Aircraft brake temperature control system

An aircraft brake temperature control system (BTCS) 100 for controlling a temperature of a brake 220 of a landing gear 201 of the aircraft 200. The BTCS 100 includes a controller 110 configured to cause at least one fluid moving device 230, 231, 232 to drive a flow of fluid onto the brake 220, selectively in one of a plurality of modes, to control the temperature of the brake 220. The BTCS 100 may be incorporated into an aircraft system 1000 with at least one fluid moving device 230, 231, 232, wherein the aircraft system is on an aircraft 200.

RELATED APPLICATION

This application claims priority to and incorporates entirely by reference United Kingdom patent application GB 2019496-5 filed Dec. 10, 2020.

TECHNICAL FIELD

The present invention relates to an aircraft brake temperature control system.

BACKGROUND

Aircraft braking systems generate heat during normal operating conditions. Increased brake temperatures can lead to increased braking distances, increased wear, and increased turnaround times between flights.

SUMMARY

A first aspect of the present invention provides an aircraft brake temperature control system for controlling a temperature of a brake of a landing gear of an aircraft. The aircraft brake temperature control system comprises a controller that is configured to cause at least one fluid moving device to drive a flow of fluid onto the brake, selectively in one of a plurality of modes, to control the temperature of the brake.

Optionally, the controller is configured to cause the at least one fluid moving device to drive the flow of fluid onto the brake to control the temperature of the brake, on the basis of a condition indicating to the controller that the aircraft is in-flight.

Optionally, the controller is configured to cause the at least one fluid moving device to drive the flow of fluid onto the brake to control the temperature of the brake, on the basis of a determination as to whether the aircraft is in-flight. Optionally, the controller is configured to cause the at least one fluid moving device to drive the flow of fluid onto the brake to control the temperature of the brake, on the basis of a further determination related to at least one of a temporal consideration, a functionality consideration of at least one component of the aircraft, and a noise, vibration and/or harshness (NVH) consideration of the aircraft (such as a noise consideration of the aircraft, a vibration consideration of the aircraft, and a harshness consideration of the aircraft). Optionally, the temporal consideration comprises at least one of a temporal operation of the aircraft and a temporal condition external to the aircraft. Optionally, the temporal operation of the aircraft comprises at least one of a flight duration of the aircraft during a given flight, an interval between successive flights of the aircraft, an elapsed flight duration during a given flight, and a remaining flight duration of the aircraft during a given flight. Optionally, the temporal condition external to the aircraft comprises at least a time of a time zone at a portion or portions of a flight of the aircraft. Optionally, the functionality consideration is related to at least one of a performance consideration and a lifespan consideration. Optionally, the landing gear and/or a landing gear bay comprises the at least one component.

Optionally, the temperature of the brake is a temperature of a braking surface. Optionally, the brake comprises a disc and the disc comprise the braking surface. Optionally the temperature is a temperature detected by a temperature sensor. Optionally the temperature sensor is located on the brake. Optionally the temperature sensor is located off the brake. Optionally the temperature sensor is located on the landing gear. Optionally the temperature sensor is located off the landing gear. Optionally the temperature sensor is located in a landing gear bay of the aircraft. Optionally, the temperature of the brake is a temperature detected by a plurality of temperature sensors.

Optionally, the controller is configured to cause at least one fluid moving device to drive the flow of fluid onto the brake to reduce the temperature of the brake. Optionally, the controller is configured to cause at least one fluid moving device to drive the flow of fluid onto the brake to reduce the temperature of the brake to a target temperature. Optionally, the target temperature is less than 300 degrees Celsius. Optionally, the target temperature is less than 200 degrees Celsius. Optionally, the target temperature is a temperature range. Optionally, the temperature range is 100 to 300 degrees Celsius. Optionally, the temperature range is 100 to 200 degrees Celsius.

Optionally, the controller is configured to cause the at least one fluid moving device to operate in a first mode of the plurality of modes to produce a relatively high flow rate (rate of flow) of the fluid onto the brake, and to operate in a second mode of the plurality of modes to produce a relatively low flow rate (rate of flow) of the fluid onto the brake. Optionally, the first mode is in a first portion of a flight duration and the second mode is in a second portion of the flight duration.

