Navigation

BASIC NAVIGATION

About the author:

The reader has a right to know the qualifications of whom isdoing the writing. I soloed in 1966 and received my Commerciallicense several months later. For the next 20-some years I mademy living flying airplanes: flight instructing, charters, mail,commuter airline and ending up as a corporate pilot for the last15 years or so. In that time I accumulated over 6,000 hours whileoperating a variety of aircraft ranging from the single-engineCessna 150 to the four-engine Dehavilland Heron. I retired fromaviation in 1988 and now ride in the back like most everyone else-and yes, I am a poor passenger.

Background information:

The act of flying an airplane from "a" to "b"can appear quite daunting to the uninitiated, however in practiceit is not all that difficult. As with most things in life, it'seasy once you know how to do it. Air navigation can be done bya variety of methods. The purpose of this manual is to explainin simple terms how this is done so that the armchair flight simmercan enjoy his experience more fully.

Navigation can be broken down into two basic groups: visual(VFR), and instrument (IFR). The acronym VFR stands for VisualFlight Rules, IFR stands for Instrument Flight Rules. You shouldhave a good understanding of the flight instruments before youread this tutorial. If you do not, please read the tutorial "How to flycomputer flight simulators" before proceeding with thistutorial.

My apologies to my non-American readers. In this tutorial Iuse the American weights and measures- inches, feet, etc. It isnot my intent to be jingoistic, it is the only system that I know.

In addition, I appreciate that the reader would like to "jumpright in and fly someplace". Flying and navigating can becomplex however, be it in real life, or on a flight simulator.For this reason it is necessary that some basic information becovered first.

Bear with me, we will get there.

Purpose of this tutorial:

At its most basic, one could depart from an airport and seethe destination airport right after takeoff. In a more advancedmode your destination lies far off over the horizon.

So, just how do you go out there and find your way "home"?Well, first off you need a map, or "chart" as it isknown in aviation. And, just to make life difficult, there ismore than one type of chart available. There are "sectionals"that cover a given part of the Earth, "WAC's" that covera larger area (and therefore require fewer charts to carry along),but because they are smaller, present fewer details than sectionalcharts do. In addition there are "private issue" chartsthat are published by companies using data furnished by the appropriategovernment authorities. Also, there are a variety of instrumentcharts, ranging from high altitude to SID's and STAR's. And lastly,there are approach plates, the visual and written procedures forlanding at a specific airport while using a specific type of approach.

In this, Part 1, I will cover basic visual navigation, gettingfrom "a" to "b", when "b" is overthe horizon. Then we will refine our trip using a dispatch formfor better organization.

And lastly, this will not be an IFR tutorial. For informationon that aspect of flying I refer you to the fine series that waswritten by Andrew Ayers.

PART 1

Below, is a very simplified, generic rendition of a sectionalchart. It differs from actual charts, but will serve our purposes,and will not require the reader to locate and purchase the realthing. I'll reference to this "chart" as I discuss flightplanning and preparation. For reference purposes, it is labeled"Chart 1".

Let's go through the items that are depicted on Chart 1.

Notice the small blue runways that illustrate the Crystal Airport.The compass rose represents the Crystal VOR (Very highfrequency Omnidirectional Radio). The relationshipshows that the VOR is located on the Crystal Airport itself. Thetop "box" shows the name of the VOR and the frequency,116.5. The small "d" indicates that the Crystal VORhas DME (Distance Measuring Equipment). Thenotation "7'E" means that the magnetic variation atthis location is seven degrees East of true North. The lower "box"identifies Crystal Airport and shows that the airport is 860 feetabove MSL (Mean Sea Level).

Alake.

Thisrepresents a town/city named Hopkins.

Thisrepresents a Restricted Area. It may, or may not, be "active".Most likely it is used by the military. It is effective from thesurface up to 16,000 feet MSL. To find out if it is active ornot you would need to contact the controlling authority or askyour weather briefer. From a practical standpoint it would bewise to either avoid it or fly over above 16,000 feet.

Thisrepresents a radio/communications tower. The top of the toweris 1,899 feet above MSL.

Another lake.

Thedistance from the Crystal Airport to the Oxford Airport.

Thered line represents the desired course from Crystal to Oxford.

AnotherVOR. The frequency is 117.3, and once again there is DME associatedwith the station. The name of this VOR is "Dolly", andthe magnetic variation is 8 degrees East of true North.

