BACKGROUND OF THE INVENTION / PROBLEM TO BE SOLVED

Passenger aircraft have become increasingly large in recent decades and have to be more economical in consumption of fuels and reduce sound emissions.

This has led to lighter constructions in which fiber plastics increasingly replace metals.

Nevertheless, the weight of the aircraft increased due to a higher number of seats. Moreover, noise protection and reduced pollutant emissions demanded the drive turbines to be designed with an increasing sheath current ratio an thus bigger turbofans, so that the lower edge of their cowling is located below the fuselage of modern mid-deck constructions.

In the case of a crash landing, this results in a scenario that the suspensions of the landing gear and engine units - as designed breaking points - would be torn off first and the nacelle alone has to absorb the friction, what in case of accidents would make it difficult to handle it. Due to the size and weight of airliners, but their sophisticated construction, lifting with cranes and straps as well as with hooks is hardly conceivable, since these cannot be applied on a large surface.

In other cases, lifting jacks may be applied, but they are generally unsuited for damaged aircraft, since they may add further damage to the comparatively filigree skin of aircraft as to their point-like loads.

Moreover, the soil off runways usually is uneven and of varying compliancy. Therefore the simultaneous use of a larger number of cranes and straps would not be feasible, because of the difficult accessibility to the terrain and the risks of different stability of the individual lifting systems on their ground.

PRIOR ART

Quite a few propositions for salvaging airplanes pertain to lifting cushions.

But even large and flat cushions, e.g. according to DE 10 2010062409 A1 and DE 10 2014 18979 A1 or pyramidal structures, as the Grainger system or according to US Pat. No.

9, 162,735 can hardly be applied, since they do not absorb lateral pressure, whereas damaged airliners rarely lie horizontally on flat ground.

Furthermore, single pneumatic cushions can only cope with heights of approx. 1 m. The height between the ground and the wing bottom edge however is up to 8 m for large aircraft, and may be quite a bit more for inclined positions and the attachment of a plurality of air cushions one above the other becomes compulsorily unstable.

Other propositions, as to US Pat. No. 2,989,98 describes a rescue process also for aircraft, but only for those submerged in water, which are to be pumped up with phenolic resin foams. C 1511759 shows a vehicle for lifting and accommodating an obviously small-scale aircraft, whereas CN202481274 (U) contains a gripper arm for rescue of aircraft. But, according to its drawing, this is intended only for the recovery of model aircraft.

EP 564687A1 proposes a towing device for airplanes which are on the ground whilst having only a defective wheel or landing gear and thus can be moved with a lowered platform on wheels. However, this is only feasible in a few cases - namely, at least partially intact landing gear and on a flat surface.

Other special methods for rescue of large aircraft are not yet known.

In individual cases - for instance, in the case of previously damaged jumbo jets, complicated substructures had to be erected from logs and planks under the wings and the fuselage, which, because of their individual dimensions, caused considerable material consumption and subsequently high levels of waste.

On the other hand conventional scaffold substructures are not designed for high vertical loads (an Airbus A380, for example, weighs up to 580 metric tons) and load-bearing bar-node trusses require time-consuming construction and the same workload later on their removal.

However, in these cases of landing mishaps and damaged aircraft, the time factor, especially when an accidental aircraft blocks takeoff or landing runways, is economically paramount: The airport loses several million Dollars or Euros per day. In addition, the airlines lose another millions due to flight cancellations and costs for possible compensation on passengers.

A further problem arises for rescue companies hired for salvage: Lifting the machines can easily lead to secondary damage, such as hair cracks on load-bearing elements, for which the contractor could be made responsible by insurances.

In order to avoid this, all applied pressures at locations must be planned and carefully be logged. This is quite difficult on non-planar subsoils.

TASK OF THE INVENTION

The object of the present invention therefore is to ensure that damaged aircraft is quickly secured for recovery even in unsafe terrain on a flat working platform, also providing security to the salvaging crew

SOLUTION / INVENTIVE STEP

The task of the invention is achieved by constructing a scaffold structure as a grid of fast-to- build, inherently stable (and preferably square) modules, individual elements being spared out e.g. for engines and landing gear. Four support points of each element on the ground as well as the lifting points under the fuselage and wings can be individually adjusted in height so that a distortion-free traction structure results, on which a flat working platform made of beams and planks can be erected. For this purpose, the heads of the columns of the grid are equipped with pressure gauges whose values are transferred by radio transmission and which are analyzed by means of an evaluation system, (e.g. a mobile app,) and can be graphically displayed.

These must be provided with lifting jacks, which then only have to provide the lift necessary to gap the required additional lift for moving the wreck.

The platform can be secured by railings according to the requirements of professional associations.

The invention is explained in more detail below with reference to the drawings, FIGs. 1 to 3:

FIG. 1 shows the structure of such a platform (1 ), the substructure of which consists of cube- shaped framework elements (2).

Their edges (3-6) are formed by metal pillars (7) with a flat bottom plate (8). These are interconnected by crossbars (9-18) and have an extendable punch (19) on which a head plate (20) is mounted, The latter bears the pressure measuring plate (21 in FIG. 2) or an equally thick dummy plate.

Further profile carriers (22, 23) can then be placed on and screwed onto these, as the usual

T-beams (24 to 26) which support the floor (27) of the actual platform.

The railings (28) necessary for the safety of the staff can thus also easily be installed.

FIG, 2 shows the structure of a pressure-sensing plate (29) according to the invention, which is immersed in a section of the head plate (20) with its measuring head (30), which contains the electronics, while the sensors (31 , 32) are arranged in longitudinal and transverse directions within the rubber of the pressure-sensing plate (29). The measuring head (30) can also contain batteries for supplying the electronics, but it is also possible to operate the system with active RFIDs which are arranged as a cuff around a free part of the plunger (31 ),