United Airlines Flight Diverts After Collision With Weather Balloon Shatters

United Airlines flight 1039, a Boeing 737-8 traveling from Denver to Los Angeles, was forced to make an emergency diversion to Salt Lake City on October 16, 2025, after colliding with an object near Moab, Utah, at approximately 36,000 feet. The collision shattered the first officer’s forward cockpit windshield, leaving the flight crew showered with glass fragments. The captain sustained multiple superficial cuts to his right arm; the first officer was uninjured. All 111 passengers and crew on board were unharmed. The National Transportation Safety Board (NTSB) opened an investigation and identified a weather balloon as the likely object.

The Collision

The captain reported seeing an object on the horizon moments before a loud bang signaled the impact. The strike cracked the multilayered windshield - which is certified to withstand bird strikes from birds up to four pounds - yet the balloon’s mass was sufficient to cause the damage. Despite the shattered glass and resulting minor injury, the crew maintained aircraft control, coordinated with air traffic control, and landed safely in Salt Lake City without further incident.

The Balloon

WindBorne Systems, which operates long-duration smart weather balloons, reported losing contact with one of its global sounding balloons (GSBs) in the area. The balloon had been launched from Spokane, Washington the previous day and tracked south through Oregon and Nevada before turning northeast into Utah, aligning with the flight’s path at the time and altitude of the collision. WindBorne stated its balloons are engineered to minimize harm in a collision event and announced it had “already implemented four additional safety measures to further reduce the possibility of any future aircraft-balloon interactions as well as mitigate harm should an impact occur again.”

The NTSB investigation into the precise cause and full circumstances of the collision was ongoing at the time of reporting.

References: Pilots ‘Showered With Glass’ After Passenger Jet Collides With Object | Plane Windshield Cracks Mid-Flight After Being Struck by an Unknown Object as Injured Pilot Makes Emergency Landing