Distancescale.

Anothertown. This one is named Eden Prairie.

Alake, with a river coming out of the Southern end.

AnotherVOR. The frequency is 114.2, and once again there is DME associatedwith the station. The name of this VOR is "Sparta",and the magnetic variation is 12 degrees East of true North.

The Oxford Airport. Field elevation is 1,200 MSL.

The town of Oxford.

Our aircraft:

The aircraft that we will be using is a Speedster 190, a twin-engineaircraft.

The Speedster 190:

Engines: Continental, normally aspirated (not turbocharged),250 horsepower.
Propellers: McCauley, constant speed, full feathering,two-bladed, 75 inch diameter.
Passenger capacity (including pilot): Six
Fuel capacity: 100 gallons (600 pounds), maximum
Average fuel burn: 100 pounds per hour
Average fuel burn at climb power: 140 pounds per hour
Average fuel burn at 75% power: 90 pounds per hour
Average cruise speed at 10,000 feet, MSL: 175 knots
All engine rate of climb @ sea level @ max. gross weight:800 feet per minute
Minimum single-engine control speed (red mark on the airspeedindicator): 80 knots
Recommended safe single-engine speed: 95 knots
Best single-engine angle of climb speed: 100 knots
Best single-engine rate of climb speed (blue mark on the airspeedindicator): 105 knots
Maximum weight in aft baggage compartment: 200 pounds
Empty weight: 3,500 pounds
Maximum gross weight (takeoff): 5,000 pounds
Maximum gross weight (landing): 4,900 pounds

Notice that you cannot fill the Speedster 190 with full passengers,full fuel and full baggage. This is not unusual. Most airplanesrequire a trade-off in these areas. You must make allowances ifyou need full fuel for a maximum range trip, or if you intendto carry six people you will not be able to fill up with fuel.

Also note that the maximum landing weight is less than themaximum takeoff weight. This, also, is not unusual. In the caseof the Speedster 190 you would have to fly for approximately onehour after a maximum gross weight departure before landing. Thiswould burn off about 100 pounds of fuel, which would meet thelanding weight restriction. As an aside, this reduced landingweight is almost always due to landing stress on the gear.

Some airspeed definitions:

Minimum single-engine control speed:Sometimes called Vmc (Velocity, minimum control). With the aircraftat maximum weight, on a "standard day", with the CGat its farthest aft point, with one engine failed and windmillingand the other engine at full power. If the aircraft goes belowthis airspeed it will start rolling over towards the failed engine,even though full rudder and aileron are applied. If this happens,the pilot must either lower the nose to gain airspeed or decreasepower. These are the only two choices that are available to thepilot.

Recommended safe single-engine speed:This is the safest recommended minimum speed for failed engineoperations. Keep in mind that operating at the minimum single-enginecontrol speed has no reserve built into it. A little turbulence,or the loss of just one knot of airspeed and the aircraft goesinto an uncontrollable roll, and you will most likely contactthe earth inverted.

Best single-engine angle of climbspeed: This speed will give the aircraft the best angleof climb in the event of engine failure. The rate of climb(feet per minute) will not be the maximum available, but if thereare obstacles ahead this is the airspeed you want to use to obtainthe maximum amount of clearance.

Best single-engine rate of climb speed:This speed will give the aircraft the best rate of climb, themost feet per minute. If there are no obstacles ahead this isthe airspeed that the pilot should us

VFR Trip planning, fuel requirements,etc.:

Basic VFR flight:

Let us make the most basic of VFR flights from Crystal to Oxford.We'll use the Speedbird 190 and take along four of our friends.The weather is clear as a bell, all of the way. You know thisbecause you did a weather briefing prior to departure.

First off let's do a little weight and balance figuring forour proposed trip.

3,500 pounds: empty weight of the Speedbird 190
850 pounds: the weight of your 4 passengers and yourself @ 170pounds each (1)
250 pounds: fuel on board (2)
4,600 pounds: gross takeoff weight

The Speedbird 190 will be 400 pounds below the maximum grosstakeoff weight.

(1) You have a couple of choices here. Either use 170 poundsas an average weight for each passenger, including their baggage.Or, use the actual weight of each passenger and the actual weightof their baggage. Obviously, the easiest way is to use the 170pound average.

