A method for assisting with the management of at least one cumulative aging process.

Abstract

The invention relates to a method for piloting assistance for an operator, for example a pilot, or for an automated system, for example an autopilot, concerning at least one cumulative aging event, for example creep, of at least a portion of a gas turbine of an aircraft during a mission of said aircraft, said method comprising a step of determining an aging progression score (SCORE) which is a function of a plurality of terms, said plurality of terms comprising TERM1, TERM2, and TERM3, said method comprising a step of providing information on said at least one cumulative aging event to the operator or the automated system for said piloting assistance, according to said aging progression score (SCORE). Abstract figure: [Fig. 1]

Description

Title of the invention: A method for assisting control in managing at least one cumulative aging process Technical field of the invention

[0001] The invention relates to a method of piloting assistance for an operator, for example a pilot, or for an automated system, for example an autopilot, concerning at least one cumulative aging, for example the finning, of at least a part of a gas turbine of an aircraft during a mission of said aircraft. Prior art

[0002] An aircraft pilot generally has access to piloting instructions relating to propulsion systems, displayed in the cockpit. These instructions notably refer to certified limits (maximum limits not to be exceeded, limits required in the flight manual), these limits being managed by the pilot or managed by the computer.

[0003] Such limits include, for example, the NI (rotational speed of the gas generator at the high-pressure shaft), the T45H conformed temperature of the high-pressure turbine, the torque of the power shaft, or an indicator combining this information. These limits constitute, for example, thresholds that must not be exceeded in stabilized flight, and for which maximum continuous operating times can be defined by regulation.

[0004] These indications do not take into account mission-specific objectives, such as a quota, or a notion of acceptable cumulative aging. They are purely instantaneous and are not intended to prevent cumulative aging patterns from leading to a need for premature overhaul of the turbomachine, for example before its scheduled general overhaul.

[0005] In a context of relatively constant and predictable usage, such as airliner missions, predictive methods exist that establish binary indices for throttle position, correctly corresponding to maintenance costs. These predictive methods also most often incorporate maintenance costs and fuel consumption costs.

[0006] For versatile applications, such as the varied missions of helicopters, the correlation of a binary setpoint (whether torque, gas generator speed, or temperature) with costs is not reliable. Currently, in this context, only ground-based monitoring of meters exists, particularly with regard to fine-tuning, which is carried out manually or with tools.

[0007] Now in this context, concerning these complex cumulative aging processes, such Post-flight monitoring does not provide any useful prospective guidance for subsequent flights and is not currently capable of helping the pilot to meet a cumulative target during the flight, for example a target given by a fleet manager.

[0008] Such monitoring or guidance also does not provide information that would allow the pilot to understand and develop an intuition about the actions to be taken to manage aging processes. Indeed, these aging phenomena are multifactorial and non-linear. Consequently, a pilot cannot develop a reliable intuition about the conditions under which these aging processes accelerate or slow down without additional guidance.

[0009] Cumulative aging is a form of damage that increases over time. Such aging corresponds perfectly to the phenomenon of turbine blade wear, within the context of the intended application, but can also be oxidation, corrosion, or mechanical wear of parts (friction wear or bearing wear, for example).

[0010] Other types of aging can also occur, such as predominantly "cyclic" aging modes, related to a number of times stress thresholds are crossed, both upwards and downwards (low-cycle fatigue (LCF), thermal cycling, number of start / stop cycles, etc.). However, it is difficult to influence such cyclic aging. Presentation of the invention

[0011] This document aims to remedy the aforementioned drawbacks.

