EP3938627A1

EP3938627A1 - Method for detecting a possible fuel leak in an oil circuit of an aircraft engine

Info

Publication number: EP3938627A1
Application number: EP20725832.8A
Authority: EP
Inventors: Sébastien Jean Fernand DENEUVE; Ruben Abraham ELBAZ; Alrick Patrick Michel Jacques VERRIER; Christophe MATHEDARRE; Nicolas Andréa FABBRO
Original assignee: Safran Aircraft Engines SAS
Current assignee: Safran Aircraft Engines SAS
Priority date: 2019-03-15
Filing date: 2020-03-05
Publication date: 2022-01-19
Also published as: CA3130266A1; FR3093806A1; US20220178272A1; CN113518851A; WO2020188179A1; FR3093806B1

Abstract

The invention relates to a method for detecting a possible fuel leak in an oil circuit of an aircraft engine, said aircraft having at least one pair of identical engines equipped with respective oil circuits, said pair of engines being associated with at least one quadruplet of measurements acquired beforehand at a measuring time during operation of the engines of the pair, said measurements corresponding to a pressure measurement and a temperature measurement of the fluid contained in each of the oil circuits of the engines of the pair. Moreover, the method includes: - a step (100) of determining a quantity Q representative of a possible difference in operation between the engines of the pair, depending on the quadruplet of measurements, - a step (200) of comparing the quantity Q with a threshold value determined beforehand, so as to obtain a comparison result, - a step (300) of detecting a possible leak of fuel in the oil circuit of one of the engines of the pair, depending on the comparison result.

Description

Title of the invention: Method for detecting a possible fuel leak in an oil circuit of an aircraft engine

Prior art

The present invention belongs to the field of monitoring

operation of an aircraft engine, when said aircraft has at least one pair of identical engines. It relates more particularly to a method for detecting a possible fuel leak in an oil circuit of an engine of such an aircraft. The invention finds a particularly advantageous application, although in no way limiting, in the case of an aircraft comprising engines of the turbomachine type.

[0002] An aircraft engine comprises many elements requiring, during operation of the aircraft, to be dynamically lubricated by oil, such as for example bearings, pistons, gears, etc., this in order to reduce any friction between them.

By "dynamic lubrication", we refer here to a lubrication

obtained by setting a lubricant in motion, in this case oil, as opposed to static lubrication corresponding to permanent soaking in a lubricant bath in which the lubricant is not set in motion.

[0004] In order to provide said dynamic lubrication, an aircraft engine conventionally comprises an oil circuit. Such an oil circuit forms a closed circuit comprising one or more pumps configured to set the oil in motion within the pipes of said oil circuit. The latter also has a reservoir, in which the oil is stored when the engine is not running, and in which the oil is pumped for circulation in the pipes.

[0005] In addition to being configured to allow oil circulation, the oil circuit also has the function, via said oil circulation and the

physico-chemical characteristics of it, to regulate the temperature of engine parts set in motion during operation of the aircraft, in particular bearings. By "regulating the temperature", one refers here to the fact of evacuating calories, or, in other words, to cool.

[0006] The lubrication and thermal regulation provided by the oil are therefore

vital for the proper functioning of the engine. Regarding more

specifically thermal regulation, this generally takes place at the level of heat exchangers installed in the engine. These exchangers are of the oil-fuel type, so that the oil circuit is in contact with the engine fuel circuit. Thus, the oil is cooled by the fuel which is stored in a dedicated tank at low temperature.

[0007] In the event that a breach would appear at an interface (such as a seal, a wall, etc.) between the oil circuit and the fuel circuit, fuel would leak into the oil circuit and contaminate the latter, due to the fact that the pressure in the fuel circuit is higher than that in the oil circuit.

[0008] Such a fuel leak in the oil circuit is problematic. She

in fact degrades the lubrication and cooling performance of the oil. More specifically, in the event of a leak, the temperature of the fluid (mixture of oil and fuel) then contained in the oil circuit increases, and therefore cools the engine less well. Moreover, said temperature increasing, the pressure of the fluid decreases accordingly. Such conditions, in the most unfavorable cases (large and / or prolonged leak for example), can lead to ignition of the oil and fuel mixture, and thus cause a fire in the engine.

[0009] We therefore understand that it is imperative to be able to detect such a fuel leak in the oil circuit as soon as possible when it occurs.

Nevertheless, and until very recently, there was no means of detecting this leakage phenomenon, mainly because of its rarity, and therefore the little data available to characterize it. The surveillance put in place was aimed above all at detecting, by means of dedicated sensors, the consequences of such a leak, such as for example a start of fire, and therefore were at best curative. [0010] In document FR 2 980 238, a solution has been proposed for attempting to detect a fuel leak in the oil circuit. This solution consists in automatically and continuously monitoring any variations in the fluid level, or equivalent variations in the volume of fluid, in the oil circuit, as a function of the operating conditions of the engine, such as for example identification of a deceleration of the engine speed in particular. Thus, if said fluid level increases during operation of the aircraft, there is reason to suspect a possible fuel leak.

[001 1] However, despite the advantages provided by this solution, there is a

need to improve fuel leak detection in an oil system.

[0012] In fact, there is a need to further simplify the implementation by making the leak detection independent of the operating conditions induced by the path of the aircraft. There is also a need to further improve the precision of the leak detection by limiting as much as possible the cases of false fault detection, or, conversely, of non-detection of a real fault. There is also a need to limit the costs and to simplify the installation by avoiding in particular, as far as possible, the use of dedicated sensors expensive and complex to install having regard to the strong constraints of structural dimensioning of the engine, especially in the case of

turbomachines.

Disclosure of the invention

[0013] The present invention aims to remedy all or part of the

drawbacks of the prior art, in particular those set out above, by proposing a solution which makes it possible to detect, in a simple and precise manner, a possible fuel leak in an oil circuit of an aircraft engine comprising a plurality of engines, while avoiding the conditions of

operation induced by the path of the aircraft, as well as avoiding any hardware reconfiguration of the aircraft engines.

To this end, and according to a first aspect, the invention relates to a method for detecting a possible fuel leak in an oil circuit of an aircraft engine, said aircraft comprising at least one pair of identical engines and equipped with respective oil circuits, said pair of motors being associated with at least one quadruple of measurements previously acquired in a measurement instant during operation of the motors of the pair and corresponding to a pressure measurement and a temperature measurement of the fluid contained in each of the oil circuits of the engines of the pair. In addition, said detection method comprises:

- a step of determining a quantity Q representative of a possible difference in operation between the motors of the pair, as a function of the quadruple of measurements,

a step of comparing the quantity Q with a predetermined threshold value, so as to obtain a comparison result,

- a step of detecting a possible fuel leak in the oil circuit of one of the engines of the pair, depending on the comparison result.

