Air carrier X TCASII RA with helicopter in air traffic area while on approach. Evasive action taken....

Attributes
ACN	249076
Time
Date	199308
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dtw
State Reference	MI
Altitude	agl bound lower : 800 agl bound upper : 800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dtw
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Helicopter
Flight Phase	landing other
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 4500 flight time type : 2000
ASRS Report	249076
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 500 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Air carrier X tracking the ILS inbound in visual conditions after having been cleared to land. At approximately 800 ft AGL, we received a TA from our TCASII which we initially assumed was ground traffic on the airport. Then an RA was received. As I arrested our descent in response we received a 'clear of conflict' from the TCASII, followed by another RA to climb as I resumed descent. By now we were about 400 ft AGL and I could see the target on the TCASII screen showing 200 ft below us and to our left. As I responded to the RA adding power and arresting our descent the captain spotted the helicopter causing the conflict and the tower advised us of its presence as well. By now I saw the helicopter as well, maneuvered around it and landed without incident. The helicopter apparently had been maneuvering to land on a helipad on the taxiway immediately to the left of the approach lights to the runway. Tower should have notified us of the traffic sooner. TCASII worked as advertised, very effectively warning us of the conflict. Less vigilance by the crew could have resulted in disaster had we failed to recognize that the TCASII was not merely indicating ground traffic.

Original NASA ASRS Text

Title: ACR X TCASII RA WITH HELI IN ATA WHILE ON APCH. EVASIVE ACTION TAKEN. SEE AND AVOID CONCEPT.

Narrative: ACR X TRACKING THE ILS INBOUND IN VISUAL CONDITIONS AFTER HAVING BEEN CLRED TO LAND. AT APPROX 800 FT AGL, WE RECEIVED A TA FROM OUR TCASII WHICH WE INITIALLY ASSUMED WAS GND TFC ON THE ARPT. THEN AN RA WAS RECEIVED. AS I ARRESTED OUR DSCNT IN RESPONSE WE RECEIVED A 'CLR OF CONFLICT' FROM THE TCASII, FOLLOWED BY ANOTHER RA TO CLB AS I RESUMED DSCNT. BY NOW WE WERE ABOUT 400 FT AGL AND I COULD SEE THE TARGET ON THE TCASII SCREEN SHOWING 200 FT BELOW US AND TO OUR L. AS I RESPONDED TO THE RA ADDING PWR AND ARRESTING OUR DSCNT THE CAPT SPOTTED THE HELI CAUSING THE CONFLICT AND THE TWR ADVISED US OF ITS PRESENCE AS WELL. BY NOW I SAW THE HELI AS WELL, MANEUVERED AROUND IT AND LANDED WITHOUT INCIDENT. THE HELI APPARENTLY HAD BEEN MANEUVERING TO LAND ON A HELIPAD ON THE TXWY IMMEDIATELY TO THE L OF THE APCH LIGHTS TO THE RWY. TWR SHOULD HAVE NOTIFIED US OF THE TFC SOONER. TCASII WORKED AS ADVERTISED, VERY EFFECTIVELY WARNING US OF THE CONFLICT. LESS VIGILANCE BY THE CREW COULD HAVE RESULTED IN DISASTER HAD WE FAILED TO RECOGNIZE THAT THE TCASII WAS NOT MERELY INDICATING GND TFC.

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.

Air carrier X TCASII RA with helicopter in air traffic area while on approach. Evasive action taken. See and avoid concept.