Flight crew thinks they were cleared to 12000 ft while ATC thinks they were cleared to 13000 ft.

Attributes
ACN	353446
Time
Date	199611
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cvg
State Reference	OH
Altitude	msl bound lower : 12000 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 8500 flight time type : 4500
ASRS Report	353446
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 13500 flight time type : 4500
ASRS Report	353570
Events
Anomaly	altitude deviation : overshoot altitude deviation : crossing restriction not met non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

We were on the jeney arrival under control of ZID and we were instructed to cross prude at 12000 ft. I responded to the instruction by saying 'cross prude at 12000 ft' and then left the frequency to check in with company for a gate assignment. When I returned to the frequency, the captain was responding to a question from the controller who had questioned our altitude of 12000 ft. He seemed to think we should have been at 13000 ft. Both the captain and I were confused since we agreed that we had been assigned 12000 ft and had verified this altitude in our response. We further confirmed that the depicted altitude on the STAR was 12000 ft expected. There was no displayed traffic on our TCASII within a 20 mi radius at the time of occurrence. The remainder of the arrival was uneventful. Whether the controller misspoke or we misheard, the fact is we ended up where he didn't think we should be. The incident reconfirms that altitude assignments are easy to miss and confusion can be eliminated by communication.

Original NASA ASRS Text

Title: FLC THINKS THEY WERE CLRED TO 12000 FT WHILE ATC THINKS THEY WERE CLRED TO 13000 FT.

Narrative: WE WERE ON THE JENEY ARR UNDER CTL OF ZID AND WE WERE INSTRUCTED TO CROSS PRUDE AT 12000 FT. I RESPONDED TO THE INSTRUCTION BY SAYING 'CROSS PRUDE AT 12000 FT' AND THEN LEFT THE FREQ TO CHK IN WITH COMPANY FOR A GATE ASSIGNMENT. WHEN I RETURNED TO THE FREQ, THE CAPT WAS RESPONDING TO A QUESTION FROM THE CTLR WHO HAD QUESTIONED OUR ALT OF 12000 FT. HE SEEMED TO THINK WE SHOULD HAVE BEEN AT 13000 FT. BOTH THE CAPT AND I WERE CONFUSED SINCE WE AGREED THAT WE HAD BEEN ASSIGNED 12000 FT AND HAD VERIFIED THIS ALT IN OUR RESPONSE. WE FURTHER CONFIRMED THAT THE DEPICTED ALT ON THE STAR WAS 12000 FT EXPECTED. THERE WAS NO DISPLAYED TFC ON OUR TCASII WITHIN A 20 MI RADIUS AT THE TIME OF OCCURRENCE. THE REMAINDER OF THE ARR WAS UNEVENTFUL. WHETHER THE CTLR MISSPOKE OR WE MISHEARD, THE FACT IS WE ENDED UP WHERE HE DIDN'T THINK WE SHOULD BE. THE INCIDENT RECONFIRMS THAT ALT ASSIGNMENTS ARE EASY TO MISS AND CONFUSION CAN BE ELIMINATED BY COM.

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.