Optionally, a rate of flow of the fluid is a volume flow rate. Optionally, the relatively high rate of flow of the fluid is greater than 100 litres per second. Optionally, the relatively low rate of flow of the fluid is less than or equal to 100 litres per second. Optionally, the relatively high rate of flow of the fluid is between 100 and 300 litres per second. Optionally, the relatively low rate of flow of the fluid is between 20 and 80 litres per second. Optionally, the rate of flow of the fluid is a mass flow rate.

Optionally, the controller is configured to cause the at least one fluid moving device to operate at a first speed in the first mode and at a second speed in the second mode, wherein the first speed is greater than the second speed. Optionally, the at least one fluid moving device is operable with a variable speed and the controller is configured to cause the at least one fluid moving device to operate at a variable speed. Optionally, a rate of flow of the fluid onto the brake is fixed in the first and/or second mode. Optionally, the rate of flow of the fluid onto the brake is variable within a range in the first and/or second mode.

Optionally, the controller is configured to cause the at least one fluid moving device to drive the flow of the fluid onto the brake, on the basis of a condition indicating to the controller that the brake requires cooling.

Optionally, the at least one fluid moving device comprises a fluid moving device that is on or mounted on the landing gear.

Optionally, the at least one fluid moving device comprises a fluid moving device that is off the landing gear. Optionally, the fluid moving device is unattached to the landing gear.

Optionally, the at least one fluid moving device comprises a fluid moving device mounted to a landing gear bay into which the landing gear is retractable. Optionally, the fluid moving device is mounted to a part of the landing gear bay.

Optionally, the at least one fluid moving device comprises plural fluid moving devices and, optionally, the controller is configured to selectively cause each fluid moving device of the plural fluid moving devices to drive a respective flow of fluid onto the brake.

Optionally, the controller is configured to cause an intake of external air into an internal environment comprising the brake and the at least one fluid moving device to cause thermal transfer between the external air and the fluid, wherein the external air is from an external environment that is external to the internal environment. Optionally, the controller is configured to cause the fluid to receive the intake of external air. Optionally, the external environment is an unpressurised region. Optionally, the external environment is external to the aircraft. Optionally, the external environment is within the aircraft. Optionally, the external environment within the aircraft is an environment of an air conditioning or ventilation system of the aircraft.

Optionally, the intake of external air is through an inlet comprising at least one opening. Optionally, the at least one opening is a slot. Optionally, the inlet comprises a plurality of openings. Optionally, at least one opening is located on a fuselage of the aircraft. Optionally, the controller is configured to cause a variation of an extent of the opening of the inlet to vary an intake of the external air.

Optionally, the controller is configured to cause an exhaust of at least a portion of the fluid and/or external air from an internal environment comprising the brake and the at least one fluid moving device.

Optionally, the exhaust of fluid and/or external air is through an outlet comprising at least one opening. Optionally, the at least one opening is a slot. Optionally, the outlet comprises a plurality of openings. Optionally, at least one opening is located on a wing of the aircraft. Optionally, at least one opening is located on a trailing edge of the wing of the aircraft. Optionally, the outlet is located further from the inlet in a longitudinal direction of the aircraft. Optionally, the controller is configured to cause a variation of an extent of the opening of the outlet to vary an exhaust of the fluid and/or external air.

Optionally, the least one fluid moving device comprises a pump and/or a fan. Optionally, the least one fluid moving device is powered by a power source. Optionally, the least one fluid moving device is powered by energy derived by a propulsion system of the aircraft. Optionally, the least one fluid moving device is powered by a battery.

Optionally, the fluid is or comprises a vapour or a gas. Optionally, the fluid is or comprises air.

A second aspect of the present invention provides an aircraft system comprising the aircraft brake temperature control system according to the first aspect and the at least one fluid moving device.

Optionally, the aircraft system comprises a landing gear and a landing gear bay.

Optionally, the aircraft system comprises a first fluid moving device on or mounted on the landing gear and a second fluid moving device that is off the landing gear. Optionally, the second fluid moving device is unattached to the landing gear. Optionally, for every fluid moving device that is on or mounted on the landing gear, the aircraft system comprises two or more fluid moving devices that is off the landing gear. Optionally, a number of the fluid moving devices that are off the landing gear is at least the same as a number of the fluid moving devices that are on or mounted on the landing gear. Optionally, the number of the fluid moving devices that are off the landing gear is at least more than number of the fluid moving devices that are on or mounted on the landing gear.

