Electric Taxiing with Disruption Management: Assignment of Electric Towing Vehicles to Aircraft

Reducing aircraft taxiing emissions will deliver a significant contribution to the worldwide goal of net-zero greenhouse gas emissions in the aviation industry. Replacing jet-engine taxiing by towing aircraft with electric towing vehicles is expected to reduce taxiing emissions by roughly 80%. Introducing a fleet of towing vehicles introduces...

Predictive Maintenance Planning Using Renewal Reward Processes and Probabilistic RUL Prognostics: Analyzing the Influence of Accuracy and Sharpness of Prognostics

We pose the maintenance planning for systems using probabilistic Remaining Useful Life (RUL) prognostics as a renewal reward process. Data-driven probabilistic RUL prognostics are obtained using a Convolutional Neural Network with Monte Carlo dropout. The maintenance planning model is illustrated for aircraft turbofan engines. The results show...

Constructing Health Indicators for Systems with Few Failure Instances Using Unsupervised Learning

Health indicators are crucial to assess the health of complex systems. In recent years, several studies have developed data-driven health indicators using supervised learning methods. However, due to preventive maintenance, there are often not enough failure instances to train a supervised learning model, i.e., the data is unlabelled with an...

Designing reliable, data-driven maintenance for aircraft systems with applications to the aircraft landing gear brakes

When designing the maintenance of multi-component aircraft systems, we consider parameters such as safety margins (used when component replacements are scheduled), and reliability thresholds (used to define data-driven Remaining-Useful-Life prognostics of components). We propose Gaussian process learning and novel adaptive sampling techniques to...

Remaining-Useful-Life prognostics for opportunistic grouping of maintenance of landing gear brakes for a fleet of aircraft

Several studies have proposed Remaining-Useful-Life (RUL) prognostics for aircraft components in the last years. However, few studies focus on integrating these RUL prognostics into maintenance planning frameworks. This paper proposes an optimization model for opportunistic maintenance scheduling of aircraft components that integrates RUL...

Novel metrics to evaluate probabilistic remaining useful life prognostics with applications to turbofan engines

Well-established metrics such as the Root Mean Square Error or the Mean Absolute Error are not suitable to evaluate estimated distributions of the Remaining Useful Life (i.e., probabilistic prognostics). We therefore propose novel metrics to evaluate the quality of probabilistic Remaining Useful Life prognostics. We estimate the distribution of...

Analyzing the impact of battery capacity and charging protocols on the dispatchment of electric towing vehicles at a large airport

The aviation industry aims for net-zero emissions by 2050. In this line, achieving climate-neutral ground operations is one of the first objectives. Electric vehicles that tow aircraft during taxiing are a promising technology to achieve climate-neutral ground operations. In this paper, we consider the dispatching of electric towing vehicles at...

Model-based Remaining-Useful-Life prognostics for aircraft cooling units

Prognostics for the Remaining-Useful-Life (RUL) of aircraft components are crucial to support efficient aircraft maintenance planning and, in particular, to limit unscheduled maintenance due to unexpected component failures. As such, predictive methods for the RUL of aircraft components are increasingly a priority for aircraft Maintenance,...

Multi-objective Analysis of Condition-based Aircraft Maintenance Strategies using Discrete Event Simulation

As aircraft maintenance is transitioning towards data- driven condition-based maintenance (CBM), its cost and performance objectives need to be re-evaluated: how are these objectives related under various CBM strategies?; which objectives are conflicting?; what are the trade-offs between the conflicting objectives?; what is the impact of this...

Criticality-based Predictive Maintenance Scheduling for Aircraft Components with a Limited Stock of Spare Components

We propose a criticality-based scheduling model for aircraft component replacements.We schedule maintenance for a fleet of aircraft, each equipped with a multi-component system. The maintenance schedule takes into account a limited stock of spare components and the Remaining-Useful-Life prognostics for the components. We propose a component...

Considering Airport Planners’ Preferences and Imbalanced Datasets when Predicting Flight Delays and Cancellations

A key part of efficient airport operational planning is to have insight into potential flight delays and cancellations. For airport planners, it is important to obtain flight delay or cancellation predictions with a high degree of certainty, i.e. a high precision. This allows planners to make sound decisions based on these predictions. To obtain...

Predictive Aircraft Maintenance: Modeling and Analysis Using Stochastic Petri Nets

Predictive aircraft maintenance is a complex process, which requires the modeling of the stochastic degradation of aircraft systems, as well as the dynamic interactions between the stakeholders involved. In this paper, we show that the stochastically and dynamically colored Petri nets (SDCPNs) are able to formalize the predictive aircraft...

A review of current technology and research in urban on-demand air mobility applications

The purpose of this report is to summarize the current technology and challenges facing the market for electric vertical takeoff and landing (eVTOL) aircraft for urban on-demand air mobility applications. This report has two parts. The first part reviews existing electric drones for on-demand air mobility services for human transportation and...

Noise analysis of aircraft departure procedures using MONTE CARLO simulation

During arrival and departure procedures at an airport, aircraft generate noise. High levels of noise during these terminal procedures can have a negative impact on the communities located near the airport. We assess the impact of the noise generated by a standard instrument departure of a twin-engine narrow body mid-range aircraft over the...

eVTOL Arrival Sequencing and Scheduling for On-Demand Urban Air Mobility

Urban Air Mobility (UAM) has the ability to reduce ground traffic congestion by enabling rapid on-demand flight through three-dimensional airspace with zero operational emissions by using electric Vertical Take-Off and Landing (eVTOL)<br/>vehicles. In the long term with more UAM flights, air traffic control is expected to limit further growth of...

Dynamic Airline Booking Forecasting

This paper proposes a model for dynamic booking forecasting using a time-inhomogeneous Markov process. The transition probabilities are estimated based on a combination of an empirical and a parametric distribution. This model is applied for flight booking forecasting, where flight forecasts are updated on a daily basis over a time horizon of up...