Method and a device for estimating the health of a power plant of an aircraft having at least one engine and a cloggable filter filtering air upstream from the engine

Abstract

A checking method for checking a power plant of an aircraft, the power plant comprising at least one engine and an air inlet for feeding said at least one engine with air, the power plant including a cloggable filter filtering the air upstream from the engine. An aircraft power check is performed by: determining, in flight or on the ground, the current power actually being developed by the engine without making any allowance for any power losses resulting from the engine being installed in the aircraft or from a level of clogging of the filter, the aircraft power check being considered as being successful when the current power is greater than or equal to a guaranteed minimum power.

Claims

1. A checking method for checking a power plant of an aircraft, the power plant comprising at least one engine and an air inlet for feeding the at least one engine with air, the power plant including a cloggable filter filtering the air upstream from the engine, the engine having an output shaft suitable for connection to a member of the aircraft that does not form part of the engine, the method comprising: performing an aircraft power check by using the following operations: determining, in flight or on the ground, a current power (Pcour) actually being developed by the engine within the aircraft at the output shaft of the engine without making any allowance for an installation power loss resulting from the engine being installed in the aircraft and from any level of clogging of the filter; and determining whether the current power (Pcour) is greater than or equal to a stored guaranteed minimum power (Pmini), the aircraft power check being considered to be successful when the current power (Pcour) is greater than or equal to the guaranteed minimum power (Pmini) and otherwise being considered to be failed; in response to the aircraft power check being failed, generating a signal for cleaning the filter and then performing the aircraft power check a second time after the filter has been cleaned; in response to the aircraft power check the second time being failed, performing an engine health check which makes allowance for the installation power loss, the engine health check being considered to be successful when the current power (Pcour) plus the installation power loss is greater than the guaranteed minimum power (Pmini) and otherwise being considered to be failed; and in response to the engine health check being failed, generating a signal for removing the engine from the aircraft.

2. The method according to claim 1; wherein the determining of the current power (Pcour) comprises the following operations: measuring engine torque, calculating the current power as being equal to the product of the engine torque multiplied by the speed of rotation of the engine, the speed of rotation of the engine being equal to the speed of rotation of the outlet shaft of the engine or equal to the speed of rotation of a shaft rotating at the same speed as the outlet shaft or to the product of a stored proportionality coefficient multiplied by the speed of rotation of a rotary member that is mechanically linked to the outlet shaft.

3. The method according to claim 1; wherein the determining that the current power (Pcour) is greater than or equal to a stored guaranteed minimum power (Pmini) comprises the following operations: calculating an aircraft power indicator (APC) that is a function solely of the current power (Pcour) and of the stored guaranteed minimum power (Pmini), the aircraft power check being considered as succeeding or failing as a function of a value of the aircraft power indicator relative to zero.

4. The method according to claim 1; wherein when an engine health check succeeds, the method includes a generation step for generating flight authorization for the aircraft complying at least with predetermined performance of the aircraft calculated on the basis of at least the guaranteed minimum power (Pmini) for the engine and on the basis of a second power loss corresponding to the filter being clogged.

5. The method according to claim 1; wherein when an aircraft power check succeeds, the method includes a generation step for generating flight authorization for the aircraft complying at least with predetermined performance of the aircraft calculated on the basis of at least the guaranteed minimum power for the engine and on the basis of a second power loss corresponding to the filter not being clogged.

6. A power-check device for automatically checking a power plant of an aircraft, the power plant comprising at least one engine and an air inlet for feeding the at least one engine with air, the power plant including a cloggable filter filtering the air upstream from the engine, the engine having an output shaft suitable for connection to a member of the aircraft that does not form part of the engine, the power-check device comprising: a measurement system for measuring, in flight or on the ground, at least one information representative of a current power (Pcour) actually being developed by the engine within the aircraft at the output shaft of the engine without evaluating an installation power loss resulting from the engine being installed in the aircraft and from any level of clogging of the filter; and a power-check computer configured to perform an aircraft power check by determining whether the current power (Pcour) is greater than or equal to a stored guaranteed minimum power (Pmini), the aircraft power check being considered to be successful when the current power (Pcour) is greater than or equal to the guaranteed minimum power (Pmini) and being otherwise considered to be failed; wherein the power-check computer is further configured to, when the aircraft power check fails, generate a signal indicating that the filter needs to be cleaned and then perform the aircraft power check a second time after the filter has been cleaned; the power-check computer is further configured to, when the aircraft power check the second time fails, perform an engine health check which makes allowance for the installation power loss, the engine health check being considered to be successful when the current power (Pcour) plus the installation power loss is greater than the guaranteed minimum power (Pmini) and otherwise being considered to be failed; and the power-check computer is further configured to, when the engine health check fails, generate a signal indicating that the engine needs to be removed from the aircraft.

