Many "ghost plane" incidents are related to decompression

On the afternoon of September 4th local time, a seaplane crashed in Puget Sound near Seattle, Washington State, USA. There were 10 people on board. Only one female victim was found, and the whereabouts of the other 9 were unknown. The cause of the accident is unknown.

Coincidentally, on September 4, a "ghost plane" flew across half of Europe as if no one was around, and finally plunged into the Baltic Sea and shattered into pieces. This was also an American-made plane. It was called a "ghost plane" because the fighter pilot who checked the sky reported that there was no pilot in the plane, and it flew forward automatically and strangely as if no one was around, until it crashed into the sea.

These two accidents happened in succession. The cause of the former is still under investigation, while the latter is a bit strange, so let’s talk about it in detail.

"Ghost plane" flies unmanned across most of Europe

The crashed plane, called "ghost" by foreign media, is a general propeller plane manufactured by Cessna Aircraft Corporation of the United States. It is a 42-year-old 551 business jet with registration number OE-FGR. The plane took off from the southern Spanish city of Jerez at 12:57 pm local time on September 4, and its destination was Cologne, Germany.

According to the investigation, there were four passengers on the plane, including a pilot, a couple and a daughter. The problem occurred when the plane was flying over the airspace of southern France, and the air traffic controllers were unable to get in touch with the plane. The French Air Force then sent fighter jets to investigate, but found that there was no one in the cockpit and the plane was flying on its own according to the established route.

The French Air Force planes could neither force it to land nor get in touch with it, so they could only fly with it and escort it out of the country. The plane then continued to fly over the airspace of Luxembourg, Belgium, and Germany without paying any attention to anyone else. Instead of landing in Cologne as planned, it crossed the border of Germany and continued on its way.

The German Air Force sent two Tornado fighters to check, but they could only fly with the French Air Force like the French Air Force fighters and escorted them out of the country. However, the pilots of the two German fighters reported different situations: one said there was no one in the cockpit, and the other said he saw an unconscious person and a figure making "unclear" gestures out of the window.

Flight radar tracking information showed that after flying out of the German border, the "ghost plane" continued to maintain an altitude of about 11 kilometers and a speed of about 670 kilometers per hour. After flying over the southern part of Gotland Island in Sweden, it began to lower its altitude and finally disappeared on the sea northwest of Ventspils, Latvia.

The preliminary investigation results showed that the plane flew for 4 hours and 51 minutes. The pilot reported to the air traffic control that the plane had a cabin pressurization problem when the plane reached an altitude of about 11 kilometers, but then lost contact. It was eventually discovered that the plane crashed in the Baltic Sea about 40 kilometers from Ventspils, and all four crew members, including the pilot, were killed.

What kind of “ghost” did the “ghost plane” encounter?

The accident investigation has not yet reached a further conclusion, but experts and industry insiders believe that this "ghost" is definitely not some supernatural phenomenon or aliens, but is likely caused by "decompression." What is decompression? It's simple to say, it means that the space pressure is less than one atmosphere.

Most humans and land animals live on the surface close to sea level. After long-term evolution, they have adapted to the pressure of one atmosphere at sea level. Body fluids and internal organs have adapted to and need to function normally under this pressure. Once the air pressure changes, they will become abnormal.

Strictly speaking, the so-called atmospheric pressure is closely related to the earth's latitude, altitude, and temperature. At sea level at a latitude of 45 degrees and a temperature of 0 degrees Celsius, the atmospheric pressure is 101.325 kPa (kilopascals). However, not all animals on Earth live in such a standard environment, so the so-called adaptation to atmospheric pressure is only relative.

Therefore, when people are exposed to an environment with a pressure less than one atmosphere, a little less will not have a big impact, but much less will make them uncomfortable, and if it is too low, their lives will be in danger, and if it is too low, they will die directly. What is this limit? Generally speaking, when the external air pressure is around 0.6~0.8 atmospheres, the human body can withstand it, and healthy people generally feel little change; but when the pressure is less than 0.5 atmospheres, most people will feel uncomfortable or comatose; and when it is less than 0.3 atmospheres, most people will be comatose or even die.

On Earth, 0.8 atmospheres of pressure is equivalent to an altitude of 2,000 meters or on a high mountain. Many famous tourist mountains in my country, such as Mount Tai, Mount Lu, and Mount Huang, are below this altitude. Only the main peaks of Mount Hua and Mount Qiyun are a little over 2,000 meters, so tourists generally do not feel uncomfortable.

