LESSON 9

Enroute Flight

There are those who say that real VFR pilots navigate by a system of pilotage, ignoring the lure of electronic navigation. They lay out a course on an aeronautical chart and direct the flight of their aircraft along that course by reference to the terrain. Pilots plan their flights by dead reckoning. That statement deserves some explanation: in the days of sail, mariners kept track of their position as accurately as they could by estimating their speed and the effects of wind and current and having a “deduced reckoning” of where they had traveled since their last known position. They logged the result as “ded. reckoning.” The airplane pilot of today lays out a course line, allows for wind and magnetic errors, derives a heading and a ground speed and estimates a time of arrival at the destination. That is dead reckoning—the planning phase. Unlike the sailor, the VFR pilot can maintain a visual track over the ground and pass over charted reference points. That is pilotage. From the early days, “pilot” has meant “navigator.” Pilotage and dead reckoning are the only methods of navigation available to recreational pilots—without an instructor’s endorsement, they are limited to trips of less than 50 nautical miles and cannot use electronic navigation aids. But they should read the section on the Global Positioning System in Lesson 10 anyway.

Aeronautical Charts

You will use two types of charts as a VFR pilot. The sectional chart is the one used most frequently because at roughly 8 nautical miles per inch, it affords sufficient detail for navigation by landmarks while retaining a manageable size. There are 38 sectionals covering the continental U.S., plus three Canadian provinces in the Northeast, 16 more for Alaska, and one for Hawaii. New charts are published every six months. Before using an expired chart, consider that an average of 128 changes are made per charting cycle.

Sectionals show roads, freeways, railroads, power lines, lakes, rivers, terrain contours, and populated areas. Airports shown on sectional charts include public, private, military, and those to be used only in an emergency. Boundaries of controlled airspace are indicated by color tint and a variety of symbols. Before you take your checkride, become familiar with the sectional chart legend because knowing your way around a sectional will play an important role in the oral exam.

Terminal area charts are published for the busiest airports…those with Class B airspace (discussed later in this lesson). Their 4-miles-per inch scale makes them quite detailed, and properly so: you must know where you are when flying in congested airspace. VFR Flyway Planning Charts are printed on the reverse sides of the Baltimore-Washington, Charlotte, Chicago, Cincinnati, Dallas-Fort Worth, Denver, Detroit, Houston, Las Vegas, Los Angeles, Miami, Orlando, Phoenix, St. Louis, Salt Lake City, San Diego, San Francisco, and Seattle Terminal Area Charts (TACs). The scale of these charts is 1:250,000, with area of coverage the same as the associated TACs. Flyway Planning Charts depict flight paths and altitudes recommended for use to bypass areas heavily traversed by large turbine-powered aircraft. Ground references on these charts provide a guide for visual orientation. VFR Flyway Planning Charts are designed for use in conjunction with TACs and are not to be used for navigation. Revised charts are issued every six months.

The Airport/Facility Directory (A/FD) is issued every 56 days, and includes information not found in any other publication. In Lesson 4, I noted that the A/FD includes an Aeronautical Chart Bulletin. Now look at the chart revision frequencies noted above…the shortest is six months. What if a cell tower has been erected since the last issuance of the sectional chart you are using? What if an airport shown as uncontrolled on your chart now has an operating control tower? What if the control tower is shown on your chart but the tower frequency has changed? Unless you refer to the A/FD’s Aeronautical Chart Bulletin, you will be flying blind. Every year, pilots get themselves into trouble by using out-of-date charts. Don’t be one of them.

Having said that, there is no provision in Part 91 that requires you to carry any charts at all, recent or outdated. There are a number of online sources that you can refer to. Keeping in mind that web addresses come and go without notice, here are some useful URLs: www.aeronav.faa.gov is the official FAA source (from that main page go to “Free Digital Products”). Unfortunately, because sectionals are large and consumer-level printers are small, you have to print out several individual charts and tape them together. Among unofficial sources are www.skyvector.com and www.1800wxbrief.com. You can “fly” your proposed trip using Google Earth, checking out visual checkpoints along the way, and you can look at the area around your destination by using the “Airports” page under www.1800wxbrief.com.

Geographical Coordinates

The sailor who “dead reckons” a voyage across untracked waters needs to be familiar with latitude and longitude—you do not. You will use latitude-longitude coordinates with some advanced radio navigation systems such as GPS, but lat-long coordinates do not play a large part in practical VFR flying. You will be using the lat-long lines on your WAC or sectional chart, however, so a brief explanation is in order.

Figure 9-1 shows parallels of latitude marching upward from the Equator (0° latitude) to the Poles (90° North or South latitude). If you slice a globe along lines of latitude, the slices get progressively smaller toward the poles, so distance measurements along latitude lines are useless.

Lines of longitude are called meridians, and divide the earth from pole to pole, the 0° meridian passing through Greenwich, England. Meridians are numbered eastward across Europe and Asia and westward across the Atlantic Ocean and the Americas until the 180° meridian is reached in mid-Pacific. The continental United States lies roughly between 70° and 125° West longitude and between 26° and 49° North latitude. Meridians are Great Circles: if you slice a globe along meridians, all of the slices will be the same size. All meridians are the same length: 10,600 nautical miles from Pole to Pole, 60 nautical miles per degree.

Each degree is further divided into 60 minutes, and this makes it possible to measure distance accurately: one minute of latitude equals one nautical mile when measured along a line of longitude toward either pole.

As you look at your aeronautical chart, lines of longitude and latitude are at right angles. As you look at a globe, however, lines of longitude converge toward the poles. Because there is some unavoidable distortion of scale between the bottom and the top of an aeronautical chart, you should make course measurements as close as possible to the mid-latitude portion of the chart.

On the excerpt of the Seattle sectional chart, find the Easton State airport (A). Count up 15 minutes from the latitude line marked 47° to find the latitude of Easton State. Count left 11 minutes from the longitude line marked 121° to find the longitude of Easton State. Its geographic position is 47°15' 15" north, 121° 11' 15" west. You don’t need to be any more accurate than the nearest minute in order to locate an airport using latitude and longitude. The geographic position of all airports is found in the A/FD.

