Maximum Takeoff Mass versus Fuel Load
Figure 4.7 shows the relationship between fuel load, Mf, and the MTOM for twenty turbofan aircraft; this graph provides the fuel fraction, Mf/MTOM. It may be
examined in conjunction with Figures 4.4, 4.5, and 4.6, which show the range increase with the MTOM increase.
Fuel mass increases with aircraft size, reflecting today’s market demand for longer ranges. The long-range aircraft fuel load, including reserves, is less than half the MTOM. For the same passenger capacity, there is statistical dispersion at the low end. This indicates that for aircraft with a wider selection of comfort levels and choice of aerodynamic devices, the fuel content is determined by the varied market demand: from short ranges of around 1,400 nm to cross-country ranges of around 2,500 nm. At the higher end, the selection narrows, showing a linear trend. Figure
4.3 indicates that larger aircraft have better structural efficiency, offering a better OEMF; Figure 4.7 indicates that they also have a higher fuel fraction for longer ranges.