A third aspect of the present invention provides an aircraft comprising the aircraft brake temperature control system according to the first aspect or the aircraft system according to the second aspect.

A fourth aspect of the present invention provides a method of controlling a temperature of a brake of a landing gear of an aircraft, the method comprising causing at least one fluid moving device to drive a flow of fluid onto the brake, selectively in one of a plurality of modes, to control the temperature of the brake.

Optionally, the causing is on the basis of a condition indicated to the controller that the aircraft is in-flight.

A fifth aspect of the present invention provides a non-transitory computer readable storage medium comprising a set of computer-readable instructions stored thereon, which, when executed by a controller of an aircraft brake temperature control system, cause the controller to cause at least one fluid moving device to drive a flow of fluid onto a brake of a landing gear of an aircraft, selectively in one of a plurality of modes, to control a temperature of the brake.

A sixth aspect of the present invention provides a fluid movement system for moving fluid along a surface of a brake of a wheel of an aircraft. The fluid movement system comprises a controller that is configured to determine an extent of operation of a powered conveyor that is used to move the fluid along the surface of the brake by forced convection of the fluid generated by the powered conveyor, and the controller is configured to cause the powered conveyor to operate on the basis of an indication to the controller as to whether the aircraft is airborne or the aircraft is on the ground.

The aircraft brake temperature control system according to the above aspects of the present invention provides better control of brake temperature of an aircraft, particularly when the aircraft is in-flight. The aircraft brake temperature control system according to the first aspect of the present invention may provide improved brake life and/or brake performance. Alternatively, or additionally, a turnaround time of the aircraft can be reduced when using the aircraft brake temperature control system according to the first aspect of the present invention, as well as a sensitivity to a cumulative brake temperature effect experienced with successive flights during an operation period.

Any optional feature(s) of any one aspect of the present invention may be equally applied to any other aspect(s) of the present invention, where appropriate.

DETAILED DESCRIPTION

An aircraft system1000, according to an embodiment of the present invention, is illustrated schematically inFIG.1. In this embodiment, the aircraft system1000comprises a landing gear of an aircraft. InFIG.1, only a portion201′ of the landing gear is shown, and the portion201′ is shown in cross-section. The landing gear comprises a wheel210, a brake220, and a brake cooling fan (BCF)230. The wheel210comprises a tyre211coupled to a rim213. The wheel210is coupled to an axle215and rotates about an axis217of the axle215. In other embodiments, a fluid moving device other than the BCF230may be used to drive a fluid (such as air) onto the brake220to control the temperature of the brake220. The BCF230is an example of a forced convection device.

In this embodiment, the landing gear is a retractable landing gear. The landing gear is therefore configured to move into and out of a landing gear bay203of the aircraft for stowage or deployment of the landing gear, respectively. InFIG.1, the portion201′ of the landing gear is in the landing bay203because the landing gear is in a stowed position. When in the stowed position, the axle215is more closely aligned with an up-and-down direction of the aircraft than the axle215is aligned with a side-to-side direction of the aircraft. The up-and-down direction is shown inFIG.2bas direction200y. The side-to-side direction is shown inFIG.2bas direction200x.

The brake220is for applying a braking force to the wheel210of the landing gear to decelerate the aircraft in a deceleration event, for example during a landing procedure of the aircraft. In this embodiment, the braking force causes friction between braking surfaces of parts221,222of the brake220. The braking surfaces comprise first and second braking surfaces of the brake220. In other embodiments, there may be plural first braking surfaces and plural second braking surfaces. The first braking surface rotates relative to the second braking surface. Therefore, in this embodiment, the braking force causes friction between a rotating friction surface of the brake220and a stationary friction surface of the brake220. The friction, generated by the braking force, causes a temperature of the brake220to increase.

The temperature of the brake220can affect an amount of wear of the brake220, for example when the brake220is a carbon brake or a steel brake, and a performance of the brake220, for example when the brake220is a steel brake. Although some heat can improve an operation of the brake220, an excessive amount of heat can cause deterioration of performance and/or increased wear. In some instances, brake wear is proportional to brake temperature in a first temperature range. In some instances, brake performance is inversely proportional to brake temperature in a second temperature range. It is therefore desirable to control the temperature of the brake220to manage brake wear and brake performance.

