United Airlines emergency landing likely caused by weather balloon

A United Airlines plane appears to have collided with a weather balloon while cruising over Utah at 36,000 feet above sea level last week, fracturing layers of its windshield and forcing an emergency landing.

A California company called Windborne Systems said it began investigating the situation on Sunday, shortly after the National Transportation Safety Board. said he was investigating. Windborne quickly concluded that the Boeing 737 Max had most likely struck one of its balloons, despite the company’s best efforts to avoid such collisions.

The plane, which was flying from Denver to Los Angeles, did not lose cabin pressure and landed safely in Salt Lake City last Thursday. United said 134 passengers and six crew members were on board.

Windborne CEO John Dean said he was surprised at the extent of the damage to the plane’s windshield, because Windborne’s balloons weigh only 2.4 pounds at takeoff with a simple sandbag serving as ballast. The impact sent glass fragments flying into the cockpit.

The company said it follows all Federal Aviation Administration rules regarding the size and design of its balloons that collect data to help improve weather forecasts.

“I find this extremely concerning and unacceptable in the case of a collision, regardless of the official regulations. This resulted in injury to a driver, which I simply do not agree with,” Dean said in an article on X.

The airline referred questions to the NTSB, which is not responding during the current government shutdown. The NTSB press release did not report any injuries.

Dean said in an email Tuesday that the flight location data closely matched the last known position and altitude of one of the company’s balloons before it stopped transmitting just around the time of the collision. Windborne has turned over all of its data to the NTSB, which will ultimately determine what happened.

Windborne has launched more than 4,000 balloons and the company said it coordinates with the FAA each time, filing pilot advisories and sharing live updates on the balloons’ positions with the FAA.

The company said it has already tweaked the software in its balloons to minimize the time they spend between 30,000 feet and 40,000 feet. The company is also investigating different ballast designs to reduce the force of any future collisions and minimize the risk of damage or injury.

NTSB investigators will release a preliminary report in a few weeks, but the full report may not be available for more than a year.