But the air pressure on the Qinghai-Tibet Plateau is greatly reduced. For example, the air pressure in Lhasa is only about 0.65, and many people begin to feel uncomfortable when they arrive there. Mount Everest is more than 8,000 meters above sea level, and the air pressure is only about 0.41. Only a very small number of trained people can reach there, and they need to rely on oxygen to relieve the symptoms of decompression.

Modern passenger planes generally fly at altitudes of around 6,000 to 8,000 meters, and some even exceed 10,000 meters. To keep passengers healthy and comfortable at such altitudes, it is necessary to maintain a certain pressure in the cabin, and the technical means used is to add oxygen and pressurize the cabin.

The plane was flying at an altitude of 11,000 meters, and the pilot had reported a pressurization failure before the crash, so decompression was most likely the "ghost" that caused it to become a "ghost plane."

Aircraft pressurization systems and consequences of depressurization/

Generally speaking, when an airplane flies above 5,000 meters, the environmental pressure will cause discomfort to the human body. Modern passenger planes generally fly at an altitude of 6,000 to 9,000 meters on domestic routes, and the flight altitude of international routes is generally above 9,000 meters. Therefore, modern aircraft are equipped with a pressurization system.

People generally live in an environment of 1 atmosphere of pressure. If the inside of an airplane could be adjusted to 1 atmosphere of pressure, it would of course be the most comfortable. However, in this case, the pressure difference between the inside and outside would be very large, which would place very high demands on the cabin structure. If all airplanes were made into this structure, the manufacturing cost would increase greatly.

In fact, people do not feel uncomfortable on mountains around 2,000 meters above sea level, where the air pressure is about 0.8 atmospheres. Therefore, the cabin pressure of general commercial passenger aircraft can be adjusted to around 0.8 atmospheres. This can ensure the safety and comfort of passengers and meet the economic needs of aircraft manufacturing.

The aircraft's pressurization system is an essential system and cannot be missing. The consequences of failure and decompression are very serious. For example, the "ghost plane" mentioned in the article flew at an altitude of 11 kilometers. The environmental pressure at this altitude is less than 0.3 atmospheres, the oxygen content is only 30% of that at sea level, and the temperature is below minus 30 degrees Celsius.

The sealing of an airplane cabin is only relative. Once the cabin loses pressure, it will quickly approach the ambient state. This environment will cause the internal gas of the human body to expand, and the blood vessels, tissues and organs to be damaged, such as lung rupture, eardrum rupture, subcutaneous bleeding, nose bleeding, etc. This is the horrifying phenomenon of boiling body fluids caused by decompression. This consequence can cause a person to quickly fall into a coma or even die.

There are two typical types of decompression. One is explosive sudden decompression, such as caused by a cabin explosion. This type of decompression may cause the occupants to quickly fall into a coma and die. The other is hidden slow decompression, in which people gradually fall into a coma or even die without noticing.

Although the former is very dangerous, it is often accompanied by obvious warnings, which can attract attention and take emergency rescue measures, such as using oxygen masks to breathe oxygen while quickly lowering the aircraft to a safe altitude of less than 5,000 meters, preferably around 3,000 meters. At this time, if the human body has not suffered irreversible damage, it can be out of danger.

The latter is often more terrifying. Slow decompression is not easy to detect, and rescue measures cannot be taken in time, causing people to slowly fall into a coma without knowing it, and death quietly approaches. The 511 business jet became a "ghost plane" under such circumstances.

It is important to note that when decompression occurs, do not think that oxygen can solve all problems. Oxygen can only solve the suffocation caused by temporary lack of oxygen, but cannot solve the problem of boiling body fluids caused by the pressure difference between the body and the environment. Therefore, once the aircraft loses pressure, there are two best ways to save it: one is to quickly restore the pressure, and the other is to quickly descend to a safe altitude.

Many "ghost plane" incidents are related to decompression/

Obviously, this 511 "ghost plane" was in a state of slow decompression. The decompression came quietly without the pilot noticing. When the pilot found that there was a problem with the pressurization system, his consciousness was already blurred and he fell into a coma before he could take any measures. Some people believe that the German Air Force pilot saw someone in the cabin waving and sending an "unclear" signal. It is very likely that it was the couple's daughter, who was calling for help from the fighter plane because of her physical condition and had not yet fallen into a complete coma.

