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Overall Air Transport System Vehicle Scenarios

Periodic Reporting for period 1 - OASyS (Overall Air Transport System Vehicle Scenarios)

Reporting period: 2019-09-01 to 2020-11-30

The environmental impact of future advanced configurations like Urban Air Mobility (UAM) vehicles and supersonic transport (SST) aircraft is on increasing attention today. The EU-sponsored OASyS (Overall Air Transport System Vehicle Scenarios) project forecasted future scenarios for these vehicles in the 2035-2050 timeframe. These capabilities have the capacity to extend the demand estimation to quantify environmental and emissions outcomes resulting from the aforementioned operations. The outcome will be a set of scenarios that will enhance the CS2 Technology Evaluator and can be used to study the impact of UAM and supersonic vehicles across the fleet in global ATS contexts such as environmental impacts.
The SST research concluded that operations can be quantified from an added value perspective (faster than subsonic) and that size and global breadth of SST network depends very heavily on assumptions or quantification of passengers switching to SST services. A very large SST network is not expected, but the results show that demand could exist for a sizeable network under certain conditions, depending on the scenario assumptions chosen. Additionally, the SST network emissions relative to current subsonic baseline network emissions are minimal.
The SSBJ analysis concluded that the SSBJ network would be comparable to subsonic business aviation in all significant respects. Compared to supersonic commercial aviation business aviation has same order of magnitude in terms of daily flights and one order of magnitude higher in terms of number of routes served. It was also noted that when the time saving requirement is very low, the added benefit of low boom full supersonic overland flight is not significant.
The UAM work found that operations would be based on mobility patterns and framework developments influencing mobility in cities. This study concludes that strong market demand exists for a range of UAM ticket costs and vertiport densities. It is noteworthy that the cruise speed of UAM vehicle may not have significant effect on UAM demand estimates. However, it was found that infrastructure and fleet size influences waiting times, and this has a substantial impact on UAM demand estimates across the investigated scenarios.
"The work performed to develop scenarios for global forecasting capabilities from 2035 to 2050 is underlined for SST, SSBJ, and UAM as follows:

SST: A bottom-up forecast methodology is devised for the commercial supersonic forecast from 2025 to 2050. The results for the high demand scenario for the future forecast years 2035 to 2050 provide a meaningful SST network with enough yearly operation to support a sizable SST fleet. The CO2 emissions from high demand scenarios are not insignificant but they represent a small portion of global CO2 emissions. The low demand scenario represents a very small viable SST network.

SSBJ: High and low demand scenarios are considered in the study to forecast the SSBJ demand from 2025 to 2050 over a period of 5-year interval. It is interesting to compare the outcome of the supersonic business aviation forecast to the supersonic commercial forecast. In terms of the estimated number of daily flights in 2035 and 2050, the estimates are in the same order of magnitude. However, the number of routes served by SSBJs is estimated to be one order of magnitude higher than SSTs. As a result, the key characteristic of business aviation (unscheduled) movements is well-reflected.

UAM: The development of a top-down methodology to forecast the demand for UAM services from 2035 to 2050 time period for global more than 500 cities have been the focus of UAM research. The results suggest that a strong demand exists for UAM services for a set of different UAM ticket prices. The demand grows exponentially when the price drops below $3 per passenger-km, this value is, of course, a global average and can be adjusted according to the cost-of-living index for each city, country, or geographical region.

The forecasted scenarios and projected fleet information in each area of study has been provided to the the Topic Manager. This data and analysis can be used to better inform the Technology Evaluator (TE) enabling it to better predict future scenarios that include the advanced configurations investigated in this study. This work was presented at the 2020 TE Annual Review Meeting (virtual) hosted by the Topic Manager, DLR.

The results of the study were published in multiple venues including conferences and the publications listed:
""Estimating supersonic commercial aircraft market and resulting CO2 emissions using public movement data"" CEAS Aeronautical Journal, Springer, 2021
“A Methodology for Supersonic Commercial Market Estimation and Environmental Impact Evaluation (Part I)” Aerospace Europe Conference 2020 in Bordeaux, France
“A Top-Down Methodology for Global Urban Air Mobility Demand Estimation” AIAA Aviation 2020 conference (virtual)
“A Comprehensive Framework for Supersonic Commercial Market Estimation and Environmental Impact Evaluation” AIAA Aviation 2020 conference (virtual)
""Estimating Global Supersonic Business Aviation Flight Movements and Environmental Impact” AIAA SciTech 2021 Conference (virtual)
""A Scenario-Based Evaluation of Global Urban Air Mobility Demand"" AIAA SciTech 2021 Conference (virtual)"
In the commercial SST (supersonic transport) research, the OASyS team developed and implemented a bottom-up approach to estimate the market demand for commercial supersonic aviation and its resulting environmental impact. The team also developed a simplified approach for estimating CO2 (carbon dixoide) and NOx (nitrogen oxides) emission indices and the resulting global full flight CO2 and NOx emissions

In the SSBJ (supersonic business jets) forecast study, the OASyS team employed a hybrid approach i.e. a combination of top-down and bottom-up methodology to forecast the SSBJ from 2025 to 2050. The business aviation growth is forecasted for each region using historical fleet growth, Real GDP per capita growth, and Millionaire population growth. The airport level data is reported on ~82% of the market in terms of flight hours.

In the UAM (urban air mobility) forecast study, the OASyS team devised a binary choice model that considers the inherent benefits of the value of travel time saving (VTTS). To execute high and low demand scenarios several metrics related to travelers income, trip time, trip distance, trip purposes, and alternate modes of transport are investigated in detail. Annual UAM passenger trips, annual UAM PKM (passenger kilometre). annual UAM utilisation and annual UAM vehicle trips are computed from 2035 to 2050 for both high and low demand scenarios.

This work adds a new capability to the TE which can exploit the project results to enhance its future projections. This will allow Clean Sky and the TE to better envision potential scenarios while lowering uncertainty for the general public in regards to the three research areas investigated in this study. Additionally, the CO2 emissions studied in the SST research will help Clean Sky and the TE to better understand the quantified emissions associated with a commercial supersonic network, allowing for enhanced planning on mitigating the potential environmental impact.
OASyS Team at Aerospace Europe Conference 2020