(2) This number is derived as follows: The distance for thetrip is 223 miles. Taking into account the slower speeds duringclimb and approach a guesstimate is made for an average trip airspeedof 150 knots. Dividing 223 miles by 150 knots yields a time of1.5 hours. With an average fuel burn of 100 pounds per hour, theSpeedbird 150 will use 150 pounds of fuel enroute. Add 30 minutesof reserve as a "comfort factor", and another 30 minutesfor "the wife and kids". This totals out to 100 poundsof reserve fuel added on to the 150 pounds consumed enroute, fora total of 250 pounds.

OK, now we know that our aircraft is capable of making thetrip, letís take a look at how we intend to get from Crystalto Oxford. For this discussion refer to Chart 1.

Our route is roughly 135 degrees from the Crystal Airport.This number is derived by looking at the compass rose for theCrystal VOR and noting that the course line crosses the rose aboutmidway between East (090) and South (180). Adding this 45 degreesto 090 yields 135 degrees as our departure heading.

We cannot fly direct from Crystal to Oxford because the restrictedairspace, R-207, lies across the direct route. This will requirethat we fly a dog-leg course.

After departure from Crystal turn to a heading of 135 degreesand fly that heading as you climb out. Keep an eye out of theright side of the aircraft for the lake that lies about 15 milesSoutheast- this is our first checkpoint. Our aircraft should passdirectly over the small peninsula that extends from the East sideof the lake. Adjust the heading of the aircraft as necessary tocross this point. As the aircraft cross the peninsula resume the135 degree heading.

Now that we have crossed our first checkpoint start lookingoff to the left side of the aircraft for the town of Hopkins.Although not as accurate a checkpoint as the peninsula was, flythe aircraft so Hopkins passes off to the left side by about 7miles. Continuing on, be looking out the windshield for the largelake that is south of the restricted area. This segment of ourtrip is the most critical as we do not want to wander into theR-207 airspace.

Restricted airspace, and its big brother prohibited airspace,are not things to take lightly. Prohibited airspace is usuallyreserved for things like a president or prime ministeríshome or "office". Restricted airspace usually involvesthe military.

As the lake nears we adjust the aircrafts heading so that wecross just South of the Northwest tip of the lake. In addition,there is a radio or TV tower just off to our right. However, towersare extremely difficult to see from the air and don't make forvery a good visual checkpoint.

After crossing the lakes tip we turn to our new heading ofabout 120 degrees for Oxford. Our next visual checkpoint is thetown of Eden Prairie. Adjust the aircraft heading so that it passesjust off to the right side. Next up is Lake Minnetonka and thesmall river that empties out of the Southeast corner. We shouldpass just to the left of the small island that is in the river-adjust the aircrafts heading if necessary.

Now we look ahead for the city of Oxford. Once the city appears,bring your vision scan to the Northwest side of the city and lookfor the airport. Once the field is in sight, start your descentfor landing.

And there you go, you just flew from one airport to another.Kinda shaky wasn't it? Here you were grinding around at 175 knotslooking for objects on the ground without having a clue as towhen they should appear. In addition, the headings were just aguess on your part. You thought that you had enough fuelfor the trip, but had no way to verify that information as thetrip went along. So, while effective, it is not the best way tonavigate an aircraft.

A better plan:

There must be a better way, and of course there is. First offI have to introduce a tool that is called a "plotter".

Plotters vary in size and format, but this is a fair representationof one. Notice that there is a protractor on the top. This protractoris marked off in 360 degree segments. The horizontal lines arefor orientation with your course, and also have various scalesso that the device can be used on a variety of charts that mayutilize different mileage scales.

Now let's apply this new tool.

First off we would like a more accurate course heading outof Crystal than our previous guesstimate. Lay the plotter overthe Crystal VOR. Center the protractor over the compass rose andalign the horizontal lines with the course that is drawn on thechart.

Reading from the protractor we can see that our course is 132degrees.

Next we want to measure the distance to our first check point,the peninsula on the lake that is Southeast of the airport. Usinga pen or pencil we make a mark on the chart where the course linecrosses the point of land. Next we line up the appropriate scaleon the plotter to measure the distance from the Crystal Airportto the checkpoint.

Reading the scale on the plotter we see that the distance to ourfirst checkpoint is 23 nautical miles.

Our next measurement will be to determine the distance to ournext checkpoint, the tip of the next lake. This will require movingthe plotter along the course line and adding up the two distances.

The distance to our next checkpoint measures off as 64 miles.Also, at this checkpoint our heading will make a change as weare now clear of R-207.

