Air carrier receives TCASII on previously issued VFR traffic that was in sight and climbs to an occu...

Attributes
ACN	242811
Time
Date	199305
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : sjc
State Reference	CA
Altitude	msl bound lower : 10500 msl bound upper : 13000
Environment
Flight Conditions	Mixed
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Military Transport
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	oversight : supervisor
Qualification	controller : radar
Experience	controller military : 3 controller radar : 23 controller supervisory : 2 flight time last 90 days : 0 flight time total : 400
ASRS Report	242811
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 17 controller supervisory : 2
ASRS Report	242304
Events
Anomaly	conflict : airborne less severe inflight encounter other non adherence : clearance non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : took evasive action other
Consequence	faa : investigated
Miss Distance	horizontal : 24000 vertical : 50
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I observed an air carrier medium large transport X at 11000 ft swbound converging with a VFR (unidented target) northbound at 10500 ft. Also converging nwbound was an mlt Y descending to 12000 ft. I heard the radar controller issue a new altitude to mlt Y to stop descent at 13000 ft. The D and right controllers both advised me air carrier X was making a TCASII RA by climbing to avoid the VFR. Air carrier X climbed to 12800 ft which caused a loss of separation with mlt Y. TA's were issued. I felt the actions taken by the radar controller were proper. I expected air carrier X to climb 500 ft or 1000 ft at the most to put a buffer on his traffic. The pilot of air carrier X claimed the TCASII showed 0 ft and the copilot told him the traffic was 'climbing into them.' I observed the VFR's mode C showing 105 (10500 ft) before, during, and after the incident. Supplemental information from acn 242304: this was a TCASII induced situation. Air carrier X was descending for sjc to 11000 ft. VFR traffic quoted crossing left to right at 10500 ft. Air carrier X reported traffic 'at his altitude and climbing' and air carrier X responded to TCASII alert to climb. ZOA mode C of VFR showed level at 10500 ft at all times. Air carrier X pilot climbed to 12800 ft which put him into conflict with mlt Y at 13000 ft. Traffic quoted and air carrier X descended again. In my opinion a TCASII alert was unnecessary. The VFR showed level at 10500 ft at all times. I was quoting traffic and air carrier X was assigned 11000 ft. In addition I believe air carrier X over-reacted to the alert by climbing almost 2000 ft. This put him in jeopardy with mlt Y at 13000 ft. Supplemental information from acn 242084: I was working d-radar sector at ZOA. The radar side cleared an air carrier X to 11000 ft. Air carrier X was level at 11000 ft and an mlt was cleared above air carrier X to 12000 ft. The 2 aircraft were merging. The radar controller issued VFR traffic to air carrier X 12 O'clock, 8 mi, 10500 ft. Air carrier X said 'the traffic was at his altitude and that he was climbing.' loss of separation occurred and ZOA investigated the incident.

Original NASA ASRS Text

Title: ACR RECEIVES TCASII ON PREVIOUSLY ISSUED VFR TFC THAT WAS IN SIGHT AND CLBS TO AN OCCUPIED ALT RESULTING IN LTSS.

Narrative: I OBSERVED AN ACR MLG X AT 11000 FT SWBOUND CONVERGING WITH A VFR (UNIDENTED TARGET) NBOUND AT 10500 FT. ALSO CONVERGING NWBOUND WAS AN MLT Y DSNDING TO 12000 FT. I HEARD THE RADAR CTLR ISSUE A NEW ALT TO MLT Y TO STOP DSCNT AT 13000 FT. THE D AND R CTLRS BOTH ADVISED ME ACR X WAS MAKING A TCASII RA BY CLBING TO AVOID THE VFR. ACR X CLBED TO 12800 FT WHICH CAUSED A LOSS OF SEPARATION WITH MLT Y. TA'S WERE ISSUED. I FELT THE ACTIONS TAKEN BY THE RADAR CTLR WERE PROPER. I EXPECTED ACR X TO CLB 500 FT OR 1000 FT AT THE MOST TO PUT A BUFFER ON HIS TFC. THE PLT OF ACR X CLAIMED THE TCASII SHOWED 0 FT AND THE COPLT TOLD HIM THE TFC WAS 'CLBING INTO THEM.' I OBSERVED THE VFR'S MODE C SHOWING 105 (10500 FT) BEFORE, DURING, AND AFTER THE INCIDENT. SUPPLEMENTAL INFO FROM ACN 242304: THIS WAS A TCASII INDUCED SIT. ACR X WAS DSNDING FOR SJC TO 11000 FT. VFR TFC QUOTED XING L TO R AT 10500 FT. ACR X RPTED TFC 'AT HIS ALT AND CLBING' AND ACR X RESPONDED TO TCASII ALERT TO CLB. ZOA MODE C OF VFR SHOWED LEVEL AT 10500 FT AT ALL TIMES. ACR X PLT CLBED TO 12800 FT WHICH PUT HIM INTO CONFLICT WITH MLT Y AT 13000 FT. TFC QUOTED AND ACR X DSNDED AGAIN. IN MY OPINION A TCASII ALERT WAS UNNECESSARY. THE VFR SHOWED LEVEL AT 10500 FT AT ALL TIMES. I WAS QUOTING TFC AND ACR X WAS ASSIGNED 11000 FT. IN ADDITION I BELIEVE ACR X OVER-REACTED TO THE ALERT BY CLBING ALMOST 2000 FT. THIS PUT HIM IN JEOPARDY WITH MLT Y AT 13000 FT. SUPPLEMENTAL INFO FROM ACN 242084: I WAS WORKING D-RADAR SECTOR AT ZOA. THE RADAR SIDE CLRED AN ACR X TO 11000 FT. ACR X WAS LEVEL AT 11000 FT AND AN MLT WAS CLRED ABOVE ACR X TO 12000 FT. THE 2 ACFT WERE MERGING. THE RADAR CTLR ISSUED VFR TFC TO ACR X 12 O'CLOCK, 8 MI, 10500 FT. ACR X SAID 'THE TFC WAS AT HIS ALT AND THAT HE WAS CLBING.' LOSS OF SEPARATION OCCURRED AND ZOA INVESTIGATED THE INCIDENT.

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.

Air carrier receives TCASII on previously issued VFR traffic that was in sight and climbs to an occupied altitude resulting in less than standard separation.