Air carrier has near midair collision in class C airspace and executes a go around.

Attributes
ACN	298044
Time
Date	199503
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sat
State Reference	TX
Altitude	msl bound lower : 1000 msl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sat
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach landing other
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	Helicopter
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 150 flight time total : 7500 flight time type : 2500
ASRS Report	298044
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : nmac non adherence : far non adherence other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 300 vertical : 300
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

Cleared for a visual approach to runway 21. Tower reported a helicopter between us and the airport at approximately our 10 O'clock position. We stated that we did not have the helicopter in sight, however, the helicopter pilot indicated that he saw us. Shortly thereafter, I picked up the helicopter low at our 11 O'clock position as he was slowly crossing our flight path. I cautioned the first officer not to descend too rapidly because it would bring us down on top of the helicopter. Approximately the same time we received a TA followed shortly by a 'monitor vertical speed' warning on TCASII. By now we were also too high to make a safe landing, and initiated a go around. An uneventful landing was made on runway 12R. On landing rollout, the tower stated 'sorry about the helicopter air carrier.' I feel that the main cause of this incident was the tower's inability to appreciate the respective different closing speeds at a mixed fixed wing/helicopter operation. This is not my first ATC problem at this airport.

Original NASA ASRS Text

Title: ACR HAS NMAC IN CLASS C AIRSPACE AND EXECUTES A GAR.

Narrative: CLRED FOR A VISUAL APCH TO RWY 21. TWR RPTED A HELI BTWN US AND THE ARPT AT APPROX OUR 10 O'CLOCK POS. WE STATED THAT WE DID NOT HAVE THE HELI IN SIGHT, HOWEVER, THE HELI PLT INDICATED THAT HE SAW US. SHORTLY THEREAFTER, I PICKED UP THE HELI LOW AT OUR 11 O'CLOCK POS AS HE WAS SLOWLY XING OUR FLT PATH. I CAUTIONED THE FO NOT TO DSND TOO RAPIDLY BECAUSE IT WOULD BRING US DOWN ON TOP OF THE HELI. APPROX THE SAME TIME WE RECEIVED A TA FOLLOWED SHORTLY BY A 'MONITOR VERT SPD' WARNING ON TCASII. BY NOW WE WERE ALSO TOO HIGH TO MAKE A SAFE LNDG, AND INITIATED A GAR. AN UNEVENTFUL LNDG WAS MADE ON RWY 12R. ON LNDG ROLLOUT, THE TWR STATED 'SORRY ABOUT THE HELI ACR.' I FEEL THAT THE MAIN CAUSE OF THIS INCIDENT WAS THE TWR'S INABILITY TO APPRECIATE THE RESPECTIVE DIFFERENT CLOSING SPDS AT A MIXED FIXED WING/HELI OP. THIS IS NOT MY FIRST ATC PROB AT THIS ARPT.

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.