There are many safety considerations when operating an aircraft. Adequate operation of the brake220of the aircraft is an example of such a safety consideration. When the aircraft is on the ground, for example between successive flights, the aircraft may be required to remain grounded when the temperature of the brake220exceeds a maximum allowable temperature. When the temperature of the brake220is acceptable, with respect to the maximum allowable temperature, the brake220may be considered acceptable for performing in a future braking event and the aircraft may then be allowed to take-off from a runway. When the aircraft is airborne and is due to land, the aircraft will be required to stop safely in a limited distance related to a length of the runway. When the temperature of the brake220, such as a steel brake, is higher than normal, a stopping distance or a stopping power will likely be higher than a normal stopping distance.

In addition to the above safety considerations, there are many duty cycle considerations when operating an aircraft. An example of a duty cycle consideration is a so-called turnaround time of the aircraft. The turnaround time of the aircraft is an example of a temporal operation of the aircraft. The temporal operation of the aircraft is a temporal condition. Another example of a temporal condition includes a temporal condition external to the aircraft, such as a time of a time zone at a portion or portions of a flight of the aircraft.

The turnaround time of the aircraft can be considered as a period of time that the aircraft is on the ground between successive flights. The period of time can be considered as the total amount of time from touchdown to takeoff. A turnaround time of the aircraft may be required to be extended by a temperature of the brake220if the temperature of the brake220is too high. Another example of a duty cycle consideration is a flight duration of the aircraft. The flight duration can be considered the time from takeoff to touchdown. The flight duration is another example of a temporal operation of the aircraft. Other examples include an elapsed flight duration during a flight, and a remaining flight duration of the aircraft during a flight.

A temperature of the brake220before touchdown may be related to the flight duration. In general, the longer the flight, the longer the time for the brake220to cool. Nevertheless, it may be desirable for the brake220to operate in a temperature window and the flight duration, whether a long or a short flight duration, may affect where the temperature of the brake220is with respect to the temperature window. Controlling the temperature of the brake220is therefore advantageous.

The aircraft system1000comprises an aircraft brake temperature control system (BTCS)100. The BTCS100comprises a controller110for controlling a temperature of the brake220. The BTCS100is operational when the aircraft is in-flight. The BTCS100is also operational when the aircraft is on the ground. Control of the temperature of the brake220, particularly when the aircraft is airborne, is advantageous in view of the above safety and duty cycle considerations. For example, the BTCS100enables the turnaround time of the aircraft to be reduced and brake performance or brake wear to be less impacted by flight time.

The controller110is configured to cause at least the BCF230to drive a flow of air onto the brake220to control the temperature of the brake220. In other embodiments, a fluid other than air may be driven onto the brake220to control the temperature of the brake220. The controller110is configured to output a signal to the BCF230to affect an operation of the BCF230and thus the flow of air interacting with the brake220. The BCF230thus generates a forced convection of the air to influence a temperature of the brake220, for example by allowing the movement of air to remove heat from the brake220.

In this embodiment, the controller110is configured to cause at least the BCF230to drive the flow of air onto the brake to control the temperature of the brake, on the basis of a condition indicating to the controller110that the aircraft is in-flight. The condition is based on detection of an event by a sensor. In this embodiment, the condition is a “weight-off” condition resulting from detection, by a sensor2015, of a change in a length of a telescopic strut of the landing gear. The “weight-off” detection indicates that the aircraft is no longer on the ground and is airborne.

In other embodiments, the sensor may be a pressure sensor, and the “weight-off” condition may result from a detection, by the pressure sensor, of a change of pressure on the landing gear201following take-off. In other embodiments, the pressure sensor may detect a specific pressure or a relative pressure. Other example conditions include a detection of a specific value, a relative value, or a change of value of one of the following: a load, a time, an altitude, an atmospheric pressure, an atmospheric temperature, an aircraft speed (for example, an indicated or true airspeed), a position (for example, of a landing gear or a portion of the landing gear (for example, a suspension component such as a strut), or a landing gear door or a portion of the landing gear).

