A United Airlines flight lost a wheel on take-off in San Francisco on Thursday morning. The wheel fell to the ground, damaging several cars in the process, with the plane diverted and later making a safe emergency landing.
The flight in question was United Flight 35. The Boeing 777 took off from San Francisco International Airport (SFO) bound for Kansai International Airport in Osaka, Japan. The take-off was captured on a live stream by YouTube channel Cali Planes. In the video, an object can be seen falling from the inside of the left rear landing gear.
With the plane leaving from runway 28R at SFO, the wheel plummeted to the ground into a staff parking lot. It landed on a fence and several vehicles, causing significant damage, before bouncing into an adjoining lot for rental cars. As covered by NBC Bay Area, staff in the area heard a loud crunch as the wheel smashed into vehicles on the ground. Thankfully, nobody was injured in the incident, with the lot largely free of pedestrians at the time.
The incident can be seen when the above livestream’s ticker reads 11:24:20 AM.
One silver sedan took the brunt of the damage, with an adjacent chain-link fence also receiving a heavy hit from the wheel. Some reports suggest a red Tesla Model 3 may have also been hit by the wheel as it bounced across two parking lots.
The plane was diverted to Los Angeles International Airport (LAX) rather than continuing on to Japan. The Boeing 777 has six wheels on each of its main landing gear, and modern airliners can safely land even with some damaged or missing wheels. The plane was able to make a safe emergency in Los Angeles shortly after 1:30 PM. Generally, in a situation where parts have fallen from the airline, it makes sense to land the plane rather than continue on a long international flight, out of an abundance of caution.
— Julian (@Aviationmech123) March 7, 2024
Julian, aka @Aviationmech123 on Twitter, captured the above video of the damage caused by the wheel. To some degree, it’s almost a surprise the incident wasn’t worse. For context, a tire from the main landing gear of a Boeing 777-200 weighs a full 265 pounds, according to Air Canada. Measuring 51 inches high and 21 inches wide, the tires are typically inflated to a pressure of 218 PSI. Changing the tires is normally handled by a small crew of technicians, as you can see in this video from the airline.
After the incident, authorities secured the wheel that fell off the plane. Contrary to some reports, it was not just a tire that fell from the aircraft. Shots taken by NBC’s aerial unit clearly show the whole wheel fell off the plane.
At this stage, it’s entirely unclear what may have caused the wheel to fall from the plane. Photographs of the wheel and plane itself are limited at this time, so we can only broadly speculate.
One thing my engineering brain picks up from these images? It’s the light-colored area visible in the center of the wheel that we see lying on the ground. It’s jagged and much lighter than the surrounding metal, which makes it look like a fracture surface. It suggests perhaps part of the wheel or hub broke off, sending it tumbling to the ground. However, these images are not clear enough to know for certain, and it could simply be a lighter-colored part of the hub assembly that we’re looking at.
It’s another ugly incident that has put a Boeing plane smack-bang in the middle of the headlines once again. It’s worth noting, though, that any fresh enmity for the Seattle company may be misdirected. The plane in question, a Boeing 777-200, was first delivered to United a full 22 years ago.
Just as you wouldn’t blame Ford if you had a wheel fall off your 2001 Taurus, Boeing may not be at fault in this case. It’s perhaps more likely that a maintenance error occurred with the fitting of the wheel or tires. This would usually be handled in-house by an airline’s own maintenance crews.
UPDATE: The tire that fell off a United Airlines plane after takeoff from SFO landed in an airport parking lot and appeared to damage multiple cars. https://t.co/HJ3vDMLaYO pic.twitter.com/EiEYEpN0er
— NBC Bay Area (@nbcbayarea) March 7, 2024
In any case, neither airlines, manufacturers, nor the general public appreciate aircraft parts falling from the sky. The NHTSB will be investigating the matter in detail to determine what happened and we should find out in due course.
Image credits: NBC Bay Area via YouTube/Twitter screenshot, @AviationMech123 via Twitter screenshot
Aircraft Engineer here. A common cause for wheel loss is improperly torqued axle nuts (as noted, requires several steps of tighten/loosen/rotate to seat bearings). The vibration causes the bearings to overheat and the heat causes the steel and aluminum to distort to the point where the hub ID is large enough to walk over the axle nut. Although the heat destruction is enough to prevent determination of a definitive cause, actual bearing failure is pretty rare.