[0012] To this end, the present document proposes a piloting assistance method for an operator, for example a pilot, or for an automated system, for example an autopilot, concerning at least one cumulative aging, for example the finning, of at least a part of a gas turbine of an aircraft during a mission of said aircraft, said method comprising a step of determining an aging progression score which is a function of a plurality of terms, said plurality of terms comprising TERM1, TERM2, and TERM3,

[0013] and we define for the calculation of the aging progression score: - the mission quota, , Q = QFactor * —

[0014] where

[0015] - QFactor is a factor, for example, between 0.1 and 10, to be returned if possible modifiable by the operator

[0016] - SD is a major maintenance trigger threshold for a counter Cumulative aging (CV), in hours

[0017] - DQ is the flight time between two overhauls of said part of the gas turbine or the target service life of said part of the gas turbine, in hours,

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] - the default quota for the mission, - DQ - the maximum quota, QmAx — a*QDEF' with 4 5, - the minimum quota, QMW — P*QDEF, with 0 < [3 < 1, - the cumulative aging counter CV, which is a value proportional to the cumulative aging, the planned flight duration of the mission entered in hours, M, for example between 0.2 and 3h, - the default estimated flight time of the mission in hours, EF, for example, approximately 1 hour, - Y is a parameter to be adapted to the application context, chosen between MDEF / 2 and - the cumulative flight time of the mission, in hours, at a time t of the mission, T(t), - a first SI threshold, for example between 0.3 and 0.8, for example equal to 0.5, - a second threshold S2, for example between 3 and 10, for example equal to 5, - The start of the mission is defined by the instant t= tO of the start of flight, - a time t= tl at the end of a so-called start-of-mission phase is also defined such that: — tl - tO greater than a duration between 1 and 15 minutes, and / or — tl is the first instant t greater than t0 for which the aircraft's flight speed is greater than a predetermined speed, for example 40 Ktas for a helicopter, and / or — tl is the first instant t greater than t0 for which the aircraft's altitude relative to the ground, also called ground clearance, is greater than a determined value, for example 500 feet, - a sliding duration X in seconds, for example between 10 and 30 seconds, for example on the order of 20 seconds, the average gradient sliding over X seconds, _ CV(t) - CV(tX) , the cumulative flight hours since the start of mission tO, at a given time t of the mission without information on the planned flight duration of mission M, CTftb-CVW. Q > T(t) the cumulative flight hours since the start of the mission, at a given moment t of the mission, anticipating a flight duration of Y's "usual short missions", in hours = CV(t) —CV(tO) ' Q * max(Y,T(t)) the cumulative flight hours since the start of the mission, at a given moment t of the mission anticipating the projected mission duration M, CV(t)-CV(tO) ' D(t) =--—---- Q * M

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033] , with y a coefficient, TERHl = MAX ¢0 ; MIN {r; Qdef Qdef Qdef ^def TERM2 = I | Bf*) if t > tl: MAX] 0; MIN1; - l) / ( Qmx / QDEr - f | — A ) VL 3600 ( [ $(0 ]) + MAX j 0 ; MIN 1 ; y-yy - 1 > ll ~xr B otherwise, 0 Qmin / Qdef) * (Qmin7 QnEFy (Qmax / Qdef (Qmin / Qdef.) ,rcr,„ o _ (If t > tl: 2 X MAX{0 ; ; C(t)]} ' IchM 3 — y . ( smon,0 said process comprising a step of providing information of said at least one cumulative aging to the operator or the automated system for said piloting assistance, according to said aging progression score. The step of providing said information to an operator can be carried out by display. The coefficient y can be equal to 2, the aging progression score being defined as follows: SCORE = TE RM 1 + TERM 2 + TE RM 3, said process further includes a step of determining an inverse aging progression score defined as follows: 100, if SCORE < 1 1 5 MAX (0-, MIN {1-,(-- * SCORE + -)}}* 100, otherwise 4 4 and said process further comprising a step of providing inverse information of said at least one cumulative aging to the operator or automated system for said piloting assistance, according to said inverse aging progression score. Defining the aging progression score as a sum of TERM1, TERM2, and TERM3 yields a continuous aging progression score (as opposed to a discretized aging progression score). If there is Inverted JSCORE = In the step of determining the inverse aging progression score in the process, the inverse aging progression score will also be continuous accordingly.

