Phl TRACON controller voiced concern regarding repeated and suspected non valid low altitude alerts;...

Attributes
ACN	790149
Time
Date	200806
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : phl.airport
State Reference	PA
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : developmental
Experience	controller limited radar : 4 controller military : 5 controller radar : 2
ASRS Report	790149
Events
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	FAA Maintenance Human Performance Navigational Facility
Primary Problem	Navigational Facility

Narrative:

The low altitude alert alarm has been going off on about 75% of the aircraft on short final. This has increased the workload on the final controller and the local east controller in the tower. The final controller must notify the tower controller whenever the alarm goes off. This problem has existed for at least 2 weeks. Co-workers have stated that it seems to have started after the last build of the stars system was installed. I recently worked about 2 hours on position and found it hard after a while to keep on top of the low altitude alerts. Your mind almost wants to block them out because they happen so frequently and you know it is a computer glitch. If an aircraft was to actually be too low; I believe that the tower and approach controllers may be so desensitized to the alarm that the pilot may not be notified in time.

Original NASA ASRS Text

Title: PHL TRACON CTLR VOICED CONCERN REGARDING REPEATED AND SUSPECTED NON VALID LOW ALT ALERTS; SUSPECTING RECENT SOFTWARE CHANGE AS CAUSAL.

Narrative: THE LOW ALT ALERT ALARM HAS BEEN GOING OFF ON ABOUT 75% OF THE ACFT ON SHORT FINAL. THIS HAS INCREASED THE WORKLOAD ON THE FINAL CTLR AND THE LCL E CTLR IN THE TWR. THE FINAL CTLR MUST NOTIFY THE TWR CTLR WHENEVER THE ALARM GOES OFF. THIS PROB HAS EXISTED FOR AT LEAST 2 WKS. CO-WORKERS HAVE STATED THAT IT SEEMS TO HAVE STARTED AFTER THE LAST BUILD OF THE STARS SYS WAS INSTALLED. I RECENTLY WORKED ABOUT 2 HRS ON POS AND FOUND IT HARD AFTER A WHILE TO KEEP ON TOP OF THE LOW ALT ALERTS. YOUR MIND ALMOST WANTS TO BLOCK THEM OUT BECAUSE THEY HAPPEN SO FREQUENTLY AND YOU KNOW IT IS A COMPUTER GLITCH. IF AN ACFT WAS TO ACTUALLY BE TOO LOW; I BELIEVE THAT THE TWR AND APCH CTLRS MAY BE SO DESENSITIZED TO THE ALARM THAT THE PLT MAY NOT BE NOTIFIED IN TIME.

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

Phl TRACON controller voiced concern regarding repeated and suspected non valid low altitude alerts; suspecting recent software change as causal.