Time

The measurement of time is an integral part of air navigation. Before leaving the discussion of longitude and the 0° meridian, the subject of time zones and time conversions should be covered. The only rational way to have flight times and weather information apply across the country and around the world is to have a single time reference. That reference is the time at Greenwich, England (on the 0° line of longitude). Once referred to as Greenwich Mean Time the time standard is now called Universal Coordinated Time (UTC). Each 15° of longitude east or west of Greenwich marks a one hour time difference. Figure 9-2 shows the time differences across the United States with a legend for time conversion to and from Universal Coordinated Time, or Zulu time. Zulu is the phonetic identifier for the letter Z; in the 24-hour clock system UTC is shown as 0800Z, 2200Z, etc. You should become familiar with time zone conversions for your area of operations. Here are two time conversion problems to illustrate:

An aircraft departs an airport in the Central Standard time zone at 0930 CST for a 2-hour flight to an airport located in the mountain standard time zone. What should the landing time be?

There are two ways of approaching this problem. First, according to the time difference chart, at the departure time of 0930 CST it is 0830 MST, and a 2 hour flight should land at 1030 MST. The second method is to add 2 hours to 0930 CST to get the CST landing time at the destination. (Forget to set your watch back?) Subtract the one hour time difference to get 1030 MST.

An aircraft departs an airport in the Pacific Standard time zone at 1030 PST for a 4-hour flight to an airport located in the Central time zone. At what ZULU time should the landing be?

What is Zulu time at departure? The chart says that to convert PST to UTC you must add 8 hours, so takeoff time is 1830Z. Arrival time after a 4-hour flight will be 2230Z.

Flight service station personnel and air traffic controllers use Zulu time, and will be reluctant to do time conversions for you. (Of course, you can buy a watch with dual time zones!) If you are planning a departure for 1800 local time and there is a forecast for thunderstorms after 2100Z at your destination, you will have to know time conversion to be able to relate that to your estimated time of arrival. As a new pilot, you will probably stay within one time zone or possibly travel between two time zones. Just remember that, for example, you live in the “plus 5” time zone (plus 4 in the summer), and conversions will come easily to you.

Statute and Nautical Mile Scale

Navigators on the sea or in the air find the use of nautical miles for distance measurement convenient, because a nautical mile is 6,000 feet (really 6,080, but that complicates things) and is also one minute of latitude. When you counted up 15 minutes to locate the latitude of Easton State airport, you counted up 15 nautical miles. You will find mileage scales for both nautical and statute miles on aeronautical charts and plotters (the distance between VORs in nautical miles is printed on sectional charts). The FAA uses nautical miles for all distance measurements except visibility, which is measured in statute miles. Airspeed indicators are calibrated in knots (nautical miles per hour) only or in knots and MPH; you will find a conversion scale on your flight computer. Winds are always given in knots, so you must be sure that you are dealing with like units when flight planning. The CX-2 Pathfinder electronic calculator contains conversion programs, including statute/nautical and nautical/statute miles.

Magnetic Variation

For flight planning purposes you must recognize that although the lines of latitude and longitude on charts are neatly perpendicular and relate to the True North Pole there is nothing in your airplane that relates to True North. The magnetic compass indicates the direction to the magnetic North Pole, which is in northern Canada (Figure 9-3).

You must take the variation between true north and magnetic north into account when flight planning.

Figure 9-4 shows isogonic lines, or lines of equal magnetic variation, across the continent. Along the line which passes through Chicago and Key West, a pilot looking toward the North Star or the True North Pole will also be looking toward the magnetic North Pole, and there will be no variation. That line of zero variation is called the agonic line. East or West of that line, the angle between true and magnetic north increases. A pilot in Los Angeles who measures a course line on an aeronautical chart in relation to the longitude lines (or true north) must subtract 14° from that true course to get a magnetic course (“East is least”), while a pilot in Philadelphia will add 10° (“West is best”). You will determine the true course by using your navigation plotter.

The variation on your sectional chart is almost certainly out-of-date. The isogonic lines on current sectionals were last updated in 2013 and will not be updated until 2016. Variations for navaids and airports are “assigned” and do not reflect the actual variation; variation for a VOR or airport can be up to three degrees different from actual variation. Next best source for variation is a current Airport/Facility Directory. You can get current variation information for airports along your route by going to www.aeronav.faa.gov.

Using the Navigation Plotter

A navigation plotter combines a protractor with mileage scales, and they are available in many forms. You use the protractor to measure the angle between a line of latitude or longitude and your course line. Refer to the Seattle sectional chart excerpt in Appendix D. Draw a line from the center of the airport symbol at Easton (A) to the center of the airport symbol at Wenatchee (H). Align the straight edge of your plotter with this course line and slide the plotter until the hole is over a vertical line of longitude; the angle should be approximately 78 degrees, indicating that the true course from Easton to Wenatchee is 078° and that the course for the return trip is 258°.

Deviation

A course, whether identified as true or magnetic, is only a line on a chart linking departure point and destination. For flight planning purposes, you must allow for magnetic influences in the airplane itself and for the effect of wind drift. Because your airplane has some iron and steel components which are affected by the earth’s magnetic field, and because it contains wiring which creates a magnetic field within the airplane itself, the airplane’s magnetic compass develops an error called deviation which varies with aircraft heading. Looking back at Figure 9-4, it is apparent that the heading of the airplane has nothing to do with magnetic variation—a pilot in Seattle must apply a 20° easterly variation regardless of the direction of flight. Because magnetic deviation is unique to each airplane and is dependent on heading, a compass correction card (Figure 9-5) must be pre-pared by accurately lining up the airplane on known magnetic headings, checking the magnetic compass reading, and recording the deviation error for each heading. Small adjustment magnets are provided so that the error can be minimized.

This compass correction table is originally made at the factory but should be re-checked by a mechanic whenever cockpit equipment installations are made. When a pilot has applied variation and deviation to a measured true course, the result is the compass course:

True ± Variation = Magnetic ± Deviation = Compass

Variation is shown on navigational charts to the nearest one-half degree. You will find that rounding off to the nearest whole degree will speed up your calculations without affecting accuracy. If you make long flights over water or featureless terrain, deviation and compass course will be very important to you, and an accurate compass correction card may be a lifesaver. Pilots who fly by reference to the surface (pilotage) will make little use of compass heading except to adjust their gyroscopic heading indicators.

Any difference between an airplane’s planned course and its track over the ground is caused by wind drift. Always compute the wind correction angle first, and then apply variation and deviation, as National Weather Service winds aloft forecasts are always referenced to True North.

