Sequential selective operation of aircraft brakes

A method of operating brakes of a multi-wheel aircraft where the aircraft has a total of N brakes and a lesser number n of the brakes may be selectively operated said method comprising:

• selectively operating the aircraft with the minimum number n.sub.1 of brakes that are initially required to control the aircraft during the landing stage of a flight spectrum which includes taxi-out, take-off, landing and taxiing-in,
• detecting a condition which at least potentially requires braking force additional to that which can be provided by said n.sub.1 brakes,
• applying additional braking force by increasing the number of brakes which are selectively operated from n.sub.1 to n.sub.2,
• detecting whether a condition requiring further additional braking force exists, and
• in response to a condition requiring further additional braking force, increasing the braking force progressively or incrementally by increasing the number of brakes which are selectively operated while said condition requiring said further additional braking force continues to exist.

An aircraft braking system comprising

• a plurality of carbon brakes, each brake having an associated actuating means for actuating the brake in response to an applied control signal,
• an electronic database for storing information concerning characteristics of each of a plurality of potential aircraft landing locations,
• selector means to select data relating to an individual landing location from the said information,
• control means operable to limit a number of brakes that may be disabled at stages of a flight spectrum including taxi-out, take-off, landing and taxiing-in whereby the number of disabled brakes is a function of monitored conditions applicable to an aircraft status at any given time, and of specified operating parameters of the control means defined by said data selected from the electronic database in response to a setting of the selector means thereby to ensure that the overall safety of the aircraft is not compromised.

An aircraft braking system comprising

• a plurality of carbon brakes, each brake having an associated actuating means for actuating the brake in response to an applied control signal,
• an electronic database for storing information concerning characteristics of each of a plurality of potential aircraft landing locations,
• selector means to select data relating to an individual landing location from the said information,
• control means operable to limit the number of brakes that may be disabled at stages of a flight spectrum including taxi-out, take-off, landing and taxiing-in,
• whereby the number of disabled brakes is a function of monitored conditions applicable to an aircraft status at any given time, said conditions including at least one parameter of the aircraft external environment selected from the group consisting of proximity of other vehicles, relative velocity of other vehicles or objects in relation to a subject aircraft, tire-ground friction coefficient, and location of the aircraft relative to predetermined zones of an airport, and specified operating parameters of the control means defined by said data selected from the electronic database in response to a setting of the selector means,
• thereby to ensure that the overall safety of the aircraft is not compromised at an individual landing location.

An aircraft braking system comprising

• a plurality of carbon brakes, each brake having an associated actuating means for actuating the brake in response to an applied control signal,
• an electronic database for storing information concerning characteristics of each of a plurality of potential aircraft landing locations,
• selector means to select data relating to an individual landing location from the said information,
• control means operable to limit the number of brakes that may be disabled during the landing stage of a flight spectrum including taxi-out, take-off, landing and taxiing-in,
• whereby the number of disabled brakes is a function of monitored conditions applicable to an aircraft status at any given time, said conditions including at least one parameter characteristic of the aircraft or its operation selected from the group consisting of aircraft velocity, wheel velocity, aircraft all up weight, and degree of wear of brake disc assemblies and at least one parameter of the aircraft external environment selected from the group consisting of proximity of other vehicles, relative velocity of other vehicles or objects in relation to a subject aircraft, tire-ground friction coefficient, and location of a subject aircraft relative to predetermined zones of an airport, and specified operating parameters of the control means defined by said data selected from the electronic database in response to a setting of the selector means,
• such that the minimum number of brakes which satisfies the instantaneous braking level requirement is applied, thereby to ensure that the overall safety of the aircraft is not compromised.

