LATAM Boeing 777 Tail Strike Investigation Reveals Critical One Hundred Ton Performance Calculation Error At Milan Malpensa

MILAN, ITALY — Aviation safety investigators have finalised their analysis of the high-profile tail-strike involving a LATAM Airlines Boeing 777-300ER, confirming that a staggering 100-ton weight miscalculation was the primary catalyst for the accident. The findings, released by Italy’s National Agency for the Safety of Flight (ANSV) as of February 2026, detail how a simple data entry error by an experienced flight crew led to a prolonged and damaging runway scrape at Milan Malpensa Airport (MXP).

Technical reports indicate that the July 2024 accident, in which the aircraft’s tail dragged across the asphalt for more than 700 meters, stemmed from a gross weight discrepancy that fundamentally invalidated the aircraft’s takeoff performance. During the preparation for Flight LA8073 to São Paulo, the crew entered a takeoff weight into their Electronic Flight Bags (EFBs) that was approximately 100 metric tons lower than the actual figure.

The error occurred when the line-training captain miscalculated the gross weight by incorrectly handling the fuel figures. According to the ANSV report:

“The result, 228.8 tonnes instead of the correct 328.4 tonnes, was verbally announced and subsequently used by both pilots.”

The Mechanics of a Near-Disaster

Because both pilots utilised the same erroneous 228.8-ton figure in their independent performance tools, the cross-check appeared to confirm the data, effectively masking the mistake. This led the onboard computers to calculate a rotation speed (Vr) of 149 knots, significantly lower than the 181 knots actually required for a fully loaded Boeing 777-300ER.

As the aircraft accelerated down Runway 35L, the pilot attempted to rotate at the prescribed (but incorrect) speed. The aircraft, being 100 tons heavier than the flight systems assumed, failed to lift off and instead pitched up until the aft fuselage struck the runway. Surveillance footage and flight data recorders confirm the tail remained in contact with the ground for 723 meters, carving a furrow up to 6 centimetres deep into the runway surface.

The "V-Speeds Unavailable" Warning

Investigators highlighted a critical moment during the pre-flight phase when the Flight Management Computer (FMC) triggered a “V-speeds unavailable” message. This occurred because the entered weight was so low that the calculated speeds fell outside the aircraft's safe operating envelope for the available runway length. However, the crew did not identify the underlying cause of the message and proceeded with the departure.

The situation was eventually corrected in the air after the cruise captain, sitting in the jumpseat, intervened.

“The cruise captain, observing the situation, ordered the selection of full takeoff thrust 12 seconds after rotation began.”

This manual override provided the necessary energy for the aircraft to finally climb away, clearing the opposite end of the runway by a mere 155 feet.

Impacted Flight Operations and Incident Summary

The following table summarises the specific flight details and operational impact resulting from the weight calculation error and subsequent airframe damage:

Note: Following the incident, the aircraft (Registration: PT-MUG) was grounded for approximately seven months for extensive structural repairs before returning to service.

Lessons in Cockpit Automation and Verification

The ANSV’s final report serves as a stark reminder of the "garbage in, garbage out" principle in modern glass cockpits. Despite having three pilots on the flight deck, including an instructor, the discrepancy of 30 knots in rotation speed went unnoticed until the physical strike occurred.

The agency has recommended that airlines implement more robust independent verification steps, suggesting that crews should manually compare EFB-generated speeds against standardised "paper" charts or previous experience to spot such massive outliers.