The impact of cell formation on layout designs in cellular manufacturing

This paper provides a procedure to address all three phases of the design for cellular manufacturing namely parts/machines grouping, intra-cell and inter-cell layout designs concurrently. It provides a platform to investigate the impact of the cell formation method on intracell and inter-cell layout designs and vice versa by generating multiple efficient layout designs for different cell partitioning strategies. This approach enables the decision maker to have wider choices with regard to the different number of cells and to assess various criteria such as travelling cost, duplication of machines, space requirement against each alternative. The performance of the model is demonstrated by applying it to an example selected from literature.<br /

A Simulation Approach to Airline Cost Benefit Analysis

In this paper we conduct a cost benefit analyses using simulation for an Airline. This study pertains to using Towbarless Towing Vehicles (commonly referred to as supertugs) to transport aircraft to and from the terminal to airline’s maintenance hangar facility at their hub. This study attempts to investigate the possibility of reducing costs through saving jet fuel by adopting supertugs and identify if their high purchasing costs are justified. This study adopts simulation to analyze the annual savings by studying the numbers needed, as well as the utilization and operation cost for these supertugs. The results are very encouraging, enabling the airline to clearly evaluate their cost and benefits for purchasing new supertugs

Determinants of Financial Health of US General Aviation Airports

This survey-based study investigates the current financial environment of US general aviation airports. Due to a dearth of data and research on the financial performance of general aviation airports, the paper provides vital information regarding the critical needs and major revenue sources of such airports.The findings suggest that general aviation airports can be self-sustaining regardless of their location, runway length and other airport-specific characteristics.The attitudes of the airport manager towards the importance of financial self-sustainability, positive relationships with local communities, and utilisation of non-traditional and non-aviation revenue sources are found to be critical for the financial health of general aviation airports. In addition, the research provides estimates of the funding needs of US general aviation airports and evidence of the cumulative demand for T-hangars on a national basis

Entrepreneurial Spirit in Government Managed Enterprises: Evidence from the U.S. General Aviation Airports

While a number of studies introduce entrepreneurship in the public sector, there is still a need for empirical research in this field. We use a survey of U.S. general aviation airport managers to investigate the benefits of entrepreneurial spirit in public sector management. The results of logistic regressions suggest that the airport managers’ beliefs in importance of self-sustainability significantly improve the likelihood of general aviation airports to be self-sustaining. On the other hand, the airport specific characteristics, such as a favorable location, county population, and others are not statistically significant in achieving self-sustainability. Our findings support the literature that argue that entrepreneurship can be a mean of achieving more efficient, flexible and adaptive management in the public sector

Developing Proactive Methods for General Aviation Data Collection

Introduction. Over the last 20 years, nearly 40,000 general aviation (GA) aircraft were involved in accidents, roughly 20% of which were fatal. To address this safety concern, scientists have often relied on accident data. Because of the rare nature of accidents, commercial aviation incident and near miss data may prove to be useful sources of safety information. In one such study, the National Transportation Safety Board interviewed GA pilots that were flying near a weather-related accident in pursuit of a different perspective than that of the accident pilot. Interviewing GA pilots about their own weather-related event may provide similar benefits. Method. To understand factors leading GA pilots to encounter adverse weather conditions, pilots involved in an adverse weather encounter were interviewed using a one-hour structured interview. The interview was developed using surveys utilized by National Aeronautics and Space Administration and the Federal Aviation Administration (FAA). In total, 27 pilots who experienced an adverse weather encounter were interviewed, of which 25 were included in the final analysis. Results. Previous studies conducted by the FAA and others found many GA accidents involving flight into adverse weather were categorized as a willful disregard for the rules and regulations of safety; violations as defined by the Human Factors Analysis and Classification System. Contrary to what the accident record seems to suggest, flight into adverse weather may also be influenced by the lack of appreciation/understanding of the hazards associated with adverse weather. Perhaps some encounters with adverse weather were motivated by outside influences or exacerbated by some manner of mechanical failure that may have led to the willful acceptance of unnecessary hazards. Conclusions. These data suggest that current beliefs surrounding flight into adverse weather by GA pilots may be incomplete. The data presented here suggest that additional effort should be placed in training, both ab initio and recurrent. Emphasis should be placed on ensuring a full understanding of the adverse impact of weather, including the recognition of instrument meteorological conditions, icing, convective events, etc. Likewise, with the proliferation of commercial weather products and on-board weather equipment, it may be time to move toward some form of standard weather package that all pilots would review before flying

Efficiency analysis of a congested Brazilian airport applying slots optimization control: Congonhas Airport Case

The current slot allocation mechanism in Brazil, based on the International Air Transport Association (IATA) rules, and its supplementary local regulation The National Civil Aviation Agency (ANAC), displays a few issues and limitations (e.g. slot misuse, allocation inefficiencies). Such issues are particularly present in the case of busy airports that works near their maximum capacity for major parts of the day. This inefficiency problem is generated because of the complexity of slot allocation added to the limited decision support available for the Brazilian system. This study focuses on the implementation of an optimal slot model, based on IATA regulations with local adaptations from ANAC at Congonhas Airport (CGH/SBSP). Final results include the reallocated slots examined within airport capacity limits and declared capacity for flights GOL 1389 and GOL 1666. This optimal solution represents an improvement in the slot allocation efficiency of 35,22% and 67,83% for flights GOL 1389 for GOL 1666 respectively. The main limitation is that the model focuses only on the availability of slots and their optimization. No consideration is given to the airport capabilities such as gate availability, baggage handling capacity and aircraft size. This leads to a less systemic analysis of the whole system

General Aviation Weather Encounter Case Studies

This study presents a compilation of 24 cases involving general aviation (GA) pilots’ weather encounters over the continental U.S. The project team interviewed pilots who had experienced a weather encounter, and we examined their backgrounds, flight experience, and weather encounter details. Results from meteorological data analysis for each weather encounter were consistent with findings of larger GA weather accident studies in terms of the types of hazards encountered and flight phase during which the encounters occurred. Investigation of pilot weather products and the sources from which they were obtained revealed a lack of uniformity of pre-flight data sources and underutilization of available en route flight information services. The team used these results to develop a set of pilot weather education and training recommendations intended to reduce the number and severity of weather encounters

LAX Tow Tugs Feasibility Study

Currently, United Airlines does not have any tow tugs at LAX and uses only tractors with pull bars. These are not suited for the lengthy tows. Due to high cost of these tow tugs a study is needed to identify economic viability of purchasing these tow tugs. In particular, the airline would like to identify metrics such NPV, payback, and IRR determined for a period of 5 years after buying these tow tugs

Manpower Planning for Maintenance Crew at SFO

The objective of this project is to optimize the use of maintenance manpower at San Francisco International Airport for efficient use of available resources and reduce flight delays. The project uses simulation for one full day of an airline\u27s operations. The simulation model developed can identify the number of delays as well as the total time of delays that may occur throughout the system due to shortage of maintenance workforc

Development of an Aviation Weather Database Highlighting Weather Encounters

The project team, which includes the FAA\u27s Civil Aerospace Medical Institute, Clemson University, and Embry-Riddle Aeronautical University, interviewed 26 General Aviation (GA) pilots over a 25-month period. The hope is that a list of items and/or data points that investigators can use to gain a better understanding of what happened within a particular weather incident/accident can be generated