BE400 FO DETERMINES ACFT OVERWT FOR DEP. CAPT DISAGREES.

Narrative

I WAS SIC ON A PART 91 CPR FLT OPERATING A BE400A. WE WERE PREPARING FOR DEP FROM PITKIN COUNTY ARPT (ASE) ASPEN; CO; TO GARY; IN (GYY) WITH PAX. THE CAPT ON HIS OWN INITIATIVE HAD PREVIOUSLY ORDERED THE FUEL. PERFORMING MY SIC DUTIES; I COMPLETED THE 'TOLD' CARD FOR OUR TKOF. WITH DATA FROM THE 'TOLD' CARD APPLIED TO OUR PERFORMANCE CHARTS (ALT; TEMP; RWY AVAILABLE; ETEC); I DETERMINED THAT WE WOULD BE SEVERAL HUNDRED POUNDS OVER OUR MAX TKOF WT FOR THE CONDITIONS ON THAT DAY. I EXPLAINED THIS SIT TO THE CAPT PRIOR TO OUR PAX ARR. HIS RESPONSE WAS THAT HE WAS AWARE OF THE TEMP AND ALT AND THAT HIS INTERP OF THE 4 CATEGORIES OF PERFORMANCE LIMITATIONS; MAX TKOF WT; MAX TKOF WT TO ACHIEVE CLB REQUIREMENTS; MAX TKOF WT LIMITED BY MAX BRAKE ENERGY AND MAX TKOF WT FOR RWY LENGTH; WAS UNDER VFR CONDITIONS; AND ONLY THE MAX TKOF WT LIMITED BY MAX BRAKE ENERGY APPLIED. WE DID COMPLY WITH THAT CATEGORY BUT NOT WITH MAX TKOF WT TO ACHIEVE CLB REQUIREMENTS OR MAX TKOF WT FOR THE RWY AVAILABLE AND CONDITIONS. AS I HAD NO MORE AVAILABLE TIME TO RESEARCH HIS RESPONSE PRIOR TO OUR PAX ARR; I FELT COMPELLED TO GO ALONG WITH THE CAPT'S RATIONAL OF THIS SIT AND CONTINUE THE FLT. THE FLT CONTINUED WITHOUT INCIDENT. IMMEDIATELY UPON REACHING MY HOME; I RESEARCHED THE CAPT'S EXPLANATION WITH THE FAR'S AND ACFT PERFORMANCE LIMITATIONS AND DETERMINED THAT ALL 4 CATEGORIES OF PERFORMANCE LIMITATIONS ARE TO BE COMPLIED WITH REGARDLESS OF VFR OR IFR CONDITIONS OR TYPE OF FLT PLAN. ON HINDSIGHT; MY PERCEPTION IS THAT THE CAPT WAS CONFUSING THE IFR CLB GRADIENT REQUIREMENT WITH ACFT MAX TKOF WT TO ACHIEVE TKOF CLB REQUIREMENTS. MY CONCERN IS THAT OTHER CAPTS OF PART 91 HIGH PERFORMANCE JET ACFT MIGHT BE UNDER A SIMILAR MISCONCEPTION OF WHAT AND HOW TO RELY ON PERFORMANCE CHARTS. THE CAPT AND I HAVE AGREED TO CONDUCT A JOINT REVIEW OF ALL AVAILABLE INFO ON PERFORMANCE CHARTS AND TO REFINE OUR CREW COORD TO NOT ALLOW THIS NEGATIVE SIT TO OCCUR AGAIN.