Rather than flying directly across the Pacific Ocean, most commercial flights take curved routes because they are actually shorter than shooting straight across a distance. This may sound counterintuitive, but since the Earth is spherical, a straight line is not necessarily the shortest distance between two points.

When flying from the United States to Asia, planes do not follow a straight line across the middle of the Pacific Ocean as it might appear on a flat map. Instead, they follow "Great Circle" routes, which take advantage of the Earth's curvature to find the shortest possible distance. For flights from the East Coast or Midwest (like NYC or Chicago) to hubs like Tokyo, Seoul, or Beijing, this often means flying north over Canada and Alaska, and sometimes even crossing near the North Pole. This is why passengers often see the frozen landscapes of the Yukon or the Aleutian Islands on their flight trackers. From the West Coast (like LAX or SFO), the route stays closer to the Pacific but still curves north toward Alaska before tracking down the coast of Russia or Japan. Another critical factor is the Jet Stream; pilots try to "hitch a ride" on these high-altitude air currents when flying eastward to save fuel and time, while they may take slightly different paths when flying westward to avoid strong headwinds. These routes are also planned to ensure the aircraft remains within a certain flying time of an emergency diversion airport, a regulatory requirement known as ETOPS (Extended-range Twin-engine Operational Performance Standards).