Assessment of Aircraft Contrails Avoidance Strategies

Some contrail avoidance options are critically analyzed. These options include the use of altitude flexibility and go-around. It is demonstrated that long-range commercial airplanes powered by high bypass turbofan engines have a vertical flexibility of up to 3,000 ft (30 flight levels) for a fuel penalty of 1%. This penalty can be recovered by adjusting the cruise Mach number. However, there are technical difficulties in implementing this option, due to air traffic constraints and safety issues. Avoidance proposals that involve a go-around are impractical, not least for the extension of the flight time, which bears additional operating costs. A sensitivity analysis is shown to indicate that single-event forecasts may be imprecise and that contrail events cannot be costed by precise methods. The paper concludes with the statement that long-term contrail effects (years or decades) obtained by single-flight procedure changes (if allowed at all) cannot be reliably predicted. Simple prediction methods cannot be used for long-term forecasting. Read More: http://arc.aiaa.org/doi/10.2514/1.C033176