[0015] The fact of looking for a possible difference in operation between the

motors of the pair, depending on the quadruple of measurements, allows

advantageously to overcome the operating conditions induced by the path of the aircraft. Indeed, the detection of a possible leak according to the invention is carried out in connection with the study of parameters (pressure, temperature) in a single measurement instant, and not in connection with the study of the variation of one or more parameters at a plurality of measurement instants. The two motors of the pair thus form a measurement reference system evaluated at a given measurement instant, the operation of one of the motors being determined according to the other motor.

[0016] Furthermore, the fact of considering pressure and temperature measurements in each of the oil circuits of the engines of the pair makes it possible to accurately assess a possible difference in operation. In fact, measurements of this type are conventionally carried out by means of pressure and temperature sensors, the design of which is largely mastered. These sensors are also of reduced cost as well as easily integrated into engines. In other words, it is not necessary to use expensive and complex sensors such as those able to take into account the altitude of the engine in flight, any expansion of the oil, etc. Finally, the implementation of the method does not require any hardware reconfiguration of the engines of the aircraft, given that the pressure and temperature measurements can be carried out by means already equipping, in a conventional manner, any engine.

In general, all of the steps of the method can be implemented by a processing device external to the engines, for example located in a ground station, so that there is no need to modify the configuration. engine material.

[0019] In particular modes of implementation, the detection method may also include one or more of the following characteristics, taken in isolation or in any technically possible combination.

In particular modes of implementation, the step of determining the quantity Q comprises:

- a calculation of a first quantity Qi representative of a pressure difference between the two motors, based on the pressure measurements of the quadruple,

- a calculation of a second quantity Q ₂ representative of a temperature difference between the two motors, as a function of the temperature measurements of the quadruplet,

- a calculation of the quantity Q as a function of the quantities Qi and Q ₂ .

The determination of deviations following the calculation of the quantities Q ₁ and Q ₂ is

particularly simple to implement, and makes it possible to compare parameters of the same unit with one another. In addition, it does not require significant calculation means, thus allowing rapid determination of the quantity Q.

In particular modes of implementation, the quantity Q is calculated according to the following formulation:

Q ^™ Q _% Q _Zf

or :

- Qi is calculated equal to the difference between the pressure measurements of the quadruplet,

- Q ₂ is calculated equal to the difference between the temperature measurements of the quadruple. [0023] In particular embodiments, said method comprises, after the step of determining the quantity Q and before the step of comparison, a step of updating the quantity Q in which the quantity Q put à jour corresponds to the absolute value of the quantity Q previously determined.

The fact of updating the quantity Q by calculating its absolute value makes it possible to simplify the management of the threshold value to be considered during the comparison step, all the numbers considered, namely the quantity Q and the value threshold, being indeed positive.

[0025] In particular embodiments, said method comprises

following the detection step and when a leak is detected, a step of issuing an alert message.

In particular embodiments, said method comprises, following the detection step and when a leak is detected, a step of identifying a faulty motor among the motors of the pair, said step identification including:

- a comparison of the pressure measurements and / or a comparison of the temperature measurements of the quadruplet associated respectively with the motors of the pair,

- identification of a faulty engine based on said comparison of pressure measurements and / or said comparison of temperature measurements.

[0027] In particular embodiments, when an alert message is sent, said alert message includes an identifier of the identified faulty engine.

In particular embodiments, each motor of the pair is also associated with at least two measurements of the volume of fluid contained in the oil circuit of said motor of the pair and previously acquired in two respective measuring instants distinct during operation of the aircraft, a measurement instant prior to take-off of the aircraft and a measurement instant subsequent to the landing of the aircraft. In addition, said method comprises, for at least one motor of the pair:

a step of determining a difference V between the two measurements of the volume of fluid associated with said motor, a step of comparing the difference V with a threshold value determined as a function of a theoretical average oil consumption of the faulty engine and of a period separating said distinct measuring instants,

and, following said identification step:

- a possible confirmation step, depending on the result of the comparison of the difference V with the threshold value, of the identity of the engine identified as faulty.

[0029] The implementation of these steps of determining a deviation V, of

comparison of this difference V with a threshold value, and for possible confirmation, advantageously makes it possible to carry out an additional verification of the possible presence of a fuel leak in an engine of the aircraft.

[0030] Thus, when a fuel leak has been detected in an engine, on the

based on pressure and temperature measurements, another detection of this leak on the basis of additional measurements of fluid volumes makes it possible to confirm said leak. Proceeding in this way increases the robustness of the detection of a leak.

In particular embodiments, several quadruplets of

measurements are considered, at least the steps of determining a quantity Q, comparing the quantity Q with a threshold value and detecting a possible leak being iterated for each of said measurement quadruplets.

In particular embodiments, the aircraft comprises several pairs of identical engines, at least the steps of determining a quantity Q, of comparing the quantity Q with a threshold value and of detecting a possible leak being iterated for each of said pairs.

[0033] According to a second aspect, the invention relates to a computer program comprising a set of program code instructions which, when executed by a processor, configure said processor to implement a detection method according to invention.

[0034] According to a third aspect, the invention relates to a recording medium readable by a computer on which is recorded a computer program according to the invention. According to a fourth aspect, the invention relates to a processing device for the detection of a possible fuel leak in an oil circuit of an aircraft engine, said aircraft comprising at least one pair of identical engines. and equipped with respective oil circuits, said pair of motors being associated with at least one quadruple of measurements previously acquired in a measurement instant during operation of the motors of the pair and

corresponding to a pressure measurement and a temperature measurement of the fluid contained in each of the oil circuits of the engines of the pair. In addition, the treatment device comprises:

- a determination module, configured to determine a quantity Q representative of a possible difference in operation between the motors of the pair, as a function of the measurement quadruple,

- a comparison module, configured to compare the quantity Q with a predetermined threshold value, so as to obtain a comparison result,

- a detection module, configured to detect a possible fuel leak in the oil circuit of one of the engines of the pair, depending on the comparison result.

[0036] In particular embodiments, the processing device may further include one or more of the following characteristics, taken in isolation or in any technically possible combination.

[0037] In particular embodiments, said device comprises a

identification module configured for, when a leak is detected:

- compare the pressure measurements and / or the temperature measurements of the quadruple associated respectively with the motors of the pair,

identifying a faulty engine as a function of said comparison of the pressure measurements and / or of said comparison of the temperature measurements.

