TCASII causes large transport to climb 500 ft above assigned altitude.

Attributes
ACN	242939
Time
Date	199305
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : scy
State Reference	TX
Altitude	msl bound lower : 28000 msl bound upper : 28000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : commercial pilot : flight engineer pilot : instrument
ASRS Report	242939
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : required legal separation
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

While cruising at FL280 we received an RA advisory that told the pilots to climb. They did until the RA went away. They then descended to FL280 again. Overall, it was a 500 ft climb. The pilots reported this to ZFW. We had an FAA inspector in the cockpit that observed all these actions. Evidently there was an aircraft below us that was supposed to level at FL270. I'm not sure whether he did or did not. Center confirmed that there was an aircraft below us at FL270.

Original NASA ASRS Text

Title: TCASII CAUSES LGT TO CLB 500 FT ABOVE ASSIGNED ALT.

Narrative: WHILE CRUISING AT FL280 WE RECEIVED AN RA ADVISORY THAT TOLD THE PLTS TO CLB. THEY DID UNTIL THE RA WENT AWAY. THEY THEN DSNDED TO FL280 AGAIN. OVERALL, IT WAS A 500 FT CLB. THE PLTS RPTED THIS TO ZFW. WE HAD AN FAA INSPECTOR IN THE COCKPIT THAT OBSERVED ALL THESE ACTIONS. EVIDENTLY THERE WAS AN ACFT BELOW US THAT WAS SUPPOSED TO LEVEL AT FL270. I'M NOT SURE WHETHER HE DID OR DID NOT. CTR CONFIRMED THAT THERE WAS AN ACFT BELOW US AT FL270.

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.