[0034] The aging progression score can, in some cases, be too demanding for the operator, as they must adjust the piloting to a median value and are therefore tempted to monitor the situation more frequently. Providing inverted information based on the inverted progression score allows the operator to adjust the piloting to 100% and assume that, even if they do not have the opportunity to monitor later, the overall objective will still be achieved. Conversely, this may prevent them from seeing opportunities to improve flight conditions in specific cases (for example: significant payload delivery mid-mission). The choice of using the information or the inverted information based on the aging progression score or the inverted aging progression score, respectively, is a decision made by the operator.

[0035] The inverse aging progression score allows a clipped result to be obtained.

[0036] Optionally, the inverse aging progression score can be rounded to the upper fifth, to the lower fifth (desired minimum resolution, for example), or truncated to the upper fifth, to the lower fifth. Optionally, the inverse aging progression score can be rounded up to the nearest hundredth, down to the nearest hundredth, or truncated to the nearest hundredth, down to the nearest hundredth.

[0037] Qmax and QM1N allow the sensitivity zone of TERM 1 and TERM 2 to be defined.

[0038] Qmax is a high threshold (or high sensitivity threshold) that allows the ceiling to be reached of calculation and then to cap above (i.e., to cap the plurality of terms in the score so that the score is less than or equal to the ceiling).

[0039] Qmin is a low threshold (or low sensitivity threshold) which allows reaching the floor 0 and then clipping below it (i.e. clipping the plurality of terms of the score so that the score is greater than or equal to the floor).

[0040] The coefficient y can be equal to 1, the aging progression score being defined as follows: 0, if 4(t) < IF TERM1 + TERM2 + TERM3, otherwise

[0041] The coefficient y allows the sensitivity of the aging progression score to variations in unstabilized flight phases to be adjusted, the coefficient being proportional to this sensitivity. Therefore, a coefficient y equal to 1 reduces the sensitivity.

[0042] As previously stated, cumulative aging of a part of a gas turbine is the damage to the part concerned which increases over time. SCORE = Such aging is primarily the phenomenon of aging, but can also be oxidation, corrosion, or mechanical wear of the parts in question.

[0043] The cumulative aging counter CV is a value generally provided by the gas turbine's computer and is proportional to the cumulative aging, measured or calculated from sensor values ​​(gas generator rotational speed, temperature within the gas turbine, torque, ambient temperature, deformations, etc.). The higher the CV value, the greater the cumulative aging of the parts in question or the gas turbine module.

[0044] An aircraft mission is defined by a succession of flight phases between a start and an end of the mission. Typically, such a mission may include one or more takeoff and landing phases, and flight phases at varying speeds.

[0045] The major maintenance trigger threshold is a predetermined threshold, set by the gas turbine manufacturer, beyond which a major maintenance operation, known as major maintenance, is necessary to ensure the proper functioning of the gas turbine or to prevent its premature damage. Such an operation generally requires the removal of the gas turbine.

[0046] The flight time between two general overhauls is known by the abbreviation TBO for "Time Between Overhauls", in English.

[0047] The target service life D may be a flight time greater than the time between two overhauls, for example equal to twice the time between two overhauls.

[0048] The estimated flight time of the mission, specified as M, is a value determined before the start of the mission and entered into an aircraft computer, for example via an interface. This time can be entered by an operator, for example a pilot.

[0049] The estimated flight time, whether default or not, of the mission specified M or M dEF is, for example, between 0.2 and 3 hours. MDEF is, for example, on the order of 1.5 hours.

[0050] M will be populated with the collection value of MDEF if M is not populated by the operator.

[0051] The flight duration of typical short missions Y will either be fixed for a given application, for example on the order of 0.8 hours if MDEF = 1.5 hours, or determined by the application and calculated as an average of the flight durations of the aircraft's previous missions less than MDEF in the interval from MDEF / 2 to

[0052] The parameter Y can be adapted for example within this range depending on whether there are more or fewer mission frequencies much shorter than MDEF.

[0053] The cumulative flight time of the mission at a time t, T(t) is the time elapsed between the start of mission tO and time t.

[0054] The CV value sliding over X seconds at a time t is equal to the difference between the CV values ​​at time t and CV at time tX.

