Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 200; Flight Crew Total 900; Flight Crew Type 300
Conflict NMAC
Flight Crew Took Evasive Action
Procedure; Airspace Structure
Merrill Tower told us to enter right downwind 25 for touch and go's. Traffic was doing a pipeline check at 900 ft.; opposite direction (almost set up for left downwind runway 7). Tower told us traffic was same altitude and to offset downwind to the north. We started a slight turn to the north and spotted traffic immediately ahead and to the north. Evasive turn to the east was required. Traffic turned further north to avoid us. Passed maybe 500 ft. from each other.
Small aircraft pilot reported a close encounter on downwind for landing to MRI airport with a transiting aircraft.