What happened
On February 18, 2024, a Boeing 767-332 ER, registration N176DZ, was operating a scheduled passenger flight from John F. Kennedy International Airport (KJFK) to El Dorado International Airport (SKBO). During the descent phase, while near the WP PAPET waypoint in the Bogotá TMA, the aircraft encountered moderate turbulence.
As the aircraft descended through the 22,000 to 18,000-foot range, the flight crew observed altocumulus and altostratus clouds ahead that were not appearing on the onboard weather radar. Based on previous flight planning information regarding potential convective activity, the pilots issued an announcement via the interphone instructing the cabin crew to secure the cabin and take their seats. However, the turbulence struck shortly after the announcement, leaving the cabin crew with only one to three minutes to secure the service equipment and reach their stations. During the event, a flight attendant sustained a serious injury consisting of a fractured tibia and fibula, while one passenger also sustained minor injuries.
The investigation
The GRIAA investigation focused on the meteorological conditions and the timing of the crew's response. Analysis of the Global Data Assimilation System (GDAS) indicated a high probability of the aircraft interacting with clear air turbulence (CAT) between 19,800 and 16,200 feet. The investigation found that there were no significant convective or storm-forming weather conditions present at the time of the event.
While the investigation noted several maintenance discrepancies during a ground inspection—including a missing nitrogen inflation placard on the nose landing gear and an oil leak in the tail cone—these findings were determined not to be contributing factors to the turbulence encounter.
Findings
- The primary cause of the event was an encounter with moderate clear air turbulence (CAT) or orographic turbulence (mountain waves) during descent.
- The turbulence was not visible on the aircraft's weather radar, as it was not associated with convective activity.
- There was insufficient time for the cabin crew to fully secure the cabin and occupy their seats following the flight crew's warning.
- The investigation suggested that the communication between the flight deck and the cabin may have lacked the necessary assertiveness to ensure immediate compliance before the onset of the turbulence.