[0055] The calculation of all or part of said terms can be carried out in real time, at time periods of less than 1 second for example, on the order of 500ms for example.

[0056] Each term serves a different purpose and therefore allows them to be combined.

[0057] When the engine stress level at time t leads to aging If the minor (SI to be defined by the engine manufacturer) condition is met, the score is reset to zero, regardless of the value of the individual terms. Indeed, there is no point in providing information, for example via display, if engine usage no longer significantly affects the final total; there is no need to continue encouraging reduced usage. This avoids unnecessarily limiting operational solutions, since exceeding the quota carries no risk and subsequent missions always offer opportunities for compensation.

[0058] The first term, TERM 1, signals to the operator a very high stress, with no obvious correlation to the acceptable operating limits. It is an initial indication to the operator that current flight conditions may lead to significant cumulative aging, and it can be displayed from the very beginning of the flight. It also provides regular feedback that enhances the operator's intuitive understanding of the situation.

[0059] The second term, TERM 2, enhances the score if the stress level at time t leads to an increase in aging that is not offset by an increase in mission flight time, versus the quota Q, or that exceeds a linear progression (if the values ​​M and Q are not defined by the operator). This indicator enhances the score when, particularly at the beginning of the mission, stress is applied at a high rate. It is an intermediate variant between the gradient and the cumulative aging, incorporating any previous debits and credits, and allows for reporting in the first part of the mission. It gradually loses relevance as the mission lengthens and subsequently no longer contributes to the score, unless the stress remains truly excessive.Furthermore, the second term, TERM 2, allows for a higher score if the cumulative total progresses more rapidly than linearly towards the specified quota Q, for the specified mission flight duration M. Since the beginning of a mission is generally more demanding, this allows for early and precise reinforcement of vigilance, indicating that pilot moderation or intervention is desirable.

[0060] The third term TERM 3 allows the score to be increased if the quota is exceeded, assuming the mission will last Y hours, and to be decreased if the duration of With flight Y exceeded, the cumulative total converged again below the quota. This term allows for an initial level of score progression in absolute terms of the cumulative hourly total, preventing an untimely score increase at the beginning of the mission if the minimum duration of Y hours was not used (which is why B(t) is not used in absolute terms). Furthermore, the third term, TERM 3, allows for a higher score by comparing the cumulative total to the quota Q, particularly in cases where it is not possible to remain within the quota during the mission, but it is still possible to limit the overrun.

[0061] Such a method can also provide piloting assistance and / or training for the operator on critical conditions leading to an aggravation of said cumulative aging.

[0062] It is also possible to freeze the score display during transitional flight phases when the pilot is otherwise occupied. Such a phase can be determined, in particular, by a significant variation in the moving average (for example, over a defined period) of engine torque, outside a narrow range (for example, ±5%) around the moving average. This allows the display to be frozen during such maneuvers.

[0063] It is also possible to display an indicator light, for example a green light, if A(t) < SI (or another value) in the display area for the aircraft's engine speed limits (first limit indicator, NI margin, T45H - defined above), this area being a priority area of ​​attention for the pilot. It is also possible to handle the case of multiple cumulative aging processes (both finning and corrosion, for example, which are two different cumulative aging processes).

[0064] The calculated terms are relatively stable, but instabilities may exist. To mitigate such instabilities, hysteresis can be applied to the score display. Some terms may have a suitable hysteresis, for example, a higher hysteresis than other terms. Cumulative aging can be due to polishing, and / or oxidation, and / or corrosion.

[0065] Said method can provide information concerning at least two different cumulative agings, the individual score of each aging being determined and a general score is calculated on the basis of said individual scores, for example in the form of an average or a weighted average, the information provided to the user being dependent on said general score.

[0066] It can be determined whether t is outside the start phase of the mission or not using the time of flight elapsed since the start of the mission, the flight speed of the aircraft and / or the altitude of the aircraft relative to the ground.

[0067] The level or quantity of information provided to the operator may vary depending on the aging score, the value of A(t) and / or the flight phase concerned.

