EP3558718A1

EP3558718A1 - Method for determining the wear condition of an aircraft tyre

Info

Publication number: EP3558718A1
Application number: EP17828957.5A
Authority: EP
Inventors: Olivier Francois; Julien Brunet
Original assignee: Compagnie Generale des Etablissements Michelin SCA
Current assignee: Compagnie Generale des Etablissements Michelin SCA
Priority date: 2016-12-20
Filing date: 2017-12-18
Publication date: 2019-10-30
Also published as: WO2018115675A1; CN110087913B; FR3060821A1; US20210129596A1; CN110087913A

Abstract

The present invention relates to a method for determining the condition of an aircraft tyre and, more specifically, to a method for determining the wear condition thereof, allowing the residual lifetime and, more specifically, the number of residual landings, to be predicted for said tyre. A method for determining the condition of an aircraft tyre, said tyre comprising a tyre tread having at least one circumferential rib comprising at least one wear indicator, said method for determining condition comprising: - a step of detecting a first pattern of the position of the wear indicator, which is intended to identify the position of said wear indicator in the tyre tread; a step of detecting a second pattern of the condition of the wear indicator, which is intended to determine the wear condition of the relevant circumferential rib at a given instant; - a step of analysing the first pattern of the position and the second pattern of the condition of the wear indicator, through a comparison with reference patterns, and of determining the wear condition of the circumferential rib at a given instant; and - a step of rendering information relating to the condition of the tyre.

Description

METHOD FOR DETERMINING WEAR CONDITION

A TIRE FOR AIRCRAFT

The present invention relates to a method for determining the state of a tire for an aircraft, and more particularly to a method for determining its state of wear.

[0002] It is known that the tread of a tire intended to come into contact with the ground via a rolling surface is the wearing part of the tire, that is to say that it undergoes a decrease in thickness resulting from the rolling of the tire. The tread is generally made of relief elements separated from each other by troughs, this combination constituting what is commonly called a sculpture. In the case of an aircraft tire, the elements in relief are most often circumferential ribs, continuous over the entire circumference of the tire and separated from each other by hollows called circumferential grooves. The wear has the effect of reducing the height of the circumferential ribs and, correlatively, the depth of the circumferential grooves, thus degrading the performance of the tire. The wear of a circumferential rib at a given moment in the life of the tire is generally quantified by a wear rate. The wear rate is equal to the ratio (Ho-H) / Ho, where Ho and H are respectively the initial height Ho of the circumferential rib, measured on the new tire, and the residual height H of the circumferential rib, measured on the worn tire. Thus, the state of wear of a tire, more precisely of its tread, and even more precisely circumferential ribs of its tread, can be defined by the respective residual heights of the circumferential ribs constituting its tread. bearing, measured at a given moment of the life of the tire, or by their corresponding respective wear rates.

Regarding the specific field of tires for aircraft, the skilled person has highlighted two types of wear according to the phase of use of the tire. On landing, the middle part of the tread, the axial width of which is at least 50% and at most equal to 80% of the total axial width of the tread, is subjected, at the time of contact of the tread surface with the ground, to a wear called "wear and tear", resulting from a high abrasion and a high temperature rise, the makes the differential speed between the speed of rotation of the tire and the speed of the aircraft. In the taxiing phase, before take-off or after landing of the airplane, the lateral parts of the tread, positioned axially on either side of the median part and whose axial widths of at least 10% and at most equal to 25% of the total axial width of the tread, are subjected to wear called "taxi wear", resulting from the braking forces exerted on these lateral parts because of their speed of rotation greater than that of the middle part. Thus the tread is mainly worn at its middle part, on landing, and at its side parts, in the taxi phase.

The use described above often results in the presence of non-uniform wear of the tread, called irregular wear, resulting from the stresses during the various phases of use of the tire: takeoff, rolling and landing. It has been more particularly highlighted a differential wear of the tread between the middle portion and the two side portions of the tread, the wear of this middle portion being generally the largest. The differential wear of the middle portion of the tread results in a limitation of the life of the tire, hence its use and its premature removal, although the tread generally has only a relatively low wear of the parts. side of the tread: which is economically disadvantageous.

