Luigi PELLARINI Airtruk -- Articles & patents

A) BACKGROUND OF THE INVENTION 1) Field of the Invention: This invention relaces to aircraft of any speed, size and use, which are endowed with enhanced safety and performance, as compared to conventional existing aircraft of equivalent payload and power, in virtue of the herein described features. As these aircraft look different, they will be called airsymbiocraft; but within this description they are called symbiocrafts, for short.

2) Prior Philosophy This invention, basically, is an amelioration of the symbiotic philosophy that the ght Brothers have embodied in their canard-biplane. They must have thought that mechanical flight does net necessarily have to simulate the flight of living beings (which are bestowed with limited velocity) and consequently they devised a truly revolutionary aircraft whose configuration had enabled them to fly safely before ii I_ anyone else. However, since this application consists of a number of complementary new ideas that improve consistently the basic concept of the Wright Brothers, then even this application should form zn invention in its own right.

It may seem paradoxical to pursue substantial improvements through a recourse, for inspiration, to biplane philosophy (long ago discarded in favour of the monoplane philosophy, which has become so familiar) nevertheless the fact is that, if the aircraft engines of the sixties were made available in the thirties, to enable the biplanes to fly efficiently at high tropospheric altitude, then the aircraft C development would have occurred in accordance with the canard biplane concept, which, at very high altitude, S g* is more aerodynamically convenient than the monoplane *e concept.

C Many experts share the conviction that the present conventional monoplanes have reached their top limits of safety, performance and economy and do not foresee any substantial economic advantage in their further development as monoplanes.

Even large aeronautical companies are involved in research for alternative solutions more advantageous than those of the present conventional monoplanes, J -3since even them judge that these monoplanes have reached a stumbling block, from the performance and economy viewpoint, despite the great achievements in propulsion, aerodynamics, structures and systems, made in the U.S. in the last fifty years.

Thus, by representing one of the most advantageous alternatives, the symbiocrafts should find a worthwhile area of application, in both civil and military aircraft fields as, in reality, nothing wrong has emerged by adapting to the symbiocraft the inspired concept of the canard biplane of Orville and Wilbur Wright, who have invented the mechanical means more convenient to fly safely and more eccnomically.

3) References and Experimental Findings in Unconventional Art: 0 0 a) FLYING WING AIRCRAFT characterised by: Simplicity, but low operating efficiency; low volumetric efficiency; lack of rotational angle of incidence in take-offe 5 landing; small wing loading; mediocre potential of development.

b) MULTIPLE FUSELAGE AIRCRAFT characterised by: Sufficient operational efficiency and good development potential but Jack of speed potential; excessive spanwise mass inertia; absence or difficult intercommunication.

7 -4c) LIFTING BODY AIRCRAFT characterised by: Insignificant operational efficienty; very low empty weight but of no use at subsonic speeds, if it is exploited alone.

d) SPANLOADER AIRCRAFT characterised by: Mediocre operational efficiency; lack of speed potential; mediocre volumetric efficiency; excessive lateral intertia; poor flying performance especially in takeoff/ andings; only apparent both simplicity and small empty weight.

15 e) AIRDYNECRAFT (as per above U.S. Patent 4 030 0 68) characterised by: Good operational efficiency; good volumetric efficiency; low empty weight, acceptable mass inertia on all three orthogonal axis; good flying 5 performance.

However: a large scale radio controlled model of the airdynecraft, during it reiterated flights in performing take-off/landings has manifested a 20 degree of potential danger, which was not evident in the wing-tunnel testings previously made with smaller mcdels. Such potential danger was due to adverse effects of the ground air-cushion, because of rotational peculiarities at take-off stage, since above a height of 2-3 times its wing m.g,c. from the ground, the model behaviour was very good and and comparatively competitive.

To get rid of such serious handicap were required various design alterations, starting from a gradual reduction of the main-plane aspect ratio of the model, and arriving to a stage in which the above mentioned U.S. Patent 4 030 688, was definitely superseded by the present concept embodied in this invention for which application now is made under the name of "Symbiocrafts".

*4 30 4) Comprehensive Principa Advantages of the U.

Invention: A new configuration and a particular type of structure providing greater and more chances of safety in general (and in particular during S* emergency landings on rough grounds or water).

0 U A configuration more suitable to carry simultaneously 35 passengers and more luggage (if the carrier is small), or a greater number of passengers and large or heavy cargo, (if the carrier is comparatively large), while providing maximum volumetric and structural efficiency for both types of payloads.

A configuration more suitable to cruise at higher jl I -6altitude, hence more economical cruising.

A configuration comparatively shorter and packed; which leads to symbiocrafts of comparatively small weight and mass inertia; therefore more suitable for further development in size and payload capacity; without imposing, for many years ahead, extensions or additional airport tarmacs or runways. In fact, the symbiocrafts can perform take-off/landings from runways no longer than those needed for conventional ~aircrafts capable of carrying only half the maximum payload carried by symbiocrafts of equal o*9 length. Therefore, the present airport runways S could remain adequate until the volume of airo traffic is much greater, (should the symbiocrafts be used).

f 10 5) Clarification concerning the description of the Symbiocrafts
Having found that the present invention is consistent and useful even if it applies to very small and slow symbiocrafts flying at relatively low altitude as well as it applies also to supersonic aircraft in general, wherein the velocity becomes imperative in determining their configuration and type of structure, the description of the invention IJ -7that follows will refer separately to small, large and supersonic symbiocrafts, so as to simplify the task of explaining them.