[0068] The level of information can in particular vary progressively by increment, for example by displaying a value between 0 and 5 or by displaying a progress bar, or by not displaying such a value or by not displaying anything outside of stabilized flight phases.

[0069] The amount of information can also vary by adding or removing information, so as to have more or less detailed information depending on the situation.

[0070] In particular, it is possible that no information will be provided (for example, no display) during certain critical flight phases, for example during the initial mission phase, or if aging is low (low score or A(t)). Increasingly complex information (different levels of information) may be provided or displayed depending on the flight phase, aging, or at the operator's request.

[0071] In general, the invention proposes to determine or calculate laws in real time and real-time tests on these laws, leading to indications (displayable or not in the cockpit, at different levels of detail or according to the phases of flight), regardless of the aircraft and the installation (single or multi-engine).

[0072] These indications are preferably not unnecessarily disruptive, particularly during flight phases requiring the pilot's full attention. (For example, they will be displayed so as to be visible during long phases—cruise or climb flight (discreet flashing, for example)—and displayed continuously, without being intrusive, or even inhibited (no flashing, etc.) during phases with significant power variations.)

[0073] These indications encourage and guide pilots to act during long, stable flight phases, managing, flight after flight, the cumulative aging of major propulsion system components. As previously mentioned, these indications can be adjusted according to the score or previous cumulative aging, the types and business objectives of the missions, and the operational context.

[0074] These indications must be progressive (several levels of alert rather than a binary alert), such progressiveness being particularly useful when aging is not very predictable, when the short-term consequences are minor, when the use of the aircraft is versatile, and to provide the pilot with a perception of the flight conditions which produce cumulative aging (not intuitive without an indication or with a binary indication).

[0075] Such indications make it possible to identify the phases which cause more or less pronounced cumulative aging, and can also contribute to more ecological management decisions (CO2 emissions, etc.).

[0076] Unlike existing applications in a non-versatile usage context, this score does not derive from an invariant cost calculation.

[0077] Here, the fleet manager, keen to get the most out of their gas turbines, can, by monitoring the trend retrospectively, modify the quota and the score guidelines to be followed by the pilot to allow for a generally controlled cumulative aging trajectory. They can do this by considering the full range of their priorities, the geographical context of operation, seasonality, engine age, air intake protection needs, and all other influencing factors, through a pragmatic method of learning and instructions using the graduated system of the invention.

[0078] On the other hand, a combination with fuel-efficient condition indicators is a logical association with this indicator, for example the addition of a fuel economy score from 0 to 2 according to the deviation from the most economical stable flight conditions.

[0079] This document may also relate to an aircraft comprising a display unit configured to provide information on at least one cumulative aging, said information being derived from a flight assistance process of the type described above.

[0080] The aircraft may be a rotary-wing aircraft, in particular a helicopter.

[0081] The display unit may be an information bar. Brief description of the figures

[0082] [Fig. 1] is a trend diagram illustrating the evolution over time of a mission (i.e., on a mission), this diagram representing the aging progression score according to an embodiment, and a previous aging progression score, during a mission of the aircraft,

[0083] [Fig.2] is a trend diagram illustrating the evolution over time of a mission, this diagram representing the inverse aging progression score, according to the implementation method of [Fig. 1], and a previous aging progression score, during an aircraft mission,

[0084] [Fig.3] is an example of displaying an information bar to the operator lifespan of aircraft blades in a given state, according to the previous aging progression score,

[0085] [Fig.4] is an example of displaying an information bar to the operator service life of aircraft blades in the state of [Fig. 3], according to the aging progression score, according to the embodiment of [Fig. 1], and

[0086] [Fig.5] is an example of displaying an information bar to the operator. lifetime of aircraft blades in the state of [Fig.3], according to the aging progression score, according to the implementation method of [Fig.2]. Detailed description of the invention

[0087] An example of an anterior art aging progression score, called SCORE_anterior in Figures 1 and 2 or anterior aging progression score, is defined as follows: ■ f O,sM'(0 <Sr Previous score = 1 iTERMl' + TERM2 + TERM3 + TERM4 + TERME, otherwise

[0088] for the calculation of which we define: - the mission quota, , sn> , Q = QFactor * — Or 'QFactor' is a factor, for example between 0.1 and 10, which should be modifiable by the operator if possible. SD' is a major maintenance trigger threshold for a cumulative aging counter CV', in hours. DQ' is the flight time between two overhauls of said part of the gas turbine or the target service life of said part of the gas turbine, in hours.

