An NTSB preliminary report points to a freak encounter with a weather balloon as the cause of an impact that busted one layer of a United Boeing 737’s windscreen last month. The owner of a balloon that was in the area of the impact, Windborne Systems, reported it lost contact with the data package on the global sounding balloon at the same time the United crew was showered in glass inside the cockpit. The NTSB plotted all the courses and did the math and while it doesn’t come right out and say the plane and balloon collided, the evidence seems clear. The 737, on its way from Denver to LAX, was on a reciprocal heading from the balloon at the same altitude when the impact occurred.
The report adds detail about the crew’s reaction to the incident. The captain, who was flying, spotted an object in the distance and before he could tell the FO, the impact occurred. Glass shards resulted in numerous minor cuts to the captain’s right arm, but the FO was uninjured. As they dealt with the alarms and figured out the diversion to Salt Lake City, the FO took over flying duties and the captain handled the radio as he did first aid on his cuts. After he patched himself up, he resumed flying for the uneventful landing in Salt Lake City. United sent another plane to take the passengers to L.A. The full preliminary report is copied below.
“busted” ???
They were very lucky. Had the data package impacted in the center of the windshield, it could well have crashed the plane. Those balloons stay aloft for weeks and drift around the world at various altitudes. Why aren’t they required to carry ADS-B out transmitters to alert manned craft on their position? As rare as such encounters may be, it only takes one tragedy to make that seem obvious.