Air carrier large transport encountered severe clear air turbulence west of den in mountain wave.

Attributes
ACN	81050
Time
Date	198801
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : den
State Reference	CO
Altitude	msl bound lower : 37000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 150 flight time total : 15000 flight time type : 2000
ASRS Report	81050
Events
Anomaly	inflight encounter : weather other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control flight crew : returned to intended course or assigned course flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	other

Narrative:

Encountered severe turbulence in mtn wave. There was no warning or visual cue such as lenticular clouds. Had airspeed fluctuations in excess of 100 KTS and loss of 1000 ft altitude. No injuries, but could have as seatbelt sign was off. Need some kind of detection and warning for this severe turbulence before it causes an accident!

Original NASA ASRS Text

Title: ACR LGT ENCOUNTERED SEVERE CLEAR AIR TURBULENCE WEST OF DEN IN MOUNTAIN WAVE.

Narrative: ENCOUNTERED SEVERE TURBULENCE IN MTN WAVE. THERE WAS NO WARNING OR VISUAL CUE SUCH AS LENTICULAR CLOUDS. HAD AIRSPD FLUCTUATIONS IN EXCESS OF 100 KTS AND LOSS OF 1000 FT ALT. NO INJURIES, BUT COULD HAVE AS SEATBELT SIGN WAS OFF. NEED SOME KIND OF DETECTION AND WARNING FOR THIS SEVERE TURBULENCE BEFORE IT CAUSES AN ACCIDENT!

Data retrieved from NASA's ASRS site as of August 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.