In particular embodiments, each motor of the pair is also associated with at least two measurements of the volume of fluid contained in the oil circuit of said motor of the pair and previously acquired in two distinct respective measuring instants during of the operation of the aircraft, an instant of measurement prior to take-off of the aircraft and an instant of measurement subsequent to the landing of the aircraft. In addition, said device comprises: a determination module, configured to determine a difference V between the two fluid volume measurements associated with a motor of the pair,

- a comparison module, configured to compare the deviation V with a threshold value determined as a function of the theoretical average oil consumption of the faulty engine and of a period between said separate measurement instants,

- a confirmation module, configured to possibly confirm, depending on the result of the comparison of the deviation V with the threshold value, the identity of the engine identified as faulty.

[0039] According to a fifth aspect, the invention relates to a system for detecting a possible fuel leak in an oil circuit of an aircraft engine, said aircraft comprising at least one pair of identical engines and equipped with respective oil circuits. In addition, said detection system comprises:

- acquisition means configured to acquire at least one quadruple of measurements in a measurement instant during operation of the motors of the pair and corresponding to a pressure measurement and a temperature measurement of the fluid contained in each of the oil circuits motors of the pair,

- a treatment device according to the invention,

- Means of communication from the measurement quadruplet to the processing device.

In particular embodiments, said acquisition means are also configured to acquire, for each engine of the pair, at least two measurements of the volume of fluid contained in the oil circuit of said engine in two measurement instants. respective distinct during operation of the aircraft, a measurement instant prior to take-off of the aircraft and a measurement instant subsequent to the landing of the aircraft, said processing device being in accordance with the invention, and the means communication systems also being configured to transmit the fluid volume measurements to the processing device.

[0041] According to a sixth aspect, the invention relates to an aircraft comprising a

detection system according to the invention.

Brief description of the drawings Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate an exemplary embodiment thereof without any limiting character. In the figures:

[Fig. 1] FIG. 1 diagrammatically represents an exemplary embodiment of a detection system according to the invention of a possible fuel leak in an oil circuit of an aircraft engine, said aircraft comprising at least one pair of identical engines;

[Fig. 2] FIG. 2 represents a flowchart of an embodiment of a method for detecting according to the invention of a possible fuel leak in an oil circuit of an engine of said aircraft, from measurements pressure and temperature;

[Fig. 3] FIG. 3 represents a preferred embodiment according to the invention of the method of FIG. 2, during which, when a leak is detected, a faulty engine is identified among the engines of the aircraft;

[Fig. 4] FIG. 4 shows a preferred embodiment according to the invention of the detection method, from measurements of pressure, temperature and volume of fluid, and during which, when a faulty engine has been identified, a

possible confirmation of the identification of this faulty engine is sought.

Description of embodiments

[0043] The present invention finds its place in the field of monitoring the operation of an aircraft engine, for an aircraft (not shown in the figures) comprising at least one pair of identical engines.

[0044] Conventionally, each engine of the aircraft is equipped with a

oil circuit, so that the aircraft has as many engines as there are oil circuits. The oil circuit of each engine forms a closed circuit comprising one or more pumps configured to set the oil in motion within pipes of said oil circuit. The latter also comprises a reservoir, in which the oil is stored when the engine that it equips is not in operation, and in which the oil is pumped for putting into circulation in the pipes. The oil circuit of an engine of the aircraft is also in contact, at a plurality of interfaces, such as for example seals, walls, equipment, etc., with a circuit fuel from said engine.

[0046] Figure 1 schematically shows an embodiment of a

system 10 for detecting a possible fuel leak in an oil circuit of an aircraft engine.

The rest of the description is aimed more specifically, but in a manner

in no way limiting, an aircraft of the airplane type equipped with two identical engines of the turboshaft type, such as, for example, turboprop engines. Since the aircraft has a pair of engines, the number of oil circuits is therefore also equal to two, these oil circuits also being identical to each other.

However, following other examples not detailed here, nothing excludes

consider other types of turbine engines, such as a

turbojet, but also, and more generally, engines which are not turboshaft engines, such as, for example, piston engines.

The invention is in fact applicable to any type of engine for which it is desired to monitor any possible contamination of its oil circuit by fuel. There is also nothing to exclude considering an aircraft of another type, such as a helicopter.

[0049] Furthermore, it should be noted that no limitation is attached to the number of pairs of identical engines of the aircraft. For example, the aircraft can have two pairs of engines, so as to be equipped with a total of four engines which can either all be identical to each other (in other words the pairs are identical to each other), or correspond to two different pairs between them , the motors within the same pair being nevertheless identical to each other. Finally, nothing excludes the aircraft also having, in addition to one or more pairs of identical engines, one or more engines which, considered individually, differ from all the other engines.

The detection system 10 comprises acquisition means 11 configured to acquire measurements of pressure and temperature of the fluid contained in each of the oil circuits of the engines of said pair. By "fluid" contained in an oil circuit, we refer here to a liquid circulating in the pipes of said circuit. Under nominal operating conditions, that is to say when no fuel leak affects an oil circuit, the fluid contained in the oil circuit naturally corresponds only to oil. Conversely, when a fuel leak occurs, the fluid contained in the oil circuit corresponds to a mixture of oil and fuel.

It should be noted that under nominal operating conditions, the

respective oil pressures and temperatures in each of the oil circuits are substantially identical and follow the same trends. This results from the fact that the engines of the pair receive identical commands, such as a displacement command during taxiing, a flight command during the cruise phase, etc., and are therefore supposed to be subjected to the same operating conditions. .

For example, the acquisition means 1 1 comprise dedicated sensors for each type of measurement, each motor then comprising a pressure sensor and a temperature sensor, also called a temperature probe. Such sensors can be chosen depending on the oil used as well as the sizing characteristics of the engines.

[0054] It is noted that the oil pressure corresponds to a relative pressure, for

example displayed on the aircraft dashboard in PSI unit (acronym for the English expression "pound per square inch"). The temperature, for its part, is for example displayed in degrees Celsius or else in degrees Fahrenheit.

The measurements acquired by the acquisition means 11 are performed in at least one measurement instant during the operation of the engines of the aircraft. By “operation of the engines of the aircraft”, reference is made here to the fact that the engines of the aircraft have started. Such a configuration naturally covers the taxiing phases before and after landing (phases still referred to as "taxi" in the English literature), the cruising phase, but also the phases during which the aircraft has not yet left its parking lot before. take-off or has already reached its parking lot after landing, its engines nonetheless being operating. Thus, at each measurement instant is associated a measurement quadruple, this measurement quadruple corresponding to a pressure measurement and to a temperature measurement of the fluid contained in each of the oil circuits of the engines of said pair.