The plotter is positioned over the nearest VOR to the airport,in this case the Sparta VOR. Align the parallel lines on the plotterwhile the protractor is centered on the VOR symbol. This yieldsa reading of 124 degrees- our heading from our last checkpoint,and also our heading to the Oxford Airport.

Next, we need the distance from the "turn checkpoint"to our "island checkpoint". This is accomplished asbefore by laying the plotter down on the course and adding upthe measurements to get the total distance. In this case it is82 miles.

Our last step is to measure the distance from this last checkpointto the Oxford Airport. The distance reading is 54 miles We alreadyhave our inbound heading from the measurement that we did earlier-124 degrees.

Now we are able to establish a more refined VFR navigationflight plan.

23 miles: Distance from the Crystal Airport to checkpoint #1(heading 132 degrees)
64 miles: Distance from checkpoint #1 to checkpoint #2 (heading132 degrees)
82 miles: Distance from checkpoint #2 to checkpoint #3 (heading124 degrees)
54 miles: Distance from checkpoint #3 to the Oxford Airport (heading124 degrees)
223 miles: Total distance for the flight

Let's refine this a little farther and come up with some timeestimates for each of the legs. Then we will take this informationand fill out a flight log for our trip.

Leg 1, departure, climb to 5,500 feet, cruise (23 miles):

Time: Figuring in the takeoff, and time to climb from860 feet msl to 5,500 feet msl at an average climb rate of 800feet per minute yields a time of 5.8 minutes- round this off to6 minutes. Flying for 6 minutes at climb airspeed of 105 knotswill cover a distance of 10.5 miles- round this off to 11 miles.At cruise speed we have 12 miles left to go on this leg (23 miles,less the 11 miles traveled during the climb). Eleven miles ata cruise speed of 175 knots is 3.7 minutes- round this off to4 minutes.

Now we have a time estimate for our first leg: 10 minutes

Fuel: Six minutes at takeoff and climb power yieldsa fuel burn of 14 pounds. (140 pph x 6 minutes). Four minutesat cruise power yields a fuel burn of 6 pounds. (90 pph x 4 minutes).

Now we have a fuel burn estimate for our first leg: 20 pounds.

Leg 2, cruise at 5,500 feet (64 miles):

Time: Flying along at 175 knots it will take 22 minutesto cover the distance of 64 miles.

Fuel: Twenty two minutes at 90 pph yields a fuel burnof 33 pounds for the leg.

Leg 3, cruise at 5,500 feet (82 miles):

Time: Flying along at 175 knots it will take 28 minutesto cover the distance of 82 miles.

Fuel: Twenty eight minutes at 90 pph yields a fuel burnof 42 pounds for the leg.

Leg 4, cruise at 5,500 feet, descend and land (54 miles):

Time: Flying along at 175 knots it will take 19 minutesto cover the distance of 54 miles.

Fuel: Nineteen minutes at 90 pph yields a fuel burnof 29 pounds for the leg.

Total estimated time enroute: 1 hour, 19 minutes

Total estimated fuel burn enroute: 124 pounds

Now we have our estimated times and fuel burns for each leg.Prior to this we had determined our headings for each leg. Letísput this information onto a form so that we can refer to theseuseful numbers enroute.

TIME OF DEPARTURE: time that the wheels leave the ground
EST. TIME ENROUTE: your flight planning estimate
TIME OF ARRIVAL (est./actual): add the estimated time enrouteto the ìwheels upî time for this figure
TOTAL FUEL ON BOARD: as appropriate
TOTAL FUEL REQUIRED: fuel required to meet VFR or IFR standards
POSITION: departure airport, checkpoint, waypoint, VOR,destination, etc.
STATION / FREQ.: frequency of the appropriate navigationalaid
DIST.: the distance for the leg
EST. LEG TIME: estimate for the amount of time to fly thisleg
TIMES: just a header for the column
ETA: estimated time of arrival at next point
ACTUAL: the actual time of arrival at the next point
TIME STATUS, + / -: based on your ETA for the leg, amountof time that you arrive early, or late
EST. FUEL BURN: estimated amount of fuel used for the leg
FUEL REMAINING: ESTIMATED: amount your pre-takeoffprojection indicates/ ACTUAL: actual amount
FUEL STATUS, + / -: amount of fuel over, or under yourestimate
REMARKS: any appropriate comments you wish to write down

Now let's go back to our last trip and use this "dispatchform".

