Flight crew of a B737 experienced severe turbulence during descent from high cruise altitude resulti...

Attributes
ACN	364699
Time
Date	199703
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : hbu
State Reference	CO
Altitude	msl bound lower : 27000 msl bound upper : 26500
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 50 flight time total : 9000 flight time type : 50
ASRS Report	364699
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	other other : other pilot : atp pilot : flight engineer pilot : private
Experience	flight time last 90 days : 172 flight time total : 7547 flight time type : 900
ASRS Report	364703
Events
Anomaly	inflight encounter : weather other anomaly other
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	flight crew : declared emergency other other
Consequence	other other
Supplementary
Primary Problem	Weather
Air Traffic Incident	other
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Flight operated normally en route from slc toward cos. Following 2 stepdown dscnts, we leveled at FL270, approximately 30 NM east of blue mesa VOR, 20 mins from launching in cos. At that time, (approximately ZB00 MST) we were handed off to a new sector controller who inquired about our ride. We responded 'smooth,' and she requested, 'keep us informed.' the first officer immediately called the flight attendants as I turned on the seat belt sign. He advised them to clear the cabin and be seated in anticipation of possible turbulence. Seconds later, the aircraft pitched up smoothly, gaining 300 ft. We then lost altitude abruptly, encountered moderate chop, followed by severe turbulence. The first officer reported moderate, then severe turbulence to ATC and requested immediate descent clearance. We were clear 'not lower than 17000 ft.' at approximately FL265, the air became smoother. We continued to FL210. 1 flight attendant was injured and required hospitalization. 2 passenger reported minor injuries. They were examined by emergency medical personnel and released. The aircraft incurred damage to the #6 slat. Supplemental information from acn 364703: upon check-in, the controller asked 'how's your ride?' I answered 'smooth.' she said 'keep us advised.' I thought this was strange, but enough of a clue that turbulence was ahead. Seconds, maybe 10-15 later, the aircraft went from smooth, to moderate, to severe turbulence. The captain took off the autoplt and began a descent as den cleared us to 'not lower than 17000 ft' with altimeter setting. We leveled at FL210. It was smoother out of FL260. I asked about injuries. The lead flight attendant said one of the flight attendants was hurt in the back of the aircraft. An emt passenger was taking care of her. The captain flew the aircraft and talked to center. I coordinated with cos ramp for emergency assistance and spoke to the passenger. We asked (via PA) any passenger who were hurt to remain on board the aircraft after landing. 2 remained, and were released later. The injured flight attendant was taken to a hospital. I have the uneasy feeling ZDV knew more than they reported. I don't think we could have done anything better given the situation, but if we had known about the severe turbulence, we could have set the flight attendants down without any delay -- emphatically.

Original NASA ASRS Text

Title: FLC OF A B737 EXPERIENCED SEVERE TURB DURING DSCNT FROM HIGH CRUISE ALT RESULTING IN INJURIES TO A CABIN ATTENDANT AND 2 PAX. ONE OF THE ACFT WING SLATES WAS ALSO DAMAGED. THE CREW WAS ALERTED TO POSSIBLE TURB ONLY MOMENTS BEFORE BY ATC ASKING ABOUT THEIR RIDE.

Narrative: FLT OPERATED NORMALLY ENRTE FROM SLC TOWARD COS. FOLLOWING 2 STEPDOWN DSCNTS, WE LEVELED AT FL270, APPROX 30 NM E OF BLUE MESA VOR, 20 MINS FROM LAUNCHING IN COS. AT THAT TIME, (APPROX ZB00 MST) WE WERE HANDED OFF TO A NEW SECTOR CTLR WHO INQUIRED ABOUT OUR RIDE. WE RESPONDED 'SMOOTH,' AND SHE REQUESTED, 'KEEP US INFORMED.' THE FO IMMEDIATELY CALLED THE FLT ATTENDANTS AS I TURNED ON THE SEAT BELT SIGN. HE ADVISED THEM TO CLR THE CABIN AND BE SEATED IN ANTICIPATION OF POSSIBLE TURB. SECONDS LATER, THE ACFT PITCHED UP SMOOTHLY, GAINING 300 FT. WE THEN LOST ALT ABRUPTLY, ENCOUNTERED MODERATE CHOP, FOLLOWED BY SEVERE TURB. THE FO RPTED MODERATE, THEN SEVERE TURB TO ATC AND REQUESTED IMMEDIATE DSCNT CLRNC. WE WERE CLR 'NOT LOWER THAN 17000 FT.' AT APPROX FL265, THE AIR BECAME SMOOTHER. WE CONTINUED TO FL210. 1 FLT ATTENDANT WAS INJURED AND REQUIRED HOSPITALIZATION. 2 PAX RPTED MINOR INJURIES. THEY WERE EXAMINED BY EMER MEDICAL PERSONNEL AND RELEASED. THE ACFT INCURRED DAMAGE TO THE #6 SLAT. SUPPLEMENTAL INFO FROM ACN 364703: UPON CHK-IN, THE CTLR ASKED 'HOW'S YOUR RIDE?' I ANSWERED 'SMOOTH.' SHE SAID 'KEEP US ADVISED.' I THOUGHT THIS WAS STRANGE, BUT ENOUGH OF A CLUE THAT TURB WAS AHEAD. SECONDS, MAYBE 10-15 LATER, THE ACFT WENT FROM SMOOTH, TO MODERATE, TO SEVERE TURB. THE CAPT TOOK OFF THE AUTOPLT AND BEGAN A DSCNT AS DEN CLRED US TO 'NOT LOWER THAN 17000 FT' WITH ALTIMETER SETTING. WE LEVELED AT FL210. IT WAS SMOOTHER OUT OF FL260. I ASKED ABOUT INJURIES. THE LEAD FLT ATTENDANT SAID ONE OF THE FLT ATTENDANTS WAS HURT IN THE BACK OF THE ACFT. AN EMT PAX WAS TAKING CARE OF HER. THE CAPT FLEW THE ACFT AND TALKED TO CTR. I COORDINATED WITH COS RAMP FOR EMER ASSISTANCE AND SPOKE TO THE PAX. WE ASKED (VIA PA) ANY PAX WHO WERE HURT TO REMAIN ON BOARD THE ACFT AFTER LNDG. 2 REMAINED, AND WERE RELEASED LATER. THE INJURED FLT ATTENDANT WAS TAKEN TO A HOSPITAL. I HAVE THE UNEASY FEELING ZDV KNEW MORE THAN THEY RPTED. I DON'T THINK WE COULD HAVE DONE ANYTHING BETTER GIVEN THE SIT, BUT IF WE HAD KNOWN ABOUT THE SEVERE TURB, WE COULD HAVE SET THE FLT ATTENDANTS DOWN WITHOUT ANY DELAY -- EMPHATICALLY.

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.

Flight crew of a B737 experienced severe turbulence during descent from high cruise altitude resulting in injuries to a cabin attendant and 2 passenger. One of the aircraft wing slates was also damaged. The crew was alerted to possible turbulence only moments before by ATC asking about their ride.