The controller110is configured to cause at least the BCF230to operate, selectively in one of a plurality of modes. The controller110is configured to receive the selection. In some embodiments, the controller110may make the selection; for example, the controller110may make the selection on the basis of data indicating whether the aircraft is in-flight or whether the aircraft is on the ground. The selection can be made on locally on the aircraft (for example, by the pilot) or from an external source that is remote from the aircraft (for example, by an operator in a control centre). The selection can also be manual or automatic.

In this example, the controller110is configured to cause at least the BCF230to operate in a first mode and a second mode. The first mode is to produce a relatively high rate of flow of the air onto the brake220. The second mode is to produce a relatively low rate of flow of the air onto the brake220. In this embodiment, the first mode is a first speed of the BCF230, and the second mode is a second speed of the BCF230. The first speed is greater than the second speed. The BCF230comprises fan blades that rotate about an axle. The speed of the BCF230is rotational speed of the axle.

By way of example, the BCF230produces a rate of flow of 250 litres per second in the first mode and a rate of flow of 40 litres per second in the second mode. The relatively high rate of flow of the air in the first mode enables the first mode to pass air onto the brake220more quickly than the second mode passes air onto the brake220. The reduced flow of the air in the second mode enables the second mode to be a quieter mode of operation than the first mode. This reduces an amount of noise that is transmitted by operation of the BCF230to a cabin of the aircraft when operating in the second mode compared to the first mode. For example, when a portion of a flight is in a period of natural darkness with significantly reduced daylight, such as nighttime, there may be a requirement to keep noise to a minimum while passengers relax or sleep during that portion of the flight. The reduced flow of the air in the second mode can also enable reduced vibrations and/or harshness levels in the aircraft, and specifically those levels felt in the cabin by cargo and/or passengers. Therefore, operating the aircraft system1000with a consideration of at least one temporal condition improves a flight experience for those onboard.

The BCF230is switchable between the first mode and the second mode. The controller110is configured to cause a switch of the BCF230to operate between the first mode and the second mode. The controller110is configured to cause the switch depending on a condition indicated to the controller110. In this aircraft system1000, the condition indicated to the controller110is a temperature of a temperature sensor220S mounted on the landing gear. The temperature sensor220S provides an indication of a brake temperature and is an example of an aircraft condition. When the temperature sensor220S indicates to the controller110that a temperature is different from a desired temperature or is outside of a desired temperature range, the controller110is configured to cause the BCF230to drive the flow of the air onto the brake220. For example, if the temperature of the temperature sensor220S is greater than the desired temperature or desired temperature range, the controller110is configured to cause the BCF230to drive the flow of the air onto the brake220. The controller110further determines whether the first mode or the second mode of the BCF230is needed, dependent on the temperature of the temperature sensor220S with respect to the desired temperature or desired temperature range. The determination by the controller110can be dependent on flight conditions, such as a remaining flight duration.

An internal environment207is provided in the aircraft system1000. The internal environment207comprises the brake220and the BCF230. The internal environment207is a space comprising the air that is driven by the BCF230onto the brake220to control the temperature of the brake220. The internal environment207is a sealed environment of the landing gear bay203. The sealed environment is achieved by sealing the landing gear bay203by closure of a landing gear door using a non-hermetic seal. In other embodiments, the sealed environment may be achieved using a hermetic seal. The internal environment207is separated from an external environment209. The external environment209is external to the internal environment207. In this example, the external environment209is the environment external to the aircraft.

The aircraft system1000comprises an inlet240and an outlet250. The inlet240is located on a forward position of the aircraft, such as a forward position of a fuselage of the aircraft. The outlet250is located on a rearward position of the aircraft, such as a trailing edge of a wing of the aircraft. The inlet240and outlet250each comprise an opening through which air can flow. The openings are vents. The vents are controllable. The inlet240and outlet250can be open or closed, or partially opened. The controller110is configured to cause an extent of opening of the inlet240and/or outlet250to open and close the inlet240and/or outlet250.