An aircraft braking system comprising

• a plurality of carbon brakes, each brake having an associated actuating means for actuating the brake in response to an applied control signal, measuring means to determine the remaining allowable wear in the brake,
• an electronic database for storing information concerning characteristics of each of a plurality of potential aircraft landing locations,
• selector means to select data relating to an individual landing location from said information,
• a plurality of status monitors to determine parameters related to the external environment of an aircraft,
• control means being operable
• to limit the number of brakes that may be disabled,
• to actuate the minimum number of brakes which satisfies the instantaneous braking level requirement,
• to identify the individual brakes that are to be disabled, and
• to activate additional brakes in a selective braking operation in response to a signal indicative of an increased instantaneous braking level requirement, at stages of a flight spectrum including taxi-out, take-off, landing and taxiing-in,
• whereby the number of disabled brakes is a function of each of a set of monitored parameters applicable to an aircraft status at any given time, said set comprising each of a first sub-set of parameters relating to the aircraft external environment and each of a second sub-set of parameters relating to the characteristics of the aircraft and its operation,
• said first sub-set being the proximity of other vehicles, the relative velocity of other vehicles or objects in relation to the subject aircraft, tire-ground friction coefficient, and location of an aircraft relative to predetermined zones of an airport, and
• said second sub-set being the aircraft velocity, wheel velocity, aircraft all up weight, and degree of wear of brake disc assemblies and
• of specified operating parameters of the control means defined by said data selected from the electronic database in response to a setting of the selector means,
• thereby to ensure that the overall safety of the aircraft is not compromised.

An aircraft braking system comprising a plurality of carbon brakes, each brake having an associated actuating means for actuating the brake in response to an applied control signal;

• control means operable
• to limit the number of brakes that may be disabled at stages of a flight spectrum including taxi-out, take-off, landing and taxiing-in and
• to activate additional brakes in response to an increased instantaneous braking level requirement and
• to apply different brake actuation pressures to different brakes such that as additional brakes are brought into operation sequentially, different brake actuation pressures are applied to the additional brakes in a manner selected to raise the temperature of the additional brakes as quickly as practical to the temperature of prior operating brakes
• such that the number of brakes which is actuated is the minimum number which satisfies the instantaneous braking level requirement thereby to ensure that the overall safety of the aircraft is not compromised.

An aircraft braking system comprising

• a plurality of carbon brakes, each brake having an associated actuating means for actuating the brake in response to an applied control signal and having measuring means to determine the remaining allowable wear in the brake,
• an electronic database for storing information concerning characteristics of each of a plurality of potential aircraft landing locations,
• a first selector means to identify data relating to an individual landing location from the said information,
• sensor means located between an aircraft runway and ancillary taxiways,
• remote signaling means transmitting signals received from said sensor means indicative of an aircraft being within a designated runway area,
• an aircraft speed measuring device,
• an aircraft wheel speed measuring device,
• an aircraft all up weight measuring device,
• a plurality of status monitors to determine parameters related to the external environment of the aircraft,
• control means operable to limit the number of brakes that may be disabled, and to actuate the minimum number of brakes which satisfies the instantaneous braking level requirement, at stages of a flight spectrum including taxi-out, take-off, landing and taxiing-in,
• said control means comprising a second selector means to identify the individual brakes that are to be operational;
• an automatic means for activating additional brakes in a selective braking operation in response to a signal related to at least one of said parameters indicative of an increased instantaneous braking level requirement and having means to apply different brake actuation pressures to different brakes such that as additional brakes are brought into operation sequentially, different brake actuation pressures are applied to the additional brakes in a manner selected to raise the temperature of the additional brakes as quickly as practical to the temperature of prior operating brakes such that the minimum number of brakes which satisfies the instantaneous braking level requirement is actuated whereby the number of disabled brakes is a function of
• monitored conditions applicable to an aircraft status at any given time, said conditions including at least one parameter of the aircraft external environment selected from the group consisting of the proximity of other vehicles, the relative velocity of other vehicles or objects in relation to a subject aircraft, tire-ground friction coefficient, location of the aircraft relative to predetermined zones of an airport, and at least one parameter relating to a characteristic of the aircraft and its operation selected from the group consisting of aircraft velocity, wheel velocity, aircraft all up weight, and degree of wear of brake disc assemblies and
• specified operating parameters of the control means defined by said data selected from the electronic database in response to a setting of the first selector means,
• thereby to ensure that the overall safety of the aircraft is not compromised at an individual landing location.

