GRINDSTONE AIR HARBOR
PORT AUSTIN, MI
Single turf runway characterizes Grindstone Air Harbor (29C), a privately owned, non-towered airport in Port Austin, Michigan. Runway 18/36 measures 1,800 by 85 feet with a turf surface. Operations occur under visual flight rules only, as no instrument approach procedures are published. Arriving and departing aircraft self-announce their positions on the common traffic advisory frequency, 122.9 MHz. Field elevation is 640 feet above mean sea level.