There is a video on the Internet of a helicopter falling out of control and falling in Erhai Lake, Dali. What was the cause of this accident?

Water and fire have no mercy, but people have love. Soldiers of the people have worked hard! At 11:14 on May 9, 2021, a forest fire broke out in Dashaba Mountain, Wanqiao Village, Wanqiao Town, Dali City. Crash

There were four crew members inside the helicopter that crashed into Erhai Lake. Through on-site search and rescue, two crew members were rescued at around 11:40 and 15:15 respectively. They died after all efforts at the scene and the hospital failed to rescue them. The other two crew members are searching and rescuing. Tail rotor failure

The first is the failure of the helicopter's tail rotor, which should be the main cause of the accident. This is what we saw in the video of the incident, where the helicopter kept "circling". Why do some people say helicopters are prone to crashing?

The first factor that makes helicopters prone to crashing is that the structure is too complex, according to an American documentary about Apache helicopters. This armed helicopter, which can only carry a few people, contains a total of 4 million parts, almost as many as civil aviation aircraft. Too many parts and pipelines are accommodated in a small space, and system failures are prone to occur once the aircraft is hit or damaged. Kobe Bryant took an ordinary civilian helicopter with a relatively simple structure. This simplicity is from the inside out. Military helicopters have added a lot of anti-collision structural designs. Civilian general-purpose helicopters have relatively simple designs in this regard, and are more likely to crash during forced landings.

The helicopter's power transmission system is the most complex among existing manned aircraft. The turboshaft engine drives the main rotor through the gearbox, and also drives the rear tail rotor on the tail through a long and complicated transmission shaft. Such a complex power structure alone is very troublesome.

The second factor that makes helicopters prone to crashing is that the rotorcraft is too sensitive to airflow. Rotary-wing aircraft mainly use the rotation of the wings to generate airflow disturbance, thereby generating lift. This determines that helicopters are more susceptible to interference than fixed-wing aircraft. Especially during the take-off and landing phases, it is also affected by ground effect reactions and is prone to instability. This is not only reflected in manned helicopters, but also in ordinary helicopter model aircraft.

Maybe because you can’t parachute, the helicopter escape issue makes people feel unsafe. But on the other hand, due to the existence of the rotor, the helicopter can effectively slow down the falling speed in the event of an accident, so the survival rate of an emergency landing is higher than that of an ordinary aircraft. This is also a characteristic of mutual advantages and disadvantages.

The third factor that makes helicopters easy to crash is the immature escape technology. Currently, the only ones in the world that have ejection seats are the Russian armed helicopters Ka-50 and Ka-52. This aircraft lost many pilots during the test ejection. It is now mature and is a unique technology of the Kamov Design Bureau. The key lies in the timing and angle of blowing up the wings. It is too dangerous for civilian helicopters to install explosives and this technique cannot be adopted. As for emergency landing, the anti-collision structure is not strong enough and not as strong as aircraft such as Black Hawk and NH90. Therefore, when the civilian helicopter Kobe Bryant was riding in had an accident, the only feasible solution was emergency control. Try your best to restore the aircraft to a vertical rotation state, which is extremely technically demanding and has a high error rate.