A TCASII RA provides separation between IFR and apparent VFR traffic on a clear night near spa VOR.

Attributes
ACN	489891
Time
Date	200010
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : spa.vortac
State Reference	SC
Altitude	msl bound lower : 8500 msl bound upper : 9000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : gsp.tracon
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : vacating altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise : level
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10000 flight time type : 3000
ASRS Report	489891
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	flight crew : took evasive action flight crew : returned to original clearance
Miss Distance	horizontal : 750 vertical : 300
Supplementary
Problem Areas	Airspace Structure ATC Human Performance Flight Crew Human Performance
Primary Problem	Airspace Structure

Narrative:

Climbing out of gsp airport, clear night, TCASII alert at about 8000 ft. We were under control of gsp departure control, cleared 040 degree heading to 10000 ft. At about 9000 ft monitor vertical speed alert became red resolution, descend now. We dropped back to about 8500 ft. Traffic passed over top of us at about 9000-9500 ft. TCASII indicated +300 ft at closest point. Departure control did not call out traffic and apparently was not talking to this unknown aircraft. Other aircraft seemed to make no course changes to avoid us. We had beacons, navigation lights and side turn off spot lights on. We could not see other aircraft until very close due to ground lights. Watch out for clear nights! If IFR this probably would not have happened. I wonder if unknown aircraft even saw us. Without TCASII the outcome might have been different.

Original NASA ASRS Text

Title: A TCASII RA PROVIDES SEPARATION BTWN IFR AND APPARENT VFR TFC ON A CLR NIGHT NEAR SPA VOR.

Narrative: CLBING OUT OF GSP ARPT, CLR NIGHT, TCASII ALERT AT ABOUT 8000 FT. WE WERE UNDER CTL OF GSP DEP CTL, CLRED 040 DEG HDG TO 10000 FT. AT ABOUT 9000 FT MONITOR VERT SPD ALERT BECAME RED RESOLUTION, DSND NOW. WE DROPPED BACK TO ABOUT 8500 FT. TFC PASSED OVER TOP OF US AT ABOUT 9000-9500 FT. TCASII INDICATED +300 FT AT CLOSEST POINT. DEP CTL DID NOT CALL OUT TFC AND APPARENTLY WAS NOT TALKING TO THIS UNKNOWN ACFT. OTHER ACFT SEEMED TO MAKE NO COURSE CHANGES TO AVOID US. WE HAD BEACONS, NAV LIGHTS AND SIDE TURN OFF SPOT LIGHTS ON. WE COULD NOT SEE OTHER ACFT UNTIL VERY CLOSE DUE TO GND LIGHTS. WATCH OUT FOR CLR NIGHTS! IF IFR THIS PROBABLY WOULD NOT HAVE HAPPENED. I WONDER IF UNKNOWN ACFT EVEN SAW US. WITHOUT TCASII THE OUTCOME MIGHT HAVE BEEN DIFFERENT.

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.