THIS paper represents an attempt to illustrate the values of octane-number improvements in aviation gasolines in terms of increased earning power of current-type transport airplanes when proper provisions have been made in the original designs. The procedure consists in computing the change in earning power of a gallon of gasoline when octane-number changes are reflected in altered fuel consumptions or take-off load capacities. In general it appears that:
Depending upon operating conditions the potential revenue earning power of one gallon of gasoline may be increased from 2 to 8 cents per octane-number improvement.
If the octane-number improvement involves a decrease in energy content, the apparent improvement must be discounted by about 2 octane numbers for each reduction of 1 per cent in heat content below that of gasoline.
The economic necessity for high-octane number fuels is particularly apparent when long-range operations are involved.
It is evident that the earning power of octane-number improvements is so great that, within practical limits, cost cannot influence the trend toward higher octane numbers to any appreciable extent.