Real
Time Tools inc.
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Navigation Calculator Help
About Aviator's Navigation Calculator The Aviator's Navigation Calculator is an easy to use calculator that operates in two modes. In Flight Planning Mode it quickly computes True and Magnetic headings as well as Track Speed (Ground Speed), Time Enroute (ETE) and Time of Arrival (ETA) for a flight leg, given;
When combined with the Range & Bearing Calculator (also available from Real Time Tools), the user has all of the computing power required to perform the navigational calculations involved in generating and flying a complete and accurate flight plan. Statement of Limited Liability While considerable effort on the part of Real Time Tools inc. (we are all pilots) has gone into insuring that the Aviator's Navigation Calculator is the best possible product we can produce it is a technically complex piece of software. As such, it is within the realm of reasonable possibility that, despite extensive testing, there may be some bug we missed. In the event that any deficiency related to design or programming is uncovered in the future, we will use best efforts to provide a corrective release update to all licensed users of NavCalc free of charge. That said, it is important to remember that as Pilot In Command of any aircraft, responsibility to evaluate the creditability and appropriateness of any information used in the preparation and execution of a flight plan rests solely with YOU. For this reason Real Time Tools cannot be held liable for any inaccuracies or errors associated with the use of this product. True Track, Wind & True Airspeed Enter True Track, Wind, and True Airspeed when the calculator is in Flight Planning Mode. True Track is the desired track that you wish to travel on and represents the actual path over the ground that the aircraft will follow. The word True reminds you that this is a true heading, not a magnetic one. It is obtained directly from the angle of the line which connects two points on a map. (True Track and Distance can also be imported directly from the Real Time Tools Range & Bearing Calculator.) True Airspeed is the calculated / documented True Airspeed of the aircraft and can be obtained by consulting the relevant performance data section of the Pilots Operating Handbook for the particular aircraft you will be flying. Wind input consists of the bearing that the wind is coming from, and the speed of the wind. The calculator permits you to enter and display wind speeds in a variety of units independent of those used for aircraft data (see Set Program Options). True Heading & Ground Speed True Heading (computed when the calculator is in Flight Planning Mode) is the heading you must fly in order to compensate for the wind and have the aircraft travel along the True Track. The calculator arrives at this heading by taking into account the speed of the aircraft and the component of the wind which is crosswind to the True Track. The word true reminds you that this is a true heading, not a magnetic one. In order to convert this to a compass heading, the calculator will apply the magnetic variation to compute magnetic heading (see Variation & Magnetic Heading). The calculator will also compute the Track Speed or Ground Speed. This is the speed at which the aircraft moves over the ground along the True Track. It is computed by calculating the component of the True Heading vector along the True Track and adding in the headwind/tailwind component of the wind. Variation & Magnetic Heading Since the Magnetic North Pole and the True North Pole aren't located in the same place, it is necessary to apply a correction to the True Heading in order to arrive at a Magnetic Heading or Course to Steer. This correction is known as the Magnetic Variation and will vary with longitude. The Agonal or point of zero magnetic variation (in the Western hemisphere) runs North and South at a longitude approximately passing through the US city of Chicago. Thus points east of this line (up to 90 degrees) will have a variation measured in degrees West and points west (up to 90 degrees) will have a variation measured in degrees East. VFR and IFR navigational maps show the values of magnetic variation over any region. Distance & Time Because the calculator can compute the Ground Speed of the aircraft it follows that, if it knows the distance to be traveled and the starting time for the leg, it can also calculate the Time Enroute (ETE) and the Time of Arrival (ETA). These values are displayed at the bottom of the calculator screen when you supply a distance and starting time (Wheels Up Time). Note that the values for units of distance and speed for the aircraft can be set separately from those of wind (see Set Program Options). In the event that units are different, the calculator will perform all of the necessary conversions. For Owners of Range & Bearing If you own the Range & Bearing Calculator - Ranger, also by Real Time Tools, you can use your Range & Bearing calculator to drive data into the Navigation calculator and further simplify the process of flight planning. With the touch of a single button, the Navigation Calculator will import the current range