How Slow is Too Slow? Economics of Aircraft Concepts with Reduced Cruise Speeds

摘要

Future aircraft concepts being studied typically offer significant reductions in fuel burn relative to current types, but some do so at the expense of cruise speed. Because of cost and revenue considerations, airlines may find that these aircraft are more costly or less profitable than faster, higher-fuel burn technologies, particularly over longer stage lengths. We model some of the cost and revenue implications of changes in cruise speed, and identify the stage-lengths over which slower, low-fuel burn technology may be more cost-effective and profitable than faster technology. After validating our approach by comparing regional jets and turboprops, two hypothetical future concepts are compared: the TOSCA Reduced Speed Open Rotor, which has low fuel burn, but at reduced cruise speeds; and the TOSCA Fast Open Rotor, which has lower fuel burn than existing aircraft, without reducing cruise speed, but higher fuel burn than the TOSCA Reduced Speed Open Rotor. Our results suggest that the direct operating costs of the slower concept are higher and likely operating profits lower than for the faster concept, over all stage lengths simulated. We conclude that for a market to exist for a reduced speed concept, a combination of relatively high fuel burn reductions and/or low speed reductions would be required relative to a similar technology that does not reduce cruise speed.