GB2506343A - Panel hydroplane for ground-effect flight - Google Patents

Abstract

A watercraft adapted for intermittent flight above the water surface comprises a rear mounted mainplane 5 that enables flight in ground-effect and which is stabilised by a foreplane 4 at the bow, which may also serve as a lifting body. The craft is formed around a pair of lateral stringers 10 extending from the foreplane to the sides of the mainplane, and another pair that extend from the foreplane to join substantially vertical keels (7, Fig 3) of the mainplane to form a pair of running surfaces 9. The hubs 1 that mount the stringers to the foreplane may be adapted to provide the wave-piercing operation of a conventional bow.

Description

PANEL IfYTDROPLANE The invention relates to the field of flying boats.

A disadvantage of conventional flying boats or WISE (Wing in Surface Effect) craft is that like aircraft there span is optimised relative to their length. A light aircraft for example is typically two-thirds as long as its span is wide. For watercraft, and especially fast watercraft, the proportions are reversed and they are designed so as to be altogether narrower in their beam measurements compared to their length.

The principal reason for this is that, unlike aircraft, watercraft are called upon to pierce waves and this requires an outline that helps cleave or ride these surfaces.

The extended span of aircraft is thus a decided disadvantage in this regard and in heavier seas flying boats were prone to "ground-loop" in the event of inadvertent contact of wave and wing-tip. Seaplanes with a narrow pair of floats are less likely to encounter such problems, but are nonetheless wholly unsuited to prolonged flight in "surface effect" as they are as prone -or even moreso -to penetrate heavier seas to calamitous effect.

What is required therefore -and what the invention provides -is a framework that is akin to the outline of a powerboat whilst sufficiently light as to form an airframe; and all the while providing conventional flying surfaces in order to achieve a stable and controllable means of flight.

The outline described provides on the one hand the salient parts of a catamaran or twin-hulled powerboat, while at the same time combining it with a flying foreplane or "canard" that controls the pitch of a mainplane at the rear. Practically lacking a hull altogether, each of these devices share an element of buoyancy to support the weight of a motor and propeller (for either marine or aerial propulsion).

The diagrams illustrate a consummate means of construction that is adaptable to composite materials but at its simplest can be conventionally produced in timber: Figi Ahub.

Fig 2 A foreplane.

Fig 3 A mainplane.

Fig 4 A stringer.

Fig5 An assembly.

In the first diagram a hub or nub (1) provides a means by which a pair of laths can be connected at differing angles: in this case at ninety degrees. An advantage of this is that one then braces the other for any lath or joist is stronger in one plane than the other. Though it may be included in the foreplane or formed as a single casting, the brackets (2) shown are attached to a box-section (3) that might be extended the length of the craft but is here foreshortened sufficiently to support a foreplane with a degree of latitude regarding its longitudinal placement. The hub (1) forms a pair.

Connected to these pair of hubs (1) is a foreplane (4) or canard, which maybe moulded into an aerofoil shape or else be of monobloc construction, like a foam laminate. It can nonetheless be fitted with, say, an elevator in either circumstance.

This appears in Fig 2. In Fig 3 and in similar material a mainplane (5) comprises a deck (6) or horizontal wing assembly and a pair of keels (7). The cross-section of their arrangement can be altered, but struoturally they provide a framework of attachment for the remaining parts and operationally they produce both static buoyancy and dynamic lift. Fig 4 features a unitary type of stringer (8) in wood.

This is all apparent from Fig 5, which includes the stringers (8). They take the form of laths set perpendicular to each other, though they might be set at different angles at the keel relative to the hub. They could for example incorporate elements of twist to accommodate this, or else pursue a different angle along the length of the craft.

(If for example they are set at around forty-five degrees at the base of a pair of keels at the rear, they will converge at the same angle at the bow where they can be fixed together. Likewise they could emerge from here fiat and be twisted through ninety degrees and joined vertically at the prow; nonetheless either contingency produces the outline of a monohull instead of a catamaran or "tunnel-hulled" boat.) Therefore in this embodiment the vertical stringers (9) emanating from the keels maintain their orientation but are flexed upward by dint of being connected at the hub (1) to the lateral stringers (10). Note that the same arrangement is effectively construed around an "L" section at both front and rear of the craft, and that the left-and right-handed elements are practically symmetrical. Another arrangement may therefore benefit from hinged keel-and-hub assemblies to benefit from fiat storage.

The strength and lightness that the framework derives is a function then of the fact that each type of stringer (8) is flexibly stressed in relation to the other by the hub (1). Nonetheless the overall craft does not enjoy the strongest relationship of parts until these apices are connected at the front end by a cross-bar or torsional element in the form of the foreplane (4). This may thus be a two-part structure comprising a plane and elevator or else an all-moving or "slab" type of trimmable surface.

There is thus sufficient a frame to support a motor with a marine or aero-propeller.

In the event of the latter, it may be located at the leading edge of the mainplane (5) or else at the rear in a pusher configuration. In the first event this provides efflux that makes any oontrol surface at the trailing edge more effective and in the second it provides room to aocommodate a human pilot. The keels themselves may be fixed at different angles, to the extent that they practically provide a "mono-ski" once the craft is underway.

Nonetheless the embodiment outlines the strongest arrangement and pitches the craft highest in the water in order to provide maximum clearance for a propeller.

This can be augmented by a float pitched between the keels at a lower level, though an alternative is to raise the mounting for either type of motor by means ofjacking.

Incidentally this provides a means by which the ends of an aero-propeiler might be adapted to provide additional thrust in water so as to raise the craft onto the plane.

Claims (9)

1. CLAIMS1. A watercraft comprising a rear-mounted mainplane, including a horizontal deck or wing assembly and a pair of keels, providing static buoyancy and dynamic lift, connected by pairs of stringers to a foreplane or bow-section, wherein at least one pair of the stringers is supported by and extends tim the sides of the deck of the mainpiane and another -of the stringers is supported by and extends from the ends of the keels and each of the stringers is flexibly stressed and brought to a curved configuration upon having its front end connected to the foreplane or bow section.
2. 2. A watercraft as claimed in claim I wherein the Ibreplane provides a slab surface supported at each side by two stringers, one of which extends from a respective one of the keels at the rear and flexes upwards in a substantially vertical plane and the other of which extends thm a respective side of the deck at the rear and flexes inwardly in a lateral plane.
3. 3. A watercraft as claimed in claim I wherein the Ibreplane lbrms a lifting body and is mounted between hubs, each hub comprising a triangular outline bracket that defines an apex in the horizontal planc and a further triangular bntckct which forms an L-scction with thc horizontal bracket and provides support for the fltnt end of the stringer which extends from the end of the respective keel.
4. 4. A watercraft as claimed in claim 2 or 3 wherein the stringers which are supported by and 0) extended from the ends of the keels are each set at an angle of 45 degrees at the base of the 1 respective keel.

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5. 5. A wateroraft as claimed in claim 3 wherein the keels of the mainplane and the hubs mounting 0 the foreplane are hinged.
6. 6. A watercraft as claimed in any preceding claim wherein the keels and the pair of stringers C\J supported by them are paired so closely as to act effectively as a mono-ski.
7. 7. A watercraft as claimed in any preceding claim that is capable of stabilised flight above the water in surface effect.
8. 8. A watercraft as claimed in any preceding claim including control surfaces on the foreplane and/or thc trailing cdgc of thc mainplanc.
9. 9. A watercraft substantially as hereinbefore described with reference to and as illustrated by Fig of the accompanying drawings.