Correcting for Wind Drift

Figure 9-6 shows the effect of wind drift on an airplane’s flight path if no corrective action is taken. The wind correction angle necessary to offset the wind drift will allow the airplane’s track over the ground to agree with the planned course. Determining wind correction angle with a known wind direction, wind velocity, true course and true airspeed is a trigonometry problem.

Solving the Wind Drift Triangle

The wind triangle consists of four known values and two unknowns. You know the angle between true north and your course (true course), and the angle between true north and the wind direction; you also know your true airspeed and the wind velocity. With these values, you can construct a triangle to solve for the unknowns: ground speed and true heading. Refer to Figure 9-7.

Wind direction = 320° true

Wind velocity = 30 knots

True course = 060°

True airspeed = 100 knots

The vertical line represents true north. Line A-B represents the true wind, and is drawn downwind—a wind from 320° “blows” the line to 140°. The length of line A-B represents the wind velocity in convenient units. Using a protractor, draw a line of indefinite length from point A so that the angle represents the true course as measured on your chart. A line with a length representing the true airspeed (100 knots) is drawn from point B to intersect the true course line at point C. The distance from point A to point C is the ground speed, (103 knots) and the angle that line B-C makes with the true north line (043°) is the true heading. The wind correction angle (17°) is the difference between the true course and the true heading. Magnetic variation must be applied to convert true heading to magnetic heading, and deviation applied to that to get compass heading. Very few pilots draw wind triangles, because the triangle can be solved mechanically and electronically much more quickly, but it’s a great way to really teach yourself the fundamentals of aerial navigation.

Winds aloft forecasts are only available for selected altitudes: 3,000 feet, 6,000 feet, 9,000 feet, etc. In most cases you will have to interpolate for your planned cruise altitude. Keep in mind that these are forecasts, and don’t expect extreme accuracy. If you use the Skew-T chart (see Lesson 7) for wind direction and velocity you will not have to interpolate.

Using The Slide-Type Computer

True course = 230°

True airspeed = 140 mph

Wind = 150° at 17 knots

(Convert wind or airspeed so that both are in the same units. 17 knots = 19.6 mph)

Orient the rotatable disk so that the true wind direction (150°) is at the true index. From the center, count up the number of units representing wind velocity, 19.6 (Figure 9-8). Rotate the disk so that the true course (230°) is aligned with the true index; note that the wind dot is now in the correct relationship to the course. Move the slide until the wind dot falls on the speed arc representing the true airspeed 140 (Figure 9-9). You have solved the wind triangle: the ground speed (135 mph) is read directly under the center grommet and the wind correction angle (8° left) is read under the wind dot. A left wind correction angle is subtracted from the true course and a right wind correction angle is added to the true course to get true heading.

True course = 115°

True airspeed = 90 knots

Wind = 240° at 38 knots

Make a wind dot where the wind direction line crosses the wind velocity arc. Rotate the disk with the wind dot to align the true course with the true index; rotate the outer disk to align the true airspeed with the true index. The position of the wind dot now shows you the number of knots of crosswind component and headwind/tailwind component. Find the number of knots of crosswind component on the outer scale; opposite it you will read the wind correction angle. If the crosswind component is more than 10% of the true airspeed, use the larger of the two angles. Apply the headwind/tailwind component to the true airspeed to get ground speed. If the wind correction angle exceeds 5° read the “Effective True Airspeed” to the left of the true index.

Right crosswind component = 31 knots

Tailwind component = 21 knots

Wind correction angle is greater than 10°

Opposite 20° on “Effective True Airspeed” scale read 84.5 knots. Add 21 knot tailwind to TAS to get ground speed of 105.5.

Accuracy

Before relying too heavily on the results of wind problems, you must consider that the data you are working with is not precise. The National Weather Service wind direction forecasts are in 10° increments and can be off as much as 45° (for wind velocities forecast to be less than 25 knots) before a corrected forecast is issued. You can calculate headings to one-half of one degree but you cannot fly that accurately. Also, most pilots understand and accept deviation error in the magnetic compass but ignore it until their heading indicator fails. It is for these reasons that you must follow your progress over the ground visually.

The CX-2 Pathfinder Electronic Calculator

ASA’s CX-2 Pathfinder electronic calculator offers a quick convenient means of solving wind and other navigation problems.

Time-speed-distance problems can be solved with a four-function pocket calculator, and you will learn how in this lesson. Without a table of trigonometric functions, a four-function calculator cannot do wind triangle solutions.

I’m sure that you are asking, “What’s up with this? I can prepare a flight log with my desktop/tablet/mobile device in a matter of seconds.” An examiner can ask you to provide a manually-prepared flight log or, if a computer flight log is acceptable, may ask detailed questions about headings and ground speeds that you do not have the answers to because you defaulted to the computer. Learn how these numbers are developed and how they relate to each other, just in case.

Ground Speed vs. Airspeed

When you drive your automobile for one hour at 60 miles per hour, you can be fairly certain that you will travel 60 miles during that hour. In flight, whether or not one hour at 60 miles per hour will actually cover 60 miles will be determined by the wind. If you somehow manage to get airborne under control and are flying into a 60 mph headwind with an airspeed of 60 mph, you aren’t going to make it out of sight of the airport: your speed over the ground will be zero. This is an extreme example, although pilots in the Great Plains states have a fund of stories about airplanes “flying” in strong winds that prove that it can happen. You need to develop an understanding of the airspeed/ground speed relationship on a more normal basis.

First, forget the comparison with the automobile and standardize all speed measurements in knots: the National Weather Service provides wind velocity information in knots and confusion will result if you mix units of measurement. The General Aviation Manufacturer’s Association has standardized on knots for airspeed indicators. The same flight computer solution that you used to determine wind correction angle gave you a ground speed figure. You entered true airspeed and true wind direction and velocity and the computer read out ground speed. You determine true airspeed by reference to cruise performance charts (Lesson 8) or by applying the 2% per 1,000 feet rule to your indicated airspeed (Lesson 3).

No matter how you arrived at the ground speed figure, you must use it in combination with the measured distance to the destination to determine time en route.

It is important to make frequent ground speed checks while en route to ensure that your actual ground speed agrees with your planned ground speed. Remember, the winds you used in flight planning were forecast winds. In planning your flight you must be sure that upon arrival at your destination you have at least 30 minutes fuel left on board in the daytime and 45 minutes reserve fuel at night. Learn to think in terms of time in your tanks instead of distance. The Owner’s Manual may say that you have a range of 450 miles, but if you are using 10 gallons per hour and have 35 gallons on board, you will only stay airborne for 3½ hours no matter how far you have managed to fly. Have in mind a clock time at which the wheels must be on the ground, and observe it—even if you must land short of your destination to refuel.