In practice, an aircraft tire is deposited when the wear rate of one or more circumferential ribs of the tread reaches a maximum permissible value, generally referenced as base 100, and the worn tire is then replaced.

A known difficulty for any operator of aircraft tires is to predict, reliably, the replacement of worn tires and schedule the corresponding maintenance operations. Poor programming of maintenance operations can cause untimely capital the aircraft incurring additional operating costs for the user. To avoid these fixed assets, storage of replacement tires is often carried out, at each of the airports frequented by the aircraft fleet operator, to be able to make tire replacements, at any time, which is penalizing by one point. from an economic point of view.

The programming of tire replacement operations is complex, due in particular to the difficulty of predicting the wear of a tire for aircraft. Indeed, the residual thickness of the tread according to the number of landings made, which characterizes the tread wear rate and more specifically the wear velocity touch, does not vary linearly. The remaining wear potential, measuring the number of residual landings that can be made before complete wear, can not be determined by simply measuring the residual height of the circumferential ribs of the tread. By way of example, the inventors have been able, in a particular case, to show that a tread, theoretically making it possible to make 400 landings until complete wear, corresponding to a wear rate of 100%, actually allowed to make 160 landings, corresponding to 40% of the total forecast number of landings, with a wear rate of 75%. In other words, the evolution of the wear rate as a function of the number of landings is not linear. In practice, the heights respectively initial Ho and residual H of a circumferential rib are often determined by a direct measurement of the corresponding depth of the adjacent circumferential groove, using a suitable measuring tool, which has the disadvantage of giving some weight to the monitoring of wear. The wear rate of the tread can also be determined using wear indicators, also called wear indicators. Conventionally, these wear indicators can be of two types: wear indicators in relief with respect to a bottom of circumferential groove and wear indicators positioned in the thickness of the circumferential ribs. A wear indicator, constituted by a raised element relative to a circumferential groove bottom, generally has a height substantially less than the initial height of the circumferential rib. When the residual height of the circumferential rib, adjacent to the circumferential groove including the wear indicator, reaches a minimum allowable value, corresponding to the upper level of the wear indicator, the maximum permissible wear rate is reached and triggers the tire replacement. Such a wear indicator does not, however, make it possible to quantify the progressive evolution of the wear of the tread during use: it simply indicates that the maximum permissible wear rate is reached.

It has also been proposed to position wear indicators in the thickness of the circumferential ribs, so that the trace of these wear indicators on the running surface can visually alert that the minimum allowable height of the ribs. circumferential, defining the maximum permissible wear rate of the circumferential rib, was reached.

All the wear indicators described above make it possible to determine, by direct visual observation, the residual heights and / or wear rates of one or more circumferential ribs of the tread of an aircraft tire. , at a given moment of the life of the tire. However, this method of determining the state of wear of a tire by direct visual observation does not make it possible, in particular, to anticipate the residual life, essentially characterized by the number of residual landings that can be made before the replacement of the tire.

The inventors have set themselves the objective of proposing a method for determining the state of a pneumatic tire for an airplane, more precisely its state of wear, making it possible to predict the residual service life of said tire. This objective has been achieved by a method for determining the state of an aircraft tire, said tire comprising a tread having at least one circumferential rib comprising at least one wear indicator, said determination method comprising:

a step of capturing a first wear indicator positioning pattern, for locating the positioning of said wear indicator in the tread, a step of capturing a second state pattern of the wear indicator, intended to determine the state of wear of the circumferential rib concerned at a given moment, a step of analyzing the first pattern of positioning and the second wear indicator state pattern captured, by comparison to reference patterns, and determining the wear condition of the circumferential rib at a given time, -a step of restitution of the information on the state of the tire.

The method for determining the state of an aircraft tire according to the invention is more precisely a method for determining its state of wear, based on the observation of the evolution of at least one indicator. positioned in the thickness of a circumferential rib of the tread of the tire. Most often the tread of an aircraft tire comprises at least three circumferential ribs axially separated from each other by at least one circumferential groove.