Preferably, the acquisition means 11 of the detection system 10 are also configured to acquire, in addition to the pressure and temperature measurements, and for each motor of the pair, at least two measurements of the volume of fluid contained in the engine oil circuit considered in two distinct respective measuring instants. For example, in addition to pressure and temperature sensors, the acquisition means 11 also include sensors dedicated to volume measurements, typically level probes. It should be noted that the fluid volume measurements do not require the aircraft engines to be in operation, and conventionally correspond to the volumes of fluid respectively contained in the engine tanks.

It should be noted that in this preferred embodiment, no limitation is attached to the measurement instants in which the fluid volume measurements are carried out. More particularly, nothing excludes the measurement instants associated with said measurement quadruplets from being at least in part, or even all, different from the measurement instants associated with volume measurements.

When measurements have been acquired by the acquisition means 11 of the detection system 10, these measurements are transmitted, by means of communication means 12 of the detection system 10, between said means

acquisition 1 1 and a processing device 13 also part of the detection system 10. Once these measurements have been received by the processing device 13, the latter can perform processing aimed at detecting a possible fuel leak in an oil circuit of one of the engines of the pair, by implementing a detection method such a possible leak.

The processing device 13 comprises for example one or more

processors and storage means (magnetic hard disk, electronic memory, optical disk, etc.) in which data and a computer program are stored, in the form of a set of program code instructions to be executed for implement all or part of the stages of method of detecting a possible leak. Alternatively or in addition, the processing device 13 also comprises one or more programmable logic circuits, of the FPGA, PLD, etc. type, and / or specialized integrated circuits (ASIC), and / or a set of discrete electronic components, etc. suitable for implementing all or part of the steps of the process for detecting a possible leak.

In other words, the processing device 13 comprises a set of means configured in software (specific computer program) and / or hardware (FPGA, PLD, ASIC, etc.) to implement the various steps of the process for detecting a possible leak.

In a first variant embodiment of the invention, the device for

treatment 13 is located on the ground, for example in the premises of the manufacturer of the engines equipping the aircraft, or in the premises of the airline to which the aircraft belongs, or even in the premises of an airport and dedicated to the analysis of flights departing / arriving at this airport.

Thus, according to this first variant embodiment, said means of

communication 12 are configured to transmit the measurements acquired within the aircraft to the processing device 13 on the ground. For example, said communication means 12 comprise ACARS units (acronym of the English expression “Airline Communications, Addressing and Reporting System”), respectively equipping the aircraft and the processing device 13, and configured to communicate according to the ARINC standard. (acronym of the Anglo-Saxon expression "Aeronautical Radio Incorporated").

[0064] According to a second variant embodiment, the processing device 13 is integrated into the aircraft. In this case, said communication means 12 are for example wired or wireless, and configured to transmit the measurements acquired to the processing device 13 according to any protocol.

adapted communication. No limitation is attached to the choice of wired or wireless transmission, as well as a particular communication protocol. The treatments carried out by the processing device 13 to detect a possible fuel leak in an oil circuit of one of the engines of the pair can be carried out in real time or else in deferred time.

For example, when several measurement quadruplets are transmitted, following measurements carried out in several measurement instants, the processing device 13 implements the detection method on each reception of one of the

quadruplets. Alternatively, all or part of the quadruplets are recorded in the storage means of the processing device 13, and analyzed in deferred time via said detection method.

According to yet another example, the detection system 10 comprises ancillary storage means, such as for example a database stored on a local server on the ground. These storage means are not integrated into the processing device 13, and receive measurements acquired, for example thanks to the transmissions of an ACARS unit, to store them and only then transmit them to the processing device 13 with a view to their analysis.

[0068] The remainder of the description aims to detail the main steps of the process for detecting a possible fuel leak in an oil circuit of one of the engines of the pair. In order to simplify said description, and unless otherwise stated, we first consider the situation in which a single quadruple of measurements has been transmitted to the processing device 13. The case where fluid volume measurements are also transmitted is treated subsequently. with reference to a preferred embodiment of the method.

In other words, a single measurement instant is considered, for example a

instant of measurement subsequent to the landing of the aircraft. The two motors of the pair are respectively denoted Mi and M ₂ . The quadruplet, for its part, is denoted (Pi, P ₂ , T ,, T ₂ ) where:

- Pi and Ti correspond to the respective pressure and temperature measurements of the fluid in the oil circuit of the M-i engine,

- P ₂ and T ₂ correspond to the respective pressure and temperature measurements of the fluid in the oil circuit of the engine M ₂ .

The choice of a particular measurement instant during the operation of the engines constitutes only one variant of implementation of the invention. By Consequently, nothing excludes said measurement instant from corresponding to a taxiing, cruising or even parking phase of the aircraft, as soon as the motors of the pair are in operation.

Furthermore, it should be noted that the number of quadruplets considered, and therefore ultimately the number of measurement instants considered, do not constitute a limitation of the invention. The same is true of the number of identical engine pairs in the aircraft. This point is dealt with subsequently with reference to particular embodiments of the method.

FIG. 2 represents a flowchart of an embodiment of the method for detecting a possible fuel leak in an oil circuit of an engine of the pair, from measurements of pressure and of temperature.

The detection method comprises several steps. In principle

In general, the method consists first of all in quantifying, as a function of the measurement quadruplet (Pi, P ₂ , Ti, T ₂ ), any difference in operation between the motors M ₁ and M ₂ of the pair. This quantification is carried out by calculating a metric representative of the phenomenon considered (fuel leak in an oil circuit), this metric then serving as a decision criterion as to the existence or not of a fuel leak.

To this end, the detection method firstly comprises a step 100 of determining a quantity Q representative of a possible difference in operation between the motors M ₁ and M ₂ of the pair, as a function of the quadruple. of measurements (Pi, P ₂ , Ti, T ₂ ).

By “quantity Q”, we refer here to the fact that Q is a real number.

The fact of looking for a possible difference in operation between the motors of the pair, as a function of the measurement quadruple, allows

advantageously to overcome the operating conditions induced by the path of the aircraft. Indeed, the detection of a possible leak in this mode of implementation is carried out in connection with the study of parameters, which are the pressure and the temperature, in a single instant of measurement, and not in connection with the study of the variation of one or more parameters at a plurality of measurement instants. The two motors M ₁ and M ₂ thus form a measurement reference evaluated at a given measurement instant, the operation of one of the motors being determined as a function of the other motor.

Furthermore, the fact of considering pressure measurements P _1; P ₂ and

temperature Ti, T ₂ in each of the oil circuits of the engines of the pair makes it possible to accurately assess any difference in

operation. The design of pressure and temperature sensors is indeed largely mastered, thus making it possible to carry out very precise measurements.

