Captain of B767-300 experiences air data computer failure while in rvsm airspace over the north atla...

Attributes
ACN	623944
Time
Date	200407
Day	Thu
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : czqx.artcc
State Reference	NF
Altitude	msl single value : 34000
Environment
Light	Night
Aircraft 1
Controlling Facilities	artcc : czqx.artcc
Operator	common carrier : air carrier
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
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 : 180 flight time type : 5500
ASRS Report	623944
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 150 flight time total : 6000 flight time type : 3000
ASRS Report	623946
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : eicas
Resolutory Action	controller : issued alert flight crew : overrode automation flight crew : overcame equipment problem other
Consequence	other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

During cruise FL340 in VMC, autothrottles reduced towards idle. There were multiple discrepancies on airspeed and altimeter on captain's side. The master caution warning and alerts sounded. Rudder ratio, aileron lockout, and overspd sounded. Minor changes in pressurization noted. Crosschecked first officer's instruments and standby instruments and determined that first officer's were accurate. First officer then flew the aircraft from that point and captain selected alternate air data computer. ATC questioned altitude and was advised of the problem. Reviewed checklist and considered diversion. Contacted maintenance controller and dispatch. Left rvsm airspace and continued flight to destination uneventfully.

Original NASA ASRS Text

Title: CAPT OF B767-300 EXPERIENCES AIR DATA COMPUTER FAILURE WHILE IN RVSM AIRSPACE OVER THE NORTH ATLANTIC.

Narrative: DURING CRUISE FL340 IN VMC, AUTOTHROTTLES REDUCED TOWARDS IDLE. THERE WERE MULTIPLE DISCREPANCIES ON AIRSPD AND ALTIMETER ON CAPT'S SIDE. THE MASTER CAUTION WARNING AND ALERTS SOUNDED. RUDDER RATIO, AILERON LOCKOUT, AND OVERSPD SOUNDED. MINOR CHANGES IN PRESSURIZATION NOTED. XCHKED FO'S INSTS AND STANDBY INSTS AND DETERMINED THAT FO'S WERE ACCURATE. FO THEN FLEW THE ACFT FROM THAT POINT AND CAPT SELECTED ALTERNATE AIR DATA COMPUTER. ATC QUESTIONED ALT AND WAS ADVISED OF THE PROB. REVIEWED CHKLIST AND CONSIDERED DIVERSION. CONTACTED MAINT CTLR AND DISPATCH. LEFT RVSM AIRSPACE AND CONTINUED FLT TO DEST UNEVENTFULLY.

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.

Captain of B767-300 experiences air data computer failure while in rvsm airspace over the north atlantic.