The wear indicator used in the method according to the invention comprises a first positioning pattern and a second state pattern. The first positioning pattern is for locating the positioning of the wear indicator in the tread. Most often it is intended to locate the axial positioning of the wear indicator, that is to say its positioning in the axial width of the tread, the axial direction being, by convention, parallel to the axis of revolution of the tire. The second state pattern is intended to quantify the rate of wear of the circumferential rib at any moment of the life of the tire.

[0017] A first and a second step of the method for determining the state of the tire are capture steps respectively of the first positioning pattern and the second state pattern of the wear indicator, with the aid of adapted means. Indeed, the first and second patterns of the wear indicator may have different aspects, may require the use of different capture means or different settings of the same capture means. For example, a capture means may be a camera possibly integrated in an optoelectronic system, for example smartphone or tablet type. A third step of the method for determining the state of the tire is a step of analyzing the first positioning pattern and the second state pattern of the tire. the wear indicator captured, compared to reference patterns, and determining the state of wear of the circumferential rib at a given time. This step is intended to identify the positioning of the wear indicator in the tread and determine its state of wear. This analysis can be done through local means or a remote database. The analysis step of the first positioning pattern and the second state pattern of the captured wear indicator is performed by comparison with reference patterns. These reference patterns, to which are compared the patterns captured on the tire, represent, for a wear indicator positioned at a given location of the tread, the various states of wear successively encountered by the circumferential rib during the tire life. These reference patterns may be stored locally, for example in the capture means, or remotely in a database to which the capture means are connected.

Finally, a fourth step of the method of determining the state of the tire is a step of restoring information on the condition of the tire. This restitution step can be implemented by means specific or identical to those of the capture step. The information on the state of wear of the tire can be of various kinds, such as for example and non-exhaustively, a rate of wear of the circumferential rib in absolute value, a differential wear rate of the rib. circumferential, in relative value, relative to the other circumferential ribs, a number of residual landings can still be made by the aircraft.

Preferably, the step of capturing a first positioning pattern of the wear indicator and the step of capturing a second state pattern of the wear indicator are simultaneous. By way of example, this step may consist of a photographic taking of the wear indicator as a whole, that is to say a simultaneous photographic taking of its respective positioning and state patterns.

The restitution step advantageously comprises a display step on an interface to a user. Such a display step provides a direct visual feedback to the user who tracks the tire, saving time. According to a first mode of restitution, the restitution step comprises information relating to a wear rate U = (H0-H) / H0 of the circumferential rib, at a given instant, HO being the initial height of the circumferential rib, measured on the tire in the new state, and H being the residual height of the circumferential rib, measured on the tire at least partly used.

According to a second mode of restitution, the restitution step comprises information relating to the number of residual landings authorized by the state of wear of the circumferential rib at a given instant. In this case, the wear rate type information is not restored as such. But the wear rate is correlated to a number of landings, according to a previously established mathematical model, it is the number of landings itself is returned to the user.

In a third mode of restitution, the restitution step comprises information relating to irregular wear of the circumferential rib at a given moment. This information may, by way of example, relate to a wear rate differential between two distinct circumferential ribs.

The method for determining the state of an aircraft tire according to the invention advantageously comprises a step of identifying the tire. It is indeed necessary to properly identify the tire, as an individual, to be able to follow the evolution of its specific wear and decide on its possible replacement. Indeed, because of their respective manufacturing characteristics and their different positions on the train of the aircraft, two tires generally have differentiated wear kinematics.

