 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Approach controller at mht is working a northbound air carrier at 10000 ft and swbound air carrier at 10000 ft on converging courses. Near the radar main bang, the ARTS conflict alert alarms drawing the controller's attention to the problem. Controller attempts to provide course separation but the northbound has changed to ZBW frequency. The other aircraft is instructed to maintain visual separation from the northbound. Separation effort may have been too late.
| Attributes | |
| ACN | 409638 |
| Time | |
| Date | 199807 |
| Day | Thu |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : mht |
| State Reference | NH |
| Altitude | msl bound lower : 10000 msl bound upper : 10000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zbw tracon : mht |
| Operator | common carrier : air taxi |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 135 |
| Flight Phase | climbout : intermediate altitude cruise other |
| Route In Use | enroute : on vectors |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | other : unknown |
| Flight Phase | climbout : intermediate altitude cruise other |
| Route In Use | enroute : on vectors |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : approach |
| Qualification | controller : radar |
| Experience | controller radar : 10 |
| ASRS Report | 409638 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Events | |
| Anomaly | conflict : airborne less severe |
| Independent Detector | atc equipment other atc equipment : unspecified other controllera other flight crewa |
| Resolutory Action | controller : issued new clearance none taken : unable other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
I was working overflt traffic at mht. Approved crossing traffic at 10000 ft. Had handed off northbound traffic to ZBW at boundary. (Sufficient time to have climbed.) wbound traffic at 10000 ft. Got busy with an arrival that didn't make the frequency change. Conflict alert went off. Being startled, I turned the northbound to a 90 degree heading and the swbound to a 270 degree heading. Should have taken care of it, but the northbound was talking to ZBW. I then issued traffic to the wbound. He picked them up and maintained visual. Because this took place over the main bang, the northbound showed no mode C. When it did show up, it was out of 11000 ft. The pilot of the northbound flight complained to ZBW. I informed them of the use of visual and that's how it ended. I just was struck how both had TCASII and said nothing and the main bang interfered with my perception of the whole thing.
Original NASA ASRS Text
Title: APCH CTLR AT MHT IS WORKING A NBOUND ACR AT 10000 FT AND SWBOUND ACR AT 10000 FT ON CONVERGING COURSES. NEAR THE RADAR MAIN BANG, THE ARTS CONFLICT ALERT ALARMS DRAWING THE CTLR'S ATTN TO THE PROB. CTLR ATTEMPTS TO PROVIDE COURSE SEPARATION BUT THE NBOUND HAS CHANGED TO ZBW FREQ. THE OTHER ACFT IS INSTRUCTED TO MAINTAIN VISUAL SEPARATION FROM THE NBOUND. SEPARATION EFFORT MAY HAVE BEEN TOO LATE.
Narrative: I WAS WORKING OVERFLT TFC AT MHT. APPROVED XING TFC AT 10000 FT. HAD HANDED OFF NBOUND TFC TO ZBW AT BOUNDARY. (SUFFICIENT TIME TO HAVE CLBED.) WBOUND TFC AT 10000 FT. GOT BUSY WITH AN ARR THAT DIDN'T MAKE THE FREQ CHANGE. CONFLICT ALERT WENT OFF. BEING STARTLED, I TURNED THE NBOUND TO A 90 DEG HDG AND THE SWBOUND TO A 270 DEG HDG. SHOULD HAVE TAKEN CARE OF IT, BUT THE NBOUND WAS TALKING TO ZBW. I THEN ISSUED TFC TO THE WBOUND. HE PICKED THEM UP AND MAINTAINED VISUAL. BECAUSE THIS TOOK PLACE OVER THE MAIN BANG, THE NBOUND SHOWED NO MODE C. WHEN IT DID SHOW UP, IT WAS OUT OF 11000 FT. THE PLT OF THE NBOUND FLT COMPLAINED TO ZBW. I INFORMED THEM OF THE USE OF VISUAL AND THAT'S HOW IT ENDED. I JUST WAS STRUCK HOW BOTH HAD TCASII AND SAID NOTHING AND THE MAIN BANG INTERFERED WITH MY PERCEPTION OF THE WHOLE THING.
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.