The Arctic is classified as a “no-fly zone” because of its extreme cold, high radiation levels, extreme weather indices and strong magnetic fields that make it unsuitable for routine flights.
Here are seven risk factors that must be understood and reduced for safer passage through the Arctic region:
Airplanes usually fly over the polar regions at an altitude of 10,000 meters. Due to the strong magnetic field and the thin ozone layer in the polar regions, they can receive cosmic radiation, magnetic storm radiation and radio dissociation radiation hundreds of times. The three kinds of radiation are proportional to the flying altitude and the length of radiation.
When the radiation dose accumulated to a certain value will suffer from radiation sickness, severe burns, fertility, tumors and other tissue damage, severe damage can lead to rapid death, cumulative radiation damage is as follows: ¡¤1000msv will suffer from radiation sickness.
¡¤2500msv can cause infertility in women.
¡¤3500msv results in male sperm survival rate less than 10%.
¡¤4000msv can cause brain tumors or fatal damage, and the damaged DNA will be passed on to future generations.
Other cosmic radiation of air defense communications, satellite communications, electronic equipment signal transmission have influence, studies have shown that under the environment of the airworthiness of each flight by radiation is at most a few dozen MSV, and within a certain range of the human body has a natural resistance and resilience, when the arctic region radiation serious, only route way to divert the far east.
When the sun is violently active, charged particles erupt and reach the polar regions. After being excited by the strong magnetic force in the polar regions, electromagnetic storms and optical phenomena are reflected in the atmosphere. There are three main elements for the formation of electromagnetic storms and optical phenomena:
The solar wind, the earth’s magnetic field, the atmosphere, as of now, the air in the medical community has no clear medical conclusion, aurora borealis how many degree of the harm of human body, but for pilots to fly over the North Pole, prone to flight illusion and visual dizziness, can only watch method, most of the energy used in instrument flight.
It is mainly about the management of low-temperature fuel. The air route is located in a high-latitude region, and the aircraft fuel is easy to freeze when flying in cold and low-temperature atmosphere for a long time. In winter, the external temperature is often below -65 ¡ã.
From 0:00 (UTC) on November 1 to 24:00 (UTC) on April 3O of the following year, the freezing point of fuel must be tested and obtained before takeoff. If there is a fuel low temperature warning at the cruising altitude of the aircraft in the actual flight, the crew can increase the fuel temperature by increasing the Mach number and flight speed.
A 0.01 increase in Mach number can increase TAT0.5-0.7, requiring 15-60 minutes of flight time to stabilize the fuel temperature.
North of latitude 82 degrees north, because the “line-of-sight” of geostationary communication satellites located above the equator affects the communication of satellite voice and data links, pilots need to use various communication devices to get in touch with ground traffic controllers to obtain information, and use various navigation devices under their command to complete flight tasks.
Basically, it is the main HF, SAT, VHF, PHONEPATCH, CPDLC, LDOC and data link communication equipment, characterized by the contact with the ground controller is always called out, a noise.
Polar regions as well as northern Canada, Greenland, northern Norway and Russia, an iceberg, a series of more than 3000 kilometers without any basic navigation equipment, the traditional inertial navigation system and the original radio navigation system affected, more because of the influence of magnetic field in the arctic, some regional variation change over 80 degrees, magnetic compass can no longer use,
Only unique navigation methods can be used: (1) the main satellite navigation GPS positioning system;
(2) Alternate TRUE track mode T: between Western hemisphere N60¡ã and Eastern Hemisphere N70¡ã put the heading reference switch in true position;
(3) Grid orientation G mode:
North of 70¡ã north latitude, it is mainly used for small aircraft with no heading reference switch. The basic calculation formula GRID BEARING=TRUE+WEST LONGITUDE GRID or true-east LONGITUDE, if the traditional way of navigation is still adopted,
The meter appears as a GIRD with a box, which automatically changes color as it descends.
Arctic route of alternate alternate different with the traditional route, in the arctic regions of both THULE airport as an example, the annual average temperature is lower than 40 ¡ã c, and the direction of the airport are based on the TRUE track T set on the basis of the direction, when using a ND way into the close, must put benchmark way switch as the TRUE, at this time to remember the wind for meteorological wind,
Instead of the traditional magnetic wind direction, the flight crew usually needs to have more understanding of the data of the alternate landing field, weather conditions, airport support, airport fire-fighting level, conditions for passengers to get on and off the plane, warmth in low temperature, medical conditions, language and contact information, etc. Therefore, Air China stipulates:
Before entering the 75 ¡ã north latitude 30 minutes after takeoff, to receive the company sent the weather index and alternate weather reports, judge whether the airworthiness, in the case of confirmed everything is ok the flight ready to fly over the polar told the company work, need to report again after passing the polar company dispatch department, normal flight can continue to fly to the destination,
If there is an emergency on board the flight before entering 75 degrees North latitude, the flight must be diverted to Anchorage ANC, the alternate airport of choice, approximately 1260 nautical miles. Once crossing 75 degrees North latitude, the flight must be diverted over the poles to Russia in any emergency.
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