A tire identification step is generally performed by recognizing an individual marking or by reading a RFID (Radio Frequency Identification) identifier of the tire. According to a first mode of identification, the individual marking of the tire, consisting of a series of numbers, is generally captured, this marking can be highlighted, for example by a chalk marking that allows a contrast with the rest of the tire . According to a second mode of identification, an RFID identifier, implanted in the tire, for example by means of a glued label, contains tire identification data which can be read by a suitable means. Most often the method for determining the state of an aircraft tire includes a step of transmitting captured information to a database. It is indeed advantageous to have a database remotely, avoiding local storage too much information. It is advantageous for the method for determining the state of an aircraft tire to include a step of transmitting captured information to a database, this captured information being relative to the geolocation of the tire and / or the date and time of the capture steps. This automatic transmission of geolocation and temporal data avoids a specific recording and recording of these data, separated from the determination method.

The invention also has for one object a system for implementing the method for determining the state of an aircraft tire according to any one of the embodiments of the method described above.

The implementation system of the method for determining the state of an aircraft tire comprises:

means of capture,

means for transmitting data,

-Means of analysis,

-a database. Preferably, the implementation system of the method for determining the state of an aircraft tire comprises means for displaying the state of the tire. This allows direct visual information from the user.

[0032] Still more preferably, the implementation system of the method for determining the state of an aircraft tire comprises capture means and / or display means and / or data transmission means and / or analysis means implemented by an optoelectronic device, preferably smartphone or tablet type. Thus, a smartphone makes it possible both to capture the image of a wear indicator by means of an integrated camera, to display it on its display, to transmit this captured image to a remote database, by way of intermediate of its transmission function, and recover, by by means of this same transmission function, information relating to the state of wear of the corresponding wear indicator and to display it on the display.

The characteristics of the invention will be better understood with reference to FIGS. 1 to 7, not shown on the scale:

FIG. 1: Schematic representation of the sequence of steps of the method for determining the state of an aircraft tire according to a preferred embodiment of the invention

FIG. 2: Partial perspective view of an aircraft tire comprising wear indicators adapted to the method for determining the state of an aircraft tire according to the invention

FIG. 3: Meridian section of the tread of an aircraft tire comprising wear indicators adapted to the method for determining the state of an aircraft tire according to the invention

-Figure 4: Perspective view of a wear indicator

FIG. 5: Top view of a wear indicator, at different wear rates

FIG 6A: Top view of 3 wear indicators, respectively positioned on a medial circumferential rib and two circumferential shoulder ribs, for a tire in new condition

FIG 6B: Top view of 3 wear indicators, positioned respectively on a medial circumferential rib and two circumferential shoulder ribs, for a totally worn tire

FIG. 7: Variation of the height H of a circumferential rib as a function of the number of landings made.

Figure 1 is a schematic representation of the sequence of steps of a preferred embodiment of the method for determining the state of a tire for aircraft. In the example presented, the tire comprises five circumferential ribs, among which a medial circumferential rib and two axially outermost circumferential shoulder ribs, comprising a wear indicator constituted by a first positioning pattern, intended to locate the positioning said wear indicator in the tread, and by a second state pattern, for determining the wear condition of the circumferential rib; concerned at a given moment. For each wear indicator, a first step consists of a step of simultaneously capturing the first positioning pattern and the second wear indicator state pattern, using an M2 type capture means. camera built into a smartphone or tablet. The display means Ml of the smartphone make it possible to directly display the image of the wear indicator thus captured. A second step is a step of transmitting the first positioning pattern and second state pattern of the wear indicator to a remote database M4 by means of communications M3 integrated with the smartphone. A third step is a step of analyzing the first positioning pattern and the second wear indicator status pattern captured and determining the wear condition of the circumferential rib at a given time, within of the remote database, by comparison with reference patterns stored in the remote database M4 and with reference to curves of evolution of the wear over the life of the tire, such as, for example, curves evolution of the residual height H of the circumferential rib as a function of the number of landings made NLPT (Number of Landings Per Tread). Finally, a last step is a step of restoring information on the state of the tire, such as the wear rate U = (H0-H) / H0 of the circumferential rib, at a given instant, HO being the initial height of the circumferential rib, measured on the tire in the new state, and H being the residual height of the circumferential rib, measured on the tire at least partly used, or the number of residual landings.

