DC8 crew encounters clear air turbulence at FL350.

Attributes
ACN	722380
Time
Date	200701
Local Time Of Day	0001 To 0600
Place
Locale Reference	navaid : omn.vortac
Altitude	msl single value : 35000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence Windshear
Light	Night
Aircraft 1
Controlling Facilities	artcc : zma.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 vortac
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 75
ASRS Report	722380
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	722725
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : turbulence
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	Weather
Primary Problem	Weather

Narrative:

The flight encountered clear air turbulence at FL350. The autoplt was engaged including altitude hold. The turbulence caused the autoplt to disconnect. The aircraft climbed at estimated 2500 FPM while still in a level attitude. The aircraft reached FL360 before control could be reestablished without stressing the airframe. The event lasted about 20 seconds. No damage to the aircraft controls or system was noted. The flight continued to its destination. A logbook write-up was entered.

Original NASA ASRS Text

Title: DC8 CREW ENCOUNTERS CLR AIR TURB AT FL350.

Narrative: THE FLT ENCOUNTERED CLR AIR TURB AT FL350. THE AUTOPLT WAS ENGAGED INCLUDING ALT HOLD. THE TURB CAUSED THE AUTOPLT TO DISCONNECT. THE ACFT CLBED AT ESTIMATED 2500 FPM WHILE STILL IN A LEVEL ATTITUDE. THE ACFT REACHED FL360 BEFORE CTL COULD BE REESTABLISHED WITHOUT STRESSING THE AIRFRAME. THE EVENT LASTED ABOUT 20 SECONDS. NO DAMAGE TO THE ACFT CTLS OR SYS WAS NOTED. THE FLT CONTINUED TO ITS DEST. A LOGBOOK WRITE-UP WAS ENTERED.

Data retrieved from NASA's ASRS site as of January 2009 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.