INADEQUATE PREFLT.

Narrative

I WALKED IN TO WORK AND THE POLICE AND CIVIL AIR PATROL INFORMED ME THAT MY ELT WAS GOING OFF. BY THE TIME I HAD TAKEN CARE OF THIS; IT WAS NEARING DEP TIME. I PICKED UP THE WX AND CHKED THE TAIL OF THE ACFT FOR ANY DENTS OF LIGHTNING STRIKES. (MY FO HAD ALREADY PREFLTED OF COURSE.) I WENT AROUND THE R WING AND NOSE AND HEADED FOR THE CABIN DOOR WHEN I NOTICED THE HYD FILL CAN ACCESS PANEL WAS OPEN. I CLOSED IT AND ENTERED THE ACFT. THE WX WAS 300 FT WITH 2 MI AND IT WAS MY FO'S LEG. WE WERE CLRED FOR TKOF AND I GAVE THE ACFT TO MY FO. HE BEGAN TO BRING THE PWR UP AND ONLY GOT THE PROPS ON THE GOVERNORS; THEN SAID NOTHING. I LOOKED AT HIM TO SEE IF HE WAS OK. HE APPEARED TO BE; SO I ASKED HIM; 'ARE YOU OK?' HE RESPONDED WITH; 'SET MAX PWR.' I DID THIS AND LOOKED AT HIS AIRSPD. WE WERE NOW AT 100 KTS. I CALLED V1; VR; V2; LOOKED AT MY SIDE OF THE ACFT; AND HAD NO AIRSPD INDICATION. THE PITOT TUBE COVER HAD BEEN LEFT ON. I SHOULD HAVE CALLED AN ABORT AS SOON AS I NOTICED THAT MY FO WAS NOT RESPONDING NORMALLY. I SHOULD HAVE ALSO TAKEN MORE TIME TO OBSERVE THE PREFLT ACTIVITIES OF MY FO.