and transported it to an awaiting barge.

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.

Attributes
ACN	907698
Time
Date	201009
Local Time Of Day	0601-1200
Place
Locale Reference	GAO.Airport
State Reference	LA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Kiowa/Kiowa Warrior/Combat Scout
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	VFR
Aircraft 2
Make Model Name	Boeing-Vertol 107
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	VFR
Person 1
Function	Single Pilot
Qualification	Flight Crew Instrument Flight Crew Commercial
Experience	Flight Crew Last 90 Days 108 Flight Crew Total 1338 Flight Crew Type 353
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 300

A helicopter pilot flying a survey mission over an oil spill reported a near midair collision with another helicopter engaged in picking up oil spill booms. The narrative implies purposeful attempts by the other pilot to intimidate the reporter.