Potential conflict that could have been a near midair collision or worse.

Attributes
ACN	204342
Time
Date	199203
Day	Wed
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : bsy
State Reference	FL
Altitude	msl bound lower : 10000 msl bound upper : 11300
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : mia tower : fyv
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Small Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10500 flight time type : 3000
ASRS Report	204342
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 1000
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Our aircraft was level at 10000, 250 KTS heading 190 all assigned by mia approach control. TCASII gave 'TA' scope revealed target at 2 O'clock 800 ft low and climbing. Visual scan did not pick up target. 5-10 seconds later TCASII alert 'climb, climb,' autoplt was disconnected power applied and 200-300 FPM climb established while still attempting visual contact. 5 seconds later TCASII alert 'increase climb, increase climb,' 1500 FPM climb established as converging aircraft was visually acquired. We stopped climb at 11300 as approach control issued 'traffic about 2 O'clock less than 1 mi and an small transport Y passed directly beneath our aircraft. I queried approach control as to whether the target had been in radar contact. The reply was affirmative and he gave a telephone number to call on the ground. The outcome of our conversation was that the small transport Y had been erroneously cleared to 10000 ft by departure control. We were pointed out as 'his traffic,' he reported us in sight but I don't believe he took any evasive action.

Original NASA ASRS Text

Title: POTENTIAL CONFLICT THAT COULD HAVE BEEN A NMAC OR WORSE.

Narrative: OUR ACFT WAS LEVEL AT 10000, 250 KTS HDG 190 ALL ASSIGNED BY MIA APCH CTL. TCASII GAVE 'TA' SCOPE REVEALED TARGET AT 2 O'CLOCK 800 FT LOW AND CLBING. VISUAL SCAN DID NOT PICK UP TARGET. 5-10 SECONDS LATER TCASII ALERT 'CLB, CLB,' AUTOPLT WAS DISCONNECTED PWR APPLIED AND 200-300 FPM CLB ESTABLISHED WHILE STILL ATTEMPTING VISUAL CONTACT. 5 SECONDS LATER TCASII ALERT 'INCREASE CLB, INCREASE CLB,' 1500 FPM CLB ESTABLISHED AS CONVERGING ACFT WAS VISUALLY ACQUIRED. WE STOPPED CLB AT 11300 AS APCH CTL ISSUED 'TFC ABOUT 2 O'CLOCK LESS THAN 1 MI AND AN SMT Y PASSED DIRECTLY BENEATH OUR ACFT. I QUERIED APCH CTL AS TO WHETHER THE TARGET HAD BEEN IN RADAR CONTACT. THE REPLY WAS AFFIRMATIVE AND HE GAVE A TELEPHONE NUMBER TO CALL ON THE GND. THE OUTCOME OF OUR CONVERSATION WAS THAT THE SMT Y HAD BEEN ERRONEOUSLY CLRED TO 10000 FT BY DEP CTL. WE WERE POINTED OUT AS 'HIS TFC,' HE RPTED US IN SIGHT BUT I DON'T BELIEVE HE TOOK ANY EVASIVE ACTION.

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.