Closely-spaced Parallel Runways Research Articles

Study of Paired Approach Wake Separation Based on Crosswinds

The effect of crosswinds on paired approach (PA) procedures for Closely Spaced Parallel Runways (CSPR) is investigated in this paper by fully utilizing the crosswind environment to implement a more efficient PA and increase runway capacity. An improved wake dissipation model is used to quickly predict the change in the wake velocity field for the PA procedures. The change in the width of the hazard zone is explored in detail using the roll moment coefficient as a determination index. The calculation method for the hazard zone of a wake encounter in a PA is designed considering the influence of crosswind, turbulence, and ground effect. The results show the diffusion rate of the hazard zone and a decrease in the width of the maximum hazard zone under a breezeless environment with increases in the turbulence intensity. The maximum hazard zone width decreases with an increase in crosswind speed. Favorable crosswinds can reduce wake separation and improve the efficiency of a PA. Lower turbulence intensity has a better crosswind effect under a normal PA. The 3-degree offset PA can accommodate larger unfavorable crosswinds, with a higher turbulence intensity having a better crosswind effect. The 3-degree offset PA can substantially increase the proportion of time when no wake affects the PA procedure.

Modeling and Simulation of Wake Safety Interval for Paired Approach Based on CFD

In order to relieve the stress caused by the surge of flight flow, Closely Spaced Parallel Runways (CSPRs) have been built in many hub airports, and a paired approach mode has been applied to CSPRs in some countries. This paper proposes a method for optimizing the wake separation between aircrafts which utilizes a paired approach, aiming at reducing longitudinal separation by using computational fluid dynamics technology. Firstly, the model of the wake vortex field of the paired lead aircraft is constructed. Secondly, the numerical simulation preparation for the characteristics of the wake vortex field is completed through the computational pretreatment of the model. Thirdly, a calculation model of wake safety interval based on paired approach operation is established. Finally, the proposed method shows its superiority comparing with other methods. This method realized visual analysis of wake vortex through optimization modeling based on computational fluid dynamics, contributing to increasing the capacity of the runway and improving the operation efficiency of an aerodrome.

Analysing and modelling some effects of solutions for matching the airport runway system capacity to demand

The paper deals with analysing and modelling some effects of three solutions for matching the airport runway system (landing) capacity to corresponding demand. These are: i) charging congestion applied to the NY LaGuardia airport (New York, USA); ii) deployment of the innovative operational procedures supported by the new technologies developing in the scope of European SESAR (Single European Sky ATM Research) and U.S. NextGen (Next Generation) program applied to the system of two closely-spaced parallel runways at Dubai International airport (Dubai, UAE (United Arab Emirates)); and iii) building the new additional runway(s) applied to the runway system of three London airports - Heathrow, Gatwick, and Stansted (London, UK).The results have shown that each of the considered solutions can contribute to more efficient and effective matching of the airport runway (landing) capacity to the current and expected (prospectively growing) airside demand under given (specified) conditions.

The Wake Vortex Prediction and Monitoring System WSVBS Part I: Design

The design of the Wake Vortex Prediction and Monitoring System WSVBS is described with all its components and their interaction. The WSVBS was developed to tactically increase airport capacity for approach and landing on closely-spaced parallel runways. The WSVBS supports dynamic adjustment of aircraft wake vortex separations dependent on weather conditions and the resulting wake vortex behavior without compromising safety. Dedicated meteorological instrumentation and short-term numerical terminal weather prediction provide the input to the prediction of wake-vortex behavior and respective safety areas. The prediction tools employ a number of conservative aircraft parameter combinations that represent the medium and heavy aircraft weight categories. Safe aircraft separations correspond to times when the predicted safety areas associated with wake vortices generated by leading heavy aircraft cannot overlap the arrival flight corridor. A LIDAR monitors the correctness of WSVBS predictions in the most critical regions at low altitude.

