details of Iran crash! Experts said there were five reasons for theplane's fire and crash.

This morning (8th), a Ukrainian Airlines Boeing 737 crashed shortly after takingoff at Iran's Khomeini International Airport in Tehran, killing all 176 peopleon board, which aroused strong attention from the international community.

The black box of the crashed airliner has been found and the cause of theaccident is under investigation.

The Ukrainian Ministry of Foreign Affairs released information on the people onboard. The victims included 82 Iranians, 63 Canadians, 11 Ukrainians(including 9 crew members and 2 passengers), 10 Swedes, 4 Afghans, 3 Germansand 3 British.

The latest verification results showed that there were no Chinese passengers onboard.

The aircraft belonging to Ukraine International Airlines took off from Iran'sTehran Khomeini International Airport at 5.15 Tehran time and crashed near theairport.

Because the crash was in Iran, public opinion is full of speculation. TheUkrainian ambassador to Iran earlier said the accident was caused by an enginefailure, not a terrorist attack.

However, the Ukrainian embassy has just updated the news, saying that the causeof the accident needs further investigation. Currently, Ukraine has set upa special investigation team to investigate the cause of theaccident. Until the investigation is clear, all statements about the causeof the crash will be considered unofficial news.

Scene: The plane is completely broken and has a burning smell.

CCTV reporters saw the search and rescue work still ongoing. The crashedplane was completely shattered, and the scorched smell could still be heard atthe scene.

At 10 am local time, Ukraine Airlines issued news of the plane crash. Allthe black boxes on the wrecked plane were found.

The crashed aircraft was a Boeing 737-800 NG and will be delivered in2016. On January 6, 2020, the aircraft just passed a comprehensivetechnical inspection and found no abnormalities. Affected by the crash,the company will suspend flights to Tehran indefinitely.

According to reports, after the accident, Ukrainian President Zelensky ordereda comprehensive inspection of all Ukrainian passenger aircraft and instructedthe Attorney General's Office to launch a criminal investigation into the causeof the accident.

Responses from various parties in

Iran: Mourning the victims

According to official Iranian media, Iranian Civil Aviation Organization spokesmanJafar Zad said the crash occurred in Robat Karim County, Tehran Province,Iran. Khirvand, the head of Iran's emergency services, said the planecaught fire when it crashed and was very hot.

On the same day, Iranian Foreign Ministry spokesman Abbas Moussavi and Iraniangovernment spokesman Ali Rabe expressed condolences to all those killed in thecrash.

Ukraine revises crash statement

Ukraine's embassy in Iran revises crash statement. In a previousstatement, the crash of a Ukrainian passenger plane in Tehran was caused by anengine failure, which ruled out the possibility of a terroristattack. However, Ukraine's latest statement states that a specialinvestigation team has been set up to investigate the cause of thecrash. The cause of the accident will be announced by the commission ofinquiry. Any claims made before then will be invalid.

The model of the crashed plane is Boeing 737-800NG, which will be shipped fromthe factory in 2016 and put into use. On January 6, 2020, the aircraftjust passed a comprehensive technical inspection and found noabnormalities. Affected by the crash, the company will suspend flights toTehran indefinitely.

Ukrainian President Zelansky has previously issued a statement expressing hisdeep sympathy to the relatives of all passengers and crew members.

Chinese Ministry of Foreign Affairs: I hope to find out the cause of theaccident as soon as possible.

Chinese Foreign Ministry spokesman Geng Shuang said at a regular pressconference on the 8th that China expresses its deep condolences to the victimsand their families. I hope relevant parties can find out the cause of theaccident as soon as possible.

Geng Shuang said that after the crash, the Chinese embassy and consulate inUkraine had contacted the relevant Ukrainian authorities to verify thesituation. Currently, they have not received any notice from Chinesecitizens on the flight. Any further information will be released in atimely manner.

When answering the question of whether China will stop flying civilian aircraftdue to increased military activities in the Middle East, Geng Shuang said thatthe Chinese civil aviation authorities are paying close attention to theaviation security situation in the Middle East. He said: "China wasworried about the current situation in the Middle East, we hope to be able tocool down the situation in the region as soon as possible, this is theconsensus of the international community.

