Passengers traveling on Lufthansa’s longest flight earlier this week were in for quite the tour of South America, including an unusual mayday call.
In this post:
Lufthansa 747 diverts to Asuncion, then Sao Paulo
Lufthansa flight LH510 is the longest distance flight in the Star Alliance carrier’s network, as it covers a distance of 7,133 miles, and ordinarily takes a little over 13 hours. However, for the flight departing on Monday, July 7, 2025, the journey took way longer than that, and the flight never reached its intended destination.
The flight was operated by a Boeing 747-8 with the registration code D-ABYM, and was scheduled to depart at 9:40PM and arrive at 6:25AM the following morning. The plane ended up departing Frankfurt just a little behind schedule, taking off at 10:28PM, and began its long journey to Buenos Aires.
Unfortunately upon approach to the airport, the weather conditions had deteriorated, with very limited visibility. So the plane entered a holding pattern at an altitude of 7,000 feet, with the hopes of weather improving. After holding for an extended period of time and conditions not improving, the pilots made the decision to divert.
Asuncion, Paraguay (ASU), was decided as the diversion point, so the plane started flying in that direction. That’s a 663-mile flight, so it was quite a journey. Weather there was fine, and the jumbo jet touched down in Asuncion at 8AM, 14hr32min after it first departed Frankfurt.
The plane then spent just under an hour on the ground in Asuncion, presumably to refuel, and hope for conditions to improve in Buenos Aires. The jet once again took off from the airport at 8:56AM.
The aircraft flew south to Buenos Aires, and entered a holding pattern, though unfortunately conditions still hadn’t improved. This time around, the decision was made to divert to Sao Paulo, Brazil (GRU), which was a 1,069-mile flight from Buenos Aires.
I imagine the decision to divert to Sao Paulo came down to the crew timing out, and therefore, it was best to divert to a station with a lot of flights, and where Lufthansa has a presence, so that customers can be assisted.
The plane ended up touching down in Sao Paulo at 1:04PM, 4hr8min after the plane diverted to Asuncion.
At that point, the flight was canceled, given that the crew timed out, as passengers had been onboard for roughly 20 hours. Passengers were rebooked on other flights to Buenos Aires, or their final destination.
As of now, the plane is still on the ground in Sao Paulo, so it remains to be seen if it’s ferried back to Frankfurt empty, or if it’s flown to Buenos Aires, and will operate a flight with passengers from there.
The Lufthansa 747 declared a mayday on its final approach
It’s interesting to note that during its approach to Sao Paulo, the pilots of the Lufthansa 747 declared a mayday, which is the highest level of distress that pilots can express, reflecting a life-threatening emergency.
So, what was the cause of that mayday call? An airplane spotter YouTube channel posted a video of the plane landing in Sao Paulo, including the air traffic control audio.
The air traffic controller asked the Lufthansa pilots what the reason was for the mayday, and they indicated that it was due to “crew fatigue and fuel shortage.” That’s interesting:
- That’s beyond my area of expertise, but is crew fatigue actually considered a legitimate reason to declare a mayday? It’s interesting how that’s mentioned before the fuel shortage, which makes me wonder if they really had mayday fuel levels
- Obviously the flight had a roundabout routing, but you’d think they would’ve loaded up enough fuel given the weather situation, and I imagine Sao Paulo was already their backup destination, so what caused the plane to not have enough fuel?
I recognize it’s standard to roll out fire trucks when there’s a mayday call, though it’s a bit odd to see four fire trucks following a Lufthansa 747 due to a combination of lack of fuel and crew fatigue, since neither seem like they’d be assisted much by fire trucks.
Bottom line
Passengers traveling on Lufthansa’s longest route were in for a long day, as the Frankfurt to Buenos Aires flight first diverted to Asuncion and then Sao Paulo, before ultimately being canceled. What’s interesting is that during the second diversion, the pilots declared a mayday, apparently due to crew fatigue and lack of fuel.
What a rough day for all involved, but sometimes Mother Nature has a mind of its own…
What do you make of this Lufthansa 747 double diversion?
