United Boeing 737 Hit By Weather Balloon, Cracking Windshield & Bruising Pilot

In recent days, there has been a lot of talk about a bizarre flight diversion incident, first flagged by JonNYC, with a lot of questions about what caused it. Well, we now have some more insights, and the likely explanation is quite something…

United Boeing 737 MAX diverts over cracked windshield

This incident happened on October 16, 2025, and it involves United Airlines flight UA1093, scheduled to operate from Denver (DEN) to Los Angeles (LAX). The planned 862-mile flight was operated by a Boeing 737 MAX 8 with the registration code N17327, and it had 140 people onboard.

While the plane was around 200 miles southeast of Salt Lake City (SLC) at an altitude of 36,000 feet, the pilots made the decision to divert. The reason? There was a crack in the (flight deck) windshield. The pilots initially descended to 26,000 feet, before ultimately diverting to Salt Lake City, where they landed on runway 16L, around 50 minutes after the incident first started.

United ended up getting a replacement Boeing 737 MAX 9 for this flight, and passengers made it to Los Angeles with a delay of around six hours.

You might not initially think much of an incident like this, because airplane windshield cracks do happen once in a while. However, this was unusual on a couple of levels. For one, the pilots reported seeing something hit the plane, and the windshield showed scorch marks, or something. Furthermore, the captain sustained bruising to his arm.

Below is a video with partial air traffic control audio of the incident.

The cracked windshield was likely due to a weather balloon

As you’d expect, this incident has been getting quite a bit of attention, since it’s not often you see a pilot claim that their aircraft was hit by something at cruising altitude, and to sustain bruising.

Initially, there had been speculation that there was some sort of space debris that might have hit the aircraft, given the altitude at which this happened. After all, if you’re at 36,000 feet, there’s not otherwise much that’s going to be above you, that could potentially hit your aircraft.

However, we now know what likely happened. The CEO of WindBorne has reported that one of the company’s weather balloons may have been the object that hit the aircraft, based on the timing. Here’s what the CEO shared on social media:

Yes, I think this was a WindBorne balloon. We learned about UA1093 and the potential that it was related to one of our balloons at 11pm PT on Sunday and immediately looked into it. At 6am PT, we sent our preliminary investigation to both NTSB and FAA, and are working with both of them to investigate further.

We file NOTAMs, follow all specifications required by FAA 14 CFR part 101, and share all live balloon positions with the FAA via API and our website. The photo from Scott is old hardware, the current version operational is about 2x lighter.

WindBorne operates a constellation of long duration lightweight weather balloons to improve weather forecast, with much of our data going to both US and international governments. We have been coordinating with the FAA for the entire history of the company.

The system is designed to not pose a risk to human life in the worst case event of a collision. This is what the FAA 101 and ICAO weight limits are for. And indeed, there were no serious injuries and no depressurization event to my knowledge as a result of the collision.

However, I’m still surprised to see spallation of the windshield on the inside. I find this extremely concerning, and unacceptable in the case of a collision, regardless of what the official regulations are. It resulted in injury to a pilot, which I’m simply not okay with whatsoever.

As mentioned, we are working closely with the FAA on this. We haven’t yet received any operational guidance. Regardless, we just deployed a software change to minimize time at active flight levels and are manually checking it across the full constellation. Additionally, we are actively working on new hardware designs to reduce impact force magnitude and concentration.

Bottom line

A United Boeing 737 MAX had to divert after the windshield cracked inflight, with the pilots reporting that they saw something hitting the aircraft. While windshield cracks happen, it’s extremely unusual to see planes hit by something at cruising altitude.

There was initially speculation that there might have been space debris (or something), but it seems we now know what likely happened. It would appear that a weather balloon may have hit the aircraft, causing this incident. That fully tracks in terms of the impact. It’ll be interesting to see what an investigation reveals…

What do you make of this cracked windshield situation?