Feasibility Analysis and Fuel Burn Benefits of Relaxing Constraints in High Altitude Cruise

Operational interventions, such as enabling more fuel-efficient trajectories, are desirable in mitigating the environmental impact of air travel due to their relatively fast implementation potential. In particular, the vertical inefficiency arising from the altitude stratification in the airspace can be mitigated by relaxing vertical constraints. The feasibility of vertical flexibility is evaluated by quantifying the rate of close encounters and the frequency of alerts that would be needed to prevent them. Substantial diurnal variability in the number of close encounters was found in the airspace, with lower rates of events during the nighttime period. Furthermore, regional differences among Air Route Traffic Control Centers were observed in the number of close encounters. The frequency of controller intervention events that would have to occur was evaluated at 25 NM and 50 NM alerting distance levels, and it was found that, given sufficient technological capabilities for alerting at the 25 NM reaction distance, most centers would have fewer than 10 alerts per hour during the nighttime period. Boston, Miami, and Seattle appeared especially promising, with approximately one alert per hour for each region. Finally, the potential fuel benefit from enabling vertically optimal trajectories was estimated to be up to 100,000 gallons of fuel savings per month in the case of a CONUS-wide nighttime implementation.

Name thesis:degree_name

Master

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Aeronautics and Astronautics

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2025

Author dc:creator

• Cezairli, Mina

Advisor dc:contributor.advisor

• Hansman, R. John

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
• Copyright retained by author(s)

Licence dc:rights.uri

• https://creativecommons.org/licenses/by-nc-nd/4.0/

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/163000

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/163000