Much of the Internet recently found itself drawn in by a flight tracker. Lufthansa flight LH9911, operated by a lengthy Airbus A340-600 quad-engine widebody airliner, just flew from Boston Logan International Airport to Frankfurt Airport, never exceeding 10,000 feet above the sea along the way. The only hint of a problem was a comment that the aircraft wasn’t pressurized. But why would a damaged, unpressurized plane fly an entire transatlantic flight? The reason actually makes a ton of sense.
Flight LH9911 was originally supposed to depart Boston on July 5 at 5:50 p.m. local time. However, that flight was canceled. The plane didn’t take off again until July 8, when it flew from Boston to Frankfurt, Germany, flying low for the entire trip. News was thin on the ground at the time, but flight tracking website Flightradar24 reported: This aircraft did not undertake a rapid descent on its previous flight. We expect that this is a pressurization issue that occurred since and needs to be fixed at a home base.
Pressurization Is A Huge Deal
Pressurization plays a critical role in why commercial airliners can fly over 30,000 feet above ground level while keeping you in relative comfort. The human body struggles with high altitudes, with one of the greatest dangers being hypoxia, or insufficient oxygen in the body. An article from the Federal Aviation Administration elaborates:
Hypoxic Hypoxia
This is the most common form of hypoxia encountered in aviation and occurs at the lung level. This type of hypoxia is commonly called altitude hypoxia. Pilots may experience hypoxic hypoxia when flying at altitude in an unpressurized aircraft. With increasing altitude, the molecules of oxygen in ambient air get farther apart and exert less pressure per square inch. The percentage of oxygen does not change as we ascend; however, the partial pressure of oxygen in ambient air decreases as we go to altitude. In other words, with increasing altitude, the partial pressure of oxygen gets lower and the lungs cannot effectively transfer oxygen from the ambient air to the blood to be carried to all tissues in the body.
FAA notes that one of the most common causes of hypoxia is flying above 10,000 feet without pressurization or supplemental oxygen. Hypoxia is an insidious thing, too, because it doesn’t cause pain, and you could be suffering from it without even noticing. But it’ll show in your reduced physiological function before you ultimately pass out.
The fuselage of a pressurized aircraft functions as a sort of pressurized vessel and goes through a cycle of pressurization with every flight. Most airliners use bleed air from the turbofan engines that is fed through several components, including an outflow valve, and then into the cabin, and is maintained at a selected pressure. Newer designs, like that of the Boeing 787 Dreamliner (below) may use a “no-bleed architecture” where electric compressors handle pressurization duties. This is more efficient than the bleed air model.
This pressure difference is strong enough that plug-style aircraft doors are pushed into their seals with more force than any normal human can overcome. This is why misbehaving airline passengers always fail to open emergency exits and cabin doors while the aircraft is cruising.
One of the big components in all of this is the fuselage. If the fuselage is damaged, it may fail to seal, or worse, a catastrophic structural failure may occur after attempted pressurization and subsequent explosive decompression. This was one of the mechanisms involved in the infamous Japan Air Lines Flight 123 tragedy.
After suffering a puncture from a high loader in Boston, Lufthansa A340-600 D-AIHZ was patched enough to make it home for permanent repairs as an unpressurized ferry flight. The flight, which will take 10h30m at just 10,000 feet, normally lasts 6h30m. https://t.co/mOv9hl3Aee pic.twitter.com/t2qkLGHOTK
— Flightradar24 (@flightradar24) July 8, 2025
This is all to say that it’s a really huge deal when even what sounds like a small accident occurs. On July 5, a Lufthansa Airbus A340-600 registration D-AIHZ was bumped into and punctured by a high loader, a piece of ground equipment used for loading cargo onto an aircraft. I embedded the flight track above.
One Of The Weirdest Big Planes
D-AIHZ took its first flight in 2009 and is a member of one of the weirdest airliner lines that’s still in the skies. As Airways Magazine writes, Airbus A340 development began in the 1970s when Airbus was developing a family of aircraft to battle the American juggernauts of Boeing and McDonnell Douglas. At first, Airbus had an idea to just build variations of A300B, its first aircraft.
However, as Simply Flying notes, the evolving airline landscape called for even greater variety. Some airlines wanted a medium-haul widebody aircraft, which could be handled by a widebody twinjet (two engines). However, some airlines wanted something that carried more than 200 passengers, was capable of flying over entire oceans, and had the range to connect two different, distant regions, like Asia and Europe.