[0089] - the default quota of the mission, f _ sd>

[0090] - the cumulative aging counter CV', which is a value proportional to the Cumulative aging, the projected flight time of the mission entered in hours, M\ for example between 0.2 and 3h, to be made modifiable by the operator if possible, the default estimated flight time of the mission in hours, MD£.F\ for example on the order of 1 hour, There's a parameter to adapt to the application context, chosen between MnFF7 2 and the cumulative flight time of the mission, in hours, at a given time t during the mission, T'(t) a first threshold SI', for example between 0.3 and 0.8, for example equal to 0.5, a second threshold S2', for example between 3 and 10, for example equal to 5, the start of the mission is defined by the instant t= t0' of the start of flight an instant t = tl' of the end of a phase called the start of the mission is also defined so that: tl' -10' greater than a duration between 1 and 15 minutes, and / or tl' is the first instant t greater than t0' for which the aircraft's flight speed is greater than a predetermined speed, for example 40 Ktas for a helicopter, and / or tl' is the first instant t greater than t0' for which the aircraft's altitude relative to the ground, also called ground clearance, is greater than a value determined, for example 500 feet, a sliding duration X' in seconds, for example between 10 and 30 seconds, for example on the order of 20 seconds, the average gradient sliding over X' seconds, _ cv, (tj - cvf(t-xn , A (t) ~ / X' \ the cumulative flight time per hour since the start of the mission (t0'), at a given moment t of the mission without information on the planned mission duration M', B'(t) CV'(t) - CV'(tO') Q' * T'(t)

[0091] - the cumulative total per flight hour since the start of the mission, at a given time t of the mission, anticipating the flight duration of Y's "usual short missions", in hours, . CV' <0 " CV'(tO') ' (.y — ?------ x Q' * max(Y',T'(t)) the cumulative flight hours since the start of the mission, at a given moment t of the mission anticipating the projected mission flight duration specified M', cv'(t)-cvW) DW =------777---- Q * M TERM 1' => S2'.' t smon, 0 r 2, « t > tl' and M' = MDEF' and Q' = QDEF' and D'(t) > (T'(t) / M'), TERM2' = jsinon 1, si t > tl' and si tendency of B'(t)surX' seconded monotonically increasing ' otherwise, 0 - (1, if t > tl' and { M' MDEF' or Q' QDEF1) and D'(t) >(T'(t) / M') (smon, 0 , And fl-t > £1' (M' MDEF'or Q' * QDEF') andD'(Û > 1' t smon, 0

[0092] Reference is now made to [Fig. 1], which compares this previous aging progression score, SCORE_previous, with the aging progression score, SCORE, according to one embodiment. In this embodiment, the following are defined: SCORE = TERM 1 + TERM 2 + TERM 3 •

[0093] SCORE and SCORE_anterior show substantially similar evolutions. However, SCORE_anterior is a discretized score, unlike SCORE. Indeed, SCORE_anterior exhibits abrupt variations between different constants of Inverted SCORE = values ​​(for example, between points P1 and P2), and SCORE exhibits continuity due to its expression as a sum of TERM1, TERM2, and TERM3. This continuity results in better resolution and sensitivity. In this way, SCORE provides the operator with more precise and reliable information for piloting assistance compared to previous SCORE values.

[0094] Reference is now made to [Fig. 2], which compares the previous aging progression score, SCORE_previous, with the inverse aging progression score, SCORE_inverted, according to the embodiment of [Fig. 1]. In this embodiment, the following are defined: 100, if SCORE < 1 1 5 MAX {O;M]N{1;(-- * SCORE + -)}} * 100, otherwise

[0095] SCORE_inverté is also continuous, unlike SCORE_anterior.

