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Air carrier X unauthorized descent from assigned altitude received TCASII RA with air carrier Y descending. Pilot deviation.
| Attributes | |
| ACN | 248849 |
| Time | |
| Date | 199308 |
| Day | Mon |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : roc |
| State Reference | NY |
| Altitude | msl bound lower : 10000 msl bound upper : 11000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | cruise other |
| Route In Use | enroute : direct enroute airway : syr |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | cruise other descent other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : approach |
| Qualification | controller : radar |
| Experience | controller radar : 5 |
| ASRS Report | 248849 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other controllera |
| Resolutory Action | flight crew : took evasive action |
| Consequence | Other |
| Miss Distance | horizontal : 48000 vertical : 1000 |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Accepted handoff on air carrier X from syr approach at 10000 ft (direct roc). Aircraft checked in with appropriate ATIS code still in syr airspace. I issued traffic to air carrier X (12 O'clock, 8 mi, opposite direction, leveling at 11000 ft). (Utilizing merging target procedures.) (not talking to other aircraft.) air carrier X said they did not visually see aircraft but were getting a TCASII alert and descending for traffic. Air carrier Y was now level at 11000 ft. Air carrier X descended to 9600 ft (observed mode C). Said they saw traffic visually and were now climbing back up to 10000 ft. All took place in syr airspace. If traffic was at 9000 ft below air carrier X, separation would have been lost. Traffic was never in a position to threaten separation loss. Aircraft were separated. TCASII takes the ATC out of the loop and many times leaves you helpless to get out of jam that you didn't create.
Original NASA ASRS Text
Title: ACR X UNAUTH DSCNT FROM ASSIGNED ALT RECEIVED TCASII RA WITH ACR Y DSNDING. PLTDEV.
Narrative: ACCEPTED HDOF ON ACR X FROM SYR APCH AT 10000 FT (DIRECT ROC). ACFT CHKED IN WITH APPROPRIATE ATIS CODE STILL IN SYR AIRSPACE. I ISSUED TFC TO ACR X (12 O'CLOCK, 8 MI, OPPOSITE DIRECTION, LEVELING AT 11000 FT). (UTILIZING MERGING TARGET PROCS.) (NOT TALKING TO OTHER ACFT.) ACR X SAID THEY DID NOT VISUALLY SEE ACFT BUT WERE GETTING A TCASII ALERT AND DSNDING FOR TFC. ACR Y WAS NOW LEVEL AT 11000 FT. ACR X DSNDED TO 9600 FT (OBSERVED MODE C). SAID THEY SAW TFC VISUALLY AND WERE NOW CLBING BACK UP TO 10000 FT. ALL TOOK PLACE IN SYR AIRSPACE. IF TFC WAS AT 9000 FT BELOW ACR X, SEPARATION WOULD HAVE BEEN LOST. TFC WAS NEVER IN A POS TO THREATEN SEPARATION LOSS. ACFT WERE SEPARATED. TCASII TAKES THE ATC OUT OF THE LOOP AND MANY TIMES LEAVES YOU HELPLESS TO GET OUT OF JAM THAT YOU DIDN'T CREATE.
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.