CS - A Couple of posts back you mention 'transport category aircraft'. Now I don't have all the details but I believe a long time ago the old DCA had a 'transport' category that covered AC with an MTOW >3500 kg engaged in RPT operations. There are not many Light twins over 3500 kg but the C404 is one of them(3810). From memory aircraft in this catergory had to have a 1.9% net (remembering flight manual figures are gross) single engine climb gradient under ambient conditions when engaged in RPT operations. Thus they often had a much reduced TOW with high ambient temps.
A company I have previously worked for at one stage conducted RPT ops (before my time) and had produced a bunch of data cards for the ports that were serviced by 404 RPT. In addition these data cards took into account the recuded runway lengths required to provide a 1.9% clear TO gradient as detailed in the ERSA runway supp. This could often reduce the TOW by several hundred kg to ensure the 1.9% (on paper anyway). Now I know all this kind of thing is predicated on accurate and lighning fast reactions by the pilot, operating engine producing full power etc.
in the event of an EFATO but I think all other things being equal these reduced weights provided a reasonable level of single engine performance given the net fudge factor. Alas I don't think this category applies anymore - is there anyone that knows otherwise or has better info on this 'transport' category. All this from memory so I could well have some details incorrect.
ps Full fuel on the 404 was around 1276 litres useable but I can't imagine why they would fill up the tanks to go 15 minutes to RTI