ASRS 2111588

Reporter 1

On a left downwind for Runway 21 GEG. Cleared for the visual approach at 6,000 ft., told to maintain 4,000 ft. until on final segment. We had briefed obstacle/towers south of the airport on the downwind. After we were cleared the PF (Pilot Flying) started a gradual descent to 4,000 ft. while still on downwind. I called out the tower. He adjusted his heading and then began a turn inbound to the FAF. We never received any terrain caution or warning, but both of us thought on the downwind we should have maintained 6,000 ft., if we had continued in the downwind, due to the vicinity of the towers which are listed at 4,553 MSL on the approach chart. My suggestion is a specific caution or note on the company information page highlighting the tower’s position and height on the downwind leg to Runway 21. Suggestion: Refine ATC procedures to ensure aircraft will not conflict with Towers. Mention conflict in company information pages.

Reporter 2

Vectored on a left downwind at 6,000 ft. for Runway 21 at GEG. Cleared for the visual 21 and maintain 4,000 ft. until established when were abeam the approach end. I began a descent to 4,000 ft. and planned to turn base at five miles. Right before my turn, the Captain calls out towers in front of us. The towers were 12 o'clock and appeared level to our altitude. We were abeam the FAF, and I turned inbound. We did not get an obstacle warning. We leveled at 4,000 ft. approximately mid base. The towers are south of 21's final at 4553 ft. MSL. The company information page only mentions the possibility of turning inbound early at 3.5 miles over the Seattle river. We did discuss that during our brief and mentioned the towers. The company information page does not mention the possibility of an ATC clearance that conflicts with the towers. We feel like extending downwind would have put the aircraft in conflict with the towers and guy wires. The situation would have been more difficult at night.