Near midair collision in proximity of TCA.

Attributes
ACN	249414
Time
Date	199308
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : new airport : msy
State Reference	LA
Altitude	msl bound lower : 5200 msl bound upper : 5200
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : msy
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	general aviation : instructional
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 180 flight time total : 7200 flight time type : 700
ASRS Report	249414
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : nmac inflight encounter : vfr in imc non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 500 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

As we were descending into new orleans through about 5500 ft, ATC advised us that we had traffic at 11 O'clock, less than a mi. The controller thought that the traffic was at 4000 ft but wasn't sure because the aircraft was operating in the TCA without a clearance. A few seconds later I saw the traffic at about 11 O'clock and it looked like he was at or slightly below our altitude. It looked as if he would pass off to our left. I checked our altitude and as we went through 5200 ft I began a shallow turn to the right. When I looked back up we were close enough to see that the traffic was a single engine small aircraft and he had just started a climbing right turn, which would put him directly in our flight path. I had to make a hard right turn to keep from hitting the small aircraft, which passed about 1/8 of a mi to our left. This situation could be avoided in the future if ATC were required to vector IFR aircraft away from VFR aircraft when the altitude of the latter is unknown.

Original NASA ASRS Text

Title: NMAC IN PROX OF TCA.

Narrative: AS WE WERE DSNDING INTO NEW ORLEANS THROUGH ABOUT 5500 FT, ATC ADVISED US THAT WE HAD TFC AT 11 O'CLOCK, LESS THAN A MI. THE CTLR THOUGHT THAT THE TFC WAS AT 4000 FT BUT WASN'T SURE BECAUSE THE ACFT WAS OPERATING IN THE TCA WITHOUT A CLRNC. A FEW SECONDS LATER I SAW THE TFC AT ABOUT 11 O'CLOCK AND IT LOOKED LIKE HE WAS AT OR SLIGHTLY BELOW OUR ALT. IT LOOKED AS IF HE WOULD PASS OFF TO OUR L. I CHKED OUR ALT AND AS WE WENT THROUGH 5200 FT I BEGAN A SHALLOW TURN TO THE R. WHEN I LOOKED BACK UP WE WERE CLOSE ENOUGH TO SEE THAT THE TFC WAS A SINGLE ENG SMA AND HE HAD JUST STARTED A CLBING R TURN, WHICH WOULD PUT HIM DIRECTLY IN OUR FLT PATH. I HAD TO MAKE A HARD R TURN TO KEEP FROM HITTING THE SMA, WHICH PASSED ABOUT 1/8 OF A MI TO OUR L. THIS SIT COULD BE AVOIDED IN THE FUTURE IF ATC WERE REQUIRED TO VECTOR IFR ACFT AWAY FROM VFR ACFT WHEN THE ALT OF THE LATTER IS UNKNOWN.

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.