Patent Application
20130271300
The current runway awareness and alerting system (RAAS) provides useful information regarding what runway the host aircraft is heading to and whether that runway provides adequate length for safe operation. The main purpose of that alert is to provide a check for any gross errors such as lining up on a runway length that would not normally be part of the aircraft operators' route structure. However, the information the RAAS provides can be improved.
For example, the current Insufficient Runway Length—On-Ground advisory is provided when the aircraft is lined up with a runway and the runway length available for takeoff is less than a defined nominal takeoff runway length. The nominal runway distance for take-off is aircraft-type specific and is set by an operator—it does not take into account prevailing conditions.
The present invention provides systems and methods for using flight management system (FMS) takeoff and landing (TOLD) data to determine when an alert (advisory and caution) is present.
In one aspect of the invention, short-runway alerts are provided on runway line-up or during approach based on FMS TOLD data. The present invention also integrates FMS TOLD data with a two(or three)-dimensional airport moving map (AMM) display to allow the AMM to display which runways can safely accommodate the aircraft given the aircraft's gross weight and takeoff performance data. Indications are provided when suitable runway length exists for an intersection departure or when suitable runway length exists for landing for any given selected runway or a runway with a land and hold short (LAHSO) clearance in affect.
Preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings:
In one embodiment, as shown in
The following is an example of some of the data the processor 30 receives and uses for making a short-runway determination: TOLD data (takeoff/landing distance required (T/LDR)) or raw data such as groundspeed, barometric pressure, ambient pressure, aircraft position, aircraft on ground, aircraft state (e.g., takeoff state, landing state, cruise state), thrust selection (FLEX or full takeoff thrust), aircraft track, outside air temperature (OAT), inertial reference unit (IRU) acceleration, heading, turn rate, altitude, runway distance, runway conditions (e.g., moisture, snow, ice), aircraft weight and balance, aircraft trim and flap positions, or friction level (Mu) (pilot entered). Runway condition (e.g., wet, dry, snow, etc.) is either pilot entry or datalinked. Each of these runway conditions is associated with rolling and braking friction coefficient data, typically as a function of groundspeed.
The processor 30 provides short-runway alerts on runway line-up and during landing approach based on the FMS TOLD data. The TOLD data includes or uses data manually entered by the flight crew and/or received from sensors, such as gross takeoff weight (GTOW), flap setting, thrust setting. The FMS 40 receives air temperature from the ADS 36 and knows the runway because it was entered as part of the flight plan or received the runway from another system (e.g., a runway picker process performed by a runway awareness and alerting system (RAAS)). The FMS 40 computes such requirements as: V speeds, runway length requirements (i.e., TOLD data), obstacle clearance and engine-aircraft limits. The processor 30 integrates the FMS TOLD data with a two-dimensional airport moving map presented on the display 46 to show which runways can safely accommodate the aircraft 20, given the aircraft's gross weight and takeoff performance data—for both takeoff and landing and takeoff/landing distance available (T/LDA) information determined by the processor 30 with available information. In one embodiment, the processor 30 presents on the display 46 an indication of whether suitable runway length exists for departure for an intersection departure (i.e., a departure that doesn't start from a beginning portion of the runway).
In another embodiment, the processor 30 presents on the display 46 an indication of whether suitable runway length exists for landing when the aircraft 20 has been assigned a land and hold short (LAHSO) clearance or for landing on any selected runway.
In one embodiment, the processor 30 receives a pilot selection of desired runway made during flight planning in order to check if a takeoff location meets takeoff requirements. This selection is made based on an action (e.g., point and click using a cursor control device) performed by a user operating the UI device 32 to select a point on a runway presented on the display 46 (an airport moving map (AMM)). Then, the processor 30 determines whether the runway meets takeoff requirements (e.g., accelerate-stop distance) for the selected point based on the TOLD data and TDA based on runway information and the selected point. A similar function can be provided during flight planning for a user selected landing runway.
If, at the decision block 112, the aircraft is determined to be on the ground, the processor 30 determines pilot intent at block 134 similar to block 116. Next, at a block 136, the processor 30 determines takeoff distance available (TDA) based on the determined pilot intent. Note that TDA could be derived from an onboard (or datalinked) airport database once intended take-off runway is known. At a block 140, processor 30 receives a takeoff distance required (TDR) value from the FMS 40. The TDR is in the TOLD data. Then, at a decision block 142, the processor 30 determines if a short-runway condition exists, based on the TDA and the TDR. If the processor 30 determines that no short-runway condition exists, then the process returns to the beginning If the processor 30 determines that a short-runway condition does exist, then, at a block 130 (same block as above?) a short-runway alert is output to one of the outputs devices.
In other embodiments, the processor 30 presents the aircraft icon in any of a number of different ways in order to visually alert the flight crew to the short-runway situation. For example, the icon flashes at a predefined flash rate or is presented in a unique pattern. Also, text may be displayed on the display device near the aircraft icon 200, which would verbally indicate the specific alert. Also, a prerecorded audio recording indicating that a short-runway alert condition exists may be outputted via the speaker(s) 48.
Other data that the processor 30 uses for determining short-runway condition include aircraft weight, aircraft flap setting, thrust selection, wind speed and direction, runway condition, and slope, air temperature, and altitude of airport.
Aural alerts may be provided instead of or in conjunction with the visual alerts. For example, an advisory alert might be “Approaching Three-Four-Right 3000 feet available” and a caution alert might be “Caution Short Runway” or “Go-Around Short Runway”.
In another embodiment, as shown in
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. 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.