Unfortunately, the pilot could not interpret her cry for help. Of course, with modern technology, even if we knew it was a cry for help, we could do nothing at an altitude of 10,000 meters. We could only watch the plane run out of fuel and crash. Its spiral descent in the Baltic Sea is completely consistent with the characteristics of running out of fuel.

There are many incidents of cabin depressurization, a typical example being the Helios Airlines Flight 522 incident. On August 14, 2005, this plane flew from Cyprus and circled over the Greek capital Athens for four hours and was reluctant to land. The air traffic controllers thought the plane was hijacked and reported it to the military, who sent two F-16 fighter jets to check and discovered something was wrong with the plane.

The pilot did not see the captain in the cockpit, only the co-pilot was lying on the dashboard; in the cabin, the passengers were wearing oxygen masks, but they all lowered their heads as if they were asleep. At this time, the fighter pilot saw someone enter the cockpit and try to control the plane, but in the end the plane crashed, and all 121 passengers were killed.

Subsequent investigations showed that this was a tragedy of aircraft decompression caused by human error. The rear door of this aircraft had not been closed many times in previous flights. Before this takeoff, the engineer changed the pressurization device from automatic to manual mode to facilitate the inspection of the rear door.

Inspection after the crash found that the plane was still in manual mode and there was no pressurization or oxygenation at all, but the captain was completely unaware of it.

When the plane climbed to 4,000 to 5,000 meters, the system temperature was too high. At this time, the captain had already suffered from hypoxia, slow reaction, confused thinking logic, and unclear language when communicating with the ground air traffic control. He probably thought that there was something wrong with the air conditioning system. So he left the cockpit to check and never came back.

When the plane climbed to an altitude of 5,000 to 6,000 meters, the decompression and hypoxia phenomenon was already obvious. The oxygen masks in the cabin fell down, and the passengers who didn't know why put on the masks. The plane was still climbing, and the decompression and hypoxia became more and more serious. The oxygen in the mask could only supply 12 minutes. After the passengers finished breathing, they fell into a coma, and most of them died from suffocation and boiling of body fluids.

The plane became a veritable "ghost flight", cruising faithfully for more than two hours on autopilot to reach its destination. The last person who entered the cockpit to try to save the plane was a male flight attendant who had diving training experience. Due to his strong lung capacity, he did not fall into a coma thanks to the remaining oxygen.

At this time, he found the fighter plane that came to observe and tried to make contact, but failed. Then he wanted to control the plane, but he had no training for Boeing 737, and due to lack of oxygen, he fell into a coma after releasing the autopilot. At this time, the fuel ran out and the plane crashed, and all the people on board died.

Another similar accident occurred on September 20, 2018, when a Jet Airways Boeing 737 took off. Because the crew forgot to turn on the pressurization system, it lost pressure during the climb phase, and the oxygen masks fell off. More than 30 of the 166 passengers suffered from bleeding ears and noses, headaches, etc. Fortunately, the decompression incident was discovered in time, and the captain decisively stopped the climb and quickly returned to Mumbai Airport, avoiding another "ghost flight".

So, was the Malaysia Airlines flight MH370, which mysteriously disappeared on March 24, 2014, also a "ghost flight" that flew until it ran out of fuel and crashed into an unknown sea? Now, eight years have passed, and no wreckage has been found. Where are they now? The flight carried 227 passengers, 154 of whom were Chinese, and 12 crew members.

It can be seen from this that aircraft decompression is an extremely dangerous thing. Once it happens, only by taking correct measures in time can you have a chance of surviving.

As an ordinary passenger, you only have 1 minute of golden time at this time, which is to quickly put on the oxygen mask that has fallen, seal your mouth and nose, and prevent the oxygen in the alveoli and airways from being sucked out by the low pressure in the cabin, so as to avoid falling into a coma. Only then can you rescue others.

The remaining operations mainly depend on the captain. If he can handle it correctly and in time and quickly lower the plane to a safe altitude, the plane can be saved from becoming a "ghost flight" and the passengers can be saved. With the continuous improvement of science and technology, the performance of aircraft is getting better and better. I hope this kind of "ghost flight" will no longer appear.

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