41IL — Great Lakes Seaplane Base, Antioch, IL

Non-ToweredAntioch, IL • 737' MSL

41IL WeatherLive METAR & TAF

41IL has 1 runway. The longest is 3W/21W at 3,451 ft × 400 ft (water).

3W/21WNo runway lights3,451 ft × 400 ftWater

FAA NASR data, cycle 2026-09-03

41IL field elevation is 737 ft MSL. The standard traffic pattern altitude at 41IL is 1,740 ft MSL (1,000 ft AGL).

Field elevation737 ft MSL

Pattern altitude1,740 ft MSL1,000 ft AGL · standard

Control towerNon-towered

FAA NASR data, cycle 2026-09-03

Check 41IL against your personal minimums, plan a route to it, and see the best runway for the current wind — free.

No, 41IL is a non-towered airport.

41IL has 1 runway (3W/21W). The longest runway is 3,451 feet.

41IL uses the standard traffic pattern altitude of 1,000 feet AGL — about 1,740 feet MSL at a field elevation of 737 feet.

41IL (Great Lakes Seaplane Base) has a field elevation of 737 feet MSL.

41IL (Great Lakes Seaplane Base) is located in Antioch, IL.