Fluidic communication is provided between the internal environment207and the external environment209when the inlet240is opened. The controller110is configured to cause the inlet240to open and close to control an intake of external air from the external environment209into the internal environment207. The controller110is configured to cause the inlet240to open and close based on an indication to the controller110that the brake220requires cooling. When the aircraft is in-flight and a temperature of the external air is lower than a temperature inside the landing gear bay203, for example when the external air is ambient air, an intake of the external air will further assist in the cooling of the brake220. The controller110is configured to determine whether the inlet240is to be opened or closed based on an aircraft condition or a flight condition. An example aircraft condition is as a temperature of the landing gear indicated by the temperature sensor220S. An example flight condition is a remaining duration of a flight of the aircraft.

Fluidic communication is further provided between the internal environment207and the external environment209when the outlet250is opened. The controller110is configured to cause the outlet250to open and close to control an exhaust of air from the internal environment207to the external environment209. The controller110is configured to cause the outlet250to open and close based on an aircraft condition or a flight condition. An example aircraft condition is as a temperature of the landing gear indicated by the temperature sensor220S or a state of the inlet240(for example, whether the inlet240is open or closed). An example flight condition is a remaining duration of a flight of the aircraft. In-flight, a pressure of the air in the external environment209at the outlet250is lower than a pressure of the air in the external environment209at the inlet240. Such a difference in pressure will allow passive suction of a boundary layer of the aircraft, such as a boundary layer of the fuselage in which the inlet240is placed. This allows the external air to be provided without driving the external air into the internal environment207.

The aircraft system1000further comprises a first auxiliary fan231and a second auxiliary fan232. The first and second auxiliary fans231,232are configured to drive a flow of air onto the brake220to control the temperature of the brake220. The first and second auxiliary fans231,232are off the landing gear and mounted in the landing gear bay203. Each of the BCF230, the first auxiliary fan231and the second auxiliary fan232is an example of a fluid moving device. The fluid moving device may be referred to as a powered conveyor or a blower. The powered conveyor or blower is used to move fluid, such as the air, along the surface of the brake220by forced convection of the air generated by the powered conveyor or blower, on the basis of an indication to the controller110that the aircraft is airborne or the aircraft is on the ground.

The first and second auxiliary fans231,232can supplement the flow or air driven by the BCF230. Each of the BCF230can be operated independently or in any possible combination. For example, at least one of the BCF230, the first auxiliary fan231, and the second auxiliary fan232is operable alone or in combination with at least one other of the BCF230, the first auxiliary fan231, and the second auxiliary fan232. The controller110is configured to selectively cause each of the fluid moving devices to drive the flow of the air onto the brake220.

The first and second auxiliary fans231,232assist with a circulation of the air within the landing gear bay203. This improves heat distribution and reduces an exposure of surfaces near to the brakes to high temperatures. The first and second auxiliary fans231,232therefore drive a flow of the air at a flow rate that is less than or equal to a flow of the air driven by the BCF230. The first and second auxiliary fans231,232are distributed around a periphery of the landing gear bay203. The distribution of the first and second auxiliary fans231,232enables improved control of the circulation of air within the landing gear bay203. A direction of flow from each of the first and second auxiliary fans231,232complements a direction of circulation of the air. For example, the first and second auxiliary fans231,232operate to flow the air in the same or similar direction. In some embodiments, at least one of the first auxiliary fan231and the second auxiliary fan232may be omitted.

An aircraft200according to an embodiment of the present invention is illustrated schematically inFIGS.2aand2b. In this embodiment, the aircraft200comprises the BTCS100shown inFIG.1. The aircraft200comprises a landing gear201, a landing gear bay203, and a landing gear door205. A portion of the landing gear201is represented by the portion201′ ofFIG.1. The landing gear201is retractable into the landing gear bay203and is closed from an outside of the aircraft200during flight of the aircraft200by the landing gear door205. That is, when the landing gear201is stowed in the landing gear bay203, the landing gear201and the landing gear bay203is closed from an external environment by the landing gear door205.

FIG.3shows an example plot of data obtained from a simulation of the aircraft system1000ofFIG.1. The plot of data is a plot of temperature on the y-axis with respect to time on the x-axis. The plot of data shows a variation of temperature, indicated by the temperature sensor220S for example, during operation of the aircraft200for a first operation period and a second operation period.

