B757 flight crew encounters severe clear air turbulence descending into slc.

Attributes
ACN	441875
Time
Date	199907
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : slc.airport
State Reference	UT
Altitude	msl bound lower : 7000 msl bound upper : 15000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : s56.tracon
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	approach : traffic pattern
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : private pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 149 flight time total : 20599 flight time type : 1000
ASRS Report	441875
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp pilot : multi engine
Experience	flight time last 90 days : 140 flight time total : 3500 flight time type : 300
ASRS Report	442112
Events
Anomaly	inflight encounter : turbulence other anomaly
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : executed go around flight crew : exited adverse environment flight crew : regained aircraft control
Supplementary
Problem Areas	Weather
Primary Problem	Weather

Narrative:

Turning base leg for runway 16R, we had experienced light turbulence on the downwind. On a heading of 090 degrees descending at 195 KTS, we experienced a violent encounter with severe turbulence. The aircraft pitched up and down along the lateral axis. Airspeed accelerated to 250+ KTS extremely rapidly. The aircraft was uncontrollable for short periods. The control column felt like a bungee cord. The aircraft did not respond to attempted control inputs. Event lasted no more than 60-90 seconds, and ceased when we were able to turn away from clear air disturbance.

Original NASA ASRS Text

Title: B757 FLC ENCOUNTERS SEVERE CLR AIR TURB DSNDING INTO SLC.

Narrative: TURNING BASE LEG FOR RWY 16R, WE HAD EXPERIENCED LIGHT TURB ON THE DOWNWIND. ON A HDG OF 090 DEGS DSNDING AT 195 KTS, WE EXPERIENCED A VIOLENT ENCOUNTER WITH SEVERE TURB. THE ACFT PITCHED UP AND DOWN ALONG THE LATERAL AXIS. AIRSPD ACCELERATED TO 250+ KTS EXTREMELY RAPIDLY. THE ACFT WAS UNCTLABLE FOR SHORT PERIODS. THE CTL COLUMN FELT LIKE A BUNGEE CORD. THE ACFT DID NOT RESPOND TO ATTEMPTED CTL INPUTS. EVENT LASTED NO MORE THAN 60-90 SECONDS, AND CEASED WHEN WE WERE ABLE TO TURN AWAY FROM CLR AIR DISTURBANCE.

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.