7. The power-check device according to claim 6 wherein the measurement system and the power-check computer are on-board the aircraft.

8. A checking method for checking a power plant of an aircraft, the power plant comprising at least one engine and an air inlet for feeding the at least one engine with air, the power plant including a cloggable filter filtering the air upstream from the engine, the engine having an output shaft suitable for connection to a member of the aircraft that does not form part of the engine, the method comprising: performing an aircraft power check by using the following operations: determining, in flight or on the ground, a current power (Pcour) actually being developed by the engine within the aircraft at the output shaft of the engine without making any allowance for an installation power loss resulting from the engine being installed in the aircraft and from any level of clogging of the filter; and determining whether the current power (Pcour) is greater than or equal to a stored guaranteed minimum power (Pmini), the aircraft power check being considered to be successful when the current power (Pcour) is greater than or equal to the guaranteed minimum power (Pmini) and otherwise being considered to be failed; in response to the aircraft power check being failed, generating a signal for cleaning the filter and then performing the aircraft power check a second time after the filter has been cleaned; in response to the aircraft power check the second time being failed, performing an engine health check while opening an air bypass channel that feeds air to the engine without filtering by the filter, the engine health check being considered to be successful when an engine power developed by the engine while the air bypass channel is opened is greater than the guaranteed minimum power (Pmini) and otherwise being considered to be failed; and in response to the engine health check being failed, generating a signal for removing the engine from the aircraft.

9. The method according to claim 8; wherein the determining of the current power (Pcour) comprises the following operations: measuring engine torque, calculating the current power as being equal to the product of the engine torque multiplied by the speed of rotation of the engine, the speed of rotation of the engine being equal to the speed of rotation of the outlet shaft of the engine or equal to the speed of rotation of a shaft rotating at the same speed as the outlet shaft or to the product of a stored proportionality coefficient multiplied by the speed of rotation of a rotary member that is mechanically linked to the outlet shaft.

10. The method according to claim 8; wherein the determining that the current power (Pcour) is greater than or equal to a stored guaranteed minimum power (Pmini) comprises the following operations: calculating an aircraft power indicator (APC) that is a function solely of the current power (Pcour) and of the stored guaranteed minimum power (Pmini), the aircraft power check being considered as succeeding or failing as a function of a value of the aircraft power indicator relative to zero.

11. The method according to claim 8; wherein when an engine health check succeeds, the method includes a generation step for generating flight authorization for the aircraft complying at least with predetermined performance of the aircraft calculated on the basis of at least the guaranteed minimum power (Pmini) for the engine and on the basis of a second power loss corresponding to the filter being clogged.

12. The method according to claim 8; wherein when an aircraft power check succeeds, the method includes a generation step for generating flight authorization for the aircraft complying at least with predetermined performance of the aircraft calculated on the basis of at least the guaranteed minimum power for the engine and on the basis of a second power loss corresponding to the filter not being clogged.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail in the context of the following description of embodiments given by way of illustration and with reference to the accompanying figures, in which:

(2) FIG. 1 is a diagrammatic view showing an aircraft of the invention; and

(3) FIG. 2 is a diagram showing the method of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) Elements that are present in more than one of the figures are given the same references in each of them.

(5) FIG. 1 shows an aircraft 1 of the invention. The aircraft 1 shown is a rotorcraft having a rotary wing 2. Nevertheless, the invention may also be applied to vehicles of other types, and in particular, to aircraft of other types, for example.

(6) The aircraft 1 has a power plant 10 including at least one engine 15. Each engine 15 has an outlet shaft 26 suitable for connection to a member that does not form part of the engine 15, with the engine 15 causing that member to move by means of the outlet shaft 26. For example, each outlet shaft 26 is connected by a mechanical transmission 5 to a main gearbox 11 that serves in particular to rotate the rotary wing 2. Such a mechanical transmission 5 may comprise at least one mechanical connector 27, at least one shaft 23.

(7) In the embodiment shown, at least one engine 15 may be a turboshaft engine. Such a turboshaft engine comprises a gas generator 16 having at least one compressor 17 connected to at least one high pressure turbine 18. Downstream from the gas generator 16, the engine may comprise a low pressure assembly 20 including at least one free low pressure turbine 21, the low pressure assembly 20 driving the outlet shaft 26 either directly or via a mechanical system.

(8) It is possible to envisage engines of other types, and for example a piston engine.

(9) Furthermore, each engine 15 may be controlled by an engine computer 25, where such an engine computer 25 is commonly referred to as an engine control unit (ECU).

(10) Independently of the number of engines 15 and of the nature of the engines 15, the power plant 10 includes an air feed system 30. Such an air feed system 30 includes at least one air inlet 31. The air inlet 33 takes in fresh air 100 coming from an external medium EXT situated outside the aircraft 1 in order to convey air to at least one engine 15, optionally via at least one duct 33.