Finally, it is also understood that the implementation of the method does not

requires no hardware reconfiguration of the aircraft engines, given that the acquisition means 1 1 are already present in any

construction of this type, and that the processing device 13, when integrated into the aircraft, may be located outside said engines, for example in the cockpit.

In a particular embodiment, the step of determining the quantity Q comprises the calculation of a first quantity Qi representative of a pressure difference between the two motors M-, and M ₂ , as a function of measurements of pressure P-, and P ₂ of the quadruplet. It also includes the calculation of a second quantity Q ₂ representative of a temperature difference between the two motors M ₁ and M ₂ , as a function of the temperature measurements Ti and T ₂ of the quadruplet. The quantity Q is finally calculated as a function of the quantities Q ₁ and

^Q ₂ .

The determination of deviations following the calculation of the quantities Qi and Q ₂ is

particularly simple to implement, and makes it possible to compare parameters (pressure, temperature) of the same unit with each other. In addition, it does not require significant computing resources, thus allowing a

rapid determination of the quantity Q.

The choice of determining the quantity Q by calculating said quantities Q1 and Q2 constitutes only one variant of implementation of the invention. Thus, nothing excludes determining the quantity Q otherwise, for example on the basis of calculations involving products (in the sense of multiplication) between pressures and temperatures, for example P1 xT1 and P2xT2, or even of pressure products between them and temperature products between them, for example P1XP2 and T ixT ₂ .

[0082] More generally, the choice of a particular determination of the

quantity Q depends, in particular, on the threshold value with which it is compared, as described later. Thus, if we have threshold values that are homogeneous to the product of a pressure and a temperature, for example following calculations carried out from measurements regularly recorded during aircraft flights or even following numerical simulations, the determination of the quantity Q is carried out in correspondence with the units of these threshold values.

In a preferred example of implementation, the quantity Q is calculated according to the following formulation:

or :

- Q1 is calculated equal to the difference between the pressure measurements of the quadruple, i.e. equal to PP ₂ (or else P ₂ -Pi, the order in the subtraction not constituting a limitation),

- Q ₂ is calculated equal to the difference between the temperature measurements of the quadruplet, that is to say equal to Ti-T ₂ (or else T ₂ -Ti, the order in the subtraction not constituting a limitation) .

It should be noted that calculating the quantity Q in this way amounts to

determine the norm of a vector whose components are Q ₁ and Q ₂ . In other words, Q corresponds to the computation of the quadratic norm L ² of this vector. It will then be understood that under nominal operating conditions, the norm of this vector is substantially zero given that the quantities Q ₁ and Q ₂ are respectively substantially zero. However, when the pressure P- differs from the pressure P ₂ and / or the temperature Ti differs from the temperature T ₂ , the norm of this vector makes it possible to quantify the operating difference between the two motors of the pair, thus forming a characteristic metric of the phenomenon of fuel leakage in the oil circuit of one of said engines. In other words, the higher the quantity Q calculated in this way, the greater the probability of the existence of a leak, and the greater the importance of the possible leak. By "magnitude of the leak", we refer here to the flow of fuel contaminating the affected oil circuit.

However, following other examples not detailed here, nothing excludes

calculate the quantity Q in a different way. For example, it is possible to consider a quantity Q ₁ (respectively Q ₂ ) representative of a pressure difference (respectively a temperature difference) assigned a weighting coefficient, the respective weighting coefficients of the quantities Qi and Q ₂ being different. According to another example, possibly taken in combination with the previous one aimed at weighting the quantities Q ₁ and Q ₂ , it is also possible to consider a quantity Q corresponding to the calculation of the norm L ^p (Lebesgue space of index p), with p an integer greater than or equal to 1, of the vector whose components are Qi and Q ₂ .

Consequently, at the end of step 100, the detection method supplies the quantity Q, so that it becomes possible to assess whether a fuel leak does indeed affect one of the two engines Mi and M ₂ .

To this end, the method comprises a step 200 of comparing the quantity Q with a predetermined threshold value, so as to obtain a comparison result.

By "comparison with a threshold value", reference is made here to determining whether the quantity Q is less than or indeed greater than said threshold value. The comparison result therefore corresponds to the fact that the quantity Q is less than or much greater than the threshold value.

The threshold value corresponds, for example, to a value obtained following a test campaign. According to another example, the threshold value is set following digital simulations modeling the operation of the engines of the aircraft.

In general, the choice of a threshold value depends on the desired tolerance in the face of possible false leak detections. In other words, the threshold value is representative of the accepted tolerance with respect to any variations in the quantity Q. It is in fact understood that, in the case where the quantity Q is calculated so as to be a number greater than or equal to zero, the closer the threshold value is to the lower limit of the quantity Q, the greater the risk of obtaining false detections, via the detection method. For example, in the case where the quantity Q is calculated, as described above, equal to the quadratic norm L ² of the vector whose

components are Q ₁ and Q ₂ , setting the threshold value equal to zero amounts to considering a high tolerance in the face of possible false leak detections. Indeed, at the slightest variation in pressure and / or temperature, the quantity becomes strictly positive, and therefore greater than the threshold value. Conversely, setting a threshold value that is too high may lead to not taking into account certain variations in pressure and / or temperature between the oil circuits of the engines, and therefore in fine in not detecting a fuel leak while it is this is happening.

A person skilled in the art knows how to adjust the threshold value according to the tolerance

target, for example by taking into account the respective ranges of variation of the sensors.

In a particular mode of implementation, the method comprises, after

the step 100 of determining the quantity Q and before the step 200 of

comparison, a step of updating the quantity Q in which the updated quantity Q corresponds to the absolute value of the previously determined quantity Q.

Indeed, nothing excludes the quantity Q being determined during step 100 so as to correspond to a negative number. For example, the quantity Q can be determined according to the following formulation:

Q = ^. ¾ + ¾

where Qi and Q ₂ are calculated according to formulations identical to those described above, that is to say equal respectively to Pi-P ₂ (or else P ₂ -Pi) and to TT ₂ (or else T ₂ - Ti). Consequently, and according to this example, the fact of updating the quantity Q by calculating its absolute value makes it possible to simplify the management of the threshold value to be considered during the comparison step 200. It is indeed understood that insofar as the updated quantity Q is necessarily greater than or equal to zero, the threshold value to be considered for said updated quantity Q must also be greater than or equal to zero. The detection method then comprises a step 300 of detecting a possible fuel leak in the oil circuit of one of the engines of the pair, as a function of the comparison result.

The detection is carried out according to the result of the comparison.

For example, in the case where the quantity Q is calculated, as described

previously, equal to the quadratic norm L ² of the vector whose

components are Qi and Q ₂ , and possibly updated so that it corresponds to a quantity greater than or equal to zero, a leak in one of the oil circuits of the pair of engines is detected when the quantity Q is greater than the threshold value. Conversely, if said quantity Q is less than said threshold value, no leak is detected.

