MOAB, Utah — A preliminary report by investigators found that a company had reported it had lost contact with its weather balloon shortly before it crashed into a United Airlines flight over Utah.
The National Transportation Safety Board report opened its investigation after a cracked windshield injured a co-pilot and forced the flight to be diverted to Salt Lake City on Oct. 16.
According to the report, the flight's captain noticed an object distant on the horizon, which crashed into the first officer's forward windshield on the Boeing 737-8 with a "loud bang," before he was able to mention the balloon to the surrounding staff.
United Airlines flight diverted to Salt Lake City due to cracked windshield
The flight had left Denver for Los Angeles International Airport when the incident occurred over Moab at 6:43 a.m. The captain sustained minor injuries, while none of the other flight crew or passengers onboard were injured.
After being diverted, the flight landed safely in Salt Lake City at 7:31 a.m.
During the investigation into the incident, NTSB investigators discovered a notice was issued for a weather balloon launch from Spokane on October 15. The balloon had been tracked all the way to Moab before WindBorne Systems Inc. reported that contact was lost with its balloon at 6:36 a.m. on the following day, approximately 10 minutes before colliding with the United flight's windshield.
The weather balloon contained no large metal pieces or "high-stiffness structural elements," the report noted, adding that it was produced from "thin, low tensile strength, plastic film."
Windshields on the Boeing 737-8 are certified to withstand the impact of a 4-pound bird "without penetration, to be capable of withstanding the maximum cabin pressurization loads with the failure of a single pane, and the internal pane must be non-splintering."
The damaged windshield was removed from the plane and brought to an NTSB lab for investigation.