All of the information that is filled out on the above dispatchform can be done before the trip.

Using the dispatch form on theCrystal to Oxford flight:

Departing Crystal we lift-off at 11:15am. Jot this time downin the "time of departure" box and turn to your headingof 132 degrees. When you have time, enter "11:25" inthe "ETA" box for the first leg. Still using our visualcheckpoints as before, we arrive over our first one at 11:23,two minutes ahead of schedule. Write down the time "11:23"in the "actual" box, and write the notation "-2"in the "time status" box. Write down "11:45"in the "ETA" box for the next checkpoint. Note the fuelremaining and write it down in the "actual" box underthe "fuel remaining" column. For the sake of this example,let's say that there is 240 pounds remaining. Enter the number"240" in the "actual" box, just below thenumber 230. Next to that, in the "Fuel Status" box,enter a "+10" indicating that you have 10 pounds morefuel than you had estimated to have at this point in the flight.

Your form would look like this (with your new entries in red):

Continuing along your flight you make the appropriate entriesas you cross over each checkpoint. Is this a lot of work? Youbet it is! Does it create a lot of "head down" timeas you make entries? It can, but if you do it properly, thinkingabout what numbers you are going to write down and where, it canbe done in an expeditious manner.

The whole point of this exercise is to remove as many unknownsa possible. Also, it has the ability to let you know well in advanceif a long trip is viable, long before you get near your destinationand are running low on fuel.

Let's say that you are taking your trusty Speedbird 190 onan extended trip, one that will push the aircraft to itísmaximum range. Your dispatch form for this trip might comprisetwenty checkpoints or more. After the first few entries you willbe able to see a trend developing. Is each leg taking longer thanyou had estimated? Does the "plus or minus" entry inthe "Time Status" box keep increasing? Do the entriesin the "Fuel Status" box continue to increase in a "negativenumber"? Well, you have problems.

But you have made this observation at the early stage of thetrip when you can take appropriate action, like a fuel stop thatyou hadn't planned on before. The point is that you will knowyour status early into the trip, not when you are "suckingfumes" with the weather going down all around you.

Aviation can be fraught with surprises. Anything thatyou can do as a pilot to eliminate as many of them as possiblewill make your task that much easier- and safer.

This form, or a variation of it can be used in "real:or virtual aviation. The one that I personally used for my corporatework had this information plus a passenger manifest. On the otherside I drew up a weather form for listing forecasts, hourly obsevations,ATIS, winds aloft and other useful information.

This ends the first part of "Basic Navigation". Inthe next part we will discuss using VOR's for VFR navigation.

PART 2

In this, Part 2, I will cover basic visual navigation usingthe VOR's (VORTAC's) for a little more refined navigation. Theestablished airways are there for both VFR and IFR operations.Right off of the bat you can see that there is a lot of informationpresented that will save you time and effort in your preflightplanning. Headings and distances are given. In addition, thereis airway altitude information for safe obstruction clearance.

There is one thing that must be kept in mind, however, when"flying the airways". Because you are on an "airialhiway" there will be more traffic- both VFR and IFR. TheVFR traffic will be flying by the "odd or even, plus 500"rules, and the IFR traffic will be flying by the "odd oreven" rules.

VFR:

If your magnetic _course_ (not heading) is from 0 to 179 degrees,and you are more than 3,000 feet above the surface, you must flyat "odd thousands" plus 500 feet. This means 3500, 5500,7500 etc.

If your magnetic _course_ (not heading) is from 180 to 359degrees, and you are more than 3,000 feet above the surface, youmust fly at "even thousands" plus 500 feet. This means4500, 6500, 8500 etc.

IFR:

IFR traffic flies at "oddî or ìeven",but without the "plus 500 feet". So, there is only 500foot of guaranteed separation between you as a VFR flight, andthe IFR traffic that is also using the airway. Also, keep in mindthat if your aircraft is faster than the average bear, you mayover-take slower traffic at the same cruising altitude. Conversely,if you are a slow cruiser, you may be over-taken by faster traffic.The bottom line is that you want to keep an eye out for traffic,of both varieties.

Chart 2:

Below, is a very simplified, generic rendition of a chart.It differs from actual charts, but will serve our purposes, andwill not require the reader to locate and purchase the real thing.I'll reference to this "chart" as I discuss flight planningand preparation. For reference purposes, it is labeled "Chart2".