FIG. 2 represents a partial perspective view of an aircraft tire, comprising wear indicators adapted to the method for determining the state of an aircraft tire according to the invention. The tire 1 comprises a tread 2 intended to come into contact with a ground via a rolling surface 3. The tread 2 comprises five circumferential ribs 4 and four circumferential grooves 5 separating the two circumferential ribs. Two circumferential shoulder ribs, axially outermost, and the median circumferential rib each comprise a wear indicator 6 comprising cylindrical cavities opening on the rolling surface 3 and independent from each other. Figure 3 shows a meridian section of the tread of an aircraft tire comprising wear indicators adapted to the method of determining the state of an aircraft tire according to the invention. The tread 2 comprises five circumferential ribs including two circumferential shoulder ribs (41, 43) and a medial circumferential rib 42, each comprising a wear indicator (61, 62, 63). Each wear indicator (61, 62, 63) comprises cylindrical cavities 7 opening on the running surface 3 and independent from each other. Each circumferential rib (41, 42, 43) has an initial height HO, measured on the tire in the new state, and is intended to be worn down to a permissible residual height HR (not shown).

Figure 4 shows a perspective view of a wear indicator. The wear indicator 6 comprises a state pattern constituted by a first family of wear cavities 8, intended to quantify the rate of wear of the circumferential rib at any moment of the life of the tire, each cavity of wear 8 being a plenum depth cylinder having an emergent surface inscribed in a circle of diameter Dl. The wear indicator 6 comprises a positioning pattern constituted by a second family of positioning cavities 9, intended to locate the axial positioning of the wear indicator, that is to say its positioning in the axial width. of the tread, each wear cavity 9 being a depth cylinder P2 _j having a through surface inscribed in a circle of diameter D2.

Figure 5 shows a top view of a wear indicator at different wear rates. The wear indicator 6 comprises a state pattern constituted by a first family of N1 = 10 wear cavities 8 having a through surface inscribed in a circle of diameter D1 and a positioning pattern constituted by a second family of N2. = 3 positioning cavities 9 having a through surface inscribed in a circle of diameter D2. The wear indicator is shown at various wear rates. As seen above, the wear rate is, by definition, equal to U = 1-Η0 / Η, H0 being the initial height of the circumferential rib, on a new tire, and H the height of the circumferential rib, on a pneumatic tire. less partially used. On the new tire, the wear rate U is therefore 0%. On the completely worn tire, the wear rate U is equal to 1-H0 / HR, where HR is the residual height Eligible: by convention, this maximum wear rate is taken as 100%. A wear rate equal to 10% corresponds to a circumferential rib height equal to H = H0-0.1 * (H0-HR) and, more generally, a wear rate equal to i% corresponds to a circumferential rib height. equals H = H0- (i / 100) * (H0-HR). For a zero wear rate, the wear indicator 6 comprises ten wear cavities 8 and three positioning cavities 9. For a wear rate equal to 10%>, a first wear cavity C1, having a depth Pl i equal to 0.1 * (H0-HR), has been completely worn out and is no longer visible on the running surface: the wear indicator 6 then comprises nine wear cavities 8 and three cavities of 9. For a wear rate equal to 20%>, a second wear cavity Cl ₂ , having a depth Pl ₂ equal to 0.2 * (H0-HR), has been completely worn out and is no longer apparent on the running surface: the wear indicator 6 then comprises eight wear cavities 8 and three positioning cavities 9. For a wear rate equal to 30%>, a third wear cavity C1 ₃ having a Pl ₃ depth equal to 0.3 * (H0-HR), has been completely worn and is no longer apparent on the tread surface: the wear indicator 6 then comprises seven wear cavities 8 and tr Finally, for a wear rate equal to 100%, all the wear cavities 8 of the wear indicator 6 have been completely worn: only the three positioning cavities 9 are visible. respective depths P2 _j , j varying from 1 to 3, are strictly greater than H0-HR. FIG. 6A shows, for a new tire with a zero wear rate, three wear indicators (61, 62, 63) respectively positioned in the medial circumferential rib 42 and the circumferential shoulder ribs (41, 43). ), said circumferential ribs not being shown in Figure 6A. The wear indicator 61 of a first circumferential shoulder rib comprises Nl = 10 wear cavities and N2 = 4 positioning cavities. The wear indicator 62 of a medial circumferential rib comprises Nl = 10 wear cavities and N2 = 3 positioning cavities. The wear indicator 63 of a second circumferential shoulder rib comprises Nl = 10 wear cavities and N2 = 5 positioning cavities. The three wear indicators (61, 62, 63) have the same number NI of wear cavities and N2 numbers of different positioning cavities, making it possible to differentiate them from one another and to identify their membership in a given circumferential rib. . Similarly, FIG. 6B shows, for a totally worn tire with a wear rate equal to 100%, three wear indicators (61, 62, 63) respectively positioned in the medial circumferential rib 42, and circumferential shoulder ribs (41, 43), said circumferential ribs not being shown in Figure 6B. Only the N 2 respective positioning cavities of each of the three wear indicators are apparent, with N 2 = 4 for the first circumferential shoulder rib, N 2 = 3 for the medial circumferential rib and N 2 = 5 for the second circumferential rib of shoulder.

