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|
Attributes | |
ACN | 218806 |
Time | |
Date | 199208 |
Day | Mon |
Local Time Of Day | 1201 To 1800 |
Place | |
Locale Reference | atc facility : zid |
State Reference | IN |
Altitude | msl bound lower : 31000 msl bound upper : 31000 |
Environment | |
Flight Conditions | VMC |
Light | Daylight |
Aircraft 1 | |
Controlling Facilities | artcc : zid |
Operator | common carrier : air carrier |
Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
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 : 10 flight time total : 10000 flight time type : 2000 |
ASRS Report | 218806 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Qualification | pilot : atp |
Events | |
Anomaly | aircraft equipment problem : less severe non adherence : far non adherence : published procedure non adherence : clearance other anomaly other other spatial deviation |
Independent Detector | other controllera |
Resolutory Action | flight crew : returned to intended course or assigned course other |
Consequence | Other |
Supplementary | |
Primary Problem | Aircraft |
Air Traffic Incident | Pilot Deviation |
Narrative:
During cruise flight, my copilot noticed that the FMS display was calculating the wind speed at almost 300 KTS, obviously too high to be correct. We then spent several mins 'playing' with the FMS computer, trying to determine and correct the problem. During this time, the autoplt was flying and navigating. After several mins of involvement with the computer, center queried us on our route of flight. Upon checking our flight instruments, we realized that the FMS had reverted to 'dead reckoning' and that the aircraft had drifted off the airway. We explained our navigational problem to center, while we returned to tracking the correct radial with the VOR and CDI. Next time that the FMS is giving us winds of 300 KTS, we will immediately think about returning to basic navigation, before we worry about what's wrong with the computer!
Original NASA ASRS Text
Title: HDG TRACK DEV.
Narrative: DURING CRUISE FLT, MY COPLT NOTICED THAT THE FMS DISPLAY WAS CALCULATING THE WIND SPD AT ALMOST 300 KTS, OBVIOUSLY TOO HIGH TO BE CORRECT. WE THEN SPENT SEVERAL MINS 'PLAYING' WITH THE FMS COMPUTER, TRYING TO DETERMINE AND CORRECT THE PROBLEM. DURING THIS TIME, THE AUTOPLT WAS FLYING AND NAVING. AFTER SEVERAL MINS OF INVOLVEMENT WITH THE COMPUTER, CTR QUERIED US ON OUR RTE OF FLT. UPON CHKING OUR FLT INSTS, WE REALIZED THAT THE FMS HAD REVERTED TO 'DEAD RECKONING' AND THAT THE ACFT HAD DRIFTED OFF THE AIRWAY. WE EXPLAINED OUR NAVIGATIONAL PROBLEM TO CTR, WHILE WE RETURNED TO TRACKING THE CORRECT RADIAL WITH THE VOR AND CDI. NEXT TIME THAT THE FMS IS GIVING US WINDS OF 300 KTS, WE WILL IMMEDIATELY THINK ABOUT RETURNING TO BASIC NAV, BEFORE WE WORRY ABOUT WHAT'S WRONG WITH THE COMPUTER!
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.