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. Additionally, the cabin depressurization discrete signal is determined not valid if an aircraft's altitude above terrain is not greater than a second predefined value.
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 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:
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 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:
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. Additionally, the cabin depressurization discrete signal is determined not valid if an aircraft's altitude above terrain is not greater than a second predefined value.
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:
A helicopter weight measuring system for detecting the loaded weight of a helicopter operating under partial or full hover conditions while the wheels of the helicopter are contacting the ground includes means for sensing loading on the landing gear of the helicopter and means for determining the lift produced by a rotating wing of the helicopter. The sensed loading on the landing gear is added to the calculated lift to produce an indication of total helicopter loading.