At the time, regulations limited twinjet aircraft to no further than 60 minutes from a diversion airport. However, trijets and quadjets didn’t apply, so if you were an airline and wanted to connect two distant locations without twin engine restrictions, you bought a Boeing 727, McDonnell Douglas DC-10, a Lockheed L-1011 TriStar, a Hawker Siddeley Trident, or a Boeing 747.
Not all of these were widebody long-haul aircraft either, as the 727 and Trident were narrow body aircraft and could fly over water to international destinations, but had less range than the large aircraft on that list. The trijet isn’t completely dead either. Notably, Dassault Aviation still builds trijets in the business jet market.
In case you’re curious, the defining feature of a widebody aircraft is a fuselage wide enough to accommodate two aisles. A Lufthansa Airbus A340-600 cabin is pictured above.
The Airbus answer to the long-haul market was the A340, which was longer than an A300 with better range than an A330. Airbus called the A340, which went into service in 1993, could fly 6,700 nautical miles nonstop. Airbus hailed the A340 as its first-ever truly long-range aircraft.
The weirdest version of the A430 family is easily the A340-600 (above), which entered service in 2002. At least in my eyes, what makes the -600 so weird is its length. At 247 feet, 5 inches, it’s 7.5 feet longer than an Airbus A380, and at the time, the A340-600 was the longest aircraft in the world. The iconic Boeing 747-8, which came later, just barely beats the A340-600 by three feet.
Yet, the A340-600 still looks far more goofy, like AI trying to make a plane. Another oddity is that the layman might expect a single-deck jet with four engines to be a bit of a hot rod. The shorter A340-200s and A340-300s came equipped with CFM International CFM56 engines and have a reputation for being a little underpowered. If these sound familiar to you, it’s because variants of this engine family were used in the Airbus A320 and the Boeing 737. The larger -500 and -600 siblings largely rectify this issue with more powerful Rolls-Royce Trent engines.
Airplane Fender Bender
I reached out to Lufthansa, Germany’s flag carrier, asking what happened to the aircraft. I also asked about why the aircraft had to fly back to Germany. I received this response:
A Lufthansa Airbus A340-600 (registration D-AIHZ) with the flight number LH9911 is currently being transferred from Boston to Frankfurt without passengers. Due to damage to the aircraft fuselage caused by a handling vehicle in Boston, this flight is being operated without a pressurized cabin at an altitude of only around 10,000 feet.
Lufthansa told other outlets that the aircraft was first patched up on the ground in Boston. This was in part because the airline determined that third-party permanent repairs would not be feasible. The plane was loaded with its crew and flown back to Frankfurt without passengers. D-AIHZ will undergo permanent repairs there in Europe. The aircraft was flown in an unpressurized state at a maximum cruising altitude of 10,000 feet mean sea level, or about a third of how high it would normally fly on the same route. According to the reported flight data, the aircraft actually spent most of its time between 8,000 feet and 9,000 feet.
According to Flightradar24, this flight took 10 hours and 37 minutes, or a whopping four hours longer than the same aircraft would normally take to fly the same route. The aircraft also flew at an indicated airspeed of around 250 knots, which explains why it took much longer.
While we don’t have photos of the damage, there is a general method for fixing puncture and tear damage to a fuselage. Typically, Simply Flying writes, the damage will be cut out and a filler plate will be mounted in its place. Then, doubler plates will be riveted in place. These plates will span an area larger than the now formerly damaged portion, ensuring that the weak area is strong. The repaired area of the fuselage will end up being thicker than the fuselage around it. Here’s a short timelapse of a crew repairing a fuselage:
After the repair is finished, the area sees regular inspections to ensure the fix is holding up. Repairs like these will also happen after tail strike incidents, impacts from foreign object debris, and damage caused by other ground equipment.
Overall, nothing out of the ordinary happened here. Sometimes, aircraft develop issues that cannot be fully repaired where they sit, so they are ferried home, where they’ll get restored. However, this particular instance was rather eye-catching because it still looks weird to see such a large jet traveling so low and so low over a whole ocean.
But really, what you’re looking at here is exactly how commercial aviation is supposed to work. Something broke, and Lufthansa used a safe method to get its aircraft back home for proper repairs so it could be put back into service. What you see here is part of why commercial aviation remains one of the safest ways to travel.
Top graphic image: Arthur CHI YEN – CC0 1.0
Thank you baggage smasher. This $2,000,000 mistake will be paid for by us- the passengers.
That is a weirdly awkward-looking plane. I have a friend who is a 777 pilot and had been a first officer on 757s, and she loves flying the 777. Apparently even on one engine, she says it’s almost ridiculously overpowered. Which is not a bad thing in a twin-engine plane.
Apparently the 757 is/was also kind of a hot rod.
