Abstract: Device for visualizing failures for gyroscopic instruments comprising, inendently of the size of the indicator which incorporates it, an intuitive warning means accounting simultaneously for the supply of the liability and for the speed conformity of the gyroscope to the required values. It comprises two complementary display zones in the rolling dial (5 and 6) made up by means of elements of liquid crystals presenting an opaque appearance in the presence of a supply voltage and showing a color required in the absence of a supply voltage. One of the zones (5) is comprised of a single active element informing of the disappearance of the supply while the other zone (6) is comprised of a plurality of juxtaposed active elements, which are progressively switched and which give a synoptic perception of the speed reduction of the gyroscopic top of the instrument.

Abstract: The invention concerns a process for the rapid detection of a wind gradie t.This process utilizes the relationship existing between the aerodynamic slope .gamma.a, the total slope .gamma..sub.T and the anemometric speed V, relation being able to be in the form ##EQU1## in which s is the Laplace operator, A is a value which is substantially constant or zero, in the case of a normal flight without disturbances, and which increases in the case of a wind gradient, wind forward becoming wind behind, the Vsel is an assigned value. This value A is mixed with a value representative of the capacity of the aircraft to overcome a wind gradient, so as to obtain a composite signal compared to a value of reference.The invention can be utilized at the moment of the phase of approach of an aircraft.