B747 crew experienced severe turbulence and wave action.

Attributes
ACN	426180
Time
Date	199901
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : rjaa
State Reference	FO
Altitude	msl bound lower : 32000 msl bound upper : 33500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : mdw
Operator	common carrier : air carrier
Flight Phase	cruise other
Route In Use	enroute : pacific enroute : other oceanic enroute other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : other oceanic enroute : pacific enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time total : 32000
ASRS Report	426180
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : exited adverse environment other
Miss Distance	horizontal : 0 vertical : 1500
Supplementary
Air Traffic Incident	other

Narrative:

Severe turbulence resulting in injuries to 18 passenger and 4 flight attendants. Estimated time to return to tokyo -- 3 hours. Time to continue to destination -- 4 hours. Injuries determined to be non life threatening, so continued to honolulu. Passenger and crew evaluated at medical center in honolulu and released. Most of the injuries were from flying debris. Initial encounter altitude gain +500 ft to FL335, then 1500 ft loss to FL320. Temperature dropped from -37 degrees to -40 degrees in about 2 seconds in wave action, then turbulence so severe I could not read instruments except in peaks and valleys. Turbulence lasted several mins. We had TCASII alert on air carrier flight abc that was above us at FL350. All they got out of the encounter was wave action +/-100 ft. I managed to get the altitude hold turned off prior to turbulence when we encountered strong wave action +/-200 ft. I went to turbulence mode in the severe turbulence.

Original NASA ASRS Text

Title: B747 CREW EXPERIENCED SEVERE TURB AND WAVE ACTION.

Narrative: SEVERE TURB RESULTING IN INJURIES TO 18 PAX AND 4 FLT ATTENDANTS. ESTIMATED TIME TO RETURN TO TOKYO -- 3 HRS. TIME TO CONTINUE TO DEST -- 4 HRS. INJURIES DETERMINED TO BE NON LIFE THREATENING, SO CONTINUED TO HONOLULU. PAX AND CREW EVALUATED AT MEDICAL CTR IN HONOLULU AND RELEASED. MOST OF THE INJURIES WERE FROM FLYING DEBRIS. INITIAL ENCOUNTER ALT GAIN +500 FT TO FL335, THEN 1500 FT LOSS TO FL320. TEMP DROPPED FROM -37 DEGS TO -40 DEGS IN ABOUT 2 SECONDS IN WAVE ACTION, THEN TURB SO SEVERE I COULD NOT READ INSTS EXCEPT IN PEAKS AND VALLEYS. TURB LASTED SEVERAL MINS. WE HAD TCASII ALERT ON ACR FLT ABC THAT WAS ABOVE US AT FL350. ALL THEY GOT OUT OF THE ENCOUNTER WAS WAVE ACTION +/-100 FT. I MANAGED TO GET THE ALT HOLD TURNED OFF PRIOR TO TURB WHEN WE ENCOUNTERED STRONG WAVE ACTION +/-200 FT. I WENT TO TURB MODE IN THE SEVERE TURB.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.