(11) Also, the aircraft 1 includes at least one filter 32, and for example a respective filter 32 for each air inlet. Such a filter 32 is arranged upstream from an engine 15 and downstream from the air inlet in order to filter the air that has been taken in and that is being conveyed to the engine 15 in order to feed the engine with oxidizer. For example, a filter 32 extends across a duct 33 of the air feed system 30. A filter 32 is a cloggable filter, i.e. a filter that can become clogged to a greater or lesser extent by the contaminants it filters. A filter may then be a vortex filter, or indeed a barrier filter, these examples not being limiting and being given by way of example.

(12) The aircraft 1 is provided with a power-check device 40 that applies the method of the invention to check the operation of the aircraft 1.

(13) The power-check device 40 may comprise a measuring system 45 for measuring information relating at least to the current power Pcour being developed by the installed engine 15 and independently of any level of clogging of the filter 32 or indeed in general manner independently of any installation losses.

(14) The measuring system 45 may comprise first and second sensors respectively measuring the torque exerted on a shaft and information that enables the speed of the shaft to be obtained.

(15) For example, a first sensor is in the form of a torque meter 46. Such a torque meter 46 is optionally positioned and configured to measure the torque being exerted on the outlet shaft 26.

(16) Also, a second sensor 47 may comprise a position sensor and a differentiator serving to obtain a speed by differentiating the position measurement, or a speed sensor, or an accelerometer and an integrator enabling a speed to be obtained by integrating the acceleration measurement. A second sensor 47 may be arranged on the outlet shaft 26. Alternatively, a second sensor 47 may be arranged on a shaft that rotates together with the outlet shaft 26 and at the same speed as the outlet shaft 26, or indeed on a member such as the rotary wing 2 or a member of the main gearbox 11 that is driven at least by the outlet shaft 26, or indeed on a member of the engine that is mechanically linked to the outlet shaft 26.

(17) In another aspect, the power-check device 40 includes power-check computer 55 configured to apply the method of the invention. In particular, the power-check computer 55 may comprise at least one processor 56 with at least one memory 57, at least one integrated circuit, at least one programmable system, and/or at least one logic circuit, these examples not limiting the scope to be given to the term “computer”. Optionally, the power-check computer 55 and the engine computer 25 form a single entity. The power-check computer 55 may comprise a plurality of computers cooperating with one another.

(18) The power-check device 40 may include an activation control 50 suitable for being operated by a human, such as a button, a touchscreen. The activation control 50 is connected to the power-check computer 55 via a wired or wireless link so that, when it is operated, a signal is generated that is transmitted to the power-check computer 55 in order to request application of the method of the invention.

(19) Also, the power-check device 40 may include a display 60 connected to the power-check computer 55 by a wired or wireless link. The power-check computer 55 may generate a signal that is transmitted to the display 60 in order to request it to display the result of a check performed in accordance with the invention, e.g. on request from a pilot via a display control such as a button, a touchscreen . . . .

(20) In one aspect, the power-check computer 55 may include an outlet of the antenna type 58 and/or of the connector type 59 so that an operator 65 can recover, if necessary, the result of a check performed in accordance with the invention, the result being stored in the power-check computer. Such a result may comprise the values of various measurements and/or information indicating whether an aircraft power check has succeeded or failed, and where applicable whether an engine health check has succeeded or failed.

(21) FIG. 2 shows an example of a method that can be performed by aircraft 1 as shown in FIG. 1. The method includes a step STP1 of performing a power check on the aircraft. For example, this step is controlled by a pilot using an activation control 50, or it is performed automatically by the power-check computer 55, e.g. at regular intervals, or during a predetermined stage of flight that can be identified in conventional manner.

(22) During this step STP1, the power-check computer 55 acts in flight or on the ground to determine the current power Pcour being developed by the engine 15 at its outlet without taking account of installation losses, i.e. power losses that result from the engine 15 being installed in the aircraft 1 and from the filter 32 being clogged.

(23) For example, a first sensor 46 measures engine torque at the outlet shaft 26 of the engine 15, and the second sensor 47 measures the speed of rotation of the outlet shaft 26. The power-check computer 55 deduces therefrom the current power Pcour, which is equal to the product of the engine torque multiplied by the speed of rotation of the outlet shaft 26.

(24) In another example, a first sensor 46 measures engine torque at the outlet shaft 26 of the engine 15, and the second sensor 47 measures the speed of rotation of a working shaft 27 that is constrained to rotate with the outlet shaft 26. The power-check computer 55 deduces therefrom the current power Pcour, which is equal to the product of the engine torque multiplied by the speed of rotation of the working shaft 27.

