DC8 encounters mountain wave turbulence in ZDV airspace.

Attributes
ACN	428025
Time
Date	199902
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : als.airport
State Reference	CO
Altitude	msl bound lower : 32700 msl bound upper : 33000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	DC-8 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute airway : ns.airway
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : flight engineer pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 24 flight time total : 4000 flight time type : 940
ASRS Report	428025
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : turbulence other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control flight crew : exited adverse environment
Supplementary
Problem Areas	Weather
Primary Problem	Weather
Air Traffic Incident	other

Narrative:

DC8 was cruising at 301 KTS, mach .84, temperature -16 degrees C. Mountain wave turbulence encountered. Temperature dropped to -27 degrees C. Mach increased to .873. Autoplt disengaged. Aircraft went into high speed buffet and very nose heavy. Lost 300 ft of altitude. Throttles were retarded to idle immediately and aircraft still accelerated.

Original NASA ASRS Text

Title: DC8 ENCOUNTERS MOUNTAIN WAVE TURB IN ZDV AIRSPACE.

Narrative: DC8 WAS CRUISING AT 301 KTS, MACH .84, TEMP -16 DEGS C. MOUNTAIN WAVE TURB ENCOUNTERED. TEMP DROPPED TO -27 DEGS C. MACH INCREASED TO .873. AUTOPLT DISENGAGED. ACFT WENT INTO HIGH SPD BUFFET AND VERY NOSE HVY. LOST 300 FT OF ALT. THROTTLES WERE RETARDED TO IDLE IMMEDIATELY AND ACFT STILL ACCELERATED.

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.