Mixing 4D-Equipped and Unequipped Aircraft in the Terminal Area

On-board 4D guidance systems, which predict and control the touchdown time of an aircraft to an accuracy of a few seconds throughout the descent, were developed and demonstrated in several flight test programs. However, in addition to refinements of the on board system, two important issues still need to be considered. First, in order to make effective use of these on-board systems, it is necessary to understand and develop the interactions of the airborne and air traffic control (ATC) system in the proposed advanced environment. Unless the total system is understood, the advanced on-board system may prove unusable from an ATC standpoint. Second, in planning for a future system in which all aircraft are 4D equipped, it is necessary to confront the transition situation in which some percentage of traffic must still be handled by conventional means. In terms of 4D, this means that some traffic must still be given radar vectors and speed clearances (that is, be spaced by conventional distance separation techniques), while the 4D-equipped aircraft need to be issued time assignments. These apparent differences are reconciled and efficient ATC operation is developed

Market-Based Alternatives for Managing Congestion at New York’s LaGuardia Airport

We summarize the results of a project that was motivated by the expiration of the “High Density Rule,” which defined the slot controls employed at New York’s LaGuardia Airport for more than 30 years. The scope of the project included the analysis of several administrative measures, congestion pricing options and slot auctions. The research output includes a congestion pricing procedure and also the specification of a slot auction mechanism. The research results are based in part on two strategic simulations. These were multi-day events that included the participation of airport operators, most notably the Port Authority of New York and New Jersey, FAA and DOT executives, airline representatives and other members of the air transportation community. The first simulation placed participants in a stressful, high congestion future scenario and then allowed participants to react and problem solve under various administrative measures and congestion pricing options. The second simulation was a mock slot auction in which participants bid on LGA arrival and departure slots for fictitious airlines.Auctions, airport slot auctions, combinatorial auctions

Computers in aeronautics and space research at the Lewis Research Center

This brochure presents a general discussion of the role of computers in aerospace research at NASA's Lewis Research Center (LeRC). Four particular areas of computer applications are addressed: computer modeling and simulation, computer assisted engineering, data acquisition and analysis, and computer controlled testing

A Scalable Low-Cost-UAV Traffic Network (uNet)

This article proposes a new Unmanned Aerial Vehicle (UAV) operation paradigm to enable a large number of relatively low-cost UAVs to fly beyond-line-of-sight without costly sensing and communication systems or substantial human intervention in individual UAV control. Under current free-flight-like paradigm, wherein a UAV can travel along any route as long as it avoids restricted airspace and altitudes. However, this requires expensive on-board sensing and communication as well as substantial human effort in order to ensure avoidance of obstacles and collisions. The increased cost serves as an impediment to the emergence and development of broader UAV applications. The main contribution of this work is to propose the use of pre-established route network for UAV traffic management, which allows: (i) pre- mapping of obstacles along the route network to reduce the onboard sensing requirements and the associated costs for avoiding such obstacles; and (ii) use of well-developed routing algorithms to select UAV schedules that avoid conflicts. Available GPS-based navigation can be used to fly the UAV along the selected route and time schedule with relatively low added cost, which therefore, reduces the barrier to entry into new UAV-applications market. Finally, this article proposes a new decoupling scheme for conflict-free transitions between edges of the route network at each node of the route network to reduce potential conflicts between UAVs and ensuing delays. A simulation example is used to illustrate the proposed uNet approach.Comment: To be submitted to journal, 21 pages, 9 figure

The Developmental Test Scheduling Problem

Developmental testing of aircraft systems in the United States Air Force requires a complex set of resources for each test. The optimal scheduling of those resources is the job of the 412th Test Wing at Edwards Air Force Base. With more than 20 different Combined Task Forces requesting resources for roughly 300 flying missions each week, manual scheduling is a difficult task. The current process takes a team of schedulers several days to get a workable result from which they can start tailoring the final schedule. While concepts and techniques can be taken from industry scheduling problems, the body of knowledge as it relates to developmental test scheduling is sparse. The contribution of this paper is to initially document the Developmental Test Scheduling Problem, define it in structured terms for which a solution methodology can be designed, and present an Integer Programming based solution. The design allows for a scheduler to tailor an initial answer to fit nuanced and timely objectives and constraints. For this prototype effort the problem is scoped to the Iron Resources while bearing in mind the extensibility of the approach to Range Resources. This study and prototype will demonstrate results that will create an initial schedule in several hours and serve as a good starting point for the final schedule

Assessing the effect of proactive maintenance scheduling on maintenance costs and airline profitability: The case of Turkish Airlines Technic

