F100 FLC HAS CAPT'S SLIDING WINDOW MALFUNCTION. RETURNS TO DEP ARPT.

Narrative

DEPARTING ELP; LOUD AIR NOISE CAME FROM CAPT'S SLIDING WINDOW. HELD OVERHEAD TO BURN DOWN TO MAX LNDG WT AND LANDED BACK AT ELP. AFTER LNDG; FOUND THE AFT LOWER CAM OF SLIDING WINDOW OUT OF THE TRACK. THE HANDLE COULD NOT BE MOVED AT ALL; YELLOW LINES MATCHED; AND THE HANDLE WAS FULL FORWARD AND LOCKED. ALSO FOUND FORWARD UPPER CAM SCREW LOOSE. 2 POSSIBILITIES CROSSED MY FO'S AND MY MIND: 1) POSSIBLE SABOTAGE; WHICH TURNED OUT NOT TO BE THE CASE. 2) SOMEONE FORCED THE WINDOW CLOSED AND WAS AFRAID TO RPT IT; TO AVOID GETTING IN TROUBLE; WHICH WASN'T THE CASE EITHER. WITH THESE CONCERNS; I CALLED FOR THE STATION MGR WHO WAS NOT THERE. THE FLT SVC SUPVR AND RAMP SUPVR CAME TO HEAR MY CONCERNS. THEY WERE VERY HELPFUL. CONTRACT MAINT ARRIVED AFTER WAITING 1 HR. THE MECH SAID THAT HE HAD WORKED ON THE ACFT THE NIGHT BEFORE; AFTER BEING CALLED BY CABIN CLEANERS ABOUT A STUCK WINDOW. HE SAID THAT HE MOUNTED THE CAM ON THE OUTSIDE OF THE TRACK AND THAT TULSA TOLD HIM TO. HE LATER CHANGED HIS STORY; THAT HE INSTALLED THE CAM INSIDE THE TRACK AND IT OP CHKED OKAY. THERE IS NO WAY THAT THE CAM COULD JUMP THE TRACK SINCE THERE IS A CAM AND TRACK DIRECTLY ABOVE THE LOWER CAM. ADDITIONALLY; NO LOGBOOK ENTRIES WERE MADE OF HIS WORK. ALSO; WE HAD FLOWN THE ACFT IN THE NIGHT BEFORE AND IT WORKED FINE. I TALKED WITH TULSA TECHNICIAN REGARDING THE PREVIOUS NIGHT'S WORK AND NO LOGBOOK ENTRIES. THIS WAS NOT COMMON PRACTICE. LESSONS LEARNED: VERY DIFFICULT TO COMMUNICATE WITH WIND NOISE; ABORT IF POSSIBLE. LOGBOOK ENTRIES MUST BE MADE FOR ALL WORK. OPEN/CLOSE WINDOW ON IT; TO AVOID GETTING IN TROUBLE.