NTSB: Missed turbulence warning led to serious injuries on United Boeing 777

A National Transportation Safety Board (NTSB) investigation has concluded that a critical turbulence report was not relayed to the crew of United Airlines Flight UA1890 before the aircraft encountered severe instability, resulting in serious injuries to three flight attendants.

The incident occurred on 10 February 2024, as the Boeing 777 was descending into Newark Liberty International Airport from Los Angeles. The NTSB’s final report, released Tuesday, closes a two-year investigation into the event.

Unacknowledged Pilot Report

Three minutes before the encounter, another aircraft in the same airspace reported “moderate turbulence” to air traffic control. According to the NTSB, the controller did not hear the transmission and therefore failed to acknowledge or disseminate the report to other aircraft operating in the area — including United UA1890 — as required under Federal Aviation Administration (FAA) procedures governing Pilot Weather Reports (PIREPs).

“The controller did not acknowledge or disseminate this report to other aircraft, including UAL1890, as required by Federal Aviation Administration procedures for Pilot Weather Reports,” the report stated.

Although thunderstorms and convective activity had been forecast in the broader region, onboard radar and electronic weather systems did not indicate significant turbulence along the flight’s planned descent path.

Sudden Wind Shear and Violent Movement

While the seatbelt sign was illuminated and cabin crew were conducting final checks prior to landing, the aircraft encountered a rapid and severe wind shift. Radar data showed wind speeds changing by nearly 75 mph within approximately 4,000 feet of altitude — consistent with strong localised wind shear.

The aircraft first experienced a sudden drop, followed by a sharp pitch-up movement.

The impact inside the cabin was severe. One flight attendant was thrown into the ceiling before striking the floor, suffering a spinal fracture. Two others were injured in the galley and lost consciousness; one sustained a shattered femur, crushed vertebrae and a head injury, while the other suffered facial lacerations and intracranial bleeding.

Additional injuries were reported among crew and passengers not secured by seatbelts. Several individuals struck the ceiling during the turbulence, including a passenger in the lavatory and an infant being held on a lap.

Procedural Breakdown

The NTSB’s findings centre on the breakdown in dissemination of the turbulence report rather than deficiencies in aircraft systems or flight crew actions. The Boeing 777’s weather radar did not detect significant convective returns along the descent corridor, underscoring the reliance on real-time pilot reports to supplement onboard weather data.

The case highlights the operational importance of PIREPs in high-density terminal environments, particularly during convective weather patterns where localised turbulence may not be fully captured by predictive radar tools.

The FAA has not yet publicly detailed any corrective actions following the report’s release, but the incident reinforces the critical role of air traffic control in ensuring timely distribution of weather hazard information to mitigate in-flight risk.