Abstract:
Using signals available into an Enhanced Ground Proximity Warning System (EGPWS), approach monitor systems and methods compare approach speed, approach angle and amount of tailwind/crosswind to the pre-selected envelopes. When the aircraft approach speed, approach angle, or tailwind/crosswind is greater than the pre-defined envelope, the approach monitor system generates an aural/visual advisory indicating the violation. The envelope is set as a function of “height above runway elevation”.

Description:
PRIORITY CLAIM  
       [0001]     This application claims the benefit of U.S. Provisional Application Ser. No. 60/715,809 filed Sep. 9, 2005, the contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Many airline operators have procedures for flight crews to adhere to when flying through “approach gates”. As part of these procedures, the non-flying pilot is instructed to monitor various flight parameters at the “approach gates.” These parameters include maximum operating speed, maximum altitude, maximum tailwind/crosswind, state of landing gear and state of landing flaps at during approach. 1,000 feet and 500 feet are typical “approach gates” altitude values. If the non-flying pilot observes that any of these parameters are outside of acceptable limits, they are instructed to inform the flying pilot. When any deviation is too great, the pilots are instructed to perform a go around or missed approach according to the company procedure.  
         [0003]     In many large airframed aircraft, when the pilot performing the approach to landing is the most experienced of the two pilots in the cockpit, the co-pilot in the monitoring position is someone of lower seniority. This can be problematic at times. If the first pilot is not flying the aircraft according to the approach gate procedures, the junior co-pilot may be reluctant to advise the more senior pilot of his poor flying.  
         [0004]     Regardless of who is in the monitoring position, the monitoring is still being performed by a human who may be distracted and thus not effectively monitor the aircraft conditions.  
         [0005]     Therefore, there exists a need to assist the flight crew in making determinations of the flight information in order to better adhere to company policies.  
       SUMMARY OF THE INVENTION  
       [0006]     Using signals available into an Enhanced Ground Proximity Warning System (EGPWS), approach monitor systems and methods compare approach speed, approach angle and amount of tailwind/crosswind to the pre-selected envelopes. When the aircraft approach speed, approach angle, or tailwind/crosswind is greater than the pre-defined envelope, the approach monitor system generates an aural/visual advisory indicating the violation. The envelope is set as a function of “height above runway elevation” or radio altitude.  
         [0007]     In other aspects of the present invention, position of landing gear and flaps are checked if they are in a landing mode configuration. An advisory is produced if either are not in the landing mode configuration at a certain distance and altitude from the runway. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings:  
         [0009]      FIG. 1  illustrates a schematic block diagram of an exemplary system formed in accordance with an embodiment of the present invention;  
         [0010]      FIG. 2  illustrates an example method performed by the system shown in  FIG. 1  in accordance with an embodiment of the present invention; and  
         [0011]      FIGS. 3-5  illustrate graphs of acceptable variables as used in an analysis step of the method shown in  FIG. 2 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]     As shown in  FIG. 1 , an aircraft  20  includes a system  22  for providing information assistance to pilots with regard to aircraft operation between approach gates when approaching to land. The system  22  includes a processing device  24  that is in data communication with a memory device  34  and flight and aircraft configuration sensors either directly (other data sources  38  such as by using discrete signals) or via a Flight Management System (FMS)  30  which in one embodiment includes an Air Data Computer (ADC)  32 . Also, the processing device  24  is in data communication with one or more displays  37  and a voice generator  36  that is connected to one or more speakers  40 .  
         [0013]     If the processing device  24  determines that aircraft parameters that are received from the FMS  30  or directly from other data sources  38  indicate that the aircraft  20  is not being flown in accordance with company policies or procedures (e.g., standard operating procedures) as they pertain to stability of the aircraft between predefined approach gates, then the processing device  24  produces advisories that are outputted via either one of the displays  37  or the speakers  40  via the voice generator  36 .  