It is noted that the detection of a possible leak corresponds here to the result of a comparison between numerical quantities (quantity Q and threshold value). In other words, at this stage of the detection method, the information according to which a possible leak has occurred corresponds to digital information, typically expressed in the form of digital bits, which is for example recorded by the storage means of the monitoring device. processing 13 to be analyzed in real time or in deferred time.

In a particular embodiment, illustrated by FIG. 2, the method comprises, following the detection step 300 and when a leak is detected, a step 400 of sending a message from alert.

[0100] Such an alert message can be sent in any form whatsoever, the choice of a particular form of emission constituting only one variant of the implementation of the invention. For example, the message can be transmitted in text format in order to be displayed by display means such as a computer screen, a tablet, a smartphone, an aircraft dashboard dial. According to another example, the alert message is emitted in sound format.

[0101] The transmission of the alert message advantageously makes it possible to warn a

operator, such as a pilot, a member of the ground maintenance personnel, etc. For example, the pilot of the aircraft, once notified of the detection of a leak, can then consider shortening the flight time, or even not taking off if necessary.

[0102] It should be noted that the transmission of the alert message can take place in real time, as soon as the leak is detected, or even in deferred time, for example once the aircraft has landed.

[0103] FIG. 3 represents a preferred embodiment of the method of FIG. 2 during which, when a leak is detected, a faulty motor is identified among the motors of the pair.

[0104] As illustrated in Figure 3, the method comprises, consecutively to

the detection step 300 and when a leak is detected, a step 350

identification of a faulty engine among the engines of the pair.

[0105] This step 350 firstly comprises a comparison of the pressure measurements and / or a comparison of the temperature measurements of the quadruple associated respectively with the motors of the pair.

[0106] Under nominal operating conditions, and as described above, the

pressures Pi and P ₂ (respectively the temperatures Ti and T ₂ ) are substantially equal. On the other hand, in the event of a fuel leak in an oil circuit, the temperature of the fluid contained in said oil circuit increases, and therefore cools the engine associated with said oil circuit less well. Accordingly, the

temperature rises, and therefore the fluid pressure decreases, so that it is possible to determine which motor is faulty by comparing the pressure or temperature reading associated with it with the corresponding reading of the other motor.

[0107] Thus, once the pressure measurements and / or the temperature measurements have been compared with each other, step 350 comprises an identification of a faulty engine as a function of said comparison of the pressure measurements and / or of said comparison of the pressure measurements. temperature measurements.

[0108] For example, in the case where the comparison consists in comparing the

pressure measurements between them, it is determined which of the pressures P ₁ or P ₂ is lower than the other. If P ₁ is less than P ₂ , this means that the motor M-, is faulty, and vice versa. Alternatively, in the case where the comparison consists in comparing the temperature measurements with one another, it is determined which of the temperatures Ti or T ₂ is lower than the other. If Ti is greater than T ₂ , this means that the motor Mi has failed, and vice versa.

[0110] According to yet another alternative, the pressure measurements are compared with each other and the temperature measurements are compared with each other. In this way, it is possible to check the correspondence between the identifications resulting respectively from the comparison of the pressure measurements and from the comparison of the temperature measurements. Proceeding in this way therefore increases the robustness of the identification of the faulty engine.

[01 11] The identification of the engine affected by the fuel leak makes it possible to generate information, comprising for example an identifier of the faulty engine, and which, when it is transmitted to an operator, for example via the alert message emitted, leads to a more precise identification of the leak. In this way, the operator can, depending on the operational context, implement an action plan to minimize or repair the fuel leak.

[01 12] For example, when the treatment device 13 is on the ground and the

alert message is sent in text format to display means controlled by an aircraft engine maintenance operator, this operator is able, once the aircraft is on the ground and once the alert message lu, to carry out maintenance operations aimed at repairing the leak by precisely targeting the faulty engine. Thus, said operator is not required to carry out preliminary examinations aimed at identifying the faulty engine.

[01 13] However, nothing excludes step 350 of identifying the faulty engine from being carried out without any warning message being issued.

[01 14] FIG. 4 represents a preferred embodiment of the detection method, from measurements of pressure, temperature and volume of fluid, and during which, when a faulty engine has been identified, a possible confirmation identification of this faulty engine is sought.

[01 15] In this preferred embodiment, it is considered that the acquisition means 1 1 of the detection system 10 have acquired, for each motor of the pair (Mi, M ₂ ), at least two measurements of the volume of fluid contained in the oil circuit of said engine in two distinct respective measuring instants during operation of the aircraft. Thus, each of the motors of the pair is associated with two measurements of the volume of fluid contained in its oil circuit.

[01 16] The two measurement instants associated with an engine of the pair correspond respectively to a measurement instant prior to take-off of the aircraft and a measurement instant subsequent to the landing of the aircraft. According to a more specific example, these measurement instants take place when the aircraft is in the taxiing phase, respectively before take-off and after landing.

[01 17] It is considered in a nonlimiting manner that the instants of measurement prior to take-off (respectively subsequent to landing), and associated

respectively to the motors of the pair, coincide with each other.

[01 18] It is also considered, for this preferred embodiment, that a fuel leak has been detected in one of the two engines of the pair, at the end of step 300, and that 'furthermore, the faulty engine was identified as such at the end of step 350.

[01 19] Consequently, and as illustrated in FIG. 4, the detection method comprises, following the step 350 of identifying the faulty engine, a step 500 of determining a difference V between the two fluid volume measurements associated with said motor.

[0120] For example, said deviation V is determined by subtracting the measurements from

fluid volume associated with the failed engine. No limitation is attached to the order in which said subtraction is carried out, the choice of a particular order having consequences similar to those already described above in relation to the comparison of the quantity Q with a threshold value during of step 200. Advantageously, said difference V corresponds to the absolute value of a subtraction of the measurements of the volume of fluid.

[0121] It should be noted that the fact of choosing measurement instants

corresponding respectively to a measurement instant prior to take-off of the aircraft and a measurement instant subsequent to the landing of the aircraft is particularly advantageous. Proceeding in this way makes it possible to compare the volumes of fluid outside the cruising phase, so as to avoid any bias linked to the flight conditions. Indeed, the fact of considering the aircraft on the ground makes it possible to ensure that the measurements are carried out under equivalent conditions for the engine which one seeks to determine if it is faulty.

[0122] The method then comprises a step 600 of comparing the difference V

with a threshold value determined as a function of a theoretical average oil consumption of the faulty engine and of a period between said separate measuring instants.

