Computer system failed causing an increase in workload and confusion.

Attributes
ACN	125341
Time
Date	198909
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zau
State Reference	IL
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Experience	controller radar : 5
ASRS Report	125341
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

At the above date and time, the chicago ARTCC computer failed. All flight plan information was lost on both aircraft in flight, and on proposals. The backup radar system (darc) which is supposed to be operational, did not work correctly. Aircraft codes could be seen, but no computer tracking of targets was available. Management had been informed at least 2 hours earlier that the darc system was unusable. The main radar was supposed to 'blink' for 1-2 seconds to reset the darc. This 1-2 second delay turned out to last over 20 mins. The problem occurred because the day started west/O a backup radar system. To compound this, the main radar was released for a 'start-over,' even though no backup system was available. A working, operational radar system should never be released for repair unless sufficient backup systems are available and operational. At the very least, this should have taken place on the midnight shift when traffic is much lighter.

Original NASA ASRS Text

Title: COMPUTER SYSTEM FAILED CAUSING AN INCREASE IN WORKLOAD AND CONFUSION.

Narrative: AT THE ABOVE DATE AND TIME, THE CHICAGO ARTCC COMPUTER FAILED. ALL FLT PLAN INFO WAS LOST ON BOTH ACFT IN FLT, AND ON PROPOSALS. THE BACKUP RADAR SYS (DARC) WHICH IS SUPPOSED TO BE OPERATIONAL, DID NOT WORK CORRECTLY. ACFT CODES COULD BE SEEN, BUT NO COMPUTER TRACKING OF TARGETS WAS AVAILABLE. MGMNT HAD BEEN INFORMED AT LEAST 2 HRS EARLIER THAT THE DARC SYS WAS UNUSABLE. THE MAIN RADAR WAS SUPPOSED TO 'BLINK' FOR 1-2 SECS TO RESET THE DARC. THIS 1-2 SEC DELAY TURNED OUT TO LAST OVER 20 MINS. THE PROB OCCURRED BECAUSE THE DAY STARTED W/O A BACKUP RADAR SYS. TO COMPOUND THIS, THE MAIN RADAR WAS RELEASED FOR A 'START-OVER,' EVEN THOUGH NO BACKUP SYS WAS AVAILABLE. A WORKING, OPERATIONAL RADAR SYS SHOULD NEVER BE RELEASED FOR REPAIR UNLESS SUFFICIENT BACKUP SYSTEMS ARE AVAILABLE AND OPERATIONAL. AT THE VERY LEAST, THIS SHOULD HAVE TAKEN PLACE ON THE MIDNIGHT SHIFT WHEN TFC IS MUCH LIGHTER.

Data retrieved from NASA's ASRS site as of August 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.