         [0014]      FIG. 2  illustrates an example process  100  performed by the processing device  24  shown in  FIG. 1 . First, at a block  102 , the position of the landing gear is checked at approximately 1,500 feet altitude above the intended runway. Other altitudes may be used for the landing gear check. At decision block  104 , the processor  24  determines if the gear is down. If the gear is determined not to be down at the decision block  104 , then at a block  106 , an advisory is output to either one of the speakers  40  via the generator  36  or the displays  37  to advise the flight crew that the gear is not down. At a block  114 , the processing device  24  checks to see the position of the flaps at approximately 1,000 feet above the intended runway. Other altitudes may be used for the flap position check. At a decision block  116 , the processing device  24  determines if the flaps are set in the landing configuration. If the flaps are not set in the landing configuration, then at a block  118 , the processing device  24  outputs an advisory to either the displays  37  or the speakers  40  alerting the flight crew that the flaps are not currently in the landing configuration.  
         [0015]     The intended runway is the runway that was selected by the flight crew or automatically selected by a runway picker algorithm performed by a processor-based device, such as the EGPWS or the device  24 . An example runway picker algorithm is described in U.S. Pat. No. 6,304,800, the contents of which are hereby incorporated by reference. Altitude information of the intended runway is retrieved from the memory device  34  or some source (other aircraft or ground via a data link) external to the aircraft  20 .  
         [0016]     After blocks  106  and  116 , if the gear is determined to be down (decision block  102 ) and if the flaps are determined to be set in the landing configuration (decision block  116 ), the process  100  continues on to block  120 . At block  120 , the processing device  24  receives air speed, tailwind, and approach angle information. At decision block  122 , the processing device  24  determines if any of these received values are outside of predefined limits. If none of these values are outside the predefined limits, the process  100  continues to decision block  124  that checks to see if the aircraft  20  is below a second gate of predefined approach gates (e.g., 500 feet above the intended runway). If the aircraft is below the second gate, the process  100  is complete. If, however, the aircraft  20  is not below the second gate, in other words, the aircraft  20  is still within the altitude limits of the approach gates, then the process  100  returns to block  120 . If at the decision block  122 , anyone of the received values is outside of the predefined limits, then at a block  128 , an appropriate advisory(ies) is outputted by the processing device  24  to one of the displays  37  or speakers  40 .  
         [0017]     Examples of outputted advisories include “too fast” if the air speed is outside of limits, “too high” if the approach angle is greater than the predefined limit, and “tailwind” if the tailwind exceeds a predefined limit. Other types of voice advisories may be used depending upon aircraft operator preference. Also, various types of visual advisories may be presented on the display  38  or may be the activation of a dedicated advisory light. Next, at a decision block  130 , if the aircraft is determined not to be below 500 feet, the process  100  returns to the block  120 . If the aircraft is below 500 feet above the runway and at least one of the values remains outside of the predefined limits, the processing device  24  outputs an unstable advisory to the displays  37  or the speakers  40 .  
         [0018]     The sampling and advisory output frequencies may be based on aircraft operator preference, but could be any value that presents the advisories to the flight crew in an effective manner.  
         [0019]      FIGS. 3-5  illustrate example predefined limits as used in the decision block  122  of  FIG. 2 . As shown in  FIG. 3 , a line  150  defines the allowed airspeed difference between a reference velocity (Vref) based on how high the aircraft  20  is above the intended runway. As shown in  FIG. 4 , a line  160  defines acceptable tailwind values based on how high the aircraft  20  is above the intended runway. As shown in  FIG. 5 , a line  170  defines acceptable approach angles based on how high the aircraft  20  is above the intended runway. The lines  150 ,  160 ,  170  may be of any geometry (curve, slope) depending upon desired results for the initiation of the associated advisories. Also, the lines  150 ,  160 ,  170  may have different limits on the x or y axis.  
         [0020]     In another embodiment, wind direction and magnitude are received and a crosswind value is determined and compared to predefined limits in a similar manner as that shown and described for tailwind in  FIG. 2 .  
         [0021]     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, the processing device  24  or functions performed by the processing device  24  may be included as part of existing devices, such as the FMS  30  or an Enhanced Ground Proximity Warning System (EGPWS) (not shown), or may be a separate unit. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.