This study mainly aims to examine the perception of Turkish Airlines Technic staff about the effect of proactive maintenance scheduling (PMS) on maintenance costs (MCs) and airline profitability(AP). Another purpose of the study is to reveal if perception of the staff changes according to demographic features and experience of the staff. As far as it is known, there is no direct study addressing the effects of PMS on MCs and airline profitability. The study is considered to be a first in this context. In the study, Turkish Airlines-THY was chosen as the company that was handled. The fact that the company has a separate special maintenance&repair group (Turkish Airlines Technic-THYT) was effective in the selection of this company. Some additional qualifications (very rooted, with corporate governance, Turkey's top largest&full service carrier, member of IATA and Star Alliance, and a listed company (in BIST) were also among other factors affecting the selection. Methodologically, it was used a quantitative survey with a sample of 133 THYT staff. Staff has been chosen among departments that takes place actively/directly in maintenance. Besides questions that aim to measure the perception of THYT staff on the effects of PMS to MCs and AP, some demographic and experience related questions were asked in order to find out if perception of the staff changes according to their qualifications. The data were collected by online survey method and analyzed with SPSS version 22. Necessary tests together with Chi-square and Fisher’s tests were carried out to analyze the results. It was concluded that there is a strong correlation between PMS and the MCs. The study proved that PMS has a great decreasing effect on MCs and a great increasing effect on AP. The study also revealed that THYT personnel is like-minded that PMS reduces MCs and increases AP as well

Space benefits: The secondary application of aerospace technology in other sectors of the economy

Benefit cases of aerospace technology utilization are presented for manufacturing, transportation, utilities, and health. General, organization, geographic, and field center indexes are included

Perceptive analysis of the effect of proactive maintenance scheduling on maintenance costs and airline profitability: A case study of Turkish Airlines Technic case

The accelerated development trend that the industry is going through has created an intensively competitive environment between global airlines. Intense competition in the sector and the pronounced decline in profit rates have increased the importance of reducing expenses and costs, in addition to the management of incomes. Towards this aim, airlines implement various methods to reduce their own costs. Maintenance comprises one of the significant expenses incurred by airlines, while airlines adopt various approaches in their cost-reduction efforts, including general maintenance enhancement programs. It has been seen that some of these methods positively affect cost-reduction efforts that have begun to be implemented. Proactive maintenance planning, on the other hand, is considered one of the methods aimed at reducing maintenance costs and thus increasing airline profitability and is actively used by many airlines…Havacılık sektörünün içerisinden geçtiği yüksek ivmeli gelişim trendi, havayolları arasında yoğun bir rekabet ortamı oluşmasına sebep olmuştur. Sektörde gözlenen yoğun rekabet ve kar oranlarındaki büyük düşüşler asli gelirlere ilaveten gider ve maliyetlerin de düşürülmesinin önemini artırmıştır. Bu bağlamda tüm havayolları, kendi maliyetlerini düşürmek için çok çeşitli yöntemler denemekte ve uygulamaktadır. Bakım maliyetleri toplam maliyetlerin içerisinde önemli yere sahip maliyet kalemlerinden bir tanesidir. Diğer tüm maliyetler gibi bakım maliyetlerini düşürmek için de çeşitli yöntemler denenmektedir. Bu yöntemlerden bazılarının maliyetleri olumlu yönde etkilediği görülmüş ve uygulanmaya başlamıştır. Proaktif bakım planlaması bakım maliyetlerini düşürmeyi ve havayolu karlılığını artırmayı amaçlayan yöntemlerden bir tanesidir ve birçok havayolu tarafından aktif olarak kullanılmaktadır

Green airport operations: Conflict and collision free taxiing using electric powered towing alternatives

Abstract Everyday millions of liters of jet fuel are burnt while airplanes are¬ running on the ground and releasing tons of air polluting gases in the earth's atmosphere. Scientists and technicians believe that more efficient taxiing strategies should replace traditional aircraft ground handling methods. Multiple factors should be considered in the airport operation programming. Environment protection, energy efficiency, safety matters, performance restrictions, and airlines' financial profit are some examples of these determinative elements. Furthermore, aircraft ground operation is the leading cause of airports' air and sound pollution. It also becomes more remarkable to the airline companies when the risk of airplane ground accident is involved. At present, airports’ control towers handle the airport's surface traffic manually. Human-made mistakes and slow responding time to high-risk occurrences may put the airplane ground handling system in serious problems. Due to this fact, the traffic control personnel have no choice except keeping departing flights in the gates and let them leave only when the entire assigned path is clear. This manual flow control approach is inefficient and causes long taxi times. Technically, a robust mathematical formulation is able to offer optimal solutions for the airport surface operation. In this study, a new, environmentally friendly optimization formulation is developed in order to minimize the total taxiing time and aircraft’s fuel consumption on the ground by eliminating unnecessary delays. Moreover, solving airplanes' conflict problems in ground movements is guaranteed during the entire taxi-paths, since without considering the aircraft collision avoidance feature, the mathematical model will not be practical. Based on the presented methodology, a combination of the single-engine taxiing method and truck-towing is suggested as the best practical solution. The conducted investigations indicate that this approach provides both economic and environmental benefits to the aviation industry. The accuracy of the offered model is validated by the daily aircraft’s data on the layout of the Montréal-Pierre Elliott Trudeau International Airport. Three extensive sets of numerical analyses have been conducted to provide better insights into the issue. In each part of these analyses, different determinant factors such as total taxi time, total fuel consumption, and total delay have been used to compare the obtained results of the proposed approach with the current situation at the airport. After studying all effective elements and analyzing the results, an environmentally friendly and economically efficient approach is offered