Optimization of Aircraft Sequencing in Terminal Airspace

Research Problem

The terminal airspace surrounding airports is one of the most complex and congested parts of the air transportation system. Aircraft arriving and departing must follow structured procedures known as Standard Arrival Routes (STARs) and Standard Instrument Departures (SIDs).

Air traffic controllers must carefully sequence aircraft while maintaining safety separation and managing operational constraints. Inefficient sequencing can lead to increased fuel consumption, delays, airborne holding, and reduced runway throughput.

With increasing air traffic demand, more advanced decision-support tools are needed to optimize aircraft sequencing in terminal airspace operations.

Contributions

Our research develops fast optimization algorithms capable of determining optimal aircraft sequences and schedules in terminal airspace operations.

Key contributions include:

• Optimization models that determine the optimal timing at each waypoint
• Algorithms that account for operational interventions such as speed control, holding patterns, vectoring, and point-merge procedures
• Integrated trajectory generation methods that ensure feasible flight paths
• Rapid-evaluation tools for testing alternative terminal airspace configurations

These approaches help reduce delays and fuel consumption while improving runway throughput.

Selected Publications

• An Optimization Approach for the Terminal Airspace Scheduling Problem
  Ng, W., Ribeiro, N. A., & Jorge, D. (2024). Transportation Research Part C: Emerging Technologies. :contentReference[oaicite:0]{index=0}
• Terminal Maneuvering Area Design Tool: Translational Research in Aviation
  Jackson, P., & Ribeiro, N. A. (2024). Proceedings of the Asia Pacific Conference on Industrial Engineering and Operations Management. :contentReference[oaicite:1]{index=1}
• A Modeling Framework for Rapid Assessment of Terminal Airspace Configurations and Planning Scenarios
  Ng, W., Ribeiro, N. A., & Jorge, D. (2022). International Conference on Research in Air Transportation (ICRAT).

Research Funding

• National Research Foundation Singapore
  Optimising Terminal Airspace Operations under Varying TBO Scenarios
  Total Award: SGD 1,373,438

• Civil Aviation Authority of Singapore
  Airfield and Airspace Management
  Total Award: SGD 720,000

• National Research Foundation Singapore
  Resilient Airspace Operations for Singapore
  Total Award: SGD 398,722

Awards

• Best Paper Award — AAAI Workshop on AI for Air Transportation (AI4AT) (2026)
• Best Paper Award — INFORMS Air Transportation Section (2025)
• Anna Valicek Silver Medal (AGIFORS) — Wayne Ng (2025)
• Best Student Presentation — INFORMS Aviation (2023)