History of Flight
On July 15, 2010, at approximately 0200 UTC, a Boeing 767-332ER, registered as N184DN and operated by Delta Airlines, encountered turbulence at flight level 360 near the TOESS intersection north of Antonio B. Won Pat International Airport (GUM) in Guam. The flight had departed GUM at 1125 UTC and was en route to Narita International Airport (NRT), landing at 0344 UTC as planned. The aircraft was operating under 14 CFR Part 121 on an instrument flight rules flight plan in visual meteorological conditions.
According to the captain, the flight was navigating around scattered cloud build-ups, and the weather radar showed no returns with the antenna tilt set between -1 and -5 degrees. The seatbelt sign was not illuminated at the time. The injured flight attendant reported walking down the aisle between the mid galley and aft galley when she fell to the floor during the turbulence.
Injuries and Damage
Of the 192 passengers and 9 crewmembers on board, only one flight attendant sustained a broken ankle. No other injuries were reported. The aircraft was not damaged.
Meteorological Information
The operator reported that no turbulence was forecast for the area at the time. Satellite imagery indicated that the airplane was in an area not conducive to turbulence when the event occurred.
Medical Information
The injured flight attendant was initially examined by a physician passenger who did not provide a diagnosis. She declined medical treatment upon arrival at Narita and traveled to her home base in Minneapolis before seeking further medical advice. A doctor later diagnosed a broken ankle.
Flight Data Recorder Data
According to the flight data recorder, vertical acceleration during the turbulence varied between +1.5 g and -0.3 g, with the encounter lasting approximately 5 seconds.