Rate Problems: Time-Speed Distance, Fuel Burn

Rate problems are solved on the slide rule side of your flight computer: the inner, rotatable disk represents time, and the outer, fixed disk represents miles or gallons. The numbers on both disks must be interpreted with common sense, because you must provide the decimal points. For instance, 30 on the computer might be 3 for one problem and 300 for another. As you try some sample problems, you will see how common sense is applied. The arrow at the 60 on the rotatable disk is the speed or rate arrow (some instructors call it the speedometer needle), and you will use it for all calculations of miles per hour, knots, or gallons per hour: read it as “something per hour.” The computer lets you mechanically solve for any single unknown in these equations:

Distance = speed x time

Gallons = fuel burn rate x time

The computer presents the information in this form, with time on the inner, rotatable disc:

If you determine that the distance between two checkpoints is 23 nautical miles, and your elapsed time between the checkpoints is 14.3 minutes (14 minutes and 18 seconds), set 14.3 on the inner time scale opposite 23 on the outer distance scale and read 96.5 opposite the speed arrow: your ground speed is 96.5 knots. It couldn’t very well be 9.65 or 965 knots, could it? Finding 14.3 and 23 in this problem isn’t too difficult because numbers between 1 and 99 are read directly. See Figure 9-11.

In preflight planning you find that the distance to your destination is 248 nm; you learn from doing a wind problem that your predicted ground speed is 114 knots. Put the speed arrow opposite 114 (now the 10 on the outside scale is read as 100, the 11 as 110, etc.) and find 248 on the outside scale. It is between 24 and 25, now read as 240 and 250. On the inner, rotatable (time) disk opposite 248, read the estimated time en route as 132 minutes or 2:12. When elapsed time is the unknown, be careful not to confuse minutes with tenths of hours. See Figure 9-12.

The cruise charts tell you that your fuel consumption rate will be 8.2 gallons per hour—how much fuel will you burn on the 248 mile trip? Place the rate arrow opposite 8.2 (between 80 and 90) and find 2:12 on the inside, time scale. Across from 2:12 (or 132) you will find 18.0 on the outside scale which now represents gallons. Make sense? Just over 2 hours at 8 gallons an hour has to be just over 16 gallons. Always check computer problems “in your head” to make sure that you are in the ballpark. See Figure 9-13.

Time-speed-distance and fuel problems can be worked out using a typical four-function calculator by cross-multiplying and then dividing. Try the three problems above with your pocket calculator. First, remember that the speed/rate arrow represents 60 and is always at the lower left. Time is always at the lower right. See the first problem you did with the slide-rule-type computer set up for a four-function calculator in Figure 9-11. Just set the problem up on your calculator as you would on the flight computer, cross-multiply and divide. But don’t throw your flight computer away—you need it for density altitude, true altitude, and true airspeed problems, plus conversions.

Miscellaneous Solutions

Around the edge of your flight computer you will find arrows with NAUT and STAT for mileage conversion, and TAS for airspeed calculations. On the rotatable disk there are windows for calculations requiring input of pressure altitude and temperature. Some computers have a window for true altitude, others only provide for density altitude and airspeed calculations.

For mileage conversions, place the known value under the appropriate arrow, NAUT or STAT, and find the converted value under the other arrow. Statute miles = nautical miles x 1.15; statute mile x .87 = nautical miles (Figure 9-14).

Density altitude and airspeed problems use the same window (Figure 9-15). You need to know the air temperature and pressure altitude to compute density altitude. True airspeed calculations require air temperature, pressure altitude, and indicated airspeed. Convert temperature to Celsius (C°) if it is in Fahrenheit (F°), and place the temperature opposite the pressure altitude in the window marked for airspeed and density altitude.

The markings are very small and extreme accuracy is difficult to achieve. When you have the temperature and pressure altitude properly set you will find the density altitude in the window marked for it. Opposite the indicated airspeed on the rotatable scale, you will find true airspeed on the outside scale. Figure 9-16 shows a solution for a temperature of -10° and a pressure altitude of 7,500 feet.

The density altitude window indicates 6,300 feet. If your indicated airspeed is 120 knots and you want to know true airspeed, don’t move anything—just look opposite 120 on the inner scale and read 131.5 on the outer scale.

Use common sense. Question wind correction angles of 30° to 40° or more and headwind/tailwind components that seem out of line. Use ground speed checkpoints that are 10 miles or more apart so that a small timing error will not have a major effect on your calculations, and choose checkpoints that allow accurate timing: roads, railroads, or shorelines make better checkpoints than city limits or tops of hills. Pick out a prominent landmark in your direction of travel that you can see from pattern altitude, and fly toward that landmark as soon as practicable. Pilots have taken off without resetting their directional gyros to agree with their magnetic compasses (or the runway number), and have been way off course before they got out of sight of the airport. Don’t rely on your flight plan information until you are over that landmark.

Always orient a chart to your direction of flight, and learn to read charts upside down, so that visual checkpoints appear in correct relationship to the nose of your airplane. Finally, if you draw a line on your chart from departure point to destination, follow the line with your finger, and fly your airplane over every visual feature (road, drive-in theater, lake, etc.) along that line, you can’t possibly get lost. Above all, do not place too much reliance on GPS—you are learning to be a VFR pilot in the tradition of Lindbergh, not a slave to electronics.

Chart Reading

In other lessons you will learn how to look at your aeronautical chart to determine radio frequencies and airspace designations. To fly by pilotage you must be able to quickly and accurately identify ground reference points visually. Bookmark the Seattle sectional chart excerpt in Appendix D; refer to it and its legend as you read this section. (Recreational pilots must be able to identify Class B, C, and D airspace in order to avoid it, unless this restriction has been removed by an instructor’s endorsement.)