[0096] Clipping above the inverted SCORE is shown in [Fig. 2]. Indeed, it can be seen that when the inverted SCORE reaches 100% at point P, clipping is achieved, whereas the SCORE shown in [Fig. 1] has not reached a zero value for a point P' with the same abscissa as point P. As mentioned in the presentation of the invention, the choice of using the information or the inverted information based on the aging progression score or the inverted aging progression score, respectively, is a choice made by the operator. In fact, both the aging progression score and the inverted aging progression score have their advantages.

[0097] Figures 3 and 4 show an example of displaying an information bar 3 to the operator indicating the service life of aircraft blades in the same initial state. [Fig. 3] illustrates the display based on the previous aging progression score, SCORE_anterior, and [Fig. 4] illustrates the display based on the aging progression score, SCORE, according to one embodiment.

[0098] The previous SCORE is discretized and can only include the integer values ​​0, 1, 2, 3, 4, and 5, which correspond to the filling of information bar 3 up to fill line 30, 31, 32, 33, 34, and 35 respectively. As illustrated in [Fig. 3], previous SCORE is equal to 3 and progress bar 33 is filled up to line 33. For previous SCORE, this state corresponds to point P3 in [Fig. 1].

[0099] SCORE is continuous and can include decimal values ​​from 1 to 6. In the embodiment of [Fig. 4], the information bar 3 is enlarged to include a sixth box between line 35 and a fill line 36. SCORE is approximately 2.3, and the progress bar 3 is filled to the intermediate line. 32' located between line 32 and line 33. For SCORE, the state corresponds to point P4 on [Fig.1], P4 having the same abscissa as P3. It can be seen that SCORE offers the operator better intuition and judgment of the blade flight fault, notably thanks to the continuity and better resolution (i.e. thanks to the decimal values ​​between 1 and 6).

[0100] The fact that information bar 3 has a sixth box is optional; other embodiments do not include the sixth box since a clipping can be performed (to keep a score less than or equal to 5). For example, this clipping can be performed with a display following the inverse aging progression score SCORE_inverted, as in [Fig. 5].

[0101] Inverted SCORE is continuous and can include percentage values ​​from 0% (fill line 30) to 100% (fill line 35). As illustrated in [Fig. 5], Inverted SCORE is equal to 90% and progress bar 3 is filled to line 34'. For Inverted SCORE, the state corresponds to point P5 in [Fig. 2], P5 having the same x-coordinate as P3. The pilot can, for example, understand that they must adjust the piloting for the remainder of the mission based on a displayed value of 100%, which they will soon reach.