In Iran after the United States launched a counterattack, the FAA announced aban on lead in American aircraft into Iran, Iraq, the Persian Gulf And OmanGulf airspace. At the same time, it also said that if necessary, measures willbe taken to ensure the global safety of U.S. civil aviation. As the Boeing 737crashed in Iran, at least six countries followed the FAA and adopted Urgentaction.

To date, seven countries, including the United States, Singapore, Malaysia, SriLanka, Vietnam, Australia and France, have announced they have avoided Iran(and Iraq) airspace or suspended flights through Iran and Iraqi airspace.According to reports, China Southern Airlines flight from Tehran to Urumqi hasno current plans.

The truth of the crash: technical reasons or was shot?

At present, tension between the United States and Iran is taking place and Iranis firing missiles at several U.S. military bases in Iraq. In retaliation for"beheading" of Iraqi troops Long military leader Sulaimani, thecause of the crash of the civilian passenger plane is still uncertain.

Captain Chen Jianguo said that the plane crashed two minutes after takeoff andlost the signal immediately after climbing 4500 feet. The flight route wasnormal within two minutes. In other words, the aircraft The signal wasinstantly lost.

According to a video taken by a resident reposted by CCTV and other media, theplane had already caught fire in the air.

From this video, the photographer's perspective was removed. The video showsthat the plane has experienced at least a few times in the air Burning orexploding. At the 6th and 27th seconds respectively.

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Judging from the debris on the plane, the debris was scattered in a large area.According to local media reports, the victim's clothes were flying away fromthe corpse, indicating that the plane had been damaged or exploded in the airbefore falling to the ground.

There have been reports of holes in the fuselage and other sharpobjects. Some people suspect that engine fragments have broken down, whileothers suspect that other metal fragments have broken down.

Iranian authorities have previously issued a statement saying that the aircraftencountered technical problems.

The Ukrainian ambassador to Iran also issued a statement saying that accordingto initial information, the plane crashed because of an engine.

So how many possibilities could cause the plane to explode, burn, and crash inthe air?

Chen Jianguo believes that there are five reasons:

1. Engine problems

Will the engine cause the aircraft to explode and crash?

Chen Jianguo: This is possible, but because this 737-800 aircraft is equippedwith a CFM56 engine, this engine was jointly developed by General Electric inthe United States and Snecma in France. This engine is very mature andwidely used in Boeing, Airbus and other aircraft. It is one of the best-sellingand most reliable engines in the world.

If the engine catches fire, will it definitely crash?

Chen Jianguo: The most dangerous problem for the engine is that the engine fanis severely detached and penetrates the wing or fuselage fuel tank, causing theaircraft fuel tank to catch fire or explode.

Although this is rare, it does happen many times. As recently as 2018,Southwest Airlines was the same 737NG aircraft as the crashed Ukrainianaircraft, and the same CFM56-7B engine also suffered non-inclusivedamage. Debris from engine blades pierced the cabin and injuredpassengers.

(Note: Non-inclusive damage means that debris that should not have penetratedthe engine case has penetrated the engine case.)

If, unfortunately, the blade damages the wing, there is a large amount of fuelon the wing, and the fuel burns It can cause an explosion, especially if thecentral fuel tank explodes, which can leave the aircraft out ofcontrol. But the chance is really small.

The following accidents were caused by non-inclusive damage to aero engines:

If the wing burns, will it definitely crash? Not necessarily.

In 2003, a DHL aircraft was hit by a surface-to-air missile, burning most ofits wings. The plane flew in the air for a long time, but still landedsafely.

2. An explosion or fire on board the

aircraft will burn in the air. Another possibility is that the aircraftcould explode or catch fire.

It may be an explosion of an aircraft fuel tank, or it may be an explosion orcombustion caused by a bomb or other combustible material.

The following flights were all caused by air explosions.

If the central fuel tank in the air explodes, or if the bomb explodes anddamages the aircraft's control system, the aircraft cannot be controlled, andit will fall out of control like this video.

The Ukrainian aircraft is a new one, and it has been more than threeyears. This

is not necessarily the case for the central fuel tank with refuelingdevices , because if you look at the part that was hit, such as the Airbus300 above, its wings were hit by missiles. Not only did the air explode,but it landed safely.

