Narrative:

I was conducting a power line inspection in class G airspace. The power line I was following was going generally in a southwest direction and was to come within approximately 2.5 miles of class D airspace ahead. I called the applicable tower twice with no response. My attention was drawn to another low-flying aircraft perhaps a mile and a half ahead. I watched the second aircraft and observed it make a tight turn near the ground; turning back to a southerly direction. This craft then went up and over a hill; disappearing for a short while. When it reappeared it was still headed in a southerly direction; and I could see that it was releasing spray. This plane was on the west side of the power line and I was on the east side and very close to the power line. At this point our flight paths were nearly parallel and he was approximately one quarter mile ahead of me. Suddenly the spray plane pulled up and made a tight climbing turn to the left; reversing direction and was now flying parallel to the power line on the east side; coming at us. As he completed the turn he dropped back down; now being at approximately our same altitude. I could not immediately give way to the right; because of being so close to the power line on my right so I made an immediate pull up; gaining approximately 100 feet of altitude. The spray plane appeared to either maintain altitude or may have decreased altitude slightly; but made no turn left or right. The spray plane passed about 100 feet below us and I made a slight maneuver so that I could keep him in sight until we passed. I then continued on the power line inspection to the south and never entered the nearby class D airspace; approximately 2 miles away. After leaving the area I discovered that I had selected the wrong frequency for the nearby control tower. My intention had been to notify the control tower of our line patrol flight path because of our proximity to class D airspace; but not because we intended to enter it.

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Original NASA ASRS Text

Title: A C182 on a power line patrol and an Agricultural aircraft experience a NMAC while performing their missions at low altitudes in Class G airspace.

Narrative: I was conducting a power line inspection in class G airspace. The power line I was following was going generally in a southwest direction and was to come within approximately 2.5 miles of class D airspace ahead. I called the applicable tower twice with no response. My attention was drawn to another low-flying aircraft perhaps a mile and a half ahead. I watched the second aircraft and observed it make a tight turn near the ground; turning back to a southerly direction. This craft then went up and over a hill; disappearing for a short while. When it reappeared it was still headed in a southerly direction; and I could see that it was releasing spray. This plane was on the west side of the power line and I was on the east side and very close to the power line. At this point our flight paths were nearly parallel and he was approximately one quarter mile ahead of me. Suddenly the spray plane pulled up and made a tight climbing turn to the left; reversing direction and was now flying parallel to the power line on the east side; coming at us. As he completed the turn he dropped back down; now being at approximately our same altitude. I could not immediately give way to the right; because of being so close to the power line on my right so I made an immediate pull up; gaining approximately 100 feet of altitude. The spray plane appeared to either maintain altitude or may have decreased altitude slightly; but made no turn left or right. The spray plane passed about 100 feet below us and I made a slight maneuver so that I could keep him in sight until we passed. I then continued on the power line inspection to the south and never entered the nearby Class D airspace; approximately 2 miles away. After leaving the area I discovered that I had selected the wrong frequency for the nearby control tower. My intention had been to notify the control tower of our line patrol flight path because of our proximity to Class D airspace; but not because we intended to enter it.

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.