Narrative:

A maui ATCT controller used 'track drop all' entry to clear out coast list. Maui approach control (ZHN) was working a tour helicopter on a tower data block, ie, they did not have track control -- the tower did. The 'track drop all' entry by the tower controller caused the data block for the helicopter to drop. As no coordination had been done, the tower controller was not aware of having control of the data block for approach control traffic and did not realize there was a problem. The loss of the data block was an apparent surprise to the approach controller, as well. Our 'walk-on handoff' procedure described in our LOA with ZHN is supported by software that switches the data blocks to tower control. Apparently some traffic is switched in error, and the approach controller working the aircraft does not always coordinate as FAA handbook 7110.65L paragraph 5-4-5B,F prescribes. The dangers are not only the loss of radar identify in error, but questions are raised about the efficacy of 'la/ca' aural alarms, speed in issuing safety alerts when there is confusion over what frequency the aircraft is on, the tab coast list to alert the controller when radar contact is lost, and the pilot's need to know when no longer getting radar service. All of these problems are cleared up when the controller working the aircraft has both communications and control of the data block as the 7110.65 requires. The problem is coordination and application of the right procedures to xfer radar identify, exacerbated by ineffectual software.

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Original NASA ASRS Text

Title: A TWR CTLR ENTERED A 'TRACK DROP ALL' ENTRY INTO THE COMPUTER RESULTING IN A DATA BLOCK DROP ON A VFR HELI ON APCH CTL FREQ. THE TWR CTLR WAS NOT AWARE THAT THE ENTRY IMPACTED APCH CTL TARGETS.

Narrative: A MAUI ATCT CTLR USED 'TRACK DROP ALL' ENTRY TO CLR OUT COAST LIST. MAUI APCH CTL (ZHN) WAS WORKING A TOUR HELI ON A TWR DATA BLOCK, IE, THEY DID NOT HAVE TRACK CTL -- THE TWR DID. THE 'TRACK DROP ALL' ENTRY BY THE TWR CTLR CAUSED THE DATA BLOCK FOR THE HELI TO DROP. AS NO COORD HAD BEEN DONE, THE TWR CTLR WAS NOT AWARE OF HAVING CTL OF THE DATA BLOCK FOR APCH CTL TFC AND DID NOT REALIZE THERE WAS A PROB. THE LOSS OF THE DATA BLOCK WAS AN APPARENT SURPRISE TO THE APCH CTLR, AS WELL. OUR 'WALK-ON HDOF' PROC DESCRIBED IN OUR LOA WITH ZHN IS SUPPORTED BY SOFTWARE THAT SWITCHES THE DATA BLOCKS TO TWR CTL. APPARENTLY SOME TFC IS SWITCHED IN ERROR, AND THE APCH CTLR WORKING THE ACFT DOES NOT ALWAYS COORDINATE AS FAA HANDBOOK 7110.65L PARAGRAPH 5-4-5B,F PRESCRIBES. THE DANGERS ARE NOT ONLY THE LOSS OF RADAR IDENT IN ERROR, BUT QUESTIONS ARE RAISED ABOUT THE EFFICACY OF 'LA/CA' AURAL ALARMS, SPD IN ISSUING SAFETY ALERTS WHEN THERE IS CONFUSION OVER WHAT FREQ THE ACFT IS ON, THE TAB COAST LIST TO ALERT THE CTLR WHEN RADAR CONTACT IS LOST, AND THE PLT'S NEED TO KNOW WHEN NO LONGER GETTING RADAR SVC. ALL OF THESE PROBS ARE CLRED UP WHEN THE CTLR WORKING THE ACFT HAS BOTH COMS AND CTL OF THE DATA BLOCK AS THE 7110.65 REQUIRES. THE PROB IS COORD AND APPLICATION OF THE RIGHT PROCS TO XFER RADAR IDENT, EXACERBATED BY INEFFECTUAL SOFTWARE.

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.