4. A foreign

object is a possible cause, such as a collision with an unmanned aerial vehicleor other aircraft.

Judging by the video taken, it was early in the morning, when drones and smallaircraft were unlikely to fly. It is less likely that other foreignobjects will collide with the aircraft and cause the aircraft to ignite andexplode immediately.

5. Other reasons

Chen Jianguo believes that the above analysis is just a few common causes ofaircraft crashes, and may also be other reasons, such as fires in aircraftelectrical systems. At present, there is no evidence to draw anyconclusions directly.

At present, unless the pilot explicitly reports an engine failure or fire, itis not appropriate to rush to determine the cause of the crash caused by theengine failure alone. According to the principle of localization, theinvestigation of the air crash should be conducted by the Iranian CivilAviation Authority. Civil Aviation Authority of Ukraine (aircraftregistration country), Ukraine Airlines (aircraft owner), Federal AviationAdministration (Manufacturer's Civil Aviation Authority), and Boeing(Manufacturer) should be invited to participate in the investigation.

As for whether it was hit by explosives or missiles, a chemical analysis of thedebris will quickly conclude. At present, the black box has been found,and I believe there will be preliminary investigation conclusions soon.

(Note: Captain Chen Jianguo is the president of China AOPA Flight TechnologyCompany. He has 11,000 Boeing 737 flight hours, 1000 Airbus A320 flight hoursand 600 Boeing 747-400 flight hours. He has served 8 domestic and foreignairlines. Captains, teachers, standards supervisors, training supervisors,etc.) Is

Boeing in crisis again and getting cold?

According to a reporter's inquiry, the plane that crashed in Iran this time wasa Boeing 737-800, with the serial number Ur-PSR. It was delivered in July2016 and is only 3.5 years old.

The latest Boeing response said that it had taken note of media reports of theIranian air crash and was collecting more information.

It is worth noting that after the crash in early 2019, the safety of Boeingaircraft has become the focus of passengers' attention.

At present, the company's Boeing 737 MAX has not resumed flight, but anothercrash occurred, which will undoubtedly seriously affect the company'sreputation and also affect investor confidence.

The latest market shows that Boeing's stock price fell nearly 3% before theclose. Since the second Boeing 737 MAX crashed and grounded worldwide inMarch, Boeing's stock price has fallen by more than 20%.

If Boeing is in trouble again due to technical problems, the company'sdominance in the global aircraft manufacturing industry may be further shaken.

Including the Iranian air crash, 526 people have boarded Boeing 737s and diedin the past year or so.

Shortly before the Iranian plane accident, the 737 Max was found to have newfatal flaws:

A senior engineer at Boeing revealed that at the request of the FederalAviation Administration, an internal audit conducted by Boeing last Decemberfound the most pressing issues It's the tail of the Boeing 737 Max-the lineproblem. A short circuit between the two wires near the tail of theaircraft could cause the aircraft to crash.

On Monday, Boeing just announced that the 3,000 employees associated with the737 MAX will be reassigned to other positions without firing anyemployees. Prior to this, Boeing had reached confidentiality agreementswith several airlines and did not announce the amount of damages due to thegrounding of the 737 MAX.

The FAA said: "We will not approve this aircraft until all aspects of thecertification process have been successfully completed."

After eight years of catch-up, Boeing's crisis has caused its old rival Airbusto regain the "world "The largest aircraft manufacturer."

Aircraft delivery directly determines the revenue of aircraftmanufacturers. Foreign media data show that Airbus delivered 863 aircraftin 2019, breaking industry records. From January to November 2019, Boeingdelivered only 345.

Boeing's third quarter report for 2019 shows that its third quarter revenue wasclose to $ 20 billion, down 21% year-on-year. Net profit in the firstthree quarters was $ 374 million, a 95% decrease year-on-year.

Although $ 20 billion in cash (as of September) is still available, claims fromvictims' families, settlements with airlines, and sharp declines in revenue dueto declining aircraft deliveries all point to this

(Original Title: Iran The details of the crash were revealed! 176 nationalityannounced! Ukraine revised the statement to reveal the truth of the crash.)