Kinda unrelated… I will say that I flew Quantas from LAX to SYD more than a decade ago in a 747 and then back in an A380 and the latter was so much quieter inside.
It’s always fun to talk to her because I never flew anything bigger than a Cessna 172 and had a few hours of not loggable stick time in a Bell 206. She’s retiring later this year.
Qantas had many 747-400s that harked back to the early 1990s. Thus, noisier engines and interior. I’ve flown on Lufthansa 747-8i from Rio de Janeiro to Frankfurt about ten years ago; -8 was very quiet as compared to the earlier 747 generations.
Interestingly, A380 was much quieter during the early days. Too quiet that passengers kept hearing each other and ambient noise of seat creaking, door opening and closing, and so forth. Some passengers felt disconcerting when they couldn’t hear the engines. So, Airbus added the “engine noise”.
That’s pretty wild about the A380. Thanks! And safe travels.
As a passenger, I absolutely loved the 757-300 in the red and grey Northwest Airlines paint scheme.
https://i0.wp.com/northwestairlineshistory.org/wp-content/uploads/2020/04/NWA_753_N583NW_MSP_2005-02-05_Norris.jpg?resize=2048%2C1165&ssl=1
The 4 doors and two windows on each side were just really cool looking to me. I got to fly on them from MSP to the west coast or Alaska a few times. Seat 1D offered the best view of the glaciers heading up to Anchorage.
If your bladder is up for it, window seats are the best.
Some of my tightest connections were through MSP. And that is a big airport!
Safe travels.
I used to fly gliders, there is an international diamond award pin one can get for gaining 16K feet of altitude after release from launch (plane or winch). I used to fly out of a Lake Tahoe area airport that was at 6000 feet, release at 8000, and we’d use supplemental oxygen (nasal cannulas) routinely up to 18K feet, the highest the regulations allowed for normal circumstances. To go higher, one would take advantage of “wave” conditions where 30 knot or so winds at 90 degrees to a mountain range would set up a predictable standing waves in the atmosphere downwind. That produces nice smooth lift (as much as 10 knots vertical) that can allow a glider to climb to upwards of 50K feet. We had negotiated at “wave window” with the FAA, so if wave was happening we could call the appropriate traffic center and get a rectangular area of VFR airspace all the way to 60K feet. All good, except few of us (except the ex-military pilots) had any experience flying above 18K feet.
So myself and several of my pilot friends got to do FAA high altitude familiarization training at the Edwards AFB Test Pilot School. The morning was all classes in the effects of high altitude. After that, we went past the really high altitude chamber that goes to 120K feet (someone in a full pressure suit getting checked out when we passed). Ours was a bit more pedestrian, it only went to 50K feet with room for the eight of us and instructors. The chamber works by having an adjacent chamber that is pumped down to a much lower pressure. Air is allowed to leak out of the larger chamber at a slow rate that simulates a leisurely climb to the normal cabin pressurization level of 8000 feet. Then BAMM, the valve is fully opened, a cloud of mist, and we’re suddenly at 32K feet (being kind to us civilians, aircrew normally go to 40K+ feet, though one still had to be on top of the Valsalva manuever). Then the hand each of us a tablet with some math some simple math equations and ask us to take off the masks. Most people couldn’t get more than the first 3 right and we got to observe all kinds of effects (mine was increasing numbers of “shooting stars” in my vision). After about a minute they told us to put the masks back on. Two had no clue what they were just asked to do, and others had to put their masks on.
So, the day came to get that pin, and I had a nasal cannula which was only legal to 18K feet, rather than the required mask. I need had to release at 9K feet due to the turbulent conditions, that meant I needed 26K to be sure. The shooting stars started at 20K, kept going, vision definitely started get wonky at 24K, kept going, moment I hit 26K, opened the dive brakes fully, then dove vertically (the dive brakes held it to 100 knots) under 18K in a matter of seconds. Probably one of the dumbest things I’ve ever done.
BTW, they likely could have flown the 340 the entire way at normal altitudes of 30K or above, but they would have had to wear the pressure breathing masks (that literally force air in and out of your lungs) the entire time, which gets tiring far more quickly than the simple supplemental mask I should have used.
I’m in no danger of getting my diamond pin any time soon, as a new flatland glider pilot in Wisconsin, just wanted to say thanks for sharing! Unless… would it count if I release at 3000, and just do laps to cloudbase? Like gain 2K eight times?
> The aircraft also flew at an indicated airspeed of around 250 knots, which explains why it took much longer.
Well, yes. It’s not a coincidence; it’s illegal to fly faster than 250kts when operating below 10,000 feet.