I would love to see the look in the insurance clerk’s face as he/she reads the incident report and wonders who will pay.
I once had a dead body land on the trunk and rear windscreen of my company provided fleet lease Mitsubishi Magna back in 1988. The deceased had been very forcefully ejected into the air after failing to successfully cross a busy Oxford street in Sydney without looking and what was left had it’s landing spot occupied by my car. It was a strange night indeed. Thankfully the car was parked at the time and it was around 2am so I was busy clubbing and getting wasted as was the tradition of the young. When I got back, there was no note, just a crushed rear end, shattered windscreen and lots of blood. I only found out later by going door to door and asking shop-owners.
United rep: “We don’t have a definite cause for the incident, but rest assured our investigators are working tirelessly.”
Boeing is no longer headquartered in Seattle. They moved the headquarters to Chicago in 2001, and then moved again to the D.C. area in 2022. The commercial airplanes division of Boeing is still based in the Seattle-area, but the company as a whole hasn’t been Seattle-based for awhile.
You picked a fine time to leave me, loose wheel.
Broke off my Boeing and bounced in a field! (Well, parking lot, but who’s counting?l
Seattle company? You mean Chicago.
You mean Arlington, VA. Gotta be close to the Pentagon and those defense dollars, you know. And it’s easier to lobby the FAA for exemptions from DC.
I wish the engineers were back in control, not the ‘business experts’ and bean counters. Quality and the perception thereof saves money in the long run.
Time for United to retire that 777?
I wonder if the maintenance crew will chock this up to a “quality escape”?
When reached for comment a NASCAR pit crew issued this statement, “Sometimes these things happens. We’ll take our lap penalty and hope for the lucky dog.”
They really did used to run 4 or even 3 out of 5 lug nuts on late-race cautions to save time in the pits. That would cause some problems.
The lug nuts are to be torqued to 44 ugga duggas. Perhaps the ground crew was a few uggas short?
I was going to say that Boeing is a Chicago company (headquarters), but did a quick Google to double check and forgot those morons moved to Arlington.
If this had launched a Kia on the highway into orbit, the circle of flight would have been complete.
Let me guess, “Parking facility is not responsible for anything that happens to your car. Park at your own risk”?
A wheel fell of an Airbus a month ago, and no one gave a crap
I hate Boeing and the C Suite that has turned the company into a laughing stock, but I’m really not a fan of this kind of pop culture pile on. Some idiot didn’t tighten the wheel correctly
In my experience, A&P mechs historically are a pretty competent and capable bunch. Is the drive for diversity, equity, and inclusion degrading the workforce?
Yea bud, just like the drive for diversity, equity, and inclusion really degraded the leadership quality at Boeing that got us all to this point.
J f’ing K. They were all rich, old white dudes (one of which married his first cousin) who had nothing on their mind but stock buybacks and profit expansion, and whose decisions lead to the deaths of hundreds of people
How does DEI have anything to do with A&Ps?
I’m asking the question not offering an opinion. Are they lowering the standards to recruit minorities and women on the flightline?
Do you even understand what the standard is?
Getting an A&P is not a joke; nobody who makes hiring choices has a say in how to get one. It is a federally regulated license with very stringent education and testing requirements. Like, you can’t get it just passing a written test you have to take an oral and practical exam as well.
And why would they have to lower the standard to get women or minorities on the flightline?
They aren’t there because they cannot do the job; they are not there because shitty attitudes like this make it an unpleasant environment for those groups.
That’s one of those questions where asking it means you already have an opinion.
Boeing: “not our fault.”
Those Pep Boys tire guys really fucked up the tire rotation this time.
Nothing to see here.
Many years ago I was flying out of SFO aboard UAL the night before Xmas eve to see my Bestie in Seattle for the Holidaze.
Once we were up in the air, the Pilot came on saying we were turning back to SFO because of a catastrophic hydraulic leak.
