Narrative:

Air carrier X departed runway 32 at tbn with assigned heading 320 degree up to 4000' by tower. Were told to contact kansas center on 133.8. We contacted center and told them we were 2.5 for 4000' heading 320 degree. Center's reply, maintain 5000' traffic 12 O'clock and 5 mi. My reply, maintain 5000' and we are IMC at this time. Center reply, maintain 4000' traffic 12 O'clock. (By this time we were passing 4800'). My reply, we are descending to 4000' and were assigned 5000' sir. Center, no reply. By 4800' we were on top of cloud layer and saw traffic pass from left to right above us and in front of us. When we got back to st louis, the controller told us there is a possible pilot deviation of altitude involved. When we returned to st louis and called, the investigator told us he was reviewing the ATC tapes of the incident. Later on in the day the investigator called our chief pilot and told him we had been cleared to 5000' and were not at fault. Supplemental information from acn 172117. Air carrier X was cleared by center to 5000' and advised of traffic at 12 O'clock. Passing through 4800' center told us maintain 4000' traffic 12 O'clock at 5000'. While beginning descent back to 4000', saw a twin engine plane passing right in front of us.

Related reports:

Google
 

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM SMT Y. SYSTEM ERROR.

Narrative: ACR X DEPARTED RWY 32 AT TBN WITH ASSIGNED HDG 320 DEG UP TO 4000' BY TWR. WERE TOLD TO CONTACT KANSAS CTR ON 133.8. WE CONTACTED CTR AND TOLD THEM WE WERE 2.5 FOR 4000' HDG 320 DEG. CTR'S REPLY, MAINTAIN 5000' TFC 12 O'CLOCK AND 5 MI. MY REPLY, MAINTAIN 5000' AND WE ARE IMC AT THIS TIME. CTR REPLY, MAINTAIN 4000' TFC 12 O'CLOCK. (BY THIS TIME WE WERE PASSING 4800'). MY REPLY, WE ARE DSNDING TO 4000' AND WERE ASSIGNED 5000' SIR. CTR, NO REPLY. BY 4800' WE WERE ON TOP OF CLOUD LAYER AND SAW TFC PASS FROM L TO R ABOVE US AND IN FRONT OF US. WHEN WE GOT BACK TO ST LOUIS, THE CTLR TOLD US THERE IS A POSSIBLE PLT DEV OF ALT INVOLVED. WHEN WE RETURNED TO ST LOUIS AND CALLED, THE INVESTIGATOR TOLD US HE WAS REVIEWING THE ATC TAPES OF THE INCIDENT. LATER ON IN THE DAY THE INVESTIGATOR CALLED OUR CHIEF PLT AND TOLD HIM WE HAD BEEN CLRED TO 5000' AND WERE NOT AT FAULT. SUPPLEMENTAL INFO FROM ACN 172117. ACR X WAS CLRED BY CTR TO 5000' AND ADVISED OF TFC AT 12 O'CLOCK. PASSING THROUGH 4800' CTR TOLD US MAINTAIN 4000' TFC 12 O'CLOCK AT 5000'. WHILE BEGINNING DSNT BACK TO 4000', SAW A TWIN ENG PLANE PASSING R IN FRONT OF US.

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.