We know that the earth is a near circle. To be exact, it is an irregular sphere with slightly flat poles and slightly bulging equator. In other words, its lateral distance is long and its longitudinal distance is short. But when the plane flies over the southern hemisphere, why not fly directly over the South Pole?
Indeed, if the plane flies in the opposite direction in the southern hemisphere (such as Russia and new york), the distance is the shortest, but it is not that simple. The most basic reason why the human resources department crosses the southern hemisphere is that the route is of little economic significance to potential airlines, because the population density and demand in this area are very low, for those very special routes. Especially when airline operators fly long distances without suitable alternate airports during the voyage, it will bring them a huge regulatory burden.
For American airlines, usually flying to the North Pole, the operational and regulatory considerations are the same, involving aircraft certification, airline certification and long-term special reliability monitoring.
Another point is that the double-engine aircraft has low reliability in engine operation. In order to cope with the improvement of engine design and reliability and meet the needs of the industry, FAA provides guidance to allow two engines to gradually expand beyond the initial 60-minute limit. At present, the reliability of engines has been improved to such a level that the safety of operation is not affected by the number of engines, but by other factors that affect the operation of all aircraft, whose routes keep them away from enough airports.
The key problem for a twin-engine plane to fly so far away from the diverted airport is how to deal with the emergency on board. What if one of the engines breaks down? An airplane not only needs enough spare power to take off from the remaining engines, but also must be able to fly at a certain height, so that the airplane can fly at a long-distance shunting airport at the speed of a single engine. Many people forget this part. All modern airline twins can fly easily with one engine, but this will inevitably greatly reduce the airspeed, and it is likely to involve flying at a lower altitude. When ICAO and FAA first issued formal regulations, the restrictions of these ETOPS flights were described according to the maximum number of minutes allowed for flights to take off from appropriate alternate airports. Previously, the flight time of twin-engine aircraft was set at 60 minutes. Starting from the early 1960s, the flight time of the third and fourth aircraft was set at 65,438+0,80 minutes, and eventually these times increased to 240 minutes or even longer, which had special requirements for polar flight. In this case, whether at high altitude or on the ground, the environmental conditions will be extreme.
Other safety considerations include how to deal with fire emergencies on board, especially in cargo holds that are usually inaccessible from the engine room or cockpit. In these cases, it is necessary to strengthen the automatic fire extinguishing system to provide longer control for such incidents, and at the same time, the plane will be transferred to an airport four hours away.
In all these EROPS cases, airlines must prove that they have the training, aircraft/engine reliability and equipment needed for these flights. They must also closely monitor the reliability of the aircraft and all problems related to EROPS to ensure that the required level of safety is maintained. Above the Antarctic, all this is very difficult, and there is no need for human beings to take risks.
One more thing, flight planning routes are generally carried out between population centers, where there is enough demand to prove the rationality of flights and make them profitable. For example, in the era when the ETOPS rules require 3-engine or 4-engine aircraft to fly away from emergency landing sites, there are enough people. These planes carry many passengers, so many people need to make a living on them.
In the southern hemisphere, only three continents go deep into the south: Africa, Australia, New Zealand and South America. If this rope (or Google Earth Line) is used to connect the major cities on these continents, they can't even walk far from the Antarctic continent. However, the ETOPS regulations require that aircraft should not stay at emergency airports for more than 4 hours. How many emergency airports are there in Antarctica? Except McMurdo, none of them can handle the landing of B747' s wheels (also far away from the normal flight route). In a station with 20-40 people in winter, how would you use B747 to provide shelter and food for more than 300 people? Even a B787 plane will be seriously overloaded, and there may not be enough fuel for the plane to climb back to the proper height, because the plane has made an important diversion to reach the airport. This weather will close the few airports in Antarctica, where there is little support from air traffic control. This line won't work.
Flights flying around the Antarctic coast, such as flights from Johannesburg to Sydney, will try to use the rapids to accelerate their eastward flight, but they will fly farther to avoid the rapids when flying west. There are other weather deviations, but they usually don't push the plane further across Antarctica.
Therefore, due to security, regulatory, economic and practical reasons, few scheduled flights cross the Antarctic continent. Occasionally, there will be charter flights just for sightseeing, but they will not land.