“If these sound familiar to you, it’s because variants of this engine family were used in the Airbus A320 and the Boeing 737.”
Mercedes, you are adorable.
These do not sound familiar to me. I would posit they sound familiar to nine of our readers.
I do love the enthusiasm, though.
What if I said the CFM56 is the jet engine equivalent of the Toyota MZ V6?
I mean, I am familiar with more engine codes than chassis codes, and more chassis codes than exist in my marque of choice, so I am good with the MZ V6 (Had a buddy swap into an MR2. That made it FUN)
But, I know heck-all about jet engines, excepting Rolls Royce made them for Spitfires in WWII?
A while back you could buy A340s in flying condition for $10 million.
For comparison a new Dassault Falcon business jet is $40 million.
Airlines switching to two motor jets were just selling them off to the first bidder.
Each motor burns at least two litres a second, so make sure you have enough for gas…
I flew a Lufthansa flight back in the early 90s. When I read they ran a plane depressurized, I assumed it was to put out all the cigarettes.
At the time Lufthansa was the last carrier that allowed smoking. Anyone that smoked was intentionally booking Lufthansa flights. The plane looked like Cheech and Chong’s old Impala before we even left the gate and it got worse on the way.
I know Lufthansa has been smoke free for decades, but I still can’t think of them as anything but the plane where you can’t read the in-flight magazine because of the smoke.
Impressive how a little Bondo goes a long way
The 340 is a bit of a freak, and to my knowledge LH is the only major carrier using them in large numbers (I could Google but I prefer conversation to pedantry 🙂 ).
It’s really a fuel burn issue that they’re not more popular, plus the adoption of ETOPS for twin engined planes crossing the ocean.
My dad is good friends with a ton of retired Boomer captains of 747s and the old joke was that if you made it across the ocean with all four engines still running, it was a good day. They were just that unreliable, so redundancy was the name of the game.
Those days are long gone, since by the early 80s the 757/767 were proving that idea wrong, even if they had to stay close to a diverter airport for most of their early careers. Icelandair was always happy to fly the single-aisle 757 over water, but since they always stopped in Iceland, they were never too far from land using the Great Circle.
I flew on Air France A-340s quite frequently on the Toronto-Paris and Paris-Bamako routes for a few years. Just looked it up and they retired them a few years ago. So yes, Lufthansa is probably the only one left.
Also like 60% sure I flew on one from Sydney to Port Morsby once. That plane had seen some things…
I used to lead a much more interesting life.
I’d hate to be the guy that ran a loader into into that thing.
That’s why God created insurance.
Well, not the 727 or Trident, as they’d fall into the water when they ran out of fuel, as they’re not long-haul aircraft.
I wonder if Lufthansa crammed a bunch of cargo in the A340’s hold to offset their losses.
I’d wager not, I expect that it being emptier allowed it to more easily reach its destination when it was flying lower. Fuel efficiency is worse down low where the air is thicker.
No, this would be what is called a ferry flight, used solely for repositioning the aircraft. Usually it will require permission from the regulator to fly and you can’t fly them for commercial purposes, which includes obviously passengers but also any paid freight.
I’m just glad I wasn’t the guy driving the high loader that punctured it.
I’m just glad I wasn’t the high guy driving the loader that punctured it.
This was super interesting!
You left out the weirdest part! LH put all the economy bathrooms in the cargo hold: https://onemileatatime.com/insights/lufthansa-a340-cargo-hold-bathrooms/
Weren’t there a few in the back on the main deck? It’s been years since I’ve flown on their -600’s. I did see the set of stairs around the middle of the plane that leads to the lower deck. So technically it has 2 levels I guess?
Not according to LH’s seatmap: https://www.lufthansa.com/ua/en/346
There are some main deck lavs for first, business, and (hopefully) econ pax with mobility issues.
Not just the weirdest part, the best part, because all the toilets are in the same place, so first come first served, rather than trying to figure out which toilets will mean less waiting, plus the lack of people toing and froing and dawdling around if you are in a seat near a bulkhead.
The EXACT SAME THING happened to me in the late 1980’s. I was the one responsible to go to the arena and buy Springsteen tickets for my friends. Unfortunately I got a flat tire and I had to drive the 20 miles there and back on my donut spare. So I did it on the right lane of the highway doing about 40 mph.
The coolest feature of the Altima (after it’s hyper futuristic CVT if course) is that they can still drive 85mph on a donut spare.
Safety third!