The importance of knowing the height of terrain and obstructions is obvious. Notice that in each rectangle formed by lines of latitude and longitude there is a large blue number with an adjacent smaller number. This represents the height above mean sea level of the highest terrain or man-made obstruction within that rectangle in thousands and hundreds of feet plus a safety margin. 8³, for instance, means that you will clear the highest obstacle if you fly at 8,300 feet or higher. The heights of specific terrain features are indicated by a dot and the measured altitude; the altitude of the highest terrain within a latitude-longitude block is in large print—note Mount Rainier at the bottom of the chart and Mt. Stuart at 47°28'N 120°54'W (see letter “N” west of airport H). You will notice that the highest obstacle is at least 100 feet below the 8³ if man-made, and at least 300 feet below if a natural obstruction. This is for added safety. Man-made obstructions such as radio and television towers have two numbers adjacent to them. The top number (in bold italics) is the height of the top of the obstruction above mean sea level, and is the most meaningful number to you in choosing an altitude in that area—add at least 1,000 feet if you plan to fly directly over the obstruction. The number in parentheses is the actual height of the structure. Towers which are more than 1,000 feet in height (which usually require supporting guy wires that are virtually invisible) have a special symbol as shown in the chart legend. They are common in the Midwest, where they enhance television coverage in relatively flat terrain. The dot at the base of the symbol represents the exact location of the obstruction. The group obstruction symbol (two symbols close together) means that there are two or more towers. There are several obstruction symbols, both single and group, north and west of Seattle-Tacoma airport.

Freeways, highways, and railroads are excellent references. Notice that major freeways are identified with their route numbers—Interstate 90 crosses the chart from Seattle to the lower right corner. You can often orient yourself by noticing an interchange or an obvious jog in a road, or by the relationship between a road and some other physical feature. Because they are centered in large right-of-way areas, power lines are just as useful as roads—you can see the cleared right-of-way much further than you can see the powerlines themselves.

Drive-in theaters and racetracks make good orientation points. Be wary of lakes—in a dry year the lake you are looking for might not be the same shape as indicated on the chart—or may not exist at all!

Do not rely on the city limits depicted so clearly in yellow on sectional charts—from the air, city limits are impossible to identify.

Changes in elevation are depicted with contour lines. On the sectional chart excerpt you can see how tightly packed the contour lines are in the Cascade Mountains. Notice the interval between contour lines. The lines are every 500 feet on sectionals.

Mountain passes are indicated by a pair of back-to-back parentheses—look about an inch to the left of airport A on the sectional chart excerpt to find Stampede Pass. These symbols do not indicate direction of flight, they simply point out that there is a pass. North of Stampede Pass, note the symbol at Snoqualmie Pass; if you fly northwest, the way the symbol is printed, you will fly into a box canyon. Always follow the natural terrain.

Always check your chart for markings that indicate parachute jumping areas (airport G), wind turbines, and low-lying cables across rivers and ravines. (Running into a skydiver or a power cable can ruin your whole day!) Where jumping is indicated, check the A/FD for details.

It is much easier to look at a prominent feature on the ground and then match it to a chart indication than it is to pick a landmark off the chart and then attempt to find that landmark on the ground. Work from the “big picture” to the chart, not the other way around.

Enroute Emergencies

When you have learned the basics of aircraft control and can fly a traffic pattern with confidence, your instructor will begin instruction in cross-country flight. Expect to hear “Where would you put it if the engine quit?” on a regular basis—this trains you to keep an eye on possible landing sites whenever you are flying. As you gain experience, your instructor will pull the throttle back to idle power and say “Engine failure—where are you going to put it?”

Engine failures due to mechanical causes are quite rare—engine stoppages are usually the result of running out of fuel (unforgivable sin) or mismanagement of the fuel system. Still, the wise pilot is always scanning the immediate area just in case. Altitude means not only a wider area from which to choose a landing spot but also more time for thinking and maneuvering, so if you fly low you are cheating yourself.

When choosing possible landing sites, remember that the airplane itself is expendable but the people inside are not. If you can reduce momentum by shedding wheels or wings against trees, bushes, or rocks, you will reduce the impact on passengers. A road should not be your first choice, because you do not see the wires, signs, and fenceposts until it is too late.

Many emergency landings would not have been necessary if the pilots had made precautionary landings when things started to unravel. There is nothing wrong with landing at an airport other than your destination airport if fuel is running low, or if the weather starts to close in. Far too many pilots have overflown airports where fuel was available, only to land in a field short of their destination. Don’t let your ego write checks that your abilities can’t cash.

What if you are simply disoriented? One of the best ways to run out of fuel is to fly around hoping to see something familiar or at least to see something that matches up with the chart, and realize too late that you no longer have enough fuel to reach safety. The rules are simple: if you are unsure of your location, Climb, Circle, Confess, and Comply. Climbing increases your range of action, your communications ability, and terrain clearance. Circling keeps you essentially in one location, not wandering all over the place. Confess your plight to anyone you can contact; setting 7700 on your transponder is the first step. As part of your flight planning, you should have noted the frequencies of air traffic control facilities along your route. Call “any station” on the International Distress Frequency, 121.5 MHz, and tell your story to whomever answers, then comply with any instructions you are given.

If you find yourself on top of a cloud deck and low on fuel, don’t waste time looking for a hole. Call a radar facility (you should have noted the frequencies before takeoff—see Lesson 11), confess your situation, and ask for a radar descent through clouds. Admit that you are not instrument rated. Keep the wings level, using rudder only to make small heading changes if required, slow to flap extension speed and extend approach flaps, and reduce power to the magneto check setting (with full carb heat). This will set up a gentle descent. Concentrate on the attitude indicator and wait to break out of the clouds.

Don’t expect a controller to understand your problem if you use words like “vacuum failure” or “static failure.” Most controllers are not pilots, so using language that would be crystal-clear to another pilot would be useless. Instead, say something like “I can’t keep the wings level” or “I can’t maintain altitude.”

There is an old wives’ tale that a pilot who declares an emergency is inundated with a flood of paperwork when the emergency is over. Not true. The controllers who handle the situation might ask for a phone call to get the details, but the purpose of the call will not be to issue a violation. Getting lost is not a violation of FAA regulations.

Airspace

As you plan a cross-country flight, you know that the ability to maneuver in three dimensions makes you responsible for being aware at all times of your position, both geographic and vertical. You must ensure that you are always in compliance with the airspace regulations. These regulations are intended to keep airplanes safely separated and, in the case of VFR pilots, to provide minimum visibility and cloud clearance distances so that conflicting traffic can be seen in time for corrective action to be taken. “See and be seen” is the basis of safe operations in the National Airspace System.