(25) In another example, a first sensor 46 measures engine torque at the outlet shaft 26 of the engine 15, and the second sensor 47 measures the speed of rotation of the rotary wing 2. The power-check computer 55 deduces therefrom the current power Pcour that is equal to the product of the engine torque multiplied by a stored proportionality coefficient and by the speed of rotation of the rotary wing 2. The current power may be measured at the same location as the guaranteed minimum power on a bench.

(26) Whatever the way in which the current power is calculated, the power-check computer 55 determines whether the current power Pcour is greater than or equal to a stored value for the guaranteed minimum power Pmini and corresponding, where appropriate, to the current engine regime, possibly to within a margin.

(27) Optionally, in order to determine whether the current power Pcour is greater than or equal to a guaranteed minimum power Pmini, the power-check computer 55 may calculate the value of an aircraft power indicator APC. This aircraft power indicator APC of the aircraft 1 should not be confused with an engine power indicator. This aircraft power indicator APC is a function solely of the current power Pcour and of the guaranteed minimum power Pmini, with the power-check computer 55 considering that the aircraft power check has succeeded or failed as a function of a value of the aircraft power indicator APC relative to zero.

(28) In an example, the aircraft power indicator APC is equal to the current power minus the guaranteed minimum power: APC=Pcour−Pmini. The aircraft power check has succeeded when the power indicator APC is greater than zero or possibly is equal to zero.

(29) In another example, the aircraft power indicator APC is equal to the current power minus the guaranteed minimum power divided by the guaranteed minimum power: APC=(Pcour−Pmini)/Pmini. The aircraft power check has succeeded when the power indicator APC is greater than zero or possibly is equal to zero.

(30) In an example, the aircraft power indicator APC is equal to the guaranteed minimum power minus the current power: APC=Pmini−Pcour. The aircraft power check has succeeded when the power indicator AFC is less than zero or possibly is equal to zero.

(31) In another example, the aircraft power indicator APC is equal to the guaranteed minimum power minus the current power divided by the guaranteed minimum power: APC=(Pmini−Pcour)/Pmini. The aircraft, power check has succeeded when the power indicator APC is less than zero or possibly is equal to zero.

(32) In all of the above situations, the aircraft power check is considered as being successful when the current power Pcour is greater than or equal to said guaranteed minimum power Pmini. As shown by arrow Y1, in the presence of the aircraft power being checked successfully, the method may include a generation step Perf1, e.g. using the power-check computer 55, to generate information allowing the aircraft 1 to fly in compliance with stored predetermined performance of the aircraft and calculated on the basis of at least one guaranteed minimum power for the engine 15 and on the basis of a power loss corresponding to the filter not being clogged. By way of example, this information may be displayed on the display 60 or transmitted to the operator via the antenna 53 and/or via the connector 59.

(33) As shown by the arrow N1, in the presence of the aircraft power check failing, the method may include a step STP2 of cleaning the filter 32.

(34) For example, the power-check computer 55 may generate a signal that is transmitted via the display 60 and/or via the antenna 58 and/or by the connector 59 indicating that the filter needs to be cleaned.

(35) After cleaning, the method provides a step STP3 of performing a new aircraft power check.

(36) The current power is calculated once more by the power-check computer 55 and it is compared with the guaranteed minimum power, using the operations described above.

(37) As shown by arrow Y2, in the presence of the aircraft power now being checked successfully, the method may include a generation step Perf1, e.g. using the power-check computer 55, to generate information allowing the aircraft 1 to fly in compliance with the stored predetermined performance of the aircraft and calculated on the basis of at least one guaranteed minimum power for the engine 15 and on the basis of a power loss corresponding to the filter not being clogged.

(38) As shown by arrow N2, in the presence of an aircraft power check failing, the method may include a step of performing an engine health check CSM while allowing for a loss of power resulting at least from the filter 32 and/or while opening the air bypass channel 35.

(39) The engine health check may be performed in conventional manner.

(40) Optionally, the power-check computer 55 calculates an engine health index SPC that is a function of said current power is Pcour plus said power loss Pinstall minus said guaranteed minimum power Pmini: EPC=Pcour+Pinstall−Pmini. Optionally, the engine health index EPC does not take said power loss of Pinstall into account, e.g. while the air bypass channel 35 is open.

(41) As shown by arrow Y3, in the presence of engine health being checked successfully, i.e. in the presence of an engine health index EPC that is positive in this example, the method may include a generation step Perf2 in which the power-check computer 55 generates flight authorization for the aircraft 1 in compliance with predetermined aircraft performance calculated on the basis of the guaranteed minimum power Pmini of the engine 15 and of a power loss corresponding to the filter 32 being clogged.

(42) As shown by arrow N3, in the presence of an engine health check that has failed, the power-check computer can generate a signal SGN in indicating that the engine needs to be removed in order to be overhauled.

(43) In the presence of a plurality of engines, this method may be applied to each engine.

(44) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described above, it should readily be understood that it is not conceivable to identify all possible embodiments exhaustively. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.