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The present paper aims to assess the reliability and the limitations of analysing flight stability of a box-wing aircraft configuration known as PrandtlPlane by means of methods conceived for conventional aircraft and well known in the literature.

Results obtained by applying vortex lattice methods to PrandtlPlane configuration, validated previously with wind tunnel tests, are compared to the output of a “Roskam-like” method, here defined to model the PrandtlPlane features.

The comparisons have shown that the “Roskam-like” model gives accurate predictions for both the longitudinal stability margin and dihedral effect, whereas the directional stability is always overestimated.

The method here proposed and related achievements are valid only for subsonic conditions. The poor reliability related to lateral-directional derivatives estimations may be improved implementing different models known from the literature.

The possibility of applying a faster method as the “Roskam-like” one here presented has two main implications: it allows to implement faster analyses in the conceptual and preliminary design of PrandtlPlane, providing also a tool for the definition of the design space in case of optimization approaches and it allows to implement a scaling procedure, to study families of PrandtlPlanes or different aircraft categories.

This paper is part of the activities carried out during the PARSIFAL project, which aims to demonstrate that the introduction of PrandtlPlane as air transport mean can fuel consumption and noise impact, providing a sustainable answer to the growing air passenger demand envisaged for the next decades.

The originality of this paper lies in the attempt of adopting analysis method conceived for conventional airplanes for the analysis of a novel configuration. The value of the work is represented by the knowledge concerning experimental results and design methods on the PrandtlPlane configuration, here made available to define a new analysis tool.

Starting from Gino Arias’s dictum on the uselessness of international trade theory for fascism, this contribution aims to demonstrate two main points. First, the free trade attitude displayed by fascism immediately before and after the “March on Rome” clashed with its nationalist origins. The nationalist movement had supported a strong protectionist policy starting from a rejection of the main principles of marginalist theory. This explains why some issues raised by Pareto and Barone which could have been used as arguments in favor of protectionism were neglected. In turn, this impasse played a major role in the rejection of Mihail Manoilescu’s theory in the thirties. The second point concerns the possibility of some – at least relatively – free theoretical debate on international trade theory and policy. When the regime set itself a clear objective, like the reduction of trade to begin with, and then autarky, the scope for free discussion narrowed to the point of eventually closing. In this context, refusing to support the regime’s choices in economic policy meant resigning oneself to becoming an outcast. A situation offering one more tessera in the complex mosaic of relations between science and politics in authoritarian regimes.