Controlled vs. Class G (Uncontrolled) Airspace

You will encounter the terms controlled and uncontrolled airspace frequently, and you must not assume that flight in controlled airspace means that Big Brother will be watching you to detect violations, or that uncontrolled airspace is a no-man’s land for flight. For your purposes as a VFR pilot, controlled and uncontrolled airspace refer to visibility and cloud clearance standards, nothing more. Controlled airspace is “controlled” to protect pilots flying under instrument flight rules from conflicts with pilots flying under visual flight rules; when a pilot operating under IFR pops out of a cloud, there should be enough visibility and cloud clearance to see and avoid a VFR flight. For this reason, you should accept the minimum visibility and cloud clearance restrictions discussed in this chapter as just that—minimums—and allow yourself a greater safety cushion whenever possible.

Controlled airspace includes Class A, B, C, D, and E airspace (Figure 9-17). Look at the sectional chart excerpt and notice the blue and magenta tints—they represent the horizontal boundaries of controlled airspace (Class A airspace begins at 18,000 feet msl, and that is as high as a sectional chart goes). Blue is only used where it abuts Class G airspace, however.

At airports with instrument approach procedures, controlled airspace can start at the surface—each of these situations will be covered in detail later. Figure 9-17 will give you an idea of what to expect. As you can see, most controlled airspace is Class E.

On the Seattle sectional chart excerpt, follow the 072 radial of the Seattle VORTAC (C) eastward—it’s the V-120 airway. Until you fly past TAGOR intersection and cross the magenta line, you are in Class E airspace if your airplane is at least 700 feet above the ground. The fact that the magenta tint fades in the direction of Seattle indicates that this floor applies in the entire area surrounded by the tint.

Note that the floor of a Victor airway (V-120 in this example) is 1,200 feet above ground level (with some exceptions) and the ceiling is 18,000 feet above mean sea level.

After you pass the magenta line flying eastward along the 072 degree radial, the floor of Class E airspace becomes 1,200 feet above the ground (no shading) and that situation remains until you get to the magenta dashed line around the Wenatchee VORTAC.

You won’t find any on the sectional chart excerpt, but there are places where Class G airspace extends from the surface to 14,000 feet (almost all are west of the Mississippi). Look for the solid edge of a blue vignetted line—the floor of controlled airspace on the shaded side is 1,200 feet above the surface, but the airspace on the solid-edge side is uncontrolled all the way up to 14,000 feet above sea level.

As you fly across the country, then, you will spend almost all of your time in controlled airspace; you must maintain at least 3 miles flight visibility, stay 500 feet below clouds and/or 1,000 feet above them, and maintain a horizontal distance from clouds of at least 2,000 feet. If you follow these simple rules you will not become a victim of general aviation’s greatest killer, visual flight into deteriorating weather.

Three miles flight visibility sounds like more than enough, but when you are traveling over the ground at 90 knots you can see only two minutes ahead. Ask your instructor to take you up when visibility is restricted to three miles; try to go flying with your instructor when the visibility is only one mile, as it must be to fly under visual flight rules in uncontrolled airspace. Make sure that there is a qualified pilot in the other seat when you first experience restricted visibility—you may decide that your personal visibility minimum is five miles, a very wise decision. John F. Kennedy, Jr.’s fatal flight taught pilots and nonpilots alike that loss of visual reference to the horizon leads rapidly to loss of control, without the knowledge and training possessed by pilots who hold instrument ratings. Treat diminishing visibility as you would the edge of a cliff, a pit of poisonous snakes, or a river full of ravenous alligators—don’t even get close.

Unless you are taking your flight training at an airport in the mountains, you will spend most of your time at altitudes below 10,000 feet msl and the visibility and cloud clearance values above will apply. When you fly higher than 10,000 feet msl, however, new rules apply. You will have no difficulty in remembering them if you keep in mind that there is no speed limit above that altitude. A cloud 2,000 feet away might hide a 240-knot turboprop or a 500-knot jet, so horizontal cloud clearance increases to 1 mile; these airplanes climb and descend at steep angles, so you must fly at least 1,000 feet above or below any clouds. Because of unrestricted speed, required flight visibility increases to 5 miles.

Class A Airspace

Class A airspace exists from 18,000 feet msl to Flight Level 600 (all altitudes above 18,000 feet are called Flight Levels; FL230 is 23,000 feet, more or less). To fly in Class A airspace you must be instrument rated and operating on an instrument clearance; there is no VFR flying in Class A airspace. If you have to climb higher than 18,000 feet to stay out of the clouds (got that oxygen handy?) you must call Air Traffic Control and declare an emergency to avoid getting a violation.

Class B Airspace

The most important thing for you to remember about Class B airspace is that you cannot operate within its boundaries unless you have a specific clearance from ATC to do so. Class B airspace (Figure 9-18) is shown on sectional charts by solid blue circles or arcs; each segment within the airspace is identified with what looks like a fraction. On the sectional chart excerpt the top of the fraction is 100, indicating that the top of Seattle’s Class B airspace is 10,000 feet msl; you can fly over the airspace at 10,500 feet without a clearance. If you are receiving radar flight following, don’t let that fact trap you into violating Class B airspace—ask the controller “Am I cleared into the Class B?” to get the clearance on ATC’s audio tape for your own protection. The use of VFR GPS waypoints (five letters, beginning with VP) will help you stay out of Class B airspace.

The bottom of the fraction is the floor of the airspace in hundreds of feet; east of Bremerton National Airport (D) you can fly beneath the Class B airspace at 5,500 feet; west of Bremerton the Class B airspace does not exist. Note that the floor of Class B airspace over Seattle-Tacoma Airport is the surface of the airport itself.

Class B airspace is controlled airspace, of course, and you must have at least 3 miles flight visibility when flying in it. Cloud clearance is a special case, however; because a controller is keeping you away from other traffic by assigning heading and altitudes, you need not observe the cloud clearance requirements of other types of controlled airspace. “Clear of clouds” is the standard.

If you want to land at or depart from the primary airport in Class B airspace when the weather is marginal and you need a Special VFR clearance, look for the notation NO SVFR above the airport data block (see Seattle-Tacoma International Airport, C). Where you see that notation you are out of luck unless you are flying a helicopter.

Lesson 4 discusses the equipment requirements in Class B airspace, so they won’t be covered here. You do need to know that the distances that define the airspace are measured horizontally on the ground, while your distance measuring equipment (DME) in the airplane reads slant range from the transmitting antenna. When your DME reads 10.0 miles, then, your horizontal distance from the antenna may be something like 9.8 miles, depending on your altitude.

Note: The distance readout from a GPS is not slant range; however, it is measured from the airport reference point, which might be near the coffee shop. Moral: Stay at least one mile outside of a charted boundary, just to be safe.

