N116CD (S/N 1017) weighs 2085 lbs (“C” package, 3-bld, & leather) for a “useful” load 815 lbs.
While there is some flexibility to trade fuel for load, load without fuel is not useful.
Full fuel leaves 479 lbs and minimum VFR fuel reserves plus two hours leaves 660lbs.
One could argue that the pilot while useful is as required as fuel reserves. At a standard 170 lbs that lowers the above numbers to 309 and 490.
These are the numbers that I think should be used to evaluate aircraft.
Evaluation of an aircraft like the SR20 for purchase may be 20% analysis and 80% rationalization, but here’s how I see the useful load.
The price for an SR20 equipped like mine varies from $191,715 to $228,400 depending on when you put your money down (granting $1000 value for avionics upgrades in latest prices).
Using the “useful” load number of 479 lbs and $191,715 this comes to $401 per pound. Using 660 lbs it is $290 per pound.
These numbers can be mashed ad nauseam by changing options, including taxes and/or radio license cost, using a speed value factor, etc, but each pound is worth at least $200 and a $300 figure is probably the most “useful” figure.
Beyond the purchase decision here’s how this number is still “useful”.
At $300/lb it is worth $19,500 to get down to that standard weight of 170 lbs.
The new Sky-Tec starter at 5.8 lbs saves 9.2 lbs for about $430 plus installation - $2760 worth of load for less than $500 and an improved center of gravity.
For Cirrus Design two to three years in the future I see a carbon fiber SR__ with a 200 to 300 hp turbo diesel having a useful load of 1200 to 1400 lbs and cruise speed at 200 to 240 knots.
A news item in this week’s Aviation Week magazine said that a new pilot plant to produce low-cost carbon fibers is in production and estimates a “long-term cost” at a fraction of current costs - less than $3 per lb.