On the afternoon of February 20, local time, United Airlines flight UA328, operated by a Boeing 777, took off from Denver International Airport to Hawaii. Shortly after the plane took off from Denver Airport, its right engine suddenly exploded, causing the entire engine to rectif

On the afternoon of February 20, local time, a United Airlines flight UA328 operated by Boeing 777 took off from Denver International Airport to Hawaii. Shortly after the plane took off from Denver Airport, its right engine suddenly broke down. It exploded and almost all the engine cowling fell off. Fortunately, the plane finally landed successfully at Denver International Airport with a burning engine "naked" and a total of 231 passengers and 10 crew members on board. The whole process was photographed by a passenger on the plane. I have to admire this passenger. Although this Boeing 777 does not have a "good heart", you do have a good heart!

The plane continued to drop parts on its way back to the airport. Several large aircraft parts were also found around the suburbs of Denver. However, fortunately, the entire accident did not cause any casualties on board or on the ground. Seeing this reminds me of an episode when I was following CCTV's " Approaching Science " many years ago. An uncle picked up a piece of ice that fell from the sky. The uncle and the villagers thought it was a rootless fire. All kinds of diseases, I started to taste them in turn, and finally after investigation, I found that it was the toilet water dropped from the plane...

Let’s get back to the subject. The Boeing 777 that caused the accident is considered to be a certain age. The aircraft was 26.3 years old and was flown in 1995. Officially delivered and put into operation, it belongs to the earlier batch of Boeing 777-200 and is also the fifth Boeing 777 manufactured by Boeing. The Boeing 777-200 uses three types of engines, namely Pratt & Whitney's PW4077D, Rolls-Royce's Trent 877 and General Electric's GE90-77B. As for which company Boeing will blame for the accident in the end, it depends on the specific accident investigation. According to the current situation, the Boeing 777 that caused the accident most likely used Pratt & Whitney's PW4077D. The Pratt & Whitney PW4077D is a relatively worry-free engine.

In fact, there are not a few aviation accidents caused by aircraft engines. Not long before the explosion of the Boeing 777 engine, there had been at least two similar accidents on Boeing aircraft , including a Boeing 737 and a Boeing 747. A few months ago, a fan blade broke on a Boeing 777, which almost resulted in a tragedy. Although the Boeing 777 is one of the most successful aircraft models in the history of Boeing aircraft manufacturing, it seems that this model has not had a good reputation since its inception. Not only have there been frequent accidents, but also the missing Malaysia Airlines MH370 and the downed Malaysia Airlines MH17. The aircraft types are Boeing 777.

Let’s go back and talk about the culprit of this accident, Pratt & Whitney PW4077D.

Pratt & Whitney PW4077D has had constant problems since it was put into service. Two of the more serious ones are the surge problem of the engine and the sulfide corrosion problem of the high-pressure turbine blades. The author is more inclined to believe that the main cause of this accident is related to problems with the high-pressure turbine blades of the engine itself. The so-called sulfide corrosion refers to the interaction between metal blades and sulfur-containing substances in a high-temperature environment to generate sulfides. After sulfide corrosion, the inner wall of the blade becomes thinner and the mechanical strength decreases, causing the blade to easily break, causing irreversible consequences.

So why is Pratt & Whitney PW4077D so prone to sulfide corrosion? The official explanation is that during the manufacturing process, sulfur-containing cleaning fluid remains in the internal chamber of some batches of blades. This cleaning fluid will weaken the anti-corrosion coating , and at the same time undergo a vulcanization reaction with the base material, causing the inside of the blade to produce Sulphide corrosion. Of course, this is just an official statement. As for what specifically caused the frequent accidents, it depends on the final accident investigation results. If you want to avoid blade corrosion and reduce the possibility of blade breakage, during routine maintenance and safety inspections, Also requires extra attention.

Although Boeing can blame the engine manufacturer for similar accidents, it is certain that Boeing's credibility in the global civil aviation market is gradually declining. Starting from the two serious air crashes of the Boeing 737 MAX8 series, Boeing has been blamed by people. It is an unsafe hat, and the impression of Boeing being "unsafe" may be difficult to recover in a short period of time.

Let’s turn our attention back to the engine explosion accident itself. Different from the many engine explosion accidents that have occurred before, this accident was recorded relatively completely by a passenger, and this scene is very important to everyone. For the audience in front of the screen, the impact can be imagined. Although the aircraft can still fly safely with one engine, an accident is an accident. If Boeing cannot take a fully responsible attitude towards its aircraft models and ensure that no accidents are caused by the design and manufacturing problems of the aircraft itself, then Boeing will It will be inevitable to continue to go downhill.