Once back on the ground and off the malfunctioning plane – we were told to go to a different gate where the replacement plane was – however there was a call for people in Row 4 and 5 to come to the desk. Turns out the replacement plane had no row 4 or 5.
You would not believe the drama – children crying, frustrated parents – all because those of us who paid extra to sit towards the front of the plane had no place to sit, every flight to Seattle afterwards was completely booked, and someone on the ground didn’t do their jobs.
Meanwhile my Bestie had rented a party Limo loaded with a bunch of our friends to pick me up at SeaTac.
That was the last time I would ever book a United flight.
“and someone on the ground didn’t do their jobs.”
Do you think mechanical issues only occur because a person failed at their job?
Yeah.
Because proper inspections and maintenance would have caught the issue before it became a problem.
Really? Please tell me how you predict a hydraulic leal because even after 30 years as a mechanic I am still frequently surprised by them…
Not every leak is from a visibly worn part.
I will also add that when it comes to aircraft ANY hydraulic leak is a catastrophic leak. If it has a visible drip it doesn’t leave the ground.
Or would you rather airlines just start letting stuff like that slide so you never miss a flight?
I’d rather Airlines not let stuff like that slide so that we aren’t forced to turn around in midair and come in for an emergency landing.
Just Google “Preventing Hydraulic Leaks” – Each has about 6 points for doing so, including ensuring the connectors are correctly tightened, the correct fluid is used, and appropriate preventative maintenance.
I do not even know where to start with that comment…
O-rings extrude, things vibrate loose, hoses rupture, crimps let go, lines crack, and a million other things can happen that will cause a leak.
In the last week, I have been on work calls to repair 4 hydraulic leaks that there was no practical way to predict or prevent. Things break and there is nothing that can be done about it.
If preventative maintenance and inspections can prevent all failures why do ANY mechanical failures occur? Like even F1 cars drop valves and break down…
They will still try to rent those cars to people, and will just tell them to look it over and note any damage. Nothing takes a car out of the rental fleet lately if it can meet the Copart requirements for a “Runs and drives” classification.
I hosted a Dart Party for the local Triumph club at my home last week. One guest’s Spitfire lost a wheel on the way to the party. (we sent a rescue party with a jack and a torque wrench). Another guest lost a rear wheel on his TR4 on the way home at 60mph on the highway! The lug studs sheered, dropped the car onto the leaf spring perch and created a 20 foot spark trail until he managed to stop on the shoulder. Fortunately a new hub and spring perch is getting him fixed up.
Morals of the story:
1) Don’t drive old Triumphs if you don’t like adventure, danger, and embarrassment
2) TORQUE YOUR WHEELS and CHECK YOUR LUGS
Great! My Triumph is supposed to get here in about two weeks…
You’ll be fine. It’s a Tronda.
Yes, but did they keep that in mind in Cowley while they were bolting it together?
I know it’s a total aside, but the lede photo of the cars… That’s a dour and cloudy colored image… from the horizon down. Can we not get any color on cars anymore? Some at least semi-aspirational manufacturer needs to step up and give us some visual stimulation. They’ll sell like hotcakes and start a new trend, and the roads will be much more cheerful.
Yesterday my gf was trying to tell me where a parking/no parking split was. “Up by the white car.” There were 5 white cars in a row, 4 SUVs and a BRZ. Sigh.
True story, I purchased a use white Audi, with one key that needed to be reprogrammed. took it out to dinner walked out to the car and the key would not open the door, the Trunk or anything. I walk in to call my son to tell them to get the other key, and meet us at the restaurant, only to find another white Audi with the trunk up 6 spots down (it was mine).
The very next day at the grocery and walk up to the trunk of the white Audi, to put groceries in, and open it to find a bunch of chairs and crap in the trunk, yes not mine again, mine was 3 spots away.
All the damn white Audi’s look alike from the back.
Last time a heavy like this had to turn around it splashed half of LA with jet fuel so it could land. I hope for they dumped it somewhere better this time like the ocean!
More likely SFO Bay on approach.
I see no problem with dumping jet fuel in the Arizona Bay area.
We already dump enough crap in the ocean.