B) SUMMARY OF THE INVENTION Various short-comings of the known aircraft designs have been resolved by the present invention by providing new arrangements of aircraft components and new configurations which suit most of the civil S* and military aircraft, irrespective of whether they Are small or large, subsonic or supersonic.

The subsonic symbiocrafts, in fact, comprise a a lower and an upper-mainplane which are held together a by a pair of fins and rudders and a central air-streamlined pilon in manner to form an aircraft with rolling, directional 25 and pitching stability and maneuvrability; wherein the lower-mainplane is similar to a blunt wedge, whose longitudinal sections form thick contours of low drag airfoils; while the upper-mainplane is more or less similar to a conventional wing of fast characteristics and great aspect ratio; hence of great lifting potential.

Therefore the main function of the lower-mainplane in the context of this invention, is to provide larte amounts of useful space for payload and fuel and also to provide an efficient basic structure for the whole symbiocraft; while the main function of the upper-mainplane -8is the generation of economical lift and good performance.

The supersonic symbiocrafts, has a configuration broadly similar to that above described, except that ooth its mainplanes, in this case, are endowed with supersonic characteristics; hence both of them are endowed with small span and small thickness ratio; thereby the payload is carried by a slander fuselage which is supported by either the upper or the lower mainplane; but preferably by the upper-mainplane, so as to make the lower-mainplane housing the power plant and undercarriage away from a a a the fuselage.

e S* The invention, especially when it refers to large symbiocrafts, may also include two approximately horizontal winglets protruding from the top-rearsides of the lowermainplane and extending outwardly to receive and structurally connect at their tips two fin and rudder units, which C extend upwards until they reach, or surpass, the bottom skin of the upper-mainplane sides so as to structurally connect them with the lower-mainplane sides; and may S extend also downwards, so as to support an engine on each side of the lower-mainplane; thus forming part of the main central power-plant system of the symbiocrafts, when so it is preferred or necessary. Besides, such winglets would increase the aspect ratio of the lowermainplane.

The invention, furthermore, includes a power-plant system formed by a single, or a group of propulsive engines concentrated in proximity of the vertical plane of symmetry of the lower-mainplane, near its trailing edge, and may be fully exposed or housed into the body thickness of the trailing edge of the central portion ot the lower-mainplane. The power-plant, or portion ot it, may also hang trom the upper-mainplane; especially an small symbiocrafts or on supersonic ones.

S* The invention also comprises a canard surface, protruding from the sides of the nose of the lower-mainplane, preferably attached to its bottom; said surface being characterised by its relative smallness in span and area; hence lightness and simplicity.

20 The invention also includes symbiocrafts with a main under-carriage at a rearward station behind the symbiocrafts' centre of gravity and located underneath of the lower-mainplane, and inwardly from its leading edges and trailing edges, at a sufficient distance from them so as to allow its full retraction into the two sides of the lower-mainplane body; the said under-carriage comprising a train of two or more legs each side, which carry two or more coaxial wheels endowed with trailing deflection and retraction.

Another part of the present invention is a set of two mainplanes forming the lifting surface of the large symbiocrafts one high above the other and staggered in respect of the symbiocraft C. of G. according to their different sweep-backs, which are complemented by two slender components laying longitudinally between them, in their symmetrical plane, and structurally holding two central pilons, instead of one, in order to increase the strength and stiffness of the symbiocraft and make it more suitable as a two or more stages air-space vehicle as shown by the attached drawings.

The invention also includes a lower-mainplane, 35 for large subsonic symbiocrafts, whose body is formed by two swept-back symmetrical side bodies plus one or more central interbodies; all of which, in their turn, 0 can be subdivided in adjacent compartments or lobbies for passengers or cargo so that, the compartments for passengers are fully inter-communicating, while the 0, compartments for cargo are endowed with the unique feature of a continuous and simultaneous loading and unloading of a cargo (without reverse motion) and yet both entry and exit are being located At the very end of the two sides of the airsymbiocrafts; thereby making the symbiocrafts *000 more suitable for carrying many very large roadable vehicles, (if so required), or more cargo each fiiynt.

Still another aspect of the invention is a lower mainplane of great thickness ratio sufficient to obtain a blunt leading edge for the application of powerful forward slats so as to enhance its lifting effect due 1- 11-to the ground cushion of air in take-off or landing stages; thereby reducing the take-off run or sot teninq the landing impact of the symbiocraft; hence ;tro i I(ng 1 k reliet tor its structure and its under-carriage.

A further part of the invention consists; in a lower mainplane whose relevant thickness ratio allows exploitation of most ot the internal partition walls as, S;tructural members; furthermore provides the high torsional stiffne;s and strength required for holding the upper-mainplane at the best level required for having the two mainplanes producing and transferring to one another the best of the aerodynamic and stressing effects that are appropriate to each of the two mainplanes.

And again a part of the invention consists in two mainplanes forming a biplane wherein the upper-mainplane generates lift and drag nearly at the rate fitting a two dimensional airflow shile, instead, the lower-mainplane generates lift and drag at the rate of a strong three dimensional, (or vertical) airflow; hence insignificant aerodynamic interference and well rounded lifting curve of the symbiocraft (particularly important at take-offlanding speeds).

In conclusion, this invention represents the result of research carried out with the flying model made in accordance with the previous U.S. Patent 4 030 688, -122 now abandoned, as mentioned above...