Abstract: Methods and systems for providing a depressurization alert. An example method includes receiving a cabin depressurization discrete signal, determining if the cabin depressurization discrete signal is valid, and issuing a cabin depressurization alert, if the cabin depressurization discrete signal was determined to be valid. In accordance with further aspects of the invention, a time delay is executed before the receiving, determining, and issuing steps are repeated. The cabin depressurization discrete signal is determined not valid if uncorrected pressure is not greater than a predefined altitude. The uncorrected pressure is a raw pressure value produced by a Pitot-Static system. Also, the cabin depressurization discrete signal is determined not valid if the aircraft's altitude above an intended runway is not greater than a first predefined value.

Abstract: Systems and methods for controlling activation of a look-ahead function of a terrain alert and warning system. The system receives rate of climb and aircraft speed information, compares the rate of climb and aircraft speed information to a predefined threshold, and deactivates a look-ahead function based on the comparison.

Abstract: Methods and systems for providing a depressurization alert. An example method includes receiving a cabin depressurization discrete signal, determining if the cabin depressurization discrete signal is valid, and issuing a cabin depressurization alert, if the cabin depressurization discrete signal was determined to be valid. In accordance with further aspects of the invention, a time delay is executed before the receiving, determining, and issuing steps are repeated. The cabin depressurization discrete signal is determined not valid if uncorrected pressure is not greater than a predefined altitude. The uncorrected pressure is a raw pressure value produced by a Pitot-Static system. Also, the cabin depressurization discrete signal is determined not valid if the aircraft's altitude above an intended runway is not greater than a first predefined value.

Abstract: Systems and methods for controlling activation of a look-ahead function of a terrain alert and warning system. The system receives rate of climb and aircraft speed information, compares the rate of climb and aircraft speed information to a predefined threshold, and deactivates a look-ahead function based on the comparison.

Abstract: Methods and systems for performing auto-recovery for an aircraft. An example system includes position and information systems, an automatic flight control system, a database, and a processor. The database includes terrain data, airport data, obstacle data, and protected airspace data. The processor determines if one of a caution alert or a warning alert exists based on data stored in the database and information received from the position and information systems. Auto-recovery instructions are generated and sent to the automatic flight control system if no positive flight control input has been performed at time of expiration of a waiting period. Auto-recovery instructions are generated based on an analysis of two or more auto-recovery routes. The system does not perform auto-recovery if components of the system fail to meet a predefined validity or integrity level.

Abstract: Methods and systems for performing auto-recovery for an aircraft. An example system includes position and information systems, an automatic flight control system, a database, and a processor. The database includes terrain data, airport data, obstacle data, and protected airspace data. The processor determines if one of a caution alert or a warning alert exists based on data stored in the database and information received from the position and information systems. Auto-recovery instructions are generated and sent to the automatic flight control system if no positive flight control input has been performed at time of expiration of a waiting period. Auto-recovery instructions are generated based on an analysis of two or more auto-recovery routes. The system does not perform auto-recovery if components of the system fail to meet a predefined validity or integrity level.

Abstract: A system and method for downlinking weather data, generated by existing weather and data sensors, to a ground station. The ground station utilizes data from multiple aircraft to form refined weather information, and uplinks the refined weather information to the aircraft. The refined weather information is stored at the aircraft and picture generating equipment, such as an existing onboard ground proximity terrain picture and symbol generator, generates pictorial information depicting weather. The pictorial information is displayed, for example by an existing EFIS or weather radar display, in the form of polygons.

Abstract: A low airspeed alerting system for alerting the pilot of an aircraft of insufficient airspeed during a landing monitors various readily available signals representative of flight parameters of an aircraft such as pitch angle, vertical speed and true airspeed and advises the pilot when the airspeed of the aircraft is approaching an airspeed (kinetic energy) that is too low with respect to the ground to maintain the aircraft flying along the desired flight path without stalling, or without action by the pilot in time to recover.

Abstract: Performance of an aircraft ground proximity warning system can be improved, especially where the performance of the aircraft itself has been degraded by a factor such as wind shear, by extending Mode 1 and Mode 3 warning envelopes down to within five feet of the ground. Additional improvements in warnings can be made by monitoring flight path angle, stall margin, angle of attack and deceleration profile, when the aircraft is close to the ground.

Abstract: A ground proximity warning system monitors the flight path angle or barometric or inertially derived descent rate of the aircraft and modulates the glide slope alerting function in accordance with flight path angle or descent rate when the aircraft is not descending rapidly even though it is below the glide slope in order to reduce nuisance warnings without compromising system sensitivity. Alternatively, the repetition rate of the alert may be varied as a function of the flight path angle or descent rate to provide less frequent alerts when the aircraft is not descending rapidly.