Notice that if varies considerably from our previous chart,"Chart 1". Now we have the airway system depicted, alongwith some limited terrain information.
Let's take a look at some of this new information.

Theseare IFR minimum obstacle clearance altitudes, in MSL. "13o"stands for 13,000 feet, "16o" stands for 16,000 feet,and so on. If our sample chart were real, there would be somevery high terrain indeed just to the North of our route.

A high altitude airway, in this case route J-13. The high altitudeairways go into effect from 18,000 feet and up. They are shownon low-altitude charts for orientation. If you were departingCrystal Airport and flying a high altitude capable aircraft, youcould file "Crystal, J-55, Spartaî, and so on. On thereverse, if you were landing at Crystal from a trip originatingto the East, you could use Sparta as your transition VOR and file"....J-55 Sparta, V-58 Crystal...". Although more likelyyou would file J-55 right to Crystal and expect vectors for loweraltitude from ATC.

Alow altitude (17,500 and below) "Victor Airway"- inthis case V-24. The airway is made up of the 125 degree radialfrom the Dolly VOR, and the radial from the next VOR, which isnot shown in this example. The "7200" is the minimumobstruction altitude for IFR flight, but for the VFR pilot givesimportant information for terrain clearance. In this case, flyingV-24, 7,500 feet and 8,500 feet should be considered as your minimumvisual altitudes.

This is the distance on the airway between VOR's, in this caseit is 155 nautical miles from Dolly to the next VOR.

Anintersection. In this case, named "Ralph". The intersectionis formed by the 055 degree radial from the Dolly VOR, and the132 degree radial from the Crystal VOR.

The "87" is the distance from the Crystal VOR tothe Ralph intersection.

So now we can see two ways to determine the Ralph intersection.

Centered on the 213 degree radial from the Crystal VOR, wewould be at the Ralph intersection:
1. At 87 miles, DME from the Crystal VOR, or
2. When we cross the 055 degree radial from the Dolly VOR

FLYING FROM CRYSTAL TO OXFORD USINGTHE AIRWAYS

Now let's make our trip again from the Crystal Airport to theOxford Airport, but this time we'll use the established airways.Once again we drag out our dispatch form and plan our route.

Leg 1, departure, climb to 5,500 feet, cruise (87 miles):

As long as the Crystal VOR is conveniently located on the airportitself, we simply have to set our Nav. one VOR to the CrystalVOR frequency of 116.5 and set the OBS to the outbound radial,132 degrees. The DME will read somewhere in the "tenths"to the VOR while we are on the ground.

After departure we will fly headings as necessary to keep theradial centered in the Nav. one display. At 87 miles DME fromthe Crystal VOR we are at the Ralph intersection. This can beverified by tuning VOR two to the Dolly VOR and selecting the055 degree radial. When the CDI centers in the display of VORtwo we are at the Ralph intersection. At Ralph we turn to a newheading of 129 degrees and track inbound on the 309 degree radial(the reciprocal of the 129 degree radial) of the Sparta VOR.

Time: Figuring in the takeoff, and time to climb from860 feet msl to 5,500 feet msl at an average climb rate of 800feet per minute yields a time of 5.8 minutes- round this off to6 minutes. Flying for 6 minutes at climb airspeed of 105 knotswill cover a distance of 10.5 miles- round this off to 11 miles.At cruise speed we have 76 miles left to go on this leg (87 miles,less the 11 miles traveled during the climb). Seventy six milesat a cruise speed of 175 knots is 26 minutes.

Now we have a time estimate for our first leg: 32 minutes

Fuel: Six minutes at takeoff and climb power yieldsa fuel burn of 14 pounds. (140 pph x 6 minutes). Twenty six minutesat cruise power yields a fuel burn of 39 pounds. (90 pph x 26minutes).

Now we have a fuel burn estimate for our first leg: 53 pounds.

Leg 2, cruise at 5,500 feet (126 miles):

Time: Flying along at 175 knots it will take 44 minutesto cover the distance of 126 miles.

Fuel: Forty four minutes at 90 pph yields a fuel burnof 66 pounds for the leg.

Leg 3, descend and land (10 miles):

Time: Descending and landing at our destination airport(Oxford) at an average airspeed ("Kentucky windage")of 155 knots, it will take 5 minutes to cover the distance of10 miles.

