On 28 December 1997, United Airlines Flight 826 experience severe turbulence on a routine flight from Japan to Hawaii, killing one person and injuring more than one hundred.
On 30 December, the National Transportation Safety Board (NTSB) issued a press release describing the incident.
The episode was reported as occuring at 1410 UTC (which is 1:10 am local time in mid-ocean) at 32.5N 159.0E, and 31,000 feet altitude (9.5 km).
Images from the Japanese Geosynchronous Meteorological Satellite (GMS) at the reported location of the turbulence show the ragged southern end of a storm front popping with individual convective towers.
However, none of the GMS images show anything extraordinary for the storm.
The University of Wisconsin has posted a nice wind analyis of this case.
Thanks to Jim Dodge NASA/HQ and Torben Nielsen Un-Hawaii, Goddard Space Flight Center is the prime server for real time GMS data in the USA:
We put together video loops from the GMS hourly IR data for 28 December using Hasler's Image Spreadsheet, and mailed a copy of the video tape to the NTSB:
Greg Salottolo NTSB, AS-30 490 L'Enfont Plaza, SW Washington, DC 20594-2000 202-314-6338The flight recorder shows a drop of only a 100 feet, but g-forces ranging from +1.8 (almost double gravity) to -0.8 ("gravity" upward) within 7 seconds.
Jim Weinman of NASA-GSFC is looking into getting other satellite data. With luck, there could have been a TRMM overpass.