SMA PLT ABORTS TKOF WHEN CABIN DOOR POPS OPEN.

Narrative

ON THE ABOVE DATE AND TIME I WAS DEPARTING GCN WHEN ON THE TKOF ROLL MY DOOR POPPED OPEN. MY PREFLT WAS DONE ON THE RAMP AND CHKLIST COMPLETED WHEN I WAS DELAYED SLIGHTLY FOR DEP SO I OPENED THE DOOR FOR VENTILATION AND TAXIED TO THE HOLD SHORT LINE AT RWY 21. WHEN CLRED FOR TKOF I CLOSED THE DOOR; GOT TO POS AND WAS CLRED FOR TKOF. ABOUT 1/2 OF THE DISTANCE REQUIRED FOR TKOF THE DOOR POPPED OPEN. I ADVISED THE TWR THAT I WAS GOING TO ABORT AND THAT 2 CHARTS FLEW OUT THE DOOR. THE TWR ADVISED ME TO RETURN TO THE RAMP; THEY WOULD HAVE MAINT RETURN MY CHARTS. IT IS NOT CERTAIN WHETHER I DOUBLE LOCKED THE DOOR OR NOT; BUT IF I DIDN'T; THAT COULD HAVE AVOIDED THE SITUATION. WHILE ON THE RAMP AN FAA REPRESENTATIVE CAME OVER THE LECTURED ME ABOUT NECESSITY OF PROPER CHKLIST USAGE WHICH MAY HAVE PREVENTED THE OCCURRENCE. HENCEFORTH AFTER SECURING THE DOOR AND DOUBLE LOCKING IT I WILL PUSH ON THE TOP REAR CORNER OF DOOR TO CHK IF IT WOULD POP OPEN. THIS MAY BE ABLE TO PREVENT OR AT LEAST DISCOVER IF ALL LOCKS ARE PROPERLY SET.