Continuous Descent Approach Procedures Research Articles

Evaluating Fuel Consumption for Continuous Descent Approach Based on QAR Data

Fuel savings are a significant aspect for evaluating the current and future technologies of civil aviation. Continuous-Descent Approach (CDA), as a representative of new concepts, requires a method for evaluating its fuel benefits. However, because of unavailability of the practical operational data, it is difficult to validate whether the previous fuel consumption mechanisms are suitable. This paper presents a unique method for quantifying potential fuel benefits. This permits an easy evaluation for the new procedures without modelling before implementing field tests. The proposed method is detailed in this paper. It derives from the inherent mechanical characteristic of aircraft engine, and utilizes historical flight data, rather than modelling, to predict fuel flow rates by matching flight conditions from Quick Access Recorder (QAR) data. The result has been shown to predict fuel consumption for conventional descent with the deviation of ±0.73%. To validate such method, a case study for our designed CDA procedure is presented. Fuel consumptions in baseline scenarios are estimated to analyse the variable impacts on fuel consumption. The estimated fuel benefits are consistent with the results in the previous field tests. This analysis helps support Air Traffic Management decisions on eventual field test by reducing the validation time and cost.

Evaluation of Fuel Benefits Depending on Continuous Descent Approach Procedures

In this work arrival traffic following a continuous descent approach profile into the Hartsfield-Jackson Atlanta International Airport was simulated based on actual recorded traffic data. The fuel burn for the simulated traffic was estimated using the Base of Aircraft Data (BADA) Thrust Specific Fuel Consumption model and compared to a baseline simulation of the as-flown trajectories, where the continuous descent approach profile was not followed. Several sources of variability that impact the fuel savings were examined, including separation minima, types of maneuver to absorb the delays, and composition of aircraft weight category in the fleet mix. The results indicate that fuel savings depended on a number of factors, including aircraft weight, number of step-downs, and the type of air traffic control maneuver used to impart delay to the aircraft. These effects are estimated using simulation.

Ecological and Operational Aspects of Continuous Descent Approach – Croatian Case

 Abstract—The impact of air traffic on total air pollution is a measurable value. This paper will present, on the Croatian example, the benefits of Continuous Descent Approach procedure in terms of reducing atmospheric emissions by reducing fuel consumption. Air traffic is accountable for 2% of global CO 2 emissions. Although that is a small percentage, due to the higher altitudes at which the emissions are released, total impact on the global warming is considered to be between 3.5% and 5%. Urgent action is required to reduce fuel burn and to make emissions savings, in order to reduce operating costs of airlines (financial aspect), and to reduce release of greenhouse gas emissions (environmental aspect). Also, it is imperative to reduce aviation noise impact on public in general. Introducing Continuous Descent Approach, as a flight operating technique in commercial aircraft operations will be a mean to achieve ecological and financial objectives. The presented results and the methodology can be used in process of operational procedures design for approach phase of the flight.

Development, Design and Flight Test Evaluation of Continuous Descent Approach Procedure in FIR Zagreb

As part of Local Conversion and Implementation Plan which is based on the EUROCONTROL Revised Convention the Republic of Croatia has undertaken to make a plan of implementing the Basic Continuous Descent Approach procedures. This paper addresses the issue of navigational path optimization for the A-319/320 commercial aircraft within the fleet of Croatia Airlines, during the approach part of flight, which has a positive effect on fuel consumption, greenhouse gas emission and area of surface affected by noise. The experiments were carried out in real conditions, using internal sensors onboard (Flight Data Recorder) and independent GPS system. Two types of approach were tested: Continuous Descent Approach (CDA) and Step Down Approach. The implementation of CDA procedures, just for the fleet of Airbus 320/319 aircraft of the Croatia Airlines results in approximate calculation in fuel saving which amounts to 1.5 x 106 kg annually (only on Zagreb airport). In this way, the productiveness of an air carrier, which is an integral part of the traffic process along with the airports and air traffic control, is directly increased, thus fulfilling the purpose of air traffic technology research. KEY WORDS: navigational procedures, continuous descent approach, air traffic, ecology

Multi-Aircraft Dynamic Continuous Descent Approach Methodology for Low-Noise and Emission Guidance

Continuous descent approaches can significantly reduce fuel burn andnoise impact by keeping arriving aircraft at their cruise altitude for longer and then having a continuous descent at near-idle thrust with no level-flight segments. The continuous descent approach procedures arefixed routes that are vertically optimized.With the changing traffic conditions and variable noise-abatement rules, the benefits of continuous descent approach are not yet fully realized. In this paper, a methodology is proposed to generate aircraft-specific dynamic continuous descent approach routes that are both laterally and vertically optimized for noise, emission, and fuel. The methodology involves discretizing the terminal airspace into concentric cylinders with artificial waypoints and uses enumeration and elimination (based on aircraft performance envelope) from one waypoint to another to identify all the possible routes. From the resulting set of possible continuous descent approach routes, routes are identified that represent the best tradeoff on the given objectives. The dynamic continuous descent approach algorithm is implemented in an air traffic simulator for the Sydney, Australia, terminal area. Dynamic continuous descent approach, as compared with a typical continuous descent approach, shows a 14.96% reduction in noise, 11.6% reduction in NO x emission, and 1.5% reduction in fuel burn. The throughput capacity of transition airspace is also investigated for multiple flights performing continuous descent approach operation for different traffic distributions. Themethodology incorporates a delay algorithm that uses the flight’s estimated time of arrival at the intermediate approach fix, which allocates a conflict-free continuous descent approach route by searching through possible routes.

Human Factors Implications of Continuous Descent Approach Procedures for Noise Abatement

Continuous Descent Approach (CDA) procedures can be effective at reducing aircraft noise in the vicinity of airports. The air traffic control human factors implications of transitioning from conventional to CDA procedures are addressed in this paper. A cognitive difference analysis revealed the impacts on intent, controllability and structure-based abstractions in the lateral, vertical and speed domains. An experiment is presented that probes the cognitive implications of changing speed profiles during the approach, which was one of the key differences between the procedures identified in the cognitive difference analysis. Based on the results, recommendations were made for CDA procedure designers to standardize deceleration profiles, design procedures to be non-interacting and to consider allocating separation authority to the pilot with a view to easing transition and controller acceptance.