In this example, the solid line on the plot of data represents the first operation period when the BCF230is not utilised by the aircraft200. The dashed line on the plot of data represents the second operation period when the BCF230is utilised by the aircraft200. The plot of data for the first and second operation periods are overlaid so that a direct comparison can be made.

The first and second operation periods successively comprise: a first taxiing-out event301,301′ (comprising a minor braking event), a first flight event302,302′, a first landing event303,303′ (comprising a major braking event), a first taxiing-in event304,304′, a second taxiing-out event305,305′ (comprising a minor braking event), a second flight event306,306′, and a second landing event307,307′ (comprising a major braking event). Each previously described event of the first operation period is shown by solid arrow lines on the plot of data, whereas each previously described event of the second operation period is shown by dashed arrow lines on the plot of data.

A general observation of the plot of data is that simulated temperatures of the temperature sensor220S when the BCF230is utilised in the second operation period (shown by the dashed line) are less than, or substantially equal to, temperatures of the temperature sensor220S when the BCF230is not utilised (shown by the solid line). The largest differences are shown between a second temperature320,320′ at an end of the first landing event303,303′ and a fifth temperature350,350′ at a start of the second landing event307,307′. This demonstrates that utilisation of the BCF230in-flight of the aircraft helps to reduce temperatures of the brake220, as detected by the temperature sensor220S. This enables a turnaround time of the aircraft, between successive flights, to be reduced and enables the brake220to perform in a desired operating window.

During the first taxiing-out event301,301′, the first flight event302,302′ and the first landing event303,303′, the BCF230is not utilized in either of the first and second operation periods because the brake temperature is already within an acceptable range. This is represented by temperatures of the first and second operation periods being substantially the same because the solid and dashed lines are directly overlaid. In these three successive events there are two peak temperatures. One peak temperature is a first temperature310,310′, that is experienced at the end of the first taxiing-out event301,301′, and another peak temperature is a second temperature320,320′, that is experienced when the aircraft200is at the end of the first landing event303,303′.

During the first landing event303,303′, the brake220is applied and the temperature of the brake220is dramatically increased in both of the first and second operation periods. Following the first landing event303,303′, the BCF230is utilized in the second operation period (shown by the dashed line); however, as mentioned above, the BCF230is not utilized in the first operation period (shown by the solid line). This results in significantly different brake temperatures in the first taxiing-in event304,304′, the second taxiing-out event305,305′ and the second flight event306,306′.

During the first taxiing-in event304,304′ and the second taxiing-out event305,305′, the BCF230is operated in the first mode with an increased air flow compared to the second mode, as previously described. The brake temperature is reduced to a third temperature330,330′ at the end of the first taxiing-in event304,304′ in both the first and second operation periods. However, a greater reduction of the brake temperature is experienced in the second operation period with the BCF230utilized, compared to a reduction of the brake temperature experienced in the first operation period with the BCF230not utilized. This enables a fourth temperature340′ of the brake220, at the end of the second taxiing-out event305′, to be more equal to the first temperature310′ of the brake220, at the end of the first taxiing-out event301′, when in the second operation period with the BCF230utilized, compared to the first operation period. In contrast, without utilization of the BCF230in the first operation period, a fourth temperature340of the brake220, at the end of the second taxiing-out event305, is substantially greater than the first temperature310of the brake220at the end of the first taxiing-out event301. Advantageously, the second flight event306′ is able to begin earlier for the second operation period, utilizing the BCF230, compared to the first operating period not utilizing the BCF230. This demonstrates how the use of the BCF230reduces the sensitivity to a cumulative brake temperature effect experienced with successive flights during an operation period.

The advantage of utilizing the BCF230in-flight is shown in a comparison of the second flight events306,306′. In-flight, the BCF230, is operated in the second mode with a reduced air flow compared to the first mode, as previously described. This helps to reduce unwanted noise to the cabin because noise produced by the BCF230in the second mode is lower than noise produced by the BCF230in the first mode. This also helps reduce vibrations and/or harshness in the aircraft, and specifically vibrations and/or harshness levels experienced in the cabin. As seen with the first flight event302,302′, the temperature of the brake220reduces with time in-flight for both the first and second operation periods. However, a fifth temperature350′ of the second operation period, utilizing the BCF230in-flight, is significantly lower than a fifth temperature350of the second operation period not utilizing the BCF230in-flight. The lower fifth temperature350′ enables a sixth brake temperature360′ at the end the second landing event307′ to be lower in the second operation period, utilizing the BCF230, than a sixth brake temperature360at the end of the second landing event307in the first operation period not utilizing the BCF230.

