Near midair collision between widebody transport air carrier and unknown small aircraft.

Attributes
ACN	180947
Time
Date	199106
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mia
State Reference	FL
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mia
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 4 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Aircraft
Flight Plan	None
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Experience	controller non radar : 2 controller radar : 8
ASRS Report	180947
Person 2
Affiliation	government : faa
ASRS Report	181208
Events
Anomaly	conflict : nmac non adherence : far
Independent Detector	other flight crewa
Resolutory Action	none taken : insufficient time
Consequence	faa : reviewed incident with flight crew faa : investigated
Miss Distance	horizontal : 400 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

Near midair collision between widebody transport air carrier X and unknown VFR Y flying above the mia TCA 15 mi north of mia at 8000 ft level as indicated by mode C readout. Air carrier X said they passed at 400-500 ft. Ground clutter and other targets made it difficult to see the unknown traffic. The VFR aircraft should have been in communication with ATC. Mandatory! Callback conversation with reporter revealed the following information: reporter gave yrs in ATC. Was working departure control at time of near midair collision. ATC was not able to track or get identify of small aircraft aircraft Y. Aircraft passed at same altitude with 400 ft lateral. Reporter statement that small aircraft Y should have been in mandatory communication with ATC was corrected during callback. Inbound IFR aircraft are descended to 8000 ft in this area, and departure aircraft are climbed reference inbound aircraft. Reporter says that there are so many VFR aircraft in mia area that it is impossible to track them even with mode C on aircraft. Supplemental information from acn 181208: the top of the TCA is 7000 ft. I observed a VFR squawk at 8000 ft after the pilot made his report. There was some 'clutter' in the area due to aircraft tags at other altitude.

Original NASA ASRS Text

Title: NMAC BTWN WDB ACR AND UNKNOWN SMALL ACFT.

Narrative: NMAC BTWN WDB ACR X AND UNKNOWN VFR Y FLYING ABOVE THE MIA TCA 15 MI N OF MIA AT 8000 FT LEVEL AS INDICATED BY MODE C READOUT. ACR X SAID THEY PASSED AT 400-500 FT. GND CLUTTER AND OTHER TARGETS MADE IT DIFFICULT TO SEE THE UNKNOWN TFC. THE VFR ACFT SHOULD HAVE BEEN IN COM WITH ATC. MANDATORY! CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR GAVE YRS IN ATC. WAS WORKING DEP CTL AT TIME OF NMAC. ATC WAS NOT ABLE TO TRACK OR GET IDENT OF SMA ACFT Y. ACFT PASSED AT SAME ALT WITH 400 FT LATERAL. RPTR STATEMENT THAT SMA Y SHOULD HAVE BEEN IN MANDATORY COM WITH ATC WAS CORRECTED DURING CALLBACK. INBOUND IFR ACFT ARE DSNDED TO 8000 FT IN THIS AREA, AND DEP ACFT ARE CLBED REF INBOUND ACFT. RPTR SAYS THAT THERE ARE SO MANY VFR ACFT IN MIA AREA THAT IT IS IMPOSSIBLE TO TRACK THEM EVEN WITH MODE C ON ACFT. SUPPLEMENTAL INFO FROM ACN 181208: THE TOP OF THE TCA IS 7000 FT. I OBSERVED A VFR SQUAWK AT 8000 FT AFTER THE PLT MADE HIS RPT. THERE WAS SOME 'CLUTTER' IN THE AREA DUE TO ACFT TAGS AT OTHER ALT.

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.