Alternate destination predictor for aircraft

A method of providing a pilot of an aircraft with information regarding a plurality of alternate landing destinations where the aircraft can be landed, comprising the steps of:

• searching a navigational database for locations of alternate landing destinations nearest the aircraft's present position, said nearest alternate landing destinations forming said plurality of alternate landing destinations;
• determining a distance between the aircraft's present position and the position of each of the alternate landing destinations;
• determining a flight plan from the aircraft's present position to each of the alternate landing destinations, the flight plan including a trip altitude at which to fly to each of the alternate landing
• destinations, an optimum climb angle to the trip altitude, a cruise segment at the trip altitude and an optimum descent angle from the trip altitude to the alternate landing destinations;
• determining the time of arrival to fly to each of the alternate landing destinations;
• and
• determining an amount of fuel remaining on the aircraft if the aircraft were to land at each of the alternate destinations by performing the steps of:
• estimating a top of descent point in the flight plan to the alternate landing destination;
• determining an amount of fuel required to fly from the aircraft's present position to the top of descent point in the flight plan;
• determining an estimate of the amount of fuel remaining on board the aircraft at the alternate landing destination;
• performing a forward determination an amount of fuel remaining at the top of descent point by determining the amount of fuel required to fly the present position of the aircraft to the estimated top of descent point;
• performing a backward determination of the amount of fuel remaining at the top of descent point by determining an amount of fuel required to fly from the top of descent point to the alternate landing destination plus the initial estimate of fuel remaining at the alternate landing destination;
• comparing the amount of fuel remaining at the top of descent point calculated by the forward and backward determination;
• and
• revising the estimate of the top of descent point and fuel remaining at the alternate landing destination as a result of the comparison;
• displaying the alternate landing destinations to the pilot, as well as the distance to each of the alternate landing destinations, the estimated time of arrival at each of the alternate destinations, and the amount of fuel remaining if the aircraft were flown from its present position to each of the alternate landing destinations.