Finally, Figure 7 shows the variation of the height H of a circumferential rib as a function of the number of landings made NLPT (LPT meaning "Landings Per Tread"). In the example presented, the height H of the circumferential rib varies from an initial value equal to 12 mm, for a new tire with a zero wear rate, when no landing has yet been made, until a permissible residual value HR equal to 2 mm, for a totally worn tire with a wear rate equal to 100%, after 400 landings. The evolution of the height H as a function of the number of landings made NLPT is not linear. Thus, wear rates U equal to 25%>, 50%> and 15% respectively correspond, in the present case, to 30, 65 and 160 landings. In practice, for a given tire, mounted on a given aircraft, the evolution curve of the height H of a given circumferential rib as a function of the number of landings made NLPT, OR wear curve, is determined during the first tire life cycle, ranging from the new tire to the fully worn tire, thanks to wear indicators positioned in said circumferential rib. This wear curve thus determined, for a circumferential rib of a given tire on a given plane, can be used to predict the remaining wear potential of the tire at each observation of the tire. This makes it possible to define when the replacement of the tire will be necessary and to plan the maintenance operations in order to reduce the downtime of the aircraft. Furthermore, the finding that, where appropriate, the wear of the circumferential rib of a tire does not follow this wear curve, may reveal an abnormal operation of the tire, for example an irregular wear, and trigger an action of Preventive maintenance. Similarly, the comparison of the tire wear curves equipping several aircraft of the same fleet allows, in case of divergence of said wear curves, identify the aircraft or aircraft on which checks and possible adjustments should be made.

The invention has been more particularly studied in the case of an aircraft tire size 46xl7R20, intended to equip the main landing gear of an airliner. For such a tire, the inflation pressure is 15.3 bars, the static load 21 tons and the maximum speed 360 km / h.

In the example studied, three circumferential ribs, including a medial circumferential rib and two circumferential shoulder ribs, each comprise six wear indicators equidistant according to the circumference of the tire, that is to say, distributed all the time. 60 °. Any wear indicator of a first circumferential shoulder rib, corresponding to the outermost circumferential rib, when the tire is mounted on the landing gear, is a pattern of 14 cylindrical cavities, constituted by a pattern of state of 10 wear cavities, 9 of which are positioned at the center and one at the periphery of the pattern, and with a positioning pattern of 4 positioning cavities, positioned at the periphery of the pattern. Any indicator of wear of the medial circumferential rib, axially in the center of the tread, is a pattern of 13 cylindrical cavities, constituted by a state pattern of 10 wear cavities, 9 of which are positioned in the center and one in the middle. periphery of the pattern, and by a positioning pattern of 3 positioning cavities, positioned at the periphery of the pattern. Any wear indicator of a second circumferential shoulder rib, corresponding to the innermost circumferential rib, when the tire is mounted on the landing gear, is a pattern of cylindrical cavities, formed by a pattern of state of 10 wear cavities, 9 of which are positioned at the center and one at the periphery of the pattern, and with a positioning pattern of 5 positioning cavities positioned at the periphery of the pattern. For each of the three types of wear indicators described above, whose numbers NI of wear cavities are all identical, the Nl = 10 wear cavities C1, i ranging from 1 to 10, have respectively equal depths P1. at i * (H0-HR), corresponding to wear rates varying between 10% and 100% in steps of 10%>. They also have circular emergent surfaces with a diameter of 2 mm. For each of the three types of wear indicators previously described, the number of positioning cavities N2 of which are different from one another, N2 varying between 3 and 5, the N2 positioning cavities C2 _j , j varying from 1 to N2, have depths P2 _j all equal to 1.2 * (H0-HR), corresponding to a wear rate equal to 120%. They also have circular emergent surfaces with a diameter of 4 mm. This configuration corresponds to the wear indicators described in FIGS. 6A and 6B.