"lack of fuel and crew fatigue, since neither seem like they’d be assisted much by fire trucks."
a) I don't think it takes very much highly-flammable aviation fuel to cause a dangerous fire.
b) In several countries the fire brigade/department is called Civil Defence - they are trained in things other than fire (floods for one!) - at airports they are the ones who know about emergency evacuations.
Just to add a little bit of context from the perspective of cabin crew:
Deciding to leave ASU and head for EZE again is totally justified. Everything at EZE has been arranged for the crew. Hotel, shuttle and also adhering to the roster you have been given are all very valueable reasons to decide to continue the flight also as a service to the passengers.
It was really bad luck for this crew...
Just to add a little bit of context from the perspective of cabin crew:
Deciding to leave ASU and head for EZE again is totally justified. Everything at EZE has been arranged for the crew. Hotel, shuttle and also adhering to the roster you have been given are all very valueable reasons to decide to continue the flight also as a service to the passengers.
It was really bad luck for this crew to then ending up having another diversion even further away. GRU also being a Lufthansa destination CLA agreements will be easier to respect for both company and crew.
The mayday call might seem strange on a first glance but don’t underestimate the stress the crew has expierenced dealing with a divertion and passengers. Adding to the workload on a long flight. Fatigue is silent killer with small mistakes having big outcomes.
I’m glad to see the crew not underestimating the situation and putting out the mayday call.
For the passengers this was a rough day as well keeping also in mind them having to get on another flight afterwards to reach their intended destination.
It’d be awesome if they were chased down the runway by one of those Red Bull cars with a giant can on the top
Entitlement is everywhere, even the Germans does it.
Mayday, I've flown 19 hours and tired. I need to land first.
Despite German being German, I hope they're not retarded enough to just walk out of cockpit when they time out mid air.
Why not divert to MVD. Any ideas?
MVD’s main runway is closed for work as they are installing ILS Cat III (Madrid flights are currently operating via Las Palmas due to lighter loads required for the shorter secondary runway). Also, MVD is very close to EZE so chances are that the weather was not ideal there either.
Probably the same weather conditions (fog). Could have diverted to Cordoba (or Santiago) but that may have brought into play other issues.
Imagine MVD has far more limited pax OAL accommodation options compared to GRH. Plus not an online LH station....
** GRU **
Regardless of regulations, I would rather see a fatigued crew declare mayday and land safely than not declare then have a mishap.
Completely agree.
Often avoiding (even a small) risk of disaster is rather mundane, rather than heroic.
"The flight was operated by a Boeing 747-8 with the registration code D-ABYM,..."
The flight WAS a Boeing 747-8, not operated by a Boeing 747-8.
You're very wrong.
Flight is usually designed to be operated by different aircraft type.
The flight was operated by a Boeing 747-8 is very correct.
It could have been operated by a B777 or an A350.
Saying "The flight was" usually refers to the flight number not the aircraft.
Of course fatigue is a valid reason, just like any other crew incapacitation. You need someone qualified and capable on board to land the plane safely. Insufficient rest can have symptoms similar to mild alcohol intoxication.
Poor economy passengers. LH B748s have literally the worst Y class in the world with abysmal "iron board" Recaro CL3520 seats. I once flew FRA-MEX in this economy, and I was almost dead after 11.5-hrs flight - it took almost 2 days to recover after the flight. I think, after 20 hrs in these seats one should urgently visit an osteopath.
I heard that! The lower back pain I experienced after a relatively short FRA - JFK on their 744 last month was hateful. Even their premium economy seats are uncomfortable.
One and done
If pilots were only 4 hours away from life threatening fatigue with a jumbo full or passengers sounds like they never should have left ASU
To be fair when they left ASU the intention was to land in EZE which would have been a much shorter flight rather than flying to GRU.
The crew likely will have used a “captains’ discretion” situation asuming weather in EZE would have been sufficient to fly there. This means the entire crew would have agreed to finish their flight even though it was within their rights to stay in ASU.
I’m a...
To be fair when they left ASU the intention was to land in EZE which would have been a much shorter flight rather than flying to GRU.
