The flight data recorders, IRUs, and attitude heading reference units were shipped to Washington, D.C., for analysis.
BY ANTHONY OMOH with AGENCY REPORTS
A navigation system failure aboard a United Airlines Boeing 787-8 caused altitude fluctuations, on the January 24, 2025 Flight 613 from Lagos to Washington Dulles. The National Transportation Safety Board (NTSB) released a preliminary report on March 18, 2025 further revealing that the aircraft cockpit voice recorder had been overwritten by the time investigators accessed it.
The aircraft carried 234 passengers and 11 crew members. It experienced altitude excursions at 36,000 feet over Côte d’Ivoire airspace. The NTSB revealed the left inertial reference unit (IRU) failed one hour and five minutes before the incident. The right IRU failed 55 minutes later, causing the autopilot to disconnect.
The flight crew took manual control, triggering master caution and warning alerts. Altitude fluctuations lasted approximately 12 minutes. The aircraft deviated from its cruising altitude, reaching 36,203 feet and dropping to 35,577 feet. The autothrottle disconnected, and the stick shaker activated, indicating an impending stall.
The autopilot was briefly reengaged but disconnected again. The crew decided to return to Lagos, landing safely at 3:22 a.m. local time. Meal service was ongoing during the fluctuations, causing unsecured items to fly. One passenger sustained serious injuries, while 15 others suffered minor injuries.
Four passengers and two crew members required hospitalization but were later discharged. The aircraft sustained minor damage. NTSB noted that the cockpit voice recorder had been overwritten by the time investigators accessed it. The NTSB said CVR only retains two hours of audio. This limitation has raised concerns about the adequacy of current recording systems, as critical audio data from the incident was lost. The flight data recorders, inertial reference units, and attitude heading reference units were removed from the aircraft and shipped to Washington, D.C., for further analysis
The flight data recorders, IRUs, and attitude heading reference units were shipped to Washington, D.C., for analysis. United Airlines described the incident as a “technical issue,” ruling out turbulence. The airline is cooperating with U.S. and Nigerian aviation authorities.
Côte d’Ivoire authorities are leading the investigation, assisted by the “Home” https://www.ntsb.gov/Pages/home.aspxNTSB. The incident highlights the critical role of navigation systems in flight safety. It also raises concerns about cockpit voice recorder retention times. NTSB noted that the cockpit voice recorder overwritten issue underscores the need for extended recording capabilities.
This event underscores the importance of addressing potential failures in advanced aircraft systems like the Boeing 787-8. It also emphasizes the need for improved investigative tools to ensure aviation safety.