[0123] It is noted that the theoretical average consumption of oil is a physical quantity homogeneous at a flow rate, that is to say the unit of which corresponds to a volume divided by a duration, for example expressed in liters per hour. In addition, the term "theoretical" here refers to oil consumption under nominal conditions, that is, when the engine is not faulty.

[0124] For example, said theoretical average oil consumption is provided by the company in charge of the engine design. Advantageously, the consumption provided by said company is obtained by a statistical method on the basis of previous oil consumption readings, so as to increase the robustness and the precision of the comparison step 600. However, there is nothing to exclude the theoretical average consumption being determined otherwise, for example on the sole basis of the technical specifications of the engine.

As regards the threshold value, this is for example substantially equal, in absolute value, to the product between said theoretical average consumption and the duration separating the instants of measurement. The fact of not choosing the threshold value exactly equal, in absolute value, to the product between the

Theoretical average consumption and the time between the instants of measurement makes it possible to refine the tolerance targeted for taking into account false fault detections, or, conversely, non-detection of a real fault.

[0126] According to another example, it is considered that the oil consumption of an engine is negligible outside the cruising phase, so that only the effective flight time between the measurement instants is taken into account in the calculation of the threshold value.

Said comparison consists in evaluating the difference between the difference V and the threshold value. Under nominal operating conditions, such a difference is substantially zero if the threshold value is equal, in absolute value, to the product between said theoretical average consumption and the time separating the instants of measurement. On the other hand, in the event of a fuel leak in the oil circuit, the quantity of fluid increases in said oil circuit, which is closed, so that the measurement of the volume of fluid in the instant subsequent to landing is greater than the measurement of fluid volume at the instant prior to takeoff. By

Consequently, in the event of a fuel leak in the oil circuit, the difference between the difference V and the threshold value increases in absolute value, thus forming a metric representative of the phenomenon considered (fuel leak in an oil circuit) .

[0128] The method then comprises a step 700 of possible confirmation, as a function of the result of the comparison of the deviation V with the threshold value, of the identity of the engine identified as faulty.

[0129] Said step 700 thus consists in testing whether the engine identified as faulty at the end of step 350 is also identified as faulty on the basis of the value of the difference between the deviation V and the threshold value. Typically, if this difference is judged to be too high, for example by comparing it to yet another threshold value, the engine concerned is again identified as faulty, thus confirming the diagnosis obtained at the end of step 350. Such a manner proceeding makes it possible to increase the criticality of the identification resulting from step 350.

[0130] It will thus be understood that the method as implemented in FIG. 4, and more particularly steps 500 to 700, makes it possible to carry out an additional verification of the possible presence of a fuel leak in an engine of the aircraft. In the event that step 700 does not confirm a failure identification resulting from step 350, different scenarios can be considered, such as, for example, considering additional measurements (pressure, temperature, volume) to reiterate the process.

[0131] Furthermore, the steps 500, 600 and 700 have been described, with reference to FIG. 4, as being executed successively, following the identification step 350. Nothing excludes that they may also be consecutive to the transmission of an alert message generated by the step 400. There is also nothing to exclude having a transmission of a message at the end of the. step 700, the one that can include a confirmation or else an invalidation of a previous message sent during a step 400.

[0132] More generally, the fact that all the steps 500, 600 and 700 are consecutive to the identification step 350 only constitutes a variant

implementation of the invention. Indeed, it is possible to consider that only the possible confirmation step 700 is executed following the identification step 350, the steps 500 and 600 being able for their part to be executed in parallel with the steps 100, 200, 300 and 350 (and optionally also from step 400 where appropriate). We understand of course that such a variant

implementation is possible as long as the measurement of the volume of fluid subsequent to the landing is acquired at the same time or well before the measurements of the quadruple, since it is necessary to be able to at least calculate the deviation V.

[0133] It is also advantageous, when the steps 500 and 600 are executed in parallel with the other steps as indicated above, to iterate the steps 500 and 600 for each motor of the pair. In this way, one avoids carrying out an execution of steps 500 and 600 for an engine which will ultimately not be identified at the end of step 350.

[0134] The invention has heretofore been described by considering a single quadruple of measurements as well as a single pair of identical motors. However, no limitation is attached to these settings.

[0135] Thus, in a particular embodiment, several quadruplets of

measurements are considered. The steps of determination 100, of comparison 200 and of detection 300, and optionally of identification 350 and emission 400 if applicable, are then iterated for each of said measurement quadruplets. Carrying out pressure and temperature measurements in several measuring instants makes it possible to regularly check the operation of the engines, and thus to detect more quickly a possible fuel leak in one of the oil circuits.

[0136] For example, the pressure and temperature measurements are carried out repeatedly, following a constant time step between two measurement instants. It is thus possible to precisely monitor the state of the engine oil circuits. [0137] It is further understood that the smaller the time step, the easier it is to identify the true instant at which the fuel leak occurred, which thus improves experience feedback and therefore also corrective actions to consider to avoid potential further fuel leaks.

[0138] However, following other examples not detailed here, nothing excludes

consider pressure and temperature measurements carried out randomly, or even measurements carried out only during one of the operating phases (parking, taxiing, flight) of the aircraft at a non-constant pitch.

[0139] According to another particular embodiment, optionally in

combination with the previous one in which several measurement quadruplets are considered, several pairs of identical motors are also considered. The steps of determination 100, of comparison 200 and of detection 300, and optionally of identification 350 and transmission 400 if necessary, being iterated for each of said pairs.

For purely illustrative purposes, let us consider an example in which the aircraft comprises four identical engines M _1; M ₂ , M ₃ and M ₄ . It is then possible to consider the pairs (Mi, M ₂ ), (M ₂ , M ₃ ), (M ₃ , M ₄ ) and (M ₄ , Mi). The fact that each engine is shown in two separate pairs also helps identify a failing engine in case a fuel leak occurs. Indeed, if a leak is detected during a first iteration of the method for one of the two motors of the pair (Mi, M ₂ ), then also during a second iteration of the method for one of the motors of the pair (M ₂ , M ₃ ), then the motor M ₂ will be identified as faulty. This identification result can be compared with that of step 350, when the latter is executed, so as to further increase the robustness of the identification of a faulty engine. In addition, it will be clear to those skilled in the art that other pairs of motors can be considered, such as for example only (Mi, M ₂ ) and (M ₃ , M ₄ ).

[0141] Those skilled in the art will also understand that nothing excludes the inclusion of the steps of determining 500 of a deviation V, of comparing 600 of the deviation V with a threshold value, and of possible confirmation 700 in said iterations. relating to pairs of identical engines. [0142] The present method of detecting a possible fuel leak in an oil circuit of an aircraft engine can be carried out in an automated manner without the intervention of an operator at any stage whatsoever. It can be implemented without limitation, depending on the operational context, within a ground station as described above, within an aircraft, within an autonomous software suite dedicated to the monitoring of the operation of aircraft engines, or be integrated into a distributed processing chain for “cloud services” type monitoring services.