The crew likely will have used a “captains’ discretion” situation asuming weather in EZE would have been sufficient to fly there. This means the entire crew would have agreed to finish their flight even though it was within their rights to stay in ASU.
I’m a crew member myself and have been in these situations as well with divertions happening on our fourth flight that day. Having to divert than to a secondary airport adding another couple of hours of flight time with passengers is very tense and stressful.
Do you know LH's duty limits and farthest destination with a two-person crew? I was on LH418 yesterday which diverted to DTW (third time in a week for that flight to divert). However, unlike UA on the same route, LH had a two pilot crew which, per their announcements, had them running up close to their max...
Crew limit is not airline specific.
It's based on the country's governing aviation body.
Usually up to 8hrs for a 2-man crew (1 captain, 1 first officer)
Up to 13hrs for 3-man crew (1 captain, 2 FO)
Up to 18hrs for 4-man crew (2 captain, 2 FO)
Union agreements can actually be stricter than the national regulations.
I am curiosu whether LH crews this flight with two, three, or four pilots?
@ AJ -- I would think four.
Incorrect, 3 Pilots only. Source: LH Pilot myself :)
@ Moto -- Fascinating, I stand corrected! Are there any routes that get four pilots then, or is three the maximum? I assumed it was similar to the US, where 12+ hours gets four pilots.
Therein lies the problem. U.S. carriers staff long haul flights always have an extra pilot. Many European carriers staff transatlantic flights with only 2 pilots. Personally, I feel safer with an extra pilot on long flights.
The US also has limits which likely would have required the cancellation of the flight before it ever could have left for the 3rd leg. a single diversion on a longhaul augmented flight is possible based on US staffing but rarely can a flight divert twice w/o triggering one of several crew limitations.
moto,
does LH staff a flight like this w/ 1 captain and two FOs? While the captain undoubtedly had to make...
The US also has limits which likely would have required the cancellation of the flight before it ever could have left for the 3rd leg. a single diversion on a longhaul augmented flight is possible based on US staffing but rarely can a flight divert twice w/o triggering one of several crew limitations.
moto,
does LH staff a flight like this w/ 1 captain and two FOs? While the captain undoubtedly had to make the decisions regarding diversions and flying extra legs, is it possible that two first officers were flying the two diversion legs? if not, it is not hard to see why the captain might have been the one that was fatigued
@Ben
It's usually over 13hrs fight that require 4 pilots (14 hrs for some countries)
Over 8hrs require 3 pilots
it is 12 hours and 1 minute for the US of scheduled block
If they didn't fuel the plane sufficiently to ensure a safe landing at GRU after a diversion, it should not have been chosen as a diversion point.
will be interesting to see what Brazil's aviation authority does with this... they do have the right to investigate including the claims of crew fatigue
Surely the mayday was about getting priority to land. And if the crew are exhausted and there's a risk of being told to hold, isn't it legitimate to declare a mayday to ensure you get onto the ground.
@ JT -- It was definitely about being given priority to land, but is fatigue really an acceptable reason for a mayday, per regulations? I'm not sure if it is or isn't, which is why I'm asking...
For sure the aircraft commander was in the chief pilot’s office first thing upon return to FRA. A fair amount of ‘splainin’ to do!
Ben, they did not refuel while in ASU hence the lack of fuel and possible mayday (?)
@ George -- Are you sure? The plane spent nearly 19 hours in the air, so that seems like a long time without refueling...
Lufthansa has become a joke as a company. They could have diverted to Cordoba (less than 1 h from EZE and capable to handle 747 — flew there in a 747 in the 1990s). Then they divert to an airport 1000 km away? What a waste of fuel, effort, and passengers time and patience. Then a MaDay because of fatigue?? This needs to be investigated
Really?! Land at a station with zero ground presence, no contracted handling, no passenger assistance facilities? Also, would Córdoba even have hotel accommodations for 350+ unannounced pax at such a short notice?
GRU was the right call from an operational perspective.
I was supposed to be on this flight! Booked from Belgrade to take advantage of a discounted F fare (around $5k roundtrip). Ended up canceling at the last minute.
What an odyssey for the passengers...