B727. ARTCC radar controller misspoke the altitude clearance.

Attributes
ACN	481760
Time
Date	200008
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zau.artcc
State Reference	IL
Altitude	msl bound lower : 29000 msl bound upper : 30000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau.artcc
Operator	common carrier : air carrier
Make Model Name	B727 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 pilot : multi engine pilot : flight engineer
Experience	flight time last 90 days : 100 flight time total : 6500 flight time type : 375
ASRS Report	481760
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : multi engine pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued advisory 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	ATC Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Climbing on the last clearance to climb to FL290, I told the first officer to request FL330 as a final cruising altitude the next time he talked with ATC. At the next frequency change, he requested FL330 as a final. I believe a few moments passed. Then ATC said '(our call sign) cleared to FL330 I have your request.' the first officer read back '(call sign) cleared to FL330' with no objection from ATC. Just before reaching FL300, ATC said '(call sign) you were cleared to FL290, say altitude.' the first officer replied 'we were cleared to FL300.' (I believe he meant to say 330.) I picked up the microphone and said 'we are descending from FL300 to FL290, we understood we were cleared to FL330 (call sign).' we leveled at FL290 shortly after that. In retrospect, it would have been best if I would have questioned a clearance where ATC said 'I have your request' -- even when the words 'cleared to FL330' were said by ATC. It also would have been better if ATC meant for us to level at FL290 to say 'cleared to FL290, I have your request for higher.' regardless of the phraseology that is chosen by ATC, if a flight crew reads back a clearance not consistent with the intent of the controller, I hope it would be caught and the clearance clarified.

Original NASA ASRS Text

Title: B727. ARTCC RADAR CTLR MISSPOKE THE ALT CLRNC.

Narrative: CLBING ON THE LAST CLRNC TO CLB TO FL290, I TOLD THE FO TO REQUEST FL330 AS A FINAL CRUISING ALT THE NEXT TIME HE TALKED WITH ATC. AT THE NEXT FREQ CHANGE, HE REQUESTED FL330 AS A FINAL. I BELIEVE A FEW MOMENTS PASSED. THEN ATC SAID '(OUR CALL SIGN) CLRED TO FL330 I HAVE YOUR REQUEST.' THE FO READ BACK '(CALL SIGN) CLRED TO FL330' WITH NO OBJECTION FROM ATC. JUST BEFORE REACHING FL300, ATC SAID '(CALL SIGN) YOU WERE CLRED TO FL290, SAY ALT.' THE FO REPLIED 'WE WERE CLRED TO FL300.' (I BELIEVE HE MEANT TO SAY 330.) I PICKED UP THE MIKE AND SAID 'WE ARE DSNDING FROM FL300 TO FL290, WE UNDERSTOOD WE WERE CLRED TO FL330 (CALL SIGN).' WE LEVELED AT FL290 SHORTLY AFTER THAT. IN RETROSPECT, IT WOULD HAVE BEEN BEST IF I WOULD HAVE QUESTIONED A CLRNC WHERE ATC SAID 'I HAVE YOUR REQUEST' -- EVEN WHEN THE WORDS 'CLRED TO FL330' WERE SAID BY ATC. IT ALSO WOULD HAVE BEEN BETTER IF ATC MEANT FOR US TO LEVEL AT FL290 TO SAY 'CLRED TO FL290, I HAVE YOUR REQUEST FOR HIGHER.' REGARDLESS OF THE PHRASEOLOGY THAT IS CHOSEN BY ATC, IF A FLC READS BACK A CLRNC NOT CONSISTENT WITH THE INTENT OF THE CTLR, I HOPE IT WOULD BE CAUGHT AND THE CLRNC CLARIFIED.

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.