Abstract: A ground proximity warning system monitors the descent rate of an aircraft and generates a warning if the descent rate is excessive for the current altitude above ground of the aircraft according to a predetermined relationship. The predetermined relationship is altered as a function of the deviation of the aircraft from the glidescope to generate the warning earlier if the aircraft is below the glidescope and later if the aircraft is above the glidescope. The warning is given as a specific aural message indicating the specific flight parameters of the aircraft.

Abstract: An instrument (10) is disclosed for an aircraft having a windshear warning system to vary the threshold alarm setting as a function of a thermodynamic property of the air and as a function of local geographic and seasonal conditions. Specifically, a function generator 16 and other circuitry is disclosed. The output from the function generator 16 and other circuitry is then added to a fixed threshold acceleraton signal to produce a threshold alarm signal which has a value that is a function of the temperature of the air, in a basic embodiment.

Abstract: A wind shear warning system monitors the flight path of an aircraft and wind shear in the vicinity of the aircraft and generates an advisory or cautionary message for the pilot based both on the magnitude of the wind shear and the flight path of the aircraft. When the aircraft is flying a normal flight path, a wind shear warning is generated only when relatively high negative wind shears are present. If the flight path of the aircraft is not normal, for example, if the aircraft is below the glide slope or descending too rapidly, a cautionary alert is given at lower values of wind shear. The alert or warning is selected to provide the pilot with information defining the nature of the hazard or potential hazard being encountered.

Abstract: A ground proximity warning system is disclosed which can recognize when an aircraft is on a final approach to an airport without utilizing a landing flap signal input. Airports together with the surrounding terrain topography are modeled by a simple geometric shape, such as, an inverted truncated cone, and stored on-board the aircraft. The system uses navigational data to determine the distance of the aircraft from the geometric model. Once the aircraft is determined to be within the area defined by the geometric model, the system provides an enabling envelope indicative that the aircraft is on a final approach for enabling various ground proximity warning systems. Also disclosed is a system for altering the enabling envelope as a function of the aircraft's alignment with a particular runway.

Abstract: An instrument (10) is disclosed for an aircraft having a windshear warning system to vary the threshold alarm setting as a function of a thermodynamic property of the air and as a function of local geographic and seasonal conditions. Specifically, a function generator 16 and other circuitry is disclosed. The output from the function generator 16 and other circuitry is then added to a fixed threshold acceleration signal to produce a threshold alarm signal which has a value that is a function of the temperature of the air, in a basic embodiment.

Abstract: An aircraft ground proximity warning system having an excessive descent rate warning mode which generates a warning signal when the descent rate of the aircraft exceeds a predetermined limit for the particular altitude of the aircraft above ground. The warning system provides for three separate warnings. A SINK RATE advisory warning is generated for combinations of lesser descent rates and greater altitudes. A PULL UP warning is generated for higher descent rates at lower radio altitudes. After a predetermined time after the SINK RATE warning is generated a TERRAIN warning is provided to indicate to the pilot of the aircraft that an excessive sink rate condition exists and the aircraft is flying over undulating or mountainous terrain. Also disclosed is logic circuitry for detecting that the aircraft is flying over undulating terrain.

Abstract: An aircraft ground proximity warning system is disclosed having an inadequate terrain clearance warning mode, wherein the criteria required to generate the warning is modified when the aircraft is flying over undulating or mountainous terrain. The system is responsive to signals representative of the radio altitude, the barometric altitude, the speed of the aircraft, the flap position and the landing gear position to provide warnings when the aircraft is operating below a predetermined altitude with either or both of the landing gear of the flaps not in a landing configuration. The warning system also provides a warning when the aircraft is traveling above a predetermined speed and below a predetermined altitude irrespective of the configuration of the landing gear or the flaps. Also disclosed is logic circuitry for detecting that the aircraft is flying over undulating or mountainous terrain and modifying the warning envelope during such condition to provide longer warning times.

Abstract: An aircraft ground proximity warning system having an excessive terrain closure warning mode and a below glide slope warning mode monitors the glide slope signal and modifies the terrain closure warning envelope to accept a lesser terrain clearance when the aircraft is within the glide slope beam.

Abstract: A terrain advisory system utilizes stored data representative of terrain and other obstacles in predetermined geographical areas of interest to provide advisory warnings of the proximity of terrain, obstacles and restricted areas as they are approached. When used in a vehicle such as an aircraft, the system monitors the position, altitude, ground speed, ground track and the vertical speed of the vehicle and provides advisory indications of the position and path of travel of the vehicle with respect to obstacles and terrain. Such advisory indications may take the form of voice warnings describing the nature and position of any obstacles, or a visual display showing the position of the obstacles and terrain with respect to the vehicle.

Abstract: In order to facilitate the installation of transducers such as accelerometers in a larger system, each transducer is provided with a memory circuit which is physically attached to the transducer and contains data reflecting the operating characteristics of that particular transducer. The data stored in the memory can be in the form of coefficients for polynomial equations that describe the operation of the transducer as the function of a variable such as temperature. Provision is made for transmitting this data along with the signal output from the transducer to the larger system.