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

Attributes
ACN	235383
Time
Date	199302
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : rdu
State Reference	NC
Altitude	msl bound lower : 11000 msl bound upper : 11400
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : rdu artcc : zny
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Fighter
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 225 flight time total : 9600
ASRS Report	235383
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 175 flight time total : 6000 flight time type : 2000
ASRS Report	235072
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 6000 vertical : 1000
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

On vectors for visual approach to rdu, we received TA followed immediately by an RA 'climb.' traffic was a flight of 2 military aircraft in a block 9000-10000 ft. We complied with the RA command. Traffic passed below, left to right under our nose. I suspect flight of 2 was in a climb, within the block, and thus generated the RA. The flight of 2 was under gsb approach and we were under rdu approach control. We climbed 400 ft to comply with RA information. TCASII works mostly as advertised with our situation being one of its few quirks. Under the assumption that the conflict traffic leveled off, the RA compliance would have been unnecessary. However, if he had failed to level off, the RA would have prevented a conflict. I asked the rdu approach controller if he had a conflict with our RA deviation (climb to 11400 ft). He said he did not.

Original NASA ASRS Text

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

Narrative: ON VECTORS FOR VISUAL APCH TO RDU, WE RECEIVED TA FOLLOWED IMMEDIATELY BY AN RA 'CLB.' TFC WAS A FLT OF 2 MIL ACFT IN A BLOCK 9000-10000 FT. WE COMPLIED WITH THE RA COMMAND. TFC PASSED BELOW, L TO R UNDER OUR NOSE. I SUSPECT FLT OF 2 WAS IN A CLB, WITHIN THE BLOCK, AND THUS GENERATED THE RA. THE FLT OF 2 WAS UNDER GSB APCH AND WE WERE UNDER RDU APCH CTL. WE CLBED 400 FT TO COMPLY WITH RA INFO. TCASII WORKS MOSTLY AS ADVERTISED WITH OUR SIT BEING ONE OF ITS FEW QUIRKS. UNDER THE ASSUMPTION THAT THE CONFLICT TFC LEVELED OFF, THE RA COMPLIANCE WOULD HAVE BEEN UNNECESSARY. HOWEVER, IF HE HAD FAILED TO LEVEL OFF, THE RA WOULD HAVE PREVENTED A CONFLICT. I ASKED THE RDU APCH CTLR IF HE HAD A CONFLICT WITH OUR RA DEV (CLB TO 11400 FT). HE SAID HE DID NOT.

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.