Narrative:

I was flying three passengers on a scenic flight. While flying south of downtown; and monitoring the local CTAF frequency; I encountered restricted visibility from haze and smoke. I descended temporarily for better visibility. Shortly after; I encountered a bright white light inside the cockpit. The light was being projected by a powerful spotlight from a police helicopter. The light was almost completely blinding. I could not determine the proximity of the aircraft except to estimate that it was flying at my 5 o'clock. One of the rear passengers estimated that the aircraft was 250 to 500 feet away. I took immediate evasive action and descended while turning to the left to put the light behind me. For several seconds; I could not see where I was flying. The aircraft continued to chase us; shining the projector directly into the cockpit as we were descending at full power. We did not know what was happening and we all thought we were being attacked. The nearest airport was ZZZ. I contacted them and advised them that we were being chased by another aircraft. They provided me with a transponder code and I continued towards ZZZ for an immediate landing. The other aircraft also contacted ZZZ tower and identified themselves as [the] police department. This was one of the most dangerous flying incidents I've encountered in my 22 years of flying. It's extremely important that the crew be advised about the potential of blinding other pilots with these projector searchlights.

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Original NASA ASRS Text

Title: GA pilot reported a NMAC with a police helicopter that aggressively blinded the pilot with a search light.

Narrative: I was flying three passengers on a scenic flight. While flying south of downtown; and monitoring the local CTAF frequency; I encountered restricted visibility from haze and smoke. I descended temporarily for better visibility. Shortly after; I encountered a bright white light inside the cockpit. The light was being projected by a powerful spotlight from a police helicopter. The light was almost completely blinding. I could not determine the proximity of the aircraft except to estimate that it was flying at my 5 o'clock. One of the rear passengers estimated that the aircraft was 250 to 500 feet away. I took immediate evasive action and descended while turning to the left to put the light behind me. For several seconds; I could not see where I was flying. The aircraft continued to chase us; shining the projector directly into the cockpit as we were descending at full power. We did not know what was happening and we all thought we were being attacked. The nearest airport was ZZZ. I contacted them and advised them that we were being chased by another aircraft. They provided me with a transponder code and I continued towards ZZZ for an immediate landing. The other aircraft also contacted ZZZ Tower and identified themselves as [the] Police Department. This was one of the most dangerous flying incidents I've encountered in my 22 years of flying. It's extremely important that the crew be advised about the potential of blinding other pilots with these projector searchlights.

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.