Narrative:

Departure clearance: cleared to lga midway 3 rv southbend as filed, expect FL330. Departure 118.4, squawk XXXX. Departing runway 31L the takeoff clearance was 'cleared for takeoff,' which still left the midway 3 for departure which is radar vectors to first fix and maintain 3000'. Took off on runway 31L, out of 400' started right hand turn to 90 degrees and was told to contact departure. Around 2000' we talked to departure on 118.4 and first thing, we were asked if we were given canal 3 departure. About the same time the first officer was answering no, we received the midway 3. We both saw the air carrier heavy transport overhead on an approach into O'hare. I leveled off around 2400' till well clear and the controller told us to climb to 6000'. I am not sure but if my memory is correct I think the controller said the heavy transport was at 4000' when he asked us if we had it in sight. (Canal 3 departure is maintain 2000' until 6 DME from midway, then maintain 3000'.) supplemental information from acn 94121: the controller seemed surprised and said, basically, 'aren't you supposed to be on the canal 3?' we called back to mdw tower and confirmed that our clearance had, in fact, been midway 3.

Related reports:

Google
 

Original NASA ASRS Text

Title: SID ISSUED BY MDW ATCT CLRNC DELIVERY WAS QUESTIONED BY DEP CTLR AFTER ACR MLG TKOF FROM MDW.

Narrative: DEP CLRNC: CLRED TO LGA MIDWAY 3 RV SOUTHBEND AS FILED, EXPECT FL330. DEP 118.4, SQUAWK XXXX. DEPARTING RWY 31L THE TKOF CLRNC WAS 'CLRED FOR TKOF,' WHICH STILL LEFT THE MIDWAY 3 FOR DEP WHICH IS RADAR VECTORS TO FIRST FIX AND MAINTAIN 3000'. TOOK OFF ON RWY 31L, OUT OF 400' STARTED RIGHT HAND TURN TO 90 DEGS AND WAS TOLD TO CONTACT DEP. AROUND 2000' WE TALKED TO DEP ON 118.4 AND FIRST THING, WE WERE ASKED IF WE WERE GIVEN CANAL 3 DEP. ABOUT THE SAME TIME THE F/O WAS ANSWERING NO, WE RECEIVED THE MIDWAY 3. WE BOTH SAW THE ACR HVT OVERHEAD ON AN APCH INTO O'HARE. I LEVELED OFF AROUND 2400' TILL WELL CLEAR AND THE CTLR TOLD US TO CLB TO 6000'. I AM NOT SURE BUT IF MY MEMORY IS CORRECT I THINK THE CTLR SAID THE HVT WAS AT 4000' WHEN HE ASKED US IF WE HAD IT IN SIGHT. (CANAL 3 DEP IS MAINTAIN 2000' UNTIL 6 DME FROM MIDWAY, THEN MAINTAIN 3000'.) SUPPLEMENTAL INFO FROM ACN 94121: THE CTLR SEEMED SURPRISED AND SAID, BASICALLY, 'AREN'T YOU SUPPOSED TO BE ON THE CANAL 3?' WE CALLED BACK TO MDW TWR AND CONFIRMED THAT OUR CLRNC HAD, IN FACT, BEEN MIDWAY 3.

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