Possible confusion regarding cleared altitude in the descent may have contributed to TCAS RA.

Attributes
ACN	722618
Time
Date	200612
Place
Locale Reference	navaid : mol.vor
State Reference	VA
Altitude	msl bound lower : 32700 msl bound upper : 33000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	Regional Jet 700 ER&LR
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zid.artcc
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : multi engine
Experience	flight time last 90 days : 200 flight time total : 3500 flight time type : 1800
ASRS Report	722618
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas other controllera
Resolutory Action	controller : issued alert controller : issued new clearance
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance Airspace Structure
Primary Problem	Ambiguous

Narrative:

We were descending from FL340 to FL300. We were at FL327 and ATC came on saying 'verify level at 330.' we saw 300 on our altitude preselect and then at that time we saw the TA come up and then ATC said 'turn 80 degrees to the right.' then the RA came on and said climb. So we climbed and turned. The captain and I discussed what happened and decided that either we read back and confirmed 300 and it wasn't caught by ATC if they gave us 330 or that we were given the wrong altitude.

Original NASA ASRS Text

Title: POSSIBLE CONFUSION REGARDING CLRED ALT IN THE DSCNT MAY HAVE CONTRIBUTED TO TCAS RA.

Narrative: WE WERE DSNDING FROM FL340 TO FL300. WE WERE AT FL327 AND ATC CAME ON SAYING 'VERIFY LEVEL AT 330.' WE SAW 300 ON OUR ALT PRESELECT AND THEN AT THAT TIME WE SAW THE TA COME UP AND THEN ATC SAID 'TURN 80 DEGS TO THE R.' THEN THE RA CAME ON AND SAID CLB. SO WE CLBED AND TURNED. THE CAPT AND I DISCUSSED WHAT HAPPENED AND DECIDED THAT EITHER WE READ BACK AND CONFIRMED 300 AND IT WASN'T CAUGHT BY ATC IF THEY GAVE US 330 OR THAT WE WERE GIVEN THE WRONG ALT.

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.