The next concern is altitude. I said earlier that you can legally fly 500 feet above the top of Class B airspace, but do you think that would be a safe thing to do when jets are climbing out at 4,000 to 6,000 feet per minute? Flight 500 feet below a shelf in the airspace, like the 5,500 feet east of Bremerton suggested earlier, might be a tad safer, but why take a chance? Unless you are going to ask for a clearance and enter Class B airspace, give it a wide berth.

As a VFR pilot, should you avoid Class B airspace entirely? What if you wanted to fly from Bremerton to an airport on the east edge of the chart excerpt. Would you fly all the way around just to keep from asking for a clearance? That doesn’t make sense to me. You should have a Terminal Area Chart for the Class B airspace, and if you are a student or a sport pilot you need specific instruction and a logbook endorsement from an instructor. In the Seattle area, with those requirements met all you need to do is call the radar facility that owns the airspace (shown on the Terminal Area Chart) and say “Seattle Approach, Whiz­bang 2345X at 2,000 feet over Bremerton, request clearance through your airspace, destination is Ellensburg.” Almost always, you will hear “Cleared to operate in the Seattle Class B airspace, maintain 2,500 feet and squawk 4566.” Occasionally, however, the controller will say “unable,” and you will have to fly all the way around. Student pilots are prohibited from operating to or from the following airports within Class B airspace:

Atlanta

Boston

Chicago

Dallas

Los Angeles

Miami

Newark

Kennedy

La Guardia

San Francisco

Washington National

Andrews AFB

Although all Class B airports have control towers, they do not have Class D airspace.

Many Class B airports have established VFR flyways (see Figure 9-19) with communication requirements, or VFR corridors in which you may be asked to monitor a frequency but are not required to communicate with ATC. You will find them on the reverse side of relevant Terminal Area Charts.

Class C Airspace

The Seattle sectional chart excerpt that has been included in Appendix D for your use does not contain any Class C airspace; however, in Figure 9-20a/b there are excerpts of the Spokane and Whidbey Island areas, where both Spokane International and Fairchild Air Force Base are in Class C airspace. Figure 9-20b shows the Class C airspace at the Whidbey Island Naval Air Station. Note how many satellite airports are located beneath the outer rings at both Spokane and Whidbey. The horizontal boundaries of Class C airspace are shown by solid magenta circles.

Many Class C areas do not operate 24 hours a day. Where operation is part-time, check the panel on the back of the sectional chart or, as advised by a chart notation near the airspace, check the A/FD for operating hours and the type of airspace the Class C reverts to when it is not in effect.

What do Spokane International and Fairchild AFB have in common? Lots of jet traffic, but not enough to qualify for designation as Class B airspace. The controllers do not need to guide your every move, as they do in Seattle, but they do need to know who you are and what you intend to do in their airspace. Note that a clearance is not required to operate in Class C airspace, just two-way communication between you and the radar controller whose airspace you want to use. Sport pilots, of course, need specific ground and flight training leading to an instructor’s logbook endorsement before entering Class C airspace.

Class C airspace is shown on sectional charts by solid magenta circles or arcs; each segment within the airspace is identified with what looks like a fraction. In Figure 9-20b the top fraction is 40, indicating that the top of Whidbey Island’s Class C airspace is 4,000 feet; you can fly over it at 4,500 feet without talking to anyone. The bottom of the fraction is the floor of the airspace in hundreds of feet—1,300 or 2,000. Note that the floor of Class C airspace over Whidbey Island Naval Air Station is the surface of the airport itself.

Extending a further 10 miles from the primary airport is the outer area; note that when you are at the edge of the outer area you are still 10 miles from the Class C airspace. The floor of the outer area is the lowest altitude at which radar coverage is available, and its ceiling is the top of the radar facility’s airspace. The purpose of the outer area is to give pilots an opportunity to contact ATC in plenty of time. If you do not intend to land at the primary airspace you can fly through the outer area without saying anything to anyone, although it helps other pilots if you tell the radar facility your position and intentions.

What is the official definition of “communication?” Of course, if you call ATC and get a specific response that includes your airplane’s N-number, you are home free. If the radar controller replies with your N-number and says “stand by,” that too constitutes two-way communication and you can continue into the Class C airspace. But what if the controller says “Aircraft calling, stand by.” That is not communication because the controller might mean someone else, not you. Wait until you hear your number. Of course, if the controller says “remain clear of the Class C airspace” you must stay outside until the controller is able to handle your flight.

A special note for departures: You must be in communication with ATC while you are within the Class C airspace itself as you depart, but the controller is required to provide radar service to you until you have left the outer area, ten miles beyond the outer circle (check the A/FD for specifics...procedures vary). Give the busy controller a break and say “Terminate my radar service and thank you for your help” as soon as you are more than 10 miles from the primary airport.

A special note for arrivals: If the controller is busy and you are told to remain clear of the Class C airspace, don’t despair—wait a few minutes while monitoring the frequency and try again when things slow down. If your destination airport lies within the Class C airspace boundaries, adding “Landing Podunk” to your initial call to ATC might get you priority over flights just passing through.

Aircraft equipment requirements for Class C airspace are covered in Lesson 4.

Class D Airspace

Class D airspace exists whenever a control tower is in operation, except for airports with Class B airspace (which includes tower functions). Class D airspace imposes two obligations. First, there is a communications requirement: you can’t fly through Class D airspace without talking to the tower or take off/land without a clearance from the tower (although if you are taking advantage of radar traffic advisories, the radar controller will clear the way for you when passing through). Second is a weather requirement. For you to operate in Class D airspace under basic visual flight rules, the ground visibility must be at least three miles and the ceiling must be at least 1,000 feet above the ground. If the tower serves the primary airport in Class B airspace, there is no Class D airspace. Here again, sport pilots can only enter the airspace after ground and flight training with a logbook endorsement.

What are the dimensions of Class D airspace? The horizontal boundary is shown on charts with a blue dashed line (the airport symbol is blue when there is a tower at the airport); the vertical extent is from the airport elevation to 2,500 feet above the airport. Figure 9-21 shows a nice cylindrical shape for clarity, but actual dimensions will vary widely. The elevation of the top of the airspace to the next highest hundred feet is shown in a little square box near the airport symbol. (Look at any tower-controlled airport except Seattle-Tacoma to check this. Sea-Tac shows -30 because it sits on a plateau above Puget Sound and the top of its Class D airspace is the 3,000-foot floor of the associated Class B airspace.)