Claims

[Claim 1] A method of detecting a possible fuel leak in an oil circuit of an aircraft engine, said aircraft comprising at least one pair of identical engines and equipped with respective oil circuits, said pair of motors being associated with at least one quadruple of measurements previously acquired in a measurement instant during operation of the motors of the pair and corresponding to a pressure measurement and a temperature measurement of the fluid contained in each of the oil circuits of the engines of the pair, the detection method comprising:

- a step (100) of determining a quantity Q representative of a possible difference in operation between the motors of the pair, as a function of the measurement quadruple,

- a step (200) of comparing the quantity Q with a predetermined threshold value, so as to obtain a comparison result,

a step (300) of detecting a possible fuel leak in the oil circuit of one of the engines of the pair, as a function of the comparison result.

[Claim 2] The method of claim 1, wherein the step of determining the quantity Q comprises:

- a calculation of a first quantity Qi representative of a pressure difference between the two motors, as a function of the pressure measurements of the quadruplet,

- a calculation of a second quantity Q2 representative of a temperature difference between the two motors, as a function of the temperature measurements of the quadruplet,

[Claim 3] A method according to claim 2, wherein the amount

Q is calculated according to the following formulation:

Q = jQi + Ql

or :

- Q ₂ is calculated equal to the difference between the temperature measurements of the quadruple.

[Claim 4] A method according to any one of claims 1 to 3, comprising, after the step (100) of determining the quantity Q and before the step (200) of comparison, a step of updating the quantity Q in which the updated quantity Q corresponds to the absolute value of the previously determined quantity Q.

[Claim 5] A method according to any one of claims 1 to 4, comprising, subsequent to the detection step (300) and when a leak is detected, a step (400) of transmitting a message from alert.

[Claim 6] A method according to any one of claims 1 to 5, comprising, subsequent to the step of detecting (300) and when a leak is detected, a step (350) of identifying a faulty engine among the motors of the pair, said identification step (350) comprising:

an identification of a faulty engine as a function of said comparison of the pressure measurements and / or of said comparison of the temperature measurements.

[Claim 7] A method according to claims 5 and 6, wherein, when an alert message is issued, said alert message includes an identifier of the identified faulty engine.

[Claim 8] A method according to any one of claims 6 to 7, in which each motor of the pair is also associated with at least two measurements of the volume of fluid contained in the oil circuit of said motor of the pair and previously acquired in two distinct respective measurement instants, a measurement instant prior to take-off of the aircraft and a measurement instant after landing of the aircraft, said method comprising, for at least one engine of the pair:

- a step (500) of determining a difference V between the two measurements of volume of fluid associated with said motor,

a step (600) of comparing the deviation V with a threshold value determined as a function of a theoretical average oil consumption of the faulty engine and of a period separating said distinct measuring instants, and, following said step of identifying (350):

a step (700) of possible confirmation, as a function of the result of comparison of the difference V with the threshold value, of the identity of the engine identified as faulty.

[Claim 9] A method according to any one of claims 1 to 8, in which several measurement quadruplets are considered, at least the steps of determining (100) a quantity Q, of comparing (200) of the quantity Q with a threshold and detection value (300) of a possible leak being iterated for each of said measurement quadruplets.

[Claim 10] A method according to any one of claims 1 to 9, in which the aircraft comprises several pairs of identical engines, at least the steps of determining (100) a quantity Q, of comparing (200) of the quantity Q with a threshold value and detection (300) of a possible leak being iterated for each of said pairs.

[Claim 11] Computer program comprising an assembly

program code instructions which, when executed by a processor, configure said processor to implement a detection method according to any one of claims 1 to 10.

[Claim 12] A computer readable recording medium on which is recorded a computer program according to claim 11.

[Claim 13] Treatment device (13) for the detection of a possible fuel leak in an oil circuit of an aircraft engine, said aircraft comprising at least one pair of identical engines and equipped with control circuits. respective oil, said pair of motors being associated with at least one quadruple of measurements previously acquired in a measurement instant during operation of the motors of the pair and corresponding to a pressure measurement and a temperature measurement of the fluid contained in each of the circuits engine oil of the pair, the treatment device (13) comprising:

- a determination module, configured to determine a quantity Q representative of a possible difference in operation between the motors of the pair, as a function of the measurement quadruplet,

a detection module, configured to detect a possible fuel leak in the oil circuit of one of the engines of the pair, as a function of the comparison result.

[Claim 14] A device (13) according to claim 13, said device comprising an identification module configured for, when a leak is detected:

- identify a faulty engine based on said comparison of pressure measurements and / or said comparison of pressure measurements

temperature.

[Claim 15] Device (13) according to claim 14, each motor of the pair also being associated with at least two measurements of the volume of fluid contained in the oil circuit of said motor of the pair and previously acquired in two measuring instants respective separate when

operation of the aircraft, a measurement instant prior to take-off of the aircraft and a measurement instant subsequent to the landing of the aircraft, said device comprising:

a determination module, configured to determine a difference V between the two fluid volume measurements associated with a motor of the pair,

a comparison module, configured to compare the deviation V with a threshold value determined as a function of a theoretical average oil consumption of the faulty engine and of a period separating said distinct measuring instants,

- a confirmation module, configured to possibly confirm, by depending on the result of the comparison of the difference V with the threshold value, the identity of the engine identified as faulty.

[Claim 16] System (10) for detecting a possible leak of

fuel in an oil circuit of an aircraft engine, said aircraft comprising at least one pair of identical engines and equipped with respective oil circuits, said detection system (10) comprising:

- acquisition means (11) configured to acquire at least one quadruple of measurements in a measurement instant during operation of the motors of the pair and corresponding to a pressure measurement and a temperature measurement of the fluid contained in each of the circuits engine oil from the pair,

- a treatment device (13) in accordance with any one of

claims 13 to 14,

- means of communication (12) from the measurement quadruplet to the processing device.

[Claim 17] A system (10) according to claim 16, said acquisition means (11) also being configured to acquire, for each motor of the pair, at least two measurements of the volume of fluid contained in the oil circuit of said one. engine in two distinct respective measurement instants during operation of the aircraft, a measurement instant prior to take-off of the aircraft and a subsequent measurement instant to the landing of the aircraft, said processing device (13) being according to claim 15, and the communication means (12) also being configured to transmit the fluid volume measurements to the processing device.

[Claim 18] An aircraft comprising a detection system according to any one of claims 16 to 17.