Narrative:

Departed cbf VFR en route to dsm (WX was cavu). Took off runway 31 with immediate right turn on course (094 degrees). Maintained pattern altitude for approximately 6 mi east of airport with speed 185 KTS. The copilot was trying to contact omaha departure as soon as the gear was up. No response until aircraft was approximately 10 mi east of cbf. Departure's response was 'squawk XXXX' and advised us of a 'possible airspace violation' and call them when I got to dsm. I called and talked with ms X. She mentioned different ways to depart cbf (my first time there) and there was no airspace violation. Supplemental information from acn 495690: we were advised of a class C airspace penetration. This was a first time at this airport destination and we were not aware of the class C airspace at this location.

Google
 

Original NASA ASRS Text

Title: DEPARTING VFR FROM CBF, BELOW THE OMAHA, NE, CLASS C AIRSPACE, CPR PLT WAS PERCEIVED BY R90 TO HAVE VIOLATED THE CLASS C AIRSPACE.

Narrative: DEPARTED CBF VFR ENRTE TO DSM (WX WAS CAVU). TOOK OFF RWY 31 WITH IMMEDIATE R TURN ON COURSE (094 DEGS). MAINTAINED PATTERN ALT FOR APPROX 6 MI E OF ARPT WITH SPD 185 KTS. THE COPLT WAS TRYING TO CONTACT OMAHA DEP AS SOON AS THE GEAR WAS UP. NO RESPONSE UNTIL ACFT WAS APPROX 10 MI E OF CBF. DEP'S RESPONSE WAS 'SQUAWK XXXX' AND ADVISED US OF A 'POSSIBLE AIRSPACE VIOLATION' AND CALL THEM WHEN I GOT TO DSM. I CALLED AND TALKED WITH MS X. SHE MENTIONED DIFFERENT WAYS TO DEPART CBF (MY FIRST TIME THERE) AND THERE WAS NO AIRSPACE VIOLATION. SUPPLEMENTAL INFO FROM ACN 495690: WE WERE ADVISED OF A CLASS C AIRSPACE PENETRATION. THIS WAS A FIRST TIME AT THIS ARPT DEST AND WE WERE NOT AWARE OF THE CLASS C AIRSPACE AT THIS LOCATION.

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.