B757 flight crew has an altitude excursion and a TCAS RA during climb.

Attributes
ACN	699404
Time
Date	200606
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ztl.artcc
State Reference	GA
Altitude	msl bound lower : 21000 msl bound upper : 22000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 182 flight time total : 16000 flight time type : 4000
ASRS Report	699404
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : returned to assigned altitude
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

On geetr departure from atlanta about 61 mi west of atl while cleared to FL230; the center controller told us to level off at FL220. We read back that altitude and put it in the MCP window. When passing FL210 he told us to level at FL210. We told him we were already passing FL215 and asked if this was correct. At that instant we got an RA with an aircraft passing FL220 and did not hear the controller's reply. We reported the RA but got no response from the controller. In fact; his radio procedures during the time we were on the frequency seemed substandard. There was no confusion or disagreement between the copilot and myself over what we heard or the clearance we received. We read back the clearance to FL220 and both checked the MCP altitude window. The TCAS prevented a very near miss or collision.

Original NASA ASRS Text

Title: B757 FLT CREW HAS AN ALT EXCURSION AND A TCAS RA DURING CLB.

Narrative: ON GEETR DEP FROM ATLANTA ABOUT 61 MI W OF ATL WHILE CLRED TO FL230; THE CTR CTLR TOLD US TO LEVEL OFF AT FL220. WE READ BACK THAT ALT AND PUT IT IN THE MCP WINDOW. WHEN PASSING FL210 HE TOLD US TO LEVEL AT FL210. WE TOLD HIM WE WERE ALREADY PASSING FL215 AND ASKED IF THIS WAS CORRECT. AT THAT INSTANT WE GOT AN RA WITH AN ACFT PASSING FL220 AND DID NOT HEAR THE CTLR'S REPLY. WE RPTED THE RA BUT GOT NO RESPONSE FROM THE CTLR. IN FACT; HIS RADIO PROCS DURING THE TIME WE WERE ON THE FREQ SEEMED SUBSTANDARD. THERE WAS NO CONFUSION OR DISAGREEMENT BTWN THE COPLT AND MYSELF OVER WHAT WE HEARD OR THE CLRNC WE RECEIVED. WE READ BACK THE CLRNC TO FL220 AND BOTH CHKED THE MCP ALT WINDOW. THE TCAS PREVENTED A VERY NEAR MISS OR COLLISION.

Data retrieved from NASA's ASRS site as of January 2009 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.