Claims

Demands

1. A method for piloting assistance for an operator, for example a pilot, or for an automated system, for example an autopilot, relating to at least one cumulative aging, for example the finning, of at least a part of a gas turbine of an aircraft during a mission of said aircraft, said method comprising a step of determining an aging progression score (SCORE) which is a function of a plurality of terms, said plurality of terms comprising TERM1, TERM2, and TERM3, and the following are defined for the calculation of the aging progression score (SCORE): - the mission quota, , 4 Q = QFactor + Or - QFactor is a factor, for example between 0.1 and 10, which should be modifiable by the operator if possible. - SD is a major maintenance trigger threshold for a cumulative aging counter CV, in hours. - DQ is the flight time between two overhauls of said part of the gas turbine or the target service life of said part of the gas turbine, in hours, - the default quota for the mission, SD, Qdef = - the maximum quota, Q,,, „ = with a > 5, 1 zVï / iÆ 'LsiLr - the minimum quota, = with 0 < P - 1, - the cumulative aging counter CV, which is a value proportional to the cumulative aging, the mission's planned flight time in hours, M, for example between 0.2 and 3 hours, - the default planned flight time of the mission in hours, for example around 1 hour, - Y, a parameter to be adapted to the application context, chosen between and - the cumulative flight time of the mission, in hours, at a time t of the mission, T(t), - a first threshold SI, for example between 0.3 and 0.8, for example equal to 0.5, - a second threshold S2, for example between 3 and 10, for example equal to 5, - the start of the mission is defined by the time t = tO of the start of the flight, - a time t = tl of the end of a so-called start-of-mission phase is also defined such that: — tl - tO greater than a duration between 1 and 15 minutes,and / or — tl is the first time t greater than t0 for which the aircraft's airspeed is greater than a predetermined speed, for example 40 knots for a helicopter, and / or — tl is the first time t greater than t0 for which the aircraft's altitude above the ground, also called ground clearance, is greater than a determined value, for example 500 feet, a moving duration X in seconds, for example between 10 and 30 seconds, for example on the order of 20 seconds, the average gradient moving over X seconds, CV(t) - CV(tX), q4—) the cumulative flight hours since the start of the mission t0, at a time t of the mission without information on the predicted mission duration M, CV(t) - CV(tO) ' Q * T(t) the cumulative flight hours since the start of the mission, at a time t of the mission, anticipating a flight duration of the "usual short missions" of Y, in hours, CV (t) - CV (tO) ' Q * max(Y,T(t)) A(t) = B(t) = C(t) = the cumulative flight hours since the start of the mission, at a time t of the mission anticipating the predicted mission flight time given M, D(t) = CV(t) - CV(t0) Q * M TE RMI = MAX {0 ; MIN {y; 5p 1 ' {; ' QMAX QmSN Qdef Qdef Qmtn Qdef Qmax Qmjn Qdef Qdef , with y a coefficient, ( ^DEr. Bit') if L > il: MAX 10 ; MIN H ; (—=—)(——l) / ( Qmax / Qdef “ Qmîn / Qdef) “ (Qmin / Qdef) / ( Qmax / Qdef “ Qmîn / Qdef): ( A dtr — a ), < L 3600 : ( [ ï) s L m U otherwise, 0 ' „„„„„ f if t> tl ■ 2 X MA¥{0; W / V[l ; C(t)]} ' / b RM 3=1. _ J [otherwise, 0 said process comprising a step of providing information of said at least one cumulative aging to the operator or the automated system for said piloting assistance, according to said aging progression score (SCORE).

2. A method according to the preceding claim, wherein y is equal to 2, the aging progression score (SCORE) being defined as follows: SCORE = TERM 1 + TERM 2 + TERM 3, said process further includes a step of determining an inverse aging progression score (inverse_SCORE) defined as follows: 100, if SCORE < 1 Inverted score = 1 5 MAX {0; MIN* SCORE + -)}} * 100, otherwise and said method further comprising a step of providing inverse information on said at least one cumulative aging to the operator or automated system for said piloting assistance, according to said inverse aging progression score (Inverted_SCORE).

3. Method according to claim 1, wherein y is equal to 1, the aging progression score (SCORE) being defined as follows: SC0RF = { Q,siA(t) <sl {te rmi + term2 term3, sinon

4. A method according to any one of the preceding claims, wherein the cumulative aging is from fining, and / or oxidation, and / or corrosion.

5. A method according to any one of the preceding claims wherein said method is capable of providing information concerning at least two different cumulative agings, the individual score of each aging being determined and a general score is calculated on the basis of said individual scores, for example in the form of an average or a weighted average, the information to be provided to the user being dependent on said general score.

6. A method according to any one of the preceding claims, wherein it is determined whether t is out of the start phase of the mission by means of a flight time elapsed since the start of the mission, the flight speed of the aircraft and / or the altitude of the aircraft relative to the ground.

7. A method according to any one of the preceding claims, wherein the level or quantity of information provided to the operator varies according to the aging score, and / or the value of A(t), and / or the flight phase concerned.

8. A method according to any one of the preceding claims, wherein the aircraft is a rotary-wing aircraft.

9. Aircraft comprising a display unit (3) configured to provide information of at least one cumulative aging, said information being derived from a flight aid method according to any one of the preceding claims.< / sl>

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