to allow planes to turn around quickly. The runways have long since been closed to air traffic. Modern visitors use the runways for flying radio-controlled aircraft, land sailing, and cycling. The end of Runway 19 contains an area where visitors can fly model airplanes. As per International Civil Aviation Organization standards, the runways were numbered based on their alignment: the value on each end was how many tens of degrees off that runway was from facing magnetic north, counting in the clockwise direction and rounding to the nearest whole number. For example, a plane landing on Runway 19 would be facing slightly magnetic southwest since it would be 190 degrees clockwise from magnetic north, while a plane landing on one of the two Runways 6 would be facing magnetic northeast since it would be 60 degrees clockwise from magnetic north. The two original runways are wide. The Runway 15–33 was lengthened to in 1936. It runs parallel to the original hangars along Flatbush Avenue. Old Runway 6–24 was the longer of the two runways, with a length of , and ran perpendicular to the original hangars. After the WPA renovations in the mid-1930s, the ends of Runway 15–33 were equipped with green runway lights, and that runway was designated as the "blind landing runway" for bad-weather or nighttime landings. The two runways constructed in 1937–1938 are wide. Runway 1–19 was originally long. It ran from the vicinity of the current main public entrance to the field at the south end of Flatbush Avenue, to the North corner of the field near the Mill Basin Inlet. Runway 12–30 was originally long. It ran from the former Coast Guard Hangar to the Northwest corner of the field near Flatbush Avenue. A brick chimney near Runway 12 was demolished because it was in the way of the flight path. For many years, the U.S. Coast Guard used a section of Runway 12–30 for helicopter operations. The NYPD Aviation Unit uses this same segment. A new Runway 6–24 was constructed in 1942. This x runway ran perpendicular to Flatbush Avenue, parallel to the old runway 6–24, but was located on the north side of the field. At this time, Old Runway 6–24 became taxiways T-1 and T-2. Runways 1–19 and 12–30 were lengthened to x . Around 1952, Runway 1–19 was expanded again to , and Runway 12–30 was expanded to . The new