A United Airlines passenger plane suddenly broke the windshield during a cruise last week and had to make an emergency landing.Many media on 21st, preliminary investigations showed that this may be because the aircraft hit a weather balloon.

According to the Associated Press, the Boeing 737 MAX took off from Denver, USA on the 16th, carrying 134 passengers and 6 crew members to Los Angeles. When cruising at an altitude of about 10,000 meters, the windshield of the aircraft broke, but the cabin did not lose pressure. Eventually, the plane made an emergency landing in Salt Lake City.

California's renowned weather balloon design and operating company, Wind Systems, began an investigation on the incident on 19th, then quickly concluded that the aircraft was likely to collide with a weather balloon flying by the company.

John Dean, CEO of the company, said that the location data of the above flight was highly consistent with the last known location of one of the company's balloons, and the balloon stopped signal transmission just before and after the collision time. The company has submitted all relevant data to the National Transportation Safety Board, and the final conclusion will be determined by the agency.

The commission has not yet responded, however, because of the U.S. government's downturn. The Associated Press expects the preliminary investigation report to be published within weeks, but the full report will take more than a year to complete.

Dean said his company has flown more than 4,000 weather balloons, which comply with all regulations of the Federal Aviation Administration in terms of size and design. Before each flight, the company will also coordinate and share the position of the balloon with the Federal Aviation Administration in real time so that the pilot receives timely notification about the collision.

Dean, however, was shocked by the extent of the damage to the windshield, since the company's weather balloon took off weighing only about a kilogram and carrying a small sandbag as ballast.

The company said it has adjusted the software to try to reduce the time the balloon stays at a height range of approximately 9,000 to 12,000 meters. At the same time, the company is also looking at different pressure cabin designs to reduce the impact force in the future when a collision occurs and minimize the potential risk of aircraft damage or personal injury.