Modelling the capacity of closely-spaced parallel runways using innovative approach procedures

This paper develops analytical models for calculating the ultimate arrival, departure, and mixed operation capacity of closely-spaced parallel runways. Each capacity is defined as the maximum number of corresponding aircraft operations accommodated during a given period of time (usually one or a quarter of an hour) under constant (i.e. sustained) demand for service. As combined, they enable the capacity coverage curve to be synthesized. In particular, the capacity model for arrivals assumes the use of two rather innovative approach procedures – the Staggered Approach Procedure (SGAP) and the Steeper Approach Procedure (SEAP) in combination with the baseline Conventional Approach Procedure (CNAP) under Instrument Meteorological Conditions (IMC) and Instrumental Flight Rules (IFR). The model for arrival capacity that aims to estimate potential of these procedures uses main inputs such as: the geometry of given parallel runways and innovative SGAP and SEAP, and baseline CNAP; the Air Traffic Control (ATC) minimum separation rules; aircraft fleet mix characterized by the wake-vortex categories; capability of using different ILS Glide (GS) angles; final approach speeds; and the arrival runway occupancy time. In addition, the model for departure capacity uses inputs that embrace: the ATC separation rules between successive departures; aircraft fleet mix; and corresponding runway occupancy times. Finally, the model for mixed operation capacity uses inputs such as: the ATC arrival–departure separation rules; corresponding runway occupancy times; aircraft fleet mix for each type of operations; and proportion of the arrival and departure demand. The models are applied to calculating the ultimate capacity of closely-spaced parallel runways at two large airports, one in Europe and other in the US, assuming safe use of innovative SGAP and SEAP in combination with CNAP under IMC. The output from the models consists of the corresponding capacities and their variations depending on particular inputs.

Vortex-Free Flight Corridors for Aircraft Executing Compressed Landing Operations

A factor that limits airport arrival and departure rates is the need to wait between operations for the wake vortices of preceding aircraft to decay to a safe level. As airport traffic demand increases, creative methods will be needed to overcome the limitations caused by the hazard posed by vortex wakes so that airport capacities can be increased. The problem addressed here is the design of vortex-free trajectories for aircraft as they fly from their cruise altitudes down to their final approach paths and to a landing. The guidelines presented recommend that the flight path of each aircraft in a group executing nearly-simultaneous landings be spaced far enough apart laterally along organized flight paths so that the vortex wakes of preceding aircraft will not intrude into the airspace to be used by following aircraft. An example is presented as to how a combination of straight lines and circular arcs is able to provide each aircraft in a group with a vortex-free trajectory so that all are able to safely form the pattern needed for nearly simultaneous landings on a set of closely-spaced parallel runways. Although the guidelines me described for aircraft on approach, they are also applicable to departure, and to en route operations.

A Phased Approach to Increase Airport Capacity through Safe Reduction of Existing Wake Turbulence Constraints

Previous wake turbulence research has suggested that using knowledge of wake turbulence behavior to develop candidate arrival and departure procedures would increase capacity at a variety of United States airports. This paper outlines the operational issues involved as well as the process through which the Federal Aviation Administration (FAA) and The MITRE Corporation’s Center for Advanced Aviation System Development (MITRE/CAASD) analyzed an evolving set of candidate procedures. This work is part of the broader effort to implement an FAA/National Aeronautics and Space Administration (NASA) Wake Turbulence Research Management Plan (RMP).We describe in detail two candidate procedures, their operational variations and the expected capacity benefits at selected airports. The first procedure is a near-term proposed change to the 2500 foot runway centerline separation minimum for dependent approaches to two Closely Spaced Parallel Runways (CSPR). When visual separation can not be provided, the current FAA rule requires parallel runways spaced less than 2500 ft to be treated as a single runway. While in-trail wake separation standards are dependent on wake categories of the generating and encountering aircraft, this rule is not. This paper shows that, by refining this standard to reflect the wake generation differences of different weight classes, substantial capacity benefits may be possible. Variations on this procedure are analyzed to explore the sensitivity of the capacity benefits to the underlying assumptions.The second procedure is a mid-term proposed change to reduce wake constraints for departures from parallel runways spaced closer than 2500 ft using a short-term prognosis of crosswinds at and near the area of aircraft rotation. A brief outline is provided of activities planned during 2004 to advance towards the specific design and implementation of these procedures. Once such activity is additional wake data collection at St. Louis (STL).