Reducing the brake temperature in-flight, using the BCF230, therefore enables peak brake temperatures experienced during landing of the aircraft200to be reduced. This can help to improve brake performance, reduce brake wear (due to reduced oxidation, which reduces downtime due to maintenance or replacement of parts), and reduce turn-around time (which in turn allows for more flights per day). The use of the BCF230also reduces the sensitivity to a cumulative brake temperature effect experienced with successive flights during an operation period.

Better control of brake temperature, and further improvements and reductions, can be achieved from other aspects of the aircraft system1000shown in the embodiment ofFIG.1. For example, the intake of external air from an external environment209and the supplementation of the air flow by first and second auxiliary fans231,231can provide benefits.

A diagram illustrating a method400according to an embodiment of the present invention is shown inFIG.4. In this embodiment, the method400is a method of controlling a temperature of a brake of a landing gear of an aircraft. An example brake is the brake220described above. The method comprises causing401at least one fluid moving device to drive a flow of the fluid, such as air, onto the brake, selectively in one of a plurality of modes, to control the temperature of the brake. Optionally, the causing401is on the basis of a condition indicating that the aircraft is in-flight. Examples of at least one fluid moving device includes the BCF230, and the first and second auxiliary fans231,232described above.

A schematic illustration of a set of computer readable instructions within a non-transitory computer-readable storage medium according to an embodiment of the present invention is shown inFIG.5. The set of computer readable instructions are executed by a controller of an aircraft brake temperature control system, for example the controller110of the BTCS100described above. When executed, the instructions cause the controller to cause515at least one fluid moving device to drive a flow of fluid, such as air, onto a brake of a landing gear of an aircraft, selectively in one of a plurality of modes, to control a temperature of the brake. Optionally, the instructions cause the controller to cause515at least one fluid moving device to drive a flow of fluid, on the basis of a condition indicating that the aircraft is in-flight. An example brake is the brake220described above. Examples of at least one fluid moving device includes the BCF230, and the first and second auxiliary fans231,232described above.

In some embodiments, the brake is a hydraulically-actuated brake. In some embodiments, the hydraulically-actuated brake comprises a hydraulic piston. In other embodiments, the brake is an electric brake. In some embodiments, the electric brake comprises electromechanical actuators. In some embodiments, the brake comprises a non-metallic material. In some embodiments, the non-metallic material comprises carbon, and the brake can be referred to as a carbon brake. In some embodiments, the brake comprises a metal. In some embodiments, the metal comprises steel, and the brake can be referred to as a steel brake.

In some embodiments, the brake is configured to hold the aircraft stationary, for example on a runway, as well as to decelerate the aircraft.

In the embodiment shown inFIG.1, two auxiliary fluid moving devices231,232are shown. In other embodiments, a different number of auxiliary fluid moving devices may be used. For example, a single auxiliary fluid moving device may be used, or none at all. The number of auxiliary fluid moving devices may be equal to or greater than a number of brake cooling fans.

Advantageously, features of the embodiments described herein provide an aircraft system that provides better control of brake temperature. Advantageously, brake performance, brake life, tyre performance, tyre life can be improved. Alternatively, or additionally, a turnaround time of the aircraft can be reduced, as well as a sensitivity to a cumulative brake temperature effect experienced with successive flights during an operation period. Furthermore, reduced brake temperatures assist in reducing exposure to other components of the aircraft to high temperatures. Example components include a wheel, a tyre, a braking housing, a rim of a wheel, an axle of a wheel. Control of brake temperature can help to mitigate a risk of tyre deflation.

It is to be noted that the term “or” as used herein is to be interpreted to mean “and/or”, unless expressly stated otherwise.

The above embodiments are to be understood as non-limiting illustrative examples of how the present invention, and aspects of the present invention, may be implemented. Further examples of the present invention are envisaged. It is to be understood that any feature described in relation to any one embodiment may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, or any combination of any other of the embodiments. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the present invention, which is defined in the accompanying claims.