An aircraft braking system comprising

• a plurality of carbon brakes, each brake having an associated actuating means for actuating the brake in response to an applied control signal and having measuring means to determine the remaining allowable wear in the brake,
• an electronic database which stores information concerning characteristics of each of a plurality of potential aircraft landing locations,
• a first selector means to identify data relating to an individual landing location from the said information,
• sensor means located between an aircraft runway and ancillary taxiways,
• remote signaling means transmitting signals recalled from said sensor means indicative of an aircraft being within a designated runway area,
• an aircraft speed measuring device,
• an aircraft wheel speed measuring device,
• an aircraft all up weight measuring device,
• a plurality of status monitors to determine parameters related to the external environment of the aircraft,
• a plurality of location devices to define a plurality of positions along an airport runway,
• an aircraft-mounted flight spectrum stage discriminator and
• control means operable to limit the number of brakes that may be disabled, and to actuate the minimum number of brakes which satisfies an instantaneous braking level requirement, at stages of a flight spectrum including taxi-out, take-off, landing and taxiing-in,
• said control means comprising
• a second selector means to identify the individual brakes that are to be operational,
• an automatic means for activating additional brakes in a selective braking operation in response to a signal related to at least one of said parameters indicative of an increased instantaneous braking level requirement and having means to apply different brake actuation pressures to different brakes such that as additional brakes are brought into operation sequentially, different brake actuation pressures are applied to the additional brakes in a manner selected to raise the temperature of the additional brakes as quickly as practical to a temperature of prior operating brakes such that a minimum number of brakes which satisfies an instantaneous braking level requirement is actuated, and being provided in the form of an electronic control box, a microprocessor control device or as part of a landing gear computer,
• whereby the number of disabled brakes is a function of
• each of a set of monitored parameters applicable to an aircraft status at any given time, said set comprising each of a first sub-set of parameters relating to a subject aircraft external environment and each of a second sub-set of parameters relating to characteristics of the subject aircraft and its operation
• said first sub-set being the proximity of other vehicles, the relative velocity of other vehicles or objects in relation to the subject aircraft, the tire-ground friction coefficient, and location of the subject aircraft relative to predetermined zones of an airport, and
• said second sub-set being the aircraft velocity, wheel velocity, aircraft all up weight, and degree of wear of brake disc assemblies and
• specified operating parameters of the control means defined by said data selected from the electronic database in response to a setting of the first selector means,
• such that the number of brakes to be disabled during a landing run may be determined in part by the approach rate of an aircraft prior to touch down and the remaining length of the runway immediately following touch down thereby to ensure that the overall safety of the aircraft is not compromised at an individual landing location.

A method of operating brakes of a multi-wheel aircraft during landing and taxiing thereof where the aircraft has a total of N brakes and wherein a lesser number of the brakes n.sub.x, . . . n.sub.2, n.sub.1 may be selectively operated and N>n.sub.x >n.sub.2 >n.sub.1 said method comprising

• selectively operating the aircraft with a minimum number n.sub.1 of brakes that are initially required to control the aircraft in a safe manner, during stages of a flight spectrum, including taxi-out, take-off, landing and taxiing-in,
• detecting a condition which at least potentially requires the use of additional braking force beyond that which can be provided by n.sub.1 brakes,
• applying said additional braking force progressively or incrementally by increasing a number of brakes which are selectively operated from n.sub.1 to n.sub.2,
• detecting whether a condition requiring additional braking force continues to exist, and
• increasing the braking force progressively or incrementally by increasing the number of brakes which are selectively operated from n.sub.2 to n.sub.x while said condition requiring additional braking force continues to exist.