Claims

1 - Method for determining the state of an aircraft tire (1), said tire comprising a tread (2) having at least one circumferential rib (4) comprising at least one wear indicator (6), said determining method comprising:

a step of capturing a first wear indicator positioning pattern, intended to locate the positioning of said wear indicator in the tread, a step of capturing a second state of wear pattern; the wear indicator, intended to determine the state of wear of the circumferential rib concerned at a given instant,

a step of analyzing the first positioning pattern and the second state pattern of the wear indicator captured, by comparison with reference patterns, and determining the state of wear of the circumferential rib at a given moment,

a step of restoring information on the state of the tire. 2 - Method for determining the state of an aircraft tire according to claim 1 wherein the step of capturing a first wear indicator positioning pattern and the step of capturing a second Condition pattern of the wear indicator are simultaneous.

3 - Method for determining the state of an aircraft tire according to any one of claims 1 or 2 wherein the step of restitution comprises a step of displaying on an interface to a user.

4 - Method for determining the state of an aircraft tire according to any one of claims 1 to 3 wherein the restitution step comprises information relating to a wear rate U = (H0-H) / H0 of the circumferential rib, at a given instant, HO being the initial height of the circumferential rib, measured on the tire in the new state, and H being the residual height of the circumferential rib, measured on the tire at least in part worn.

5 - Method for determining the state of an aircraft tire according to any one of claims 1 to 4 wherein the restitution step comprises information relating to the number of residual landings authorized by the state of wear of the circumferential rib at a given time, the wear rate being correlated to a number of landings, according to a previously established mathematical model.

6 - Method for determining the state of an aircraft tire according to any one of claims 1 to 5 wherein the restitution step comprises information relating to irregular wear of the circumferential rib at a given instant, such as that a wear rate differential between two distinct circumferential ribs.

7 - Method for determining the state of an aircraft tire according to any one of claims 1 to 6 comprising a step of identifying the tire by recognizing an individual marking, consisting of a series of numbers.

8 - Method for determining the state of an aircraft tire according to any one of claims 1 to 6, comprising a step of identifying the tire by reading an RFID identifier of the tire, containing identification data of the tire. pneumatic can be read by a suitable means.

9 - Method for determining the state of an aircraft tire according to any one of claims 1 to 8 comprising a step of transmitting captured information to a database.

10 - Method for determining the state of an aircraft tire according to any one of claims 1 to 9 comprising a step of transmitting captured information to a database, the captured information being related to the geolocation of the tire and / or the date and time of the capture steps.

11 - System for implementing a method for determining the state of an aircraft tire according to any one of claims 1 to 10 comprising

means of capture,

means for transmitting data,

-Means of analysis,

-a database. 12 - System for implementing a method for determining the state of an aircraft tire according to claim 11 comprising means for displaying the state of the tire.

13 - System for implementing a method for determining the state of an aircraft tire according to one of claims 11 or 12 wherein the capture means and / or the display means and / or the data transmission means and / or the analysis means are implemented by an optoelectronic device, preferably of the smartphone type.