Air carrier medium large transport excursion from assigned cruising flight level due to failure of a...

Attributes
ACN	268398
Time
Date	199404
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : lkv
State Reference	OR
Altitude	msl bound lower : 32800 msl bound upper : 33600
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zse
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise 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 : 180 flight time total : 8500
ASRS Report	268398
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

During cruise at FL330 autoplt and automatic throttle kicked off followed by over speed warning. The only flag on captain's instruments was the red flag in airspeed indicator. Captain's altimeter read 32800 ft so started slow climb while investigating problem. Copilot reported his altimeter read 33600 ft so we quizzed center as to what their reading was and they said 33.6. CADC was switched to both on #2 after which both sets of instruments were in agreement. #1 CADC was replaced at next stop which corrected problem.

Original NASA ASRS Text

Title: ACR MLG EXCURSION FROM ASSIGNED CRUISING FLT LEVEL DUE TO FAILURE OF AN AIR DATA COMPUTER.

Narrative: DURING CRUISE AT FL330 AUTOPLT AND AUTO THROTTLE KICKED OFF FOLLOWED BY OVER SPD WARNING. THE ONLY FLAG ON CAPT'S INSTS WAS THE RED FLAG IN AIRSPD INDICATOR. CAPT'S ALTIMETER READ 32800 FT SO STARTED SLOW CLB WHILE INVESTIGATING PROB. COPLT RPTED HIS ALTIMETER READ 33600 FT SO WE QUIZZED CENTER AS TO WHAT THEIR READING WAS AND THEY SAID 33.6. CADC WAS SWITCHED TO BOTH ON #2 AFTER WHICH BOTH SETS OF INSTS WERE IN AGREEMENT. #1 CADC WAS REPLACED AT NEXT STOP WHICH CORRECTED PROBLEM.

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.

Air carrier medium large transport excursion from assigned cruising flight level due to failure of an air data computer.