Flying Wings. A New Paradigm for Civil Aviation?

Over the last 50 years, commercial aviation has been mainly based what is currently called the conventional layout, characterized by a slender fuselage mated to a high aspect ratio wing, with aft-tail planes and pod-mounted engines under the wing. However, it seems that this primary configuration is approaching an asymptote in its productivity and performance characteristics. One of the most promising configurations for the future is the flying wing in its distinct arrangements: blended-wing-body, C-wing, tail-less aircraft, etc. These layouts might provide significant fuel savings and, hence, a decrease in pollution. This configuration would also reduce noise in take-off and landing. All this explains the great deal of activity carried out by the aircraft industry and by numerous investigators to perform feasibility and conceptual design studies of this aircraft layout to gain better knowledge of its main characteristics: productivity, airport compatibility, passenger acceptance, internal architecture, emergency evacuation, etc. The present paper discusses the main features of flying wings, their advantages over conventional competitors, and some key operational issues, such as evacuation and vortex wake intensity.

Integration of UAS in the civil airworthiness regulatory system: present and future

The last years are witnessing a number of initiatives worldwide devoted to assess the safety levels of the unmanned aircraft. These initiatives are very heterogeneous; some of them are centred in airworthiness aspects while others focus on operations. From the point of view of a potential UAS manufacturer the actual situation is plenty of uncertainties in relation to the regulations to be applied for certifying the design, manufacturing and maintenance, and from the point of view of the potential operator the situation is analogous with respect to operational procedures. In the present work the emphasis is on the manufacturer’s situation. The objective of this work is to clarify the present civil airworthiness regulatory scene by summarizing all the regulatory efforts up to date and preparing a comparative analysis of them. In this comparison, the manned regulations are included too. The most representative state-of-the-art UAS are analyzed from the point of view of the existing and the future regulatory framework. The main aspects to be considered are related to the airworthiness certification (performances, structural design, etc) for which a quantitative comparison is established in order to clarify how the new regulatory framework, mainly based on the conventional aircraft certification codes, will affect future UAS, compared to the existing regulation

Flight Dynamics of the flying wing

Flying wings are one of the most promising concepts for the future of commercial aviation, regarding the market, technology and environmental driving factors. The research reported here is part of a long term project on the 300 seats category flying wings. In several previously published works the feasibility, efficient performance and airport compatibility of the concept have been assessed. The present paper concentrates on the flight dynamic aspects of the aircraft, which have been scarcely analyzed in open literature. The results obtained show that the flying wing configuration can be dynamically stable; however, the longitudinal and lateral directional oscillations decay so slowly that a stability augmentation system would be required to assure an acceptable dynamic response of the aircraft

Comment on "Deuterium--tritium fusion reactors without external fusion breeding" by Eliezer et al

Inclusion of inverse Compton effects in the calculation of deuterium-deuterium burn under the extreme conditions considered by Eliezer et al. [Phys. Lett. A 243 (1998) 298] are shown to decrease the maximum burn temperature from about 300 keV to only 100--150 keV. This decrease is such that tritium breeding by the DD --> T + p reaction is not sufficient to replace the small amount of tritium that is initially added to the deuterium plasma in order to trigger ignition at less than 10 keV.Comment: 6 pages, 1 tabl

Airplane design; a must in aeronautical engineering education

The trend towards European academic homogenisation, budget cuts and other threats lead to shrinking the time for the aeronautical engineering programs. Some topics, knowledge and skills will have no place in future curricula. The paper advocates for keeping airplane design as a corner stone of the aeronautical engineering syllabi since it is the only topic that educates students in synthesis perspective, binds many independent disciplines and counterbalances18 years of well developed analytical mentality

SF-1 a key player in the development and differentiation of steroidogenic tissues

Since its discovery in the early 1990s, the orphan nuclear receptor SF-1 has been attributed a central role in the development and differentiation of steroidogenic tissues. SF-1 controls the expression of all the steroidogenic enzymes and cholesterol transporters required for steroidogenesis as well as the expression of steroidogenesis-stimulating hormones and their cognate receptors. SF-1 is also an essential regulator of genes involved in the sex determination cascade. The study of SF-1 null mice and of human mutants has been of great value to demonstrate the essential role of this factor in vivo, although the complete adrenal and gonadal agenesis in knock-out animals has impeded studies of its function as a transcriptional regulator. In particular, the role of SF-1 in the hormonal responsiveness of steroidogenic genes promoters is still a subject of debate. This extensive review takes into account recent data obtained from SF-1 haploinsufficient mice, pituitary-specific knock-outs and from transgenic mice experiments carried out with SF-1 target gene promoters. It also summarizes the pros and cons regarding the presumed role of SF-1 in cAMP signalling

Effect of uncommon exit location in the emergency evacuation of transport airplanes

The objective of the present paper is to show the effect of uncommon exit arrangement in the evacuation process of narrow-body airliners, from the point of view of emergency evacuation certification, using the ETSIA model. Two main possibilities will be considered: large longitudinal shifting of the main embarking/disembarking doors; and suppression of some over-the-wing exits

Initiating a Conversation Between Culture and Nature Through Sculpture

A thesis submitted to the Faculty of the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Master of Fine Arts in the Department of Art.Master of Fine Art