Clark R. Lunsford

Potential benefits of a Paired Approach procedure to closely spaced parallel runways in instrument and marginal visual conditions

This paper discusses a concept called ldquopaired approachesrdquo which is designed to facilitate approaches to closely spaced parallel runways (CSPRs) - i.e., runways separated by 700 ft to 2500 ft, in instrument meteorological conditions (IMC). Such runway pairs experience a significant loss of arrival capacity during IMC and marginal visual conditions because currently, runway pairs like this can only be used for simultaneous arrivals when pilots can provide visual separation. The basic procedure design, operations concept, the required cockpit tools and initial feasibility of the paired approach concept were developed in the 1990psilas and included real time pilot and controller simulations and evaluations. These initial simulations indicated that the paired approach procedure was feasible for both pilots and controllers. This paper focuses on the potential benefits of the procedure. It first provides a brief review of the procedure and prior work. It discusses the variety of procedures currently available for parallel runways, and discusses the magnitude of the delay problem in the National Airspace System (NAS) not addressed by any of these existing procedures or procedures under development, but which the proposed paired approach procedure would address. It presents the potential capacity gain from the paired approach procedure at two representative major airports, and the percentage of time that the procedure could be available. The paper also presents a brief summary of potential infrastructure requirements for implementing the procedure, and concludes by providing an outline of the research and development needed to establish its deployment in the NAS.

Increasing airport arrival capacity in NextGen with wake turbulence avoidance

Arrival capacity at major airports is a primary constraint that must be overcome to reach the Next Generation Air Transportation System (NextGen) capacity goals. At the nations busiest airports with closely spaced parallel runways for arrivals, capacity can be reduced significantly when weather at these airports falls below visual approach minima. When visual approaches can be used for arriving aircraft, pilots can apply their experience and judgment to position their aircraft to avoid wake turbulence generated by other aircraft they are following to the airport. This practice allows for the best arrival capacity to be achieved in good weather. When ceiling and visibility fall below that required for visual approaches, airports that would normally arrive on two parallel runways spaced less than 2500 feet (ft) apart, must discontinue parallel approaches, thus reducing the arrival rate to what can be achieved with a single runway. This reduction in capacity is due to the air traffic control (ATC) requirement that parallel runways spaced this closely must be treated as one runway for application of wake turbulence separation.

Some New Potential ASAS Applications in the Terminal and En Route Domains

This paper documents new Airborne Separation Assistance System (ASAS) applications for consideration by the ASAS community for further analysis and development. It identifies several potential applications of the information displayed on a cockpit display of traffic information (CDTI) which may substitute for direct visual contact with a particular airplane of interest. CDTI assisted “visual” separation (CAVS) may provide operational efficiency in the terminal area under instrument meteorological conditions (IMC) that could approach that of pure visual operations in visual meteorological conditions (VMC). If proved feasible IMC CAVS applications would provide significant capacity benefits in the terminal domain. Several CAVS applications are presented, including CDTI based spacing during instrument approaches (IMC CAVS) to single and parallel runways and departure spacing during high demand departure operations (Departure CAVS). The document describes the problems associated with holding patterns in the National Airspace System (NAS) and postulates an evolutionary ASAS application of ADS-B based spacing and separation for reducing ATC workload during holding and improving the spacing accuracy out of holding patterns. The paper also includes description of an application of merging and spacing for departures. The proposed applications include a need statement citing examples from current NAS operations, and conclude with a brief application description. It is recommended that these proposals be analyzed in greater detail to determine their NAS-wide benefits and feasibility.

Enabling aircraft-based observation of winds in the U.S. and Europe: Progress and benefits

It has been known for decades that aircraft, with appropriate provisioning, have the capability to measure and report meteorological data at a high resolution, under all weather conditions, and over areas of operational interest to a wide audience within the aviation community. Significant progress has been made in collaborative standards definition that will enable these data to be downlinked to ATM ground automation and increase NextGen and SESAR efficiencies. This paper reviews this progress and its ramifications. It examines possible coverage in time/space, illustrating how rich a source of information this avenue can provide. A sample NextGen wake turbulence mitigation application is discussed, along with analysis of its wind requirements and beneficial impact of access to near real-time aloft wind observations. Findings show the potential for a substantial increase in procedure availability at a challenging site when aircraft-based observations are available.

Wake turbulence avoidance automation: Evaluation of feasibility and impact

Wake turbulence encounters are a significant concern to pilots flying in the National Airspace System (NAS). The MITRE Corporations Center for Advanced Aviation System Development (CAASD) has worked with the Federal Aviation Administration (FAA) to increase efficiency and capacity in the NAS that will come with the FAAs Next Generation Air Transportation System (NextGen). By increasing efficiency and capacity, there will be a corresponding reduction in required separations that exist in operations today. As operations are optimized and these separations are reduced, it is important that there is not an increase in wake encounter rates that would tend to limit the acceptance of NextGen. NextGen technology, however, may enable the community to provide better tools to pilots and controllers for avoiding wake, thereby bounding the wake encounter rate at no more than todays operationally acceptable level. In this paper, arrival and departure procedures that take advantage of Automatic Dependent Surveillance-Broadcast (ADS-B) and Cockpit Display of Traffic Information (CDTI) technology in the cockpit are reviewed and their performance during a human-in-the-loop evaluation discussed.

Development of Approach and Departure Aircraft Speed Profiles

Information on the suggested aircraft airspeeds can be obtained from flight manuals, but the actual airspeeds flown by an aircraft will vary based on the aircraft landing weight, airport altitude, wind conditions, and other Air-Traffic-Control related factors. The recent advent of new tools and an abundance of new, highly accurate aircraft surveillance data have enabled a reevaluation of past airspeed profile assumptions. The resulting analysis provides a stronger representation for airspeeds flown on final approach and initial departure by the aircraft types comprising a large percentage of U.S. Instrument Flight Rules operations. Furthermore, the time to fly is calculated to determine how long it takes the trailer aircraft to fly the distance to the point where the leader generates a particular portion of the wake. Although this work is performed to provide improved inputs for Recategorization Phase II analyses, the airspeed profiles derived from aircraft surveillance data will also be valuable to other...

Feasibility and availability of pairing departures from closely spaced parallel runways for wake avoidance

Air traffic is expected to increase more than 70 percent by the year 2025. A major challenge for supporting this type of growth is the arrival and departure capacity at major airports. There are many initiatives being developed to address the arrival capacity issue at these airports, but very few are designed to enable a corresponding increase in the departure capacity. As a part of The MITRE Corporations Center for Advanced Aviation System Development (CAASD) research program, a concept that could increase the departure capacity at 14 of the 35 busiest U.S. airports is being investigated.

Exploration of key operational issues for the midterm NAS

The FAAs Flight 2000 project is an innovative initiative to implement and validate selected operational improvements leading to Free Flight. It integrates new avionics, new ground systems, new procedures, avionics certification, and operational approval. This paper discusses some key operational issues that need to be resolved in developing new capabilities for the National Airspace System (NAS) to ensure that they will result in improved NAS operations. Three experiments are described that are proposed for Flight 2000 to explore the feasibility and utility of planned operational improvements. The implications for the NAS architecture and the expected impact on NAS operations are also discussed.