MAIN GEAR FAILS TO RETRACT.

Narrative

AT ABOUT CF40 AM WE WERE CLRED TO TKOF. WE HAD A NORMAL TKOF AND AS I CALLED FOR GEAR UP THE COPLT POSITIONED THE GEAR HANDLE TO UP; AT THIS TIME THE NOSE GEAR RTRACTED BUT THE MAIN GEAR DID NOT! WE ASKED ATC FOR A VECTOR OUT OF THE AREA WHILE WE CHKED ARE ABNORMAL CHKLIST WE TRIED TO RAISE THE GEAR ONCE AGAIN NO LUCK; WE CHKED OUR OPS MANUAL FOR AN OVERWT LNDG PROC WHICH WE FOLLOWED AND WENT BACK TO MSP AND LANDED UNEVENTFUL. AS I TAXIED THE AIRPLANE TO THE GATE OUR COMPANY MECH WALKED UNDER THE AIRPLANE AND AS I PARKED THE PLANE HE CAME UP TO THE COCKPIT VERY UPSET AND SAID THAT SOMEBODY HAD REINSTALLED THE MAIN GEAR PINS; AS HE SAID THAT HE PULLED THEM AT XXAM WHEN HE GOT THE AIRPLANE READY FOR TOW TO THE GATE. I ASKED THE ENGINEER IF HE HAD SEEN THEM ON HIS WALK AROUND AND HE SAID NO HE DID NOT SEE THEM. THE MECH SHOWED US THAT THE FLAGS HAD BEEN TIED IN SMALL KTS AND COULD NOT BE SEEN. OUR MECH FEELS THAT SOMEBODY ON THE RAMP INSTALLED THEM AND TIED UP THE FLAGS SO NOBODY COULD SEE THEM. THE PROB IS OUR CHKLIST CALLS FOR (CHALLENGE) GEAR PINS -- (RESPONSE) REMOVED AND ON BOARD. THIS IS A RESPONSE FROM THE ENGINEER WHEN I ASKED HIM IF HE HAD SEEN THEM HE COULD NOT REMEMBER SEEING THEM ON BOARD! THE BOTTOM LINE IS THAT THE ENG ANSWERED REMOVED ON BOARD BUT WASN'T SURE HE HAD SEEN THEM. I KNOW AS CAPT I'M RESPONSIBLE FOR EVERYTHING; BUT DON'T FEEL I HAVE TO DO A WALK AROUND EVERY TIME I FLY. I ALSO FEEL THAT OUR GEAR PINS SHOULD BE MOUNTED IN THE COCKPIT SO THE ENTIRE CREW CAN SEE THEM RATHER THAN JUST HAVING THEM ON THE COCKPIT FLOOR.