Got ya beat. Back around 2010, my wife and I were driving back from Dallas to Little Rock in my Lexus IS-F, never getting below 80mph. Struck a piece of metal in the road about 100 miles outside of Dallas and blew out a rear tire. Being Sunday, and a somewhat difficult tire to find, had to drive 250 miles on the donut, limited to 50mph. I remember an RV that I blew past earlier flying past me later 🙁
You could have done 50.
Driving too slow that day is the least of my regrets from the 80’s.
Is this why Jason’s a day late getting to England via Bermuda?
Jason falls under Transportation of Dangerous Goods rules, so there’s only certain planes they’ll fly him on. I think it’s a biohazard thing.
He only flies on AN-2 biplanes…
I “captured” an AN-2 Colt. Cubans used them as crop dusters, probably still do. Pilot convinces his government minder that he just did a repair, needs a quick check flight, have a cup of coffee, I’ll be right back. Takes off, lands on a road and picks up his family, flies to the Naval Air Station at Guantanamo Bay Cuba, so low that he has to climb to clear the fence and scares the Marine in the watch tower. No comms, just plops down on the field, downwind.
Marines crash the field, family comes spilling out. One man appears disabled and retarded, turns out he drank an entire bottle of rum on a 12 minute flight. We push the plane into a hanger as fast as we can, but it was the middle of the day.
Cuban government asks, via Swiss Embassy, about the crew and passengers. Our official US answer is “You didn’t pick them up? They all got scared and swam away in the ocean, we thought you had them.” Cubans say “Yeah, ok, but we need our plane back.”
Next day two Cuban pilots come down the bay in a little motor boat, met by two Navy pilots in their boat. They exchange wings, we help check the oil, Cubans fly away.
No, NCIS, there were no cigars on that plane when we got to it. None at all.
Awww, you had to give the plane back? Bummer, those things are so cool. Glad it was used for a good purpose though.
Nice! My dad was stationed at Gitmo when it was a sleepy fleet training base. I was just a baby so don’t remember it. But heard lots of fun stories from our time there.
The manager of the McDonald’s was the most important person on the base!
Haha, they said it was a really big deal when McDonald’s opened!
Scoping out islands to start Jasonia.
The pressurization also stiffens the fuselage.
The “wear & tear” of an unpressurized flight can be worse than a pressurization cycle.
Other than the altitude and speed, there are a bunch of other restrictions imposed on the flight: clear weather only, no non-emergency abrupt manoevres, etc.
A lot of paperwork needed.
Can be a challenge if your airports is a mountain range. A flight like this in/out of Zurich may need an indirect routing.
Pedant alert incoming:
The A340-200/300, powered by CFM56 engines (a derivative of engines on the 737 Next Gen and original A320) was noted for being relatively underpowered compared to the competition. Those engines have been called ‘hairdryers’ due to their proportionally small size on an otherwise large aircraft.
The A340-500/600, powered by the Rolls Royce Trent 500 had more than adequate power; it was noted for being a fuel-guzzler relative to the Boeing 777-300ER and sold poorly as a result.
Anyway, flying at 10,000 feet was probably quite costly in terms of fuel for Lufthansa due to the drag of thick air and extended flight time.
Great pedant-ing! I debated with myself about filling out that section more versus keeping it simple, since it was more of a sidebar. I went ahead and filled in a little more detail.
There’s an old joke about the A340:
An A340 doesn’t climb, it flies level and uses the curvature of the earth to gain altitude.
Also said of the A-model C5 Galaxy.
That’s what I was thinking…this flight likely used an ungodly amount of fuel! I can’t believe LH still uses these planes along with the 744’s
I applaud them for that. They might not be the most fuel efficient but they are the V8s of the aircraft world and stand out when sitting next to yet-another twinjet.
I guess LH more than makes up for those quadjets with the ton of anonymous looking planes they have
They use them for the same reason Delta still flies those ancient and gas-guzzling 757s – they are long since paid for, so the extra operating expense is offset by minimal capital costs. And even more so than than the 757s (freight dogs love those), the A340s are about worthless in resale value. So they might as well fly the wings off them until they get uneconomic to maintain.
They were worried that any US operator would take it behind the hangar and shoot it, so taking it home to Germany ensures a more humane repair 🙂
Another reputation of the 340 is that it’s also a common retrofit for private usage among specific oligarchs and royals, especially in countries where money flows out of the ground like some sort of black liquid, and operating costs are basically a non-issue.
Did you guys know the new Mazda CX-5 was revealed today??
Not until you posted. Thank you.
And I should care about yet another gormless CUV why exactly?
ZZZzzzz-ZZZzzzz
I’m actually quite impressed they’re keeping it. I had honestly expected it to “merge” with the CX-50 in some sort of design that blended the best of both.