An air carrier medium large transport climbed in response to a TCASII command.

Attributes
ACN	249817
Time
Date	199308
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : gso
State Reference	NC
Altitude	msl bound lower : 3000 msl bound upper : 3900
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : gso
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other cruise other
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 : 11000 flight time type : 4800
ASRS Report	249817
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 300 flight time total : 9200 flight time type : 1200
ASRS Report	249797
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 9000 vertical : 900
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During ILS approach pattern vectoring at 3000 ft MSL to a runway 23 ILS at greensboro, nc, on aug/fri/93, we encountered a traffic conflict with a GA aircraft that was not in contact with gso approach control. The conflict aircraft was seen on TCASII at our altitude and approximately 6 mi on a direct bearing for our aircraft. The conflict aircraft's distance from us slowly decreased until such time that our TCASII system issued a climb RA. We complied and notified approach control. We climbed to 3900 ft MSL in the RA maneuver, advised the controller and descended back to 3000 ft MSL as soon as we established contact with ATC. The conflict aircraft was seen to remain airborne, without radio contact in the ILS approach traffic pattern for some time after we turned from ILS downwind to pattern base leg. Approach control indicated there were no traffic conflicts resulting from our initiation of the TCASII RA maneuver. Callback conversation with reporter revealed the following: the reporting captain states that there was an aircraft out there, but there was no warning from approach control. The aircraft apparently was outside the air traffic area but slightly in the way of incoming aircraft. The intruding aircraft was not in contact with approach control.

Original NASA ASRS Text

Title: AN ACR MLG CLBED IN RESPONSE TO A TCASII COMMAND.

Narrative: DURING ILS APCH PATTERN VECTORING AT 3000 FT MSL TO A RWY 23 ILS AT GREENSBORO, NC, ON AUG/FRI/93, WE ENCOUNTERED A TFC CONFLICT WITH A GA ACFT THAT WAS NOT IN CONTACT WITH GSO APCH CTL. THE CONFLICT ACFT WAS SEEN ON TCASII AT OUR ALT AND APPROX 6 MI ON A DIRECT BEARING FOR OUR ACFT. THE CONFLICT ACFT'S DISTANCE FROM US SLOWLY DECREASED UNTIL SUCH TIME THAT OUR TCASII SYS ISSUED A CLB RA. WE COMPLIED AND NOTIFIED APCH CTL. WE CLBED TO 3900 FT MSL IN THE RA MANEUVER, ADVISED THE CTLR AND DSNDED BACK TO 3000 FT MSL AS SOON AS WE ESTABLISHED CONTACT WITH ATC. THE CONFLICT ACFT WAS SEEN TO REMAIN AIRBORNE, WITHOUT RADIO CONTACT IN THE ILS APCH TFC PATTERN FOR SOME TIME AFTER WE TURNED FROM ILS DOWNWIND TO PATTERN BASE LEG. APCH CTL INDICATED THERE WERE NO TFC CONFLICTS RESULTING FROM OUR INITIATION OF THE TCASII RA MANEUVER. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: THE RPTING CAPT STATES THAT THERE WAS AN ACFT OUT THERE, BUT THERE WAS NO WARNING FROM APCH CTL. THE ACFT APPARENTLY WAS OUTSIDE THE ATA BUT SLIGHTLY IN THE WAY OF INCOMING ACFT. THE INTRUDING ACFT WAS NOT IN CONTACT WITH APCH CTL.

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.