Runway overrun monitor and method for monitoring runway overruns

Abstract

A critical point on a runway indicates a point at which an aircraft may experience a runway overrun if landing beyond the critical point. A path projection is extended from the aircraft at a descent slope angle to determine whether the aircraft will land beyond the critical point at the current descent slope. Timely alerts may be provided by accounting for the time required to announce a distance value, and the distance traveled during the announcement.

What is claimed is:  
     
         1 . A method of providing situational awareness during landing of an aircraft, comprising: 
 determining a critical point on a runway, the critical point indicating a point at which if the aircraft lands beyond the critical point, there is a likelihood of the aircraft overrunning the runway;    determining whether a path projection of the aircraft intersects the runway in front of or beyond the critical point; and    providing an alert if the path projection intersects the runway beyond the critical point.    
     
     
         2 . The method of  claim 1 , wherein determining whether a path projection of the aircraft intersects the runway in front of or beyond the critical point comprises: 
 periodically making said determination during the aircraft's approach to the runway.    
     
     
         3 . The method of  claim 1 , wherein determining a critical point on a runway comprises: 
 determining a required landing distance for the aircraft.    
     
     
         4 . The method of  claim 3 , wherein determining a required landing distance for the aircraft comprises: 
 adjusting a landing distance value according to one or more of the following factors: tailwind component, runway gradient, runway altitude, and temperature.    
     
     
         5 . The method of  claim 3 , wherein determining whether a path projection of the aircraft intersects the runway in front of or beyond the critical point comprises; 
 extending the path projection from the aircraft at a descent slope angle.    
     
     
         6 . The method of  claim 5 , wherein the descent slope angle is constant during approach.  
     
     
         7 . The method of  claim 1 , wherein providing an alert comprises: 
 announcing a runway distance remaining.    
     
     
         8 . The method of  claim 1 , comprising: 
 determining whether the aircraft exceeds a maximum groundspeed; and    providing an alert if the aircraft exceeds the maximum groundspeed.    
     
     
         9 . The method of  claim 1 , comprising: 
 determining whether a maximum tailwind component is exceeded; and    providing an alert if the maximum tailwind component is exceeded.    
     
     
         10 . The method of  claim 1 , comprising: 
 determining whether a maximum crosswind component is exceeded; and    providing an alert if the maximum crosswind component is exceeded.    
     
     
         11 . A method of providing timely alert messages in an aircraft during landing, the method comprising: 
 determining message data regarding the aircraft's status during a landing phase;    determining aircraft speed;    adjusting a message based on the message data according to the aircraft speed; and    announcing the adjusted message.    
     
     
         12 . The method of  claim 11 , wherein adjusting a message comprises: 
 determining a time required to announce a message;    determining a distance to be traveled during the required announcement time; and    adjusting the message to reflect the distance traveled.    
     
     
         13 . The method of  claim 12 , wherein determining a distance to be traveled during the required announcement time comprises: 
 multiplying aircraft speed by the time required to announce a message.    
     
     
         14 . The method of  claim 12 , wherein determining aircraft speed comprises: 
 determining aircraft groundspeed.    
     
     
         15 . The method of  claim 11 , wherein determining aircraft speed comprises: 
 determining aircraft groundspeed.    
     
     
         16 . A method for monitoring for runway overrun when an aircraft is landing on a runway, comprising: 
 determining an aircraft's position on the runway after the aircraft has touched down;    determining the aircraft's groundspeed;    calculating a runway distance remaining before the aircraft on the runway;    calculating a distance required to reach a desired speed; and    generating an alert if the required distance is greater than the remaining runway distance.    
     
     
         17 . The method of  claim 16 , comprising: 
 determining the aircraft's deceleration.    
     
     
         18 . The method of  claim 17 , wherein calculating a distance required to reach a desired speed comprises: 
 calculating a distance required to reach a desired speed at said deceleration    
     
     
         19 . The method of  claim 18 , wherein determining an aircraft's deceleration comprises: 
 calculating the aircraft deceleration function as a rate of change of said aircraft groundspeed.    
     
     
         20 . The method of  claim 16 , wherein calculating a runway distance remaining comprises: 
 comparing the aircraft position to a runway end position; and    calculating the distance along a length of the runway between the aircraft position and the runway end position.    
     
     
         21 . The method of  claim 17 , comprising: 
 determining a required deceleration to reach the desired speed; and    generating an alert if the absolute value of the current deceleration is less than the absolute value of the required deceleration.    
     
     
         22 . A method of providing timely alert messages in an aircraft, the method comprising: 
 determining a range between an aircraft and traffic;    determining a closure rate between the aircraft and the traffic;    adjusting the range according to the closure rate; and    announcing the adjusted range.    
     
     
         23 . The method of  claim 22 , wherein adjusting the range according to the closure rate comprises: 
 decreasing the range by an expected decrease in range occurring during announcement of the range.