When LATAM flight LA8073 lined up on runway 35L at Milan Malpensa on 9 July 2024, nothing in the cockpit suggested the crew were seconds away from one of the most serious tail‑strike events ever recorded on a Boeing 777‑300ER.
The weather was benign, the aircraft was serviceable, and the three‑pilot crew — a Line Training Captain (LTC), a captain undergoing line training, and a cruise captain — were operating a routine long‑haul departure to São Paulo with 398 people on board.
Yet 723 metres of scorched asphalt, a destroyed tail skid, and a damaged APU fire‑extinguishing system would soon tell a different story.
The ANSV’s final report, now published, reveals a chain of human‑factor failures, procedural gaps, and system‑design limitations that allowed a 100‑tonne weight‑entry error to go unnoticed — right up to the moment the aircraft rotated far too early and dragged its tail down the runway.
This is the story of how it happened.
The Accident in Milan: A Routine Departure That Wasn’t
The LATAM 777‑300ER, registration PT‑MUG, pushed back from Malpensa shortly after 11:00 UTC.
The crew had completed their pre‑flight preparations under time pressure: the LTC later remarked that the one‑hour ground window was “barely enough” to complete all required tasks.
The loadsheet final — the definitive document containing the aircraft’s Zero Fuel Weight (ZFW), Takeoff Weight (TOW), centre of gravity and passenger count — arrived roughly ten minutes before pushback.
The ZFW was correctly entered into the FMC. But the next step, calculating the takeoff performance using Boeing’s Onboard Performance Tool (OPT) on the iPad EFBs, would prove decisive.
The LTC mentally subtracted taxi fuel from the FMC’s gross weight to estimate the takeoff weight.
In doing so, he made a catastrophic arithmetic error: instead of 328,425 kg, he announced 228,800 kg — a full 100 tonnes too light.
Because he spoke the number aloud, both pilots entered the same incorrect value into their OPT apps.
The cross‑check — intended to be independent — became a shared single point of failure.
The OPT, unaware of the error, produced a full set of performance data: flap 5, assumed temperature 56°C, and V‑speeds of V1 145 kt, VR 149 kt, V2 156 kt. These were entirely plausible — for an aircraft weighing 100 tonnes less.
The correct speeds for the real weight would have been V1 173 kt, VR 181 kt, V2 186 kt.
The crew validated the matching (but wrong) results on both iPads and transferred the numbers into the FMC.
A Warning the Crew Didn’t Understand
When the pilots entered the OPT‑derived data into the FMC, the system refused to compute its own V‑speeds. Instead, it displayed:
This message appears when the FMC cannot generate a valid takeoff solution — typically due to extreme environmental conditions or incorrect inputs.
Crucially, Boeing’s documentation does not clearly explain that erroneous weight or thrust‑setting entries can also trigger it.
The crew noticed the missing FMC reference speeds. The cruise captain suggested checking the REF SPEEDS selector, but it was already ON.
None of the three pilots — including two experienced widebody captains — understood why the FMC was refusing to compute speeds.
The ANSV notes that the message should have been a “major red flag”. Instead, the crew pressed on.
The Takeoff from Milan: A 12‑Second Crisis
At 11:25:58 UTC, PT‑MUG began its takeoff roll with reduced thrust based on the incorrect assumed temperature.
The aircraft accelerated normally until the call of “V1… rotate”.
At 150 kt, the LTC pulled back on the control column. The 777’s nose lifted — but the aircraft did not fly.
The pitch reached 8.3°, then 9°, then 10°. The tail‑strike protection system activated, limiting further elevator deflection. But the aircraft was still glued to the runway.
At 11:26:42, the tail made contact with the asphalt. Sparks and smoke trailed behind the aircraft as it scraped along the runway for more than 700 metres.
The LTC, startled, exclaimed that the aircraft “wasn’t going”. The cruise captain — the only pilot not task‑saturated — shouted “TOGA!” twice. On the second call, the LTC advanced the thrust levers to maximum.
Six seconds later, with engines spooling to 106% N1, the 777 finally lifted off — at 178 kt, barely 800 metres from the end of the runway.
The aircraft crossed the far threshold at just 155 ft AGL.
Damage and Aftermath in Milan…
The tail skid assembly was destroyed.
The tail‑strike sensor was torn away. The APU fire‑extinguishing bottles discharged due to impact damage.
The runway surface suffered deep gouges up to 6 cm.
The crew declared PAN and climbed to 6,000 ft to dump fuel. Over 72 tonnes were jettisoned before the aircraft returned to land safely on runway 35R at 12:36 UTC.
PT‑MUG remained grounded at Malpensa for five days before being ferried for repairs. It did not return to service until February 2025.
Why the Error Happened
The ANSV identifies several contributing factors:
1. Breakdown of Independent Cross‑Checks
The LTC’s verbal announcement of the (incorrect) takeoff weight contaminated both pilots’ calculations. The intended redundancy collapsed instantly.
2. Inadequate Understanding of FMC Alerts
None of the pilots recognised the significance of “V‑SPEEDS UNAVAILABLE”. Boeing’s documentation, the ANSV notes, does not clearly explain the full range of causes.
3. High Cognitive Load and Role Complexity
The LTC was simultaneously:
- acting as instructor,
- supervising a trainee,
- performing PF duties from the right seat,
- and managing time pressure.
This increased the likelihood of error.
4. Lack of Technical Barriers
The 777 lacks:
- an onboard weight‑and‑balance system (OBWBS),
- a takeoff performance monitoring system (TOPMS),
- or any automated gross‑error detection.
The ANSV emphasises that these systems — already available on some aircraft types — would likely have prevented the accident.
A Systemic Problem, Not a One‑Off
The report places the LATAM event within a long history of similar accidents and serious incidents, including the 2015 Air France 777F tail strike at Paris CDG — also caused by a 100‑tonne weight‑entry error.
Between 1999 and 2015, at least 31 major events were linked to incorrect takeoff performance data, including three fatal accidents.
The ANSV echoes previous calls from BEA, AAIB, and DSB for mandatory installation of automated takeoff‑performance monitoring systems.
EASA’s current regulatory roadmap, however, only requires TOPMS for new aircraft types from the early 2030s — leaving today’s fleets unprotected.
A Preventable Accident in Milan…
The ANSV’s conclusion of the accident in Milan is stark:
“The tail strike was caused by rotation at a speed significantly lower than required for the aircraft’s actual weight.”
The root cause was human — but the context was systemic. A single arithmetic slip, unchallenged by procedures or technology, cascaded into a near‑catastrophic event.
The crew recovered the situation with professionalism once airborne. But the investigation makes clear: the industry cannot continue relying on human vigilance alone.
The LATAM 777 tail strike at Malpensa is not just an isolated error. It is a warning — one the aviation system has seen many times before.
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