I can’t believe this video from Milan taken by CCTV last month. I’ve never seen a tail strike quite so… prolonged.
The video was taken on the 9th of July 2024 at Milan Malpensa Airport in Italy and reported on by Corriere Della Sera (in Italian). The eleven-year-old Boeing 777-300ER, owned by Latam Airlines and registered in Brazil as PT-MUG, was operating flight LA8073 from Milan to São Paulo, Brazil. I’ve not seen any numbers for souls on board but the 777-300ER’s configuration data as listed on Planespotters.net (C38W50Y322) is for 38 Business Class, 50 Premium Economy and 322 Economy.
The CCTV surveillance footage captured the aircraft attempting to take off from runway 35L. The nose is high in the air with the Boeing’s tail scraping along the runway as a grey plume of smoke forms. As they were already at take-off speed and with most of the runway behind them, the crew continued in hopes of getting the aircraft into the air. Eventually, the video shows the Boeing gain enough airspeed to lift off and climb away.
Once safely off the ground, the flight crew climbed to 5,000 feet and informed Air Traffic Control that they would be returning to the airport to have the aircraft checked over. They then climbed another thousand feet and entered a holding pattern, circling for over an hour to burn off or dump excess fuel, reducing the weight of the aircraft.
Screenshot courtesy of Flightradar24.com
They then made an emergency landing at Milan on runway 35R. The Boeing landed safely and was able to taxi to the gate. There were no injuries to passengers or crew. The aircraft was grounded.
Based on the Boeing’s ASDB data, it flew the 9,500 kilometres back to São Paulo on the 14th of July and is still located there.
Local media initially reported that the back end suddenly dropped after an apparent malfunction; however, the first comment I saw on the matter was “Oh dear, someone has badly miscalculated the take-off data on that aircraft.” This seems like the more likely answer to me.
There are a number of tail strike incidents caused by the take-off weight being logged as lower than it actually was. This affects the take-off performance calculation, as the airspeed required for take-off is lower if the aircraft is lighter. The Pilot Flying gently applies back pressure on the control column, pitching the aircraft nose up to transition from rolling on the ground to flying in the air. This transition of lifting off is called rotation. However, if the take-off performance calculation is off, the heavier aircraft cannot achieve sufficient lift at that speed to safely rotate, and the tail strikes the ground as the aircraft struggles to take off.
Under normal circumstances, the Boeing 777 takes off with a pitch angle from 7 to 9 degrees, with the tail lifting off at around 8.5°. The pitch angle looks closer to 10° in the video.
As we can see from this video, once the aircraft gathers more speed, it is able to lift off and enter the climb.
There are many checks and balances which should catch a slip like this, as the wrong weight has serious consequences: not just that the airspeed is too high or low for rotation, but that all of the V-speeds are off, which affects go/no-go decisions.
Generally, the sequence is pretty simple. The crew gives the final fuel figures to the load controller. The load controller also verifies whether all planned passengers are accounted for and receives the final baggage and cargo weights from the airline staff. The loadsheet is then generated from this information and passed to the flight crew. The captain checks the loadsheet and signs it. The captain then enters the information into his or her Electronic Flight Bag and reads the data aloud so that the first officer can confirm the data and also program it into his or her own Electronic Flight Bag, as well as the Flight Management System. Then the two pilots will crosscheck the take-off performance calculation, including the take-off reference speeds.
I make it three specific checks where someone should notice if the weights or speeds are not as expected. But obviously, it doesn’t always happen that way.
The same aircraft had an incident in 2016, when it suffered electrical problems and had to land overweight. Twelve tyres burst on landing and it was out of service for two months.
Another aspect is that the Boeing 777 has Tail Strike Protection (TSP) specifically for this circumstance. The TSP system automatically adjusts the elevator in an attempt to limit over-rotation during takeoff. If the TSP was activated and functioning correctly, the pilots would have had to override the TSP inputs to continue at that pitch. Under normal circumstances, as soon as the aircraft did not rotate, the best option is to stay on the runway and gather more speed.
The Italian agency for flight safety, (ANSV) has opened an investigation. This is a rough translation:
The ANSV has opened a safety investigation into the serious incident that occurred on July 9, 2024, at Milan Malpensa Airport involving the Boeing 777-300ER registration PT-MUG, flight LA8073 of the airline LATAM Brasil. After collecting the initial evidence, used for the correct classification of the event, the ANSV initiated a safety investigation, classifying the event as a serious incident.
As per ICAO Annex 13, the investigative bodies of Brazil (country of the operator) and the US (country of manufacture) have been invited to take part.
In 2020, the Dutch Safety Board released a report on Erroneous takeoff performance calculation, Boeing 777 (pdf) following a tail strike at Amsterdam Airport Schiphol. In this instance, the load sheet was manually corrected when a passenger did not show, but instead of reducing the full load of 299,075 kg by 100kg, it was corrected to 229,075, making for a difference of 70,000 kilograms. The Dutch Safety Board strenuously recommended that Take Off Performance Monitoring Systems be developed and required in order to catch this issue before the aircraft is on the runway.
At the time of writing this report the overall feasibility of TOPMS has still not been demonstrated because of the complexity of such a system. As a result, no technical specifications or guidance materials to define the operational performance of such a system have been drafted. At the same time, takeoff performance occurrences continue to occur, and therefore the development of technological solutions is still urgent. Systems detecting gross input errors and deviations in parameter settings or comparing predicted and actual aeroplane acceleration during the takeoff run are systems that are considered feasible as a first step towards a more complex TOPMS.
To end on a lighter note, a comment on PPRuNe from DogTailRed2 made me laugh out loud. It says only: “Probably needs worming.”