Air carrier flight crew readback 1600 ft on clearance rather than the 16000 ft they were cleared to.

Attributes
ACN	807754
Time
Date	200810
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 1600
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	807754
Events
Anomaly	non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

First officer picked up clearance. Read back '...af 1600 ft FL360 10 mins after....' when we took off we turned to a tower assigned heading of 030 degrees and the first officer contacted departure and ATC said 'through 2000 ft cleared direct to lee county.' the first officer asked; at my direction; to clarify the altitude cleared to. The controller reported back 16000 ft. This lead us to believe that the original clearance should have been 16000 ft as opposed to 1600 ft. We leveled at 1600 ft for probably 10 seconds and then continued the climb to 16000 ft. We then clarified the clearance with ATC again to be sure we both heard direct lee county after the confusion. The controller never mentioned anything relating to an error or loss of separation. We looked at our paperwork and the first officer did indeed write down 1600 ft and read back 1600 ft. We figured out something was wrong when told to go direct to lee county after passing 2000 ft when we understood our clearance to be 1600 ft. I am not quite sure why the event occurred. Either clearance delivery said 1600 ft or the first officer thought he said 1600 ft when he really said 16000 ft. Either way; he wrote down and read back 1600 ft.

Original NASA ASRS Text

Title: ACR FLT CREW READBACK 1600 FT ON CLEARANCE RATHER THAN THE 16000 FT THEY WERE CLEARED TO.

Narrative: FO PICKED UP CLRNC. READ BACK '...AF 1600 FT FL360 10 MINS AFTER....' WHEN WE TOOK OFF WE TURNED TO A TWR ASSIGNED HDG OF 030 DEGS AND THE FO CONTACTED DEP AND ATC SAID 'THROUGH 2000 FT CLRED DIRECT TO LEE COUNTY.' THE FO ASKED; AT MY DIRECTION; TO CLARIFY THE ALT CLRED TO. THE CTLR RPTED BACK 16000 FT. THIS LEAD US TO BELIEVE THAT THE ORIGINAL CLRNC SHOULD HAVE BEEN 16000 FT AS OPPOSED TO 1600 FT. WE LEVELED AT 1600 FT FOR PROBABLY 10 SECONDS AND THEN CONTINUED THE CLB TO 16000 FT. WE THEN CLARIFIED THE CLRNC WITH ATC AGAIN TO BE SURE WE BOTH HEARD DIRECT LEE COUNTY AFTER THE CONFUSION. THE CTLR NEVER MENTIONED ANYTHING RELATING TO AN ERROR OR LOSS OF SEPARATION. WE LOOKED AT OUR PAPERWORK AND THE FO DID INDEED WRITE DOWN 1600 FT AND READ BACK 1600 FT. WE FIGURED OUT SOMETHING WAS WRONG WHEN TOLD TO GO DIRECT TO LEE COUNTY AFTER PASSING 2000 FT WHEN WE UNDERSTOOD OUR CLRNC TO BE 1600 FT. I AM NOT QUITE SURE WHY THE EVENT OCCURRED. EITHER CLRNC DELIVERY SAID 1600 FT OR THE FO THOUGHT HE SAID 1600 FT WHEN HE REALLY SAID 16000 FT. EITHER WAY; HE WROTE DOWN AND READ BACK 1600 FT.

Data retrieved from NASA's ASRS site as of May 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.