A MAINT TECHNICIAN FAILED TO COMPLETE TIGHTENING THE SCREWS ON AN UNDER WING PANEL AS REQUIRED.

Narrative

I WAS REMOVING SCREWS FROM THE PANEL FORWARD OF PANEL 264CR TO PERFORM THE DEICE BOOT SYS CHK. 1 SCREW WOULD NOT COME OUT; SO I REMOVED PANEL 264CR TO GAIN ACCESS TO THE NUT PLATE OF THE BAD SCREW. THE NUT PLATE WAS GOOD; AND I WAS ABLE TO REMOVE THE BAD SCREW USING PLIERS. I PUT THE PANEL (264CR) BACK ON AND FINGER TIGHTENED THE SCREWS. I WAS PLANNING OT FINISH TIGHTENING THE SCREWS WITH MY SPD HANDLE; WHEN A FELLOW WORK MATE WALKED BY. I ASKED IF HE COULD HELP ME PERFORM THE DEICE BOOT CHK. IT'S A 2 MAN OP AND IT'S CUSTOMARY TO ASK WHOEVER IS IN THE AREA TO HELP YOU AS SOON AS YOU SEE SOMEONE. AFTER THE CHK; I DISCONNECTED THE AIR LINE AND INSTALLED THE PANEL FOR THE DEICE BOOT LINE WITH NEW SCREWS. I GOT DOWN FROM THE LADDER AND TOOK A LAST GLANCE UP AT THE PANEL AREA. AT THAT TIME I DID NOT NOTICE THE OTHER PANEL STILL HAD THE SCREWS LOOSE BECAUSE IT WAS DARK UNDER THE WING AND THE SCREWS AND PANEL WERE PAINTED BLUE. I REALIZE NOW THAT I FORGOT TO TIGHTEN PANEL 264CR DOWN. THE CONTRIBUTING FACTORS WHICH MAY HAVE CAUSED MY ERROR WERE: LACK OF SLEEP PRIOR TO RPTING TO WORK. I HAD ONLY 3 HRS THAT DAY. LACK OF NUTRITION. I HADN'T EATEN THAT DAY AND WAS ANTICIPATING TAKING A BREAK PRIOR TO THIS INCIDENT. I BELIEVE THAT IF I HAD MORE LIGHTING IN THE AREA; I WOULD HAVE CAUGHT MY MISTAKE. ALSO; IF INSPECTORS WOULD MAKE A WALKAROUND CHK BEFORE THESE ACFT ARE SENT OUT TO THE GATES; THIS TYPE OF ERROR MAY BE CAUGHT IN THE FUTURE. I HAVE BEEN FORMALLY COUNSELED AND SUSPENDED FROM WORK WITHOUT PAY FOR 1 WK THUS FAR PENDING AN ONGOING FAA INVESTIGATION INTO THIS MATTER.