Fuel: Five minutes at 90 pph yields a fuel burn of 8pounds for the leg.

TOTALS FOR OUR TRIP:

Total estimated time enroute: 1 hour, 21 minutes

Total estimated fuel burn enroute: 127 pounds

Notice how much easier it was to fill out our dispatch formwith the information that was already available from this typeof chart. The down side of using these charts for VFR navigationis that very little surface information is given. Towns, railroads,water towers, lakes (except for the larger ones) are not shown.

FLYING FROM CRYSTAL TO OXFORD USINGAREA NAVIGATION (RNAV):

Area navigation (RNAV) is a convenient and relatively inexpensiveform of navigation that allows a pilot to fly in a direct lineor, on a longer trip, a great circle route. It is not as userfriendly as GPS, which is rapidly taking over this facet of aviationnavigation.

When using RNAV, you are in effect creating a "phantomVOR" by electronically moving an existing for to a locationof your choice. Let's set up an example to use for more explanation.

In our above example we wish to fly from "A" to "B".Notice that at our three enroute checkpoints the "cardinal"radials have been chosen. "Cardinal" radials are OOO,090, 180 and 270. While any radial can be chosen, picking thecardinal ones makes it easier to layout with your plotter as theyare clearly defined on the charts. In a perfect world, you woulduse the radial that crosses your flight path at a ninety degreeangle, as this yields a more precise definition of the point inspace. However, the above usage is more than acceptable.

HOW IT WORKS:

There are three basic windows in an RNAV unit.

1. The "frequency window", used to tune in the selectedVOR. In some installations,
this window is not present. By selecting "RNAV" fromthe radio menu, the RNAV unit
automatically is fed the information from radio one or two aspredetermined at the
time of radio installation.

2. The "radial window", used to select the desiredradial from the VOR in use.

3. The "distance window", used to set the distanceyou wish to "move" the VOR.

OK, I admit that this may be a little confusing right now,but trust me- RNAV really is a simple concept. For this example,our RNAV unit is fed input from radio number one. By placing theswitch on the unit to "RNAV" it will be fed the VORand DME information from our Nav. one radio.

Before departure, during our flight planning stageî,we have used our now familiar plotter and determined our courseheading for each leg, the distance for each leg, and the desiredradial and distance for our "waypoints".

So, here we are on the ground at "A" in our trustySpeedbird 190 wanting to fly this fancy RNAV direct route to "B".How do we go about this? First, tune Nav. 1 to the frequency ofthe VOR that will form our first waypoint, Shorty, 117.4. Next,dial in the radial, 000 degrees, and the distance, 021 miles.Turn the OBS on your nav. 1 display to 120 degrees. Also, fororientation sakes, set your heading bug to the course- 120 degrees.(We're going to use a no-wind situation here.)

After departure, turn to your heading of 120 degrees. Assumingthat the Shorty VOR is being received, your display will showyou as on course, the "TO / FRO"î arrow will bein the "TO" position, and the display will show 12 miles.As far as your readouts are concerned, the Shorty VOR is at yourwaypoint. As you close on the waypoint, the readout will "count-down"to zero, the "TO / FROM" flag will flip to the "FROM"position, and the mileage will begin counting up again as youcross the waypoint.

The OBS setting remains at 120 degrees as we track outboundfrom our waypoint. When you have a stable signal from the FlandarVOR, dial in the radial, 180 degrees, and the distance, 049 milesin the RNAV unit. Also, using the OBS set your course to 121 degrees.The displayed mileage will start counting down to our next waypoint,and the "TO / FROM" indicator will display "TO".Once again the mileage counts down until we reach our next waypoint.

Finally, as we near our landing site, "B", we tunein the Billy VOR and the 048 degree @ 023 coordinates. The displaywill show our distance from the center of the airport, and thedistance will count down accordingly.

Pretty nifty, huh? With RNAV you can "place a VOR"anywhere you want to- over an Outer Marker for orientation duringan ILS- with distance display to the Marker. Or, you can set upyour holding pattern in a more understandable display. In short,RNAV not only saves you time and money by permitting direct routingflights, it is a great orientation device.

GPS:

I regret that the writer has no working knowledge of GPS, sothat aspect of our navigation primer will have to be left out-my apologies.

I hope that this has proven helpful to the reader.

This tutorial is available on aCD

This tutorial, along with additional content, is availableon a CD. Click here formore information.

Thank you.

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