A LAST MIN ACFT TYPE CHANGE FOR A SCHEDULED ACR FLT ENDS UP WITH ATC ATTEMPTING TO CLB THE FLT TO AN ALT THAT WAS OUTSIDE OF THE ACFT'S PERFORMANCE LIMITS. DISPATCH HAD NOT ADVISED ATC REGARDING THE DEP OUT OF ORD; IL.

Narrative

I WAS ON THIS FLT; LEVEL AT WHAT I THOUGHT WAS OUR FILED CRUISE ALT OF FL330 (WITH REF TO THE FLT PLAN FILED). CTR THEN ASSIGNED US FL370; FOR WHICH WE WERE TOO HVY. I THEN NOTICED NOT ONLY THAT THE PDC NOT ONLY LISTED FL370 AS OUR FILED ALT; BUT THAT THE TYPE ACFT WAS AN A319. THIS WAS AN EQUIPMENT SUBSTITUTE FLT AND I FAILED TO CATCH THAT DISPATCH HAD NOT REFILED THE TYPE ACFT OR THAT WE HAD FAILED TO GET A NEW PDC REFLECTING THE CHANGE IN ACFT TYPE. THIS IS CLRLY MY FAULT FOR NOT HAVING READ THE PDC CLOSELY AS REQUIRED BY THE FOM. NEVERTHELESS; THIS IS EXACTLY THE TYPE OF THING THAT CAN OCCUR DUE TO THE UNDERSTAFFING OF MY POS ON THIS ACFT. I AM A RESERVE PLT. I WAS ON MY 6TH DAY OF DUTY; AND ON WHAT WAS TO HAVE BEEN MY 'DAY OFF;' AND I HAD HAD THIS ADDITIONAL FLYING TACKED ON TO AN ALREADY LONG DAY. FURTHERMORE; SCHEDULING WAS SO SHORT OF PLTS THAT THEY GAVE ME A CONNECT TIME OF 27 MINS; FROM ORD GATE X TO Y; SO THAT BY THE TIME I GOT TO THE ACFT; I HAD ABOUT 17 MINS BEFORE DEP. FURTHERMORE; THIS WAS A DCA FLT; WITH ALL THAT ENTAILS. FORTUNATELY; THE FO HAD DUTIFULLY PREPARED THE FLT FOR DEP; BUT WE BOTH STILL MISSED THE FAULTY PDC. SUPPLEMENTAL INFO FROM ACN 614284: WAS ORIGINALLY SCHEDULED TO FLY WITH A T/A319/R AND THE FLT PLAN WAS WORKED UP AND FILED AS SUCH. LATER IN THE MORNING; AN EQUIP SUBSTITUTION OCCURRED ON THE FLT; CHANGING TO A T/B733/F. THE FLT PLAN WAS RERUN CORRECTLY SHOWING THE NEW TAIL NUMBER AND ACFT EQUIP TYPE; BUT I FAILED TO CONTACT ATC (CHICAGO FLT DATA) WITH THE CHANGE IN THE EQUIP TYPE.