Narrative:

While on vectors for approach for runway 32 at ind was given the following clearance: 'air carrier X, turn left to 180 degree heading, descend to 9000'.' 9000' was set in the altitude alerter. As aircraft was descending out of 9800' MSL, controller advised numerous targets at 9000'. I questioned the cleared altitude and controller advised cleared to 10000'. At the time of this verification aircraft reached 9500'. Aircraft was promptly returned to 10000'. As pull-up was initiated, crossing traffic medium large transport Y was observed passing left to right 500' below and less than 1/2 mi. No evasive maneuver was required to prevent a collision. I questioned the controller about the 9000' clearance and was advised that she had not given us clearance to 9000' but to 10000', and that the previous 9000' call was about traffic. Normal approach/landing made at ind. I called the supervisor at ind approach and he advised me that they were reviewing the tape to decide what action to take as the close proximity of the passing traffic had set off the alarm. A review of the tape revealed that the controller had in fact given the 9000' descent clearance. It was an error, she had been decertified and would be retrained, etc. I believe that there needs to be a limit/restriction on the # of items in a clearance at one time. Often they include 3 or more items (a speed reduction, descent, turn and traffic). I believe altitude clrncs should be separate so that the pilot and controllers can remember what has been said. Proper listen-back procedures are a must since we read back the 9000' clearance, and the controller failed to catch her error at this point. Writing down cleared altitude in addition to placing the altitude in the altitude alerter is also a good procedure.

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Original NASA ASRS Text

Title: CLRNC TO WRONG ALT RESULTS IN LESS THAN STANDARD SEPARATION.

Narrative: WHILE ON VECTORS FOR APCH FOR RWY 32 AT IND WAS GIVEN THE FOLLOWING CLRNC: 'ACR X, TURN LEFT TO 180 DEG HDG, DSND TO 9000'.' 9000' WAS SET IN THE ALT ALERTER. AS ACFT WAS DSNDING OUT OF 9800' MSL, CTLR ADVISED NUMEROUS TARGETS AT 9000'. I QUESTIONED THE CLRED ALT AND CTLR ADVISED CLRED TO 10000'. AT THE TIME OF THIS VERIFICATION ACFT REACHED 9500'. ACFT WAS PROMPTLY RETURNED TO 10000'. AS PULL-UP WAS INITIATED, XING TFC MLG Y WAS OBSERVED PASSING LEFT TO RIGHT 500' BELOW AND LESS THAN 1/2 MI. NO EVASIVE MANEUVER WAS REQUIRED TO PREVENT A COLLISION. I QUESTIONED THE CTLR ABOUT THE 9000' CLRNC AND WAS ADVISED THAT SHE HAD NOT GIVEN US CLRNC TO 9000' BUT TO 10000', AND THAT THE PREVIOUS 9000' CALL WAS ABOUT TFC. NORMAL APCH/LNDG MADE AT IND. I CALLED THE SUPVR AT IND APCH AND HE ADVISED ME THAT THEY WERE REVIEWING THE TAPE TO DECIDE WHAT ACTION TO TAKE AS THE CLOSE PROX OF THE PASSING TFC HAD SET OFF THE ALARM. A REVIEW OF THE TAPE REVEALED THAT THE CTLR HAD IN FACT GIVEN THE 9000' DSNT CLRNC. IT WAS AN ERROR, SHE HAD BEEN DECERTIFIED AND WOULD BE RETRAINED, ETC. I BELIEVE THAT THERE NEEDS TO BE A LIMIT/RESTRICTION ON THE # OF ITEMS IN A CLRNC AT ONE TIME. OFTEN THEY INCLUDE 3 OR MORE ITEMS (A SPD REDUCTION, DSNT, TURN AND TFC). I BELIEVE ALT CLRNCS SHOULD BE SEPARATE SO THAT THE PLT AND CTLRS CAN REMEMBER WHAT HAS BEEN SAID. PROPER LISTEN-BACK PROCS ARE A MUST SINCE WE READ BACK THE 9000' CLRNC, AND THE CTLR FAILED TO CATCH HER ERROR AT THIS POINT. WRITING DOWN CLRED ALT IN ADDITION TO PLACING THE ALT IN THE ALT ALERTER IS ALSO A GOOD PROC.

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.