and bearing data from Ranger (see Import Data From Range & Bearing). When used together, these two calculators provide you with all of the computing power you need to perform the navigational calculations required of any flight plan. Enter Data Data entry into the calculator is straightforward. For all fields requiring a bearing (True Track, Wind From and True Heading) enter a number between 0 and 359. Magnetic Variation is entered as a number between 0 and 90. Whether this represents east or west variation is indicated by the radio buttons to the left of the field. All speeds and distances are entered as positive whole numbers. Work in Flight Planning Mode To put the calculator into Flight Planning Mode select Edit>Planning Mode. When the calculator is in this mode the following fields are available for input;
As an example, suppose you wish to fly from point A to point B at a planned true airspeed of 160 Kts. Suppose further that by consulting your map (or your Range & Bearing Calculator) you have determined that you will have to fly a true track of 30 degrees for a distance of 120 NM. If the predicted winds are to be from 45 degrees at 15 knots, and the magnetic variation in your area is 11 degrees west, the calculator shows that you will have to fly at a magnetic heading of 42 degrees and your estimated time enroute will be 49 minutes. If you pass over point A at 23:32 UTC, your estimated time of arrival at point B will be 00:21 UTC. Your true heading (for those who prefer to fly a GPS heading) is shown as 31 degrees. Your calculated ground speed for the flight will be 145 Kts. Work in Enroute Mode To put the calculator into Enroute Planning Mode select Edit>Enroute Mode. When the calculator is in this mode the following fields are available for input;
As an example, suppose when we attempt to fly the leg we planned in the previous section (see Work in Flight Planning Mode) we discover (perhaps by consulting a GPS or a VOR) that in order to stay on our true track, we have to fly on a true heading of 33 degrees. If we also notice (perhaps by consulting a GPS or a DME) that our actual track speed is only 140 Kts., then the calculator tells us that the actual winds we are encountering are from 52 degrees at 22 Kts. and that the impact this has had on our estimated time enroute is to extend it from 49 minutes to 51 minutes. As before, if you pass over point A at 23:32 UTC, your new estimated time of arrival at point B will now be 00:23 UTC. Set Program Options Program defaults for the calculator can be preset from the Options dialog. Select Edit>Options from the menu or press the  button on the toolbar.
The Options dialog allows you to select:
Note: because the calculator rounds off all displayed values to the nearest Nautical Mile, Statute Mile, or Kilometer, round off error will be apparent if you use this dialog to convert the display fields to different units and then back again. This type of round off error is normal and does not happen when the calculator performs computations with data provided in different units. Import Data from Range & Bearing The Aviator's Navigation Calculator has been designed to work with the Range & Bearing Calculator - Ranger, also from Real Time Tools. When Ranger is installed, the  button on NavCalc's toolbar will be
enabled each time the Ranger has been used for a calculation, and the results exported using the
reciprocal button on it's toolbar.
To import the results of a Range & Bearing calculation, simply press this button on the toolbar or select Edit>Import Range and Bearing from the menu. In addition to importing the True Track field and the Distance field, NavCalc will also import the name of the destination station and display this at the top of the true track frame. The button (and the menu item) in NavCalc will disable each time Ranger
performs a new calculation and remain that way until Ranger exports it. This insures that you can
never import data which is inconsistent with what is currently displayed in Ranger.
Note also that if the unit value set for Distance (NM, SM, or KM) in Ranger is different from the default Aircraft/Distance unit value set in NavCalc, the value will be converted to reflect the current settings in NavCalc. For example, if Ranger has calculated the distance will be 280 NM, and NavCalc's Aircraft/Distance units are set to SM, the display will be updated with 322 SM. Information about setting unit values appear in Set Program Options If the Import button is not enabled, one of these two conditions applies:
Obtain a Valid License The Aviator's Navigation Calculator is made available as shareware. This means that you have a limited use (30 day) license during which time the product is fully functional in order that you may evaluate it. After the trial period is over the program will cease to operate unless you obtain a valid end user license. You can obtain a license at any time by contacting Real Time Tools inc at www.realtimetools.com Please note that you will need to provide your Product Code number which is available from the Licensing dialog. This dialog is available to unlicensed users when the calculator first starts up. |
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