The shape of Class D airspace varies with local conditions. There will be extensions to provide protected airspace for incoming instrument flights, cutouts to exempt satellite airports from the communication and weather requirements, or shelves to allow pilots to fly into and out of airports beneath the edges of the airspace (Figure 9-22). If an extension is 2 miles or less (still shown with blue dashed lines), you need tower permission to fly in that airspace; if the extension is more than 2 miles (shown with magenta dashed lines) the communication requirement does not apply to the extension. The fact that these extensions exist to protect instrument pilots is a clue that you should be alert when flying in or across them.

Look at Hoskins Airport (44T), just east of Olympia (airport F on the chart excerpt) inside its Class D airspace. A pilot taking off from or landing at Hoskins (44T) must communicate with Olympia Tower and advise the controller of his or her intentions. There are no examples of cutouts or shelves on the chart excerpt.

The existence of Class D airspace is dependent on an operating control tower. There are hundreds of control towers that operate part-time, and when the controller goes home the Class D airspace requirements usually go, too—the airspace then becomes Class E airspace that extends all the way to the sur-face (Figure 9-17 “non-towered airport”).

You have to look at the A/FD to be absolutely sure which classification of airspace is left behind when the controller at a part-time tower goes home. Look at the towered airports on the sectional excerpt for the Tacoma Narrows tower (J). It is a part-time tower, and if you look just below the “E” you will find “See NOTAMS/Directory for Class D/E (sfc) hrs.” Olympia and Paine Field are also part-time with similar notations. What “Directory” are they referring you to? The A/FD, of course. When these airports shut down, their surface areas become Class E down to 700 feet above the surface. There are part-time tower-controlled airports that go from Class D to Class G (uncontrolled) when the tower closes, but there are none on this chart. There is no substitute for the A/FD in making this determination.

Class E Airspace

This class of airspace has already been fairly well defined; it exists above the floors defined by magenta dashed lines (the surface), the blue and magenta tints (700 or 1,200 agl), and the msl figures in mountainous areas (or 14,500 feet msl). It extends upward to the floor of the overlying airspace (either Class A, B, or C).

Victor airways, the blue lines identified with VOR radials, are intended to be flown on their centerlines as accurately as possible. To allow for instrument errors, the airspace is protected from obstacles/terrain for four nautical miles on either side of the centerline. Victor airways extend upward from 1,200 feet above ground level (except in mountainous areas, where the floor of Class E airspace is designated on sectionals with a chain-link blue line) to 18,000 feet above sea level, and they do not lose their identity when passing through Class B, C, D, or E airspace.

The FAA is establishing Tango airways, to be navigated using GPS navigators. They are also blue lines, but the airway identifier is T, as in T-139. They provide an easy way to circumnavigate congested and special use airspace without giving up the accuracy of GPS. T-routes are designated for low-altitude airspace (below 18,000 feet msl).

Move off to the right when climbing or descending; use shallow left and right turns to clear the air ahead, especially when climbing, because a nose-high attitude blocks forward visibility.

Look at the airport data block for Paine Field (B), Tacoma Narrows (J), or Olympia (F). See the asterisk next to the tower frequency? That means that these are part-time towers, and you can find the actual operating hours on the back of the sectional chart or in the A/FD. When the tower is not in operation the airspace reverts to Class E; the communication requirement goes away but the visibility and cloud clearance requirements of Class E airspace are the same. That is, if you want to land or take off in marginal weather you must call a flight service station for a Special VFR clearance.

Look at the Bremerton National airport (D) at the left edge of the chart excerpt or Wenatchee (H) airport at the right edge. The magenta dashed line indicates that Class E airspace extends from the floor of the overlying controlled airspace down to the surface. At Bremerton, the overlying airspace begins at either 18,000 msl or 6,000 feet msl if within the Seattle Class B airspace boundary. At Wen­atchee (Pangborn Memorial), Class E airspace starts at the surface within the dashed, magenta line, and begins at 700 feet agl within the magenta rectangle. In both areas, the top of Class E airspace is 18,000 feet msl (Class A airspace).

Now look at the Ellensburg airport (I) at the lower right edge of the excerpt. No dashed line, but Ellensburg does have an instrument approach, although you can’t tell that from the chart. An inbound instrument pilot’s protection stops at 700 feet agl at Ellensburg; below that altitude the pilot is in Class G (uncontrolled) airspace and must mix in with the VFR traffic.

Class G Airspace

An easy definition of Class G airspace is that it exists wherever other classes do not. Most of the Class G airspace lies beneath floors at 700 or 1,200 feet above the ground. In this thin sliver of airspace you can fly (in the daytime) with only 1 mile flight visibility and the ability to remain clear of clouds. Most pilots call this “scud running,” because it usually means trying to stay below a ragged cloud layer in poor visibility. At night, the cloud clearance and visibility requirements in Class G airspace are the same as daytime requirements in Class E airspace—flight visibility of at least 3 miles and lots of cloud clearance. You say that you can’t see the clouds at night? Then why are you scud running? (As I write this, rescue teams are removing three bodies from a Cessna 172 that hit a mountain 1,400 feet up. Low clouds, night, VFR pilot, 80 hours flight time.)

Special case: If you want to practice takeoffs and landings in Class G airspace at night with visibility less than 3 miles but more than 1 mile, you can do so if you stay within one-half mile of the runway.

There are such things as permanent, operating control towers in Class G airspace. Lake City, Florida, is one (see Appendix D). They have the same communications requirement as towers in Class D airspace and you would be wise to treat them the way you would treat any operating control tower.

Important note: Occasionally, the FAA establishes temporary control towers in Class G airspace for special functions such as fly-ins, Super Bowls, etc. As you might imagine, these towers do not show up on sectional charts (but they are announced by Notice to Airmen). Treat a temporary tower just as you would any operating control tower—mentally, draw a five-mile circle around the airport and get permission from the tower before entering its airspace.

Terminal Radar Service Area

A type of airspace that is rapidly disappearing is the Terminal Radar Service Area (TRSA, Figure 9-23). Indicated on charts by a solid black circle, a TRSA is a kind of voluntary Class C airspace. That is, radar service is available if you want it, but you don’t have to use it.

Because TRSAs are usually at joint military/civil fields, though, it is to your advantage to call in and get traffic advisories. When departing from an airport in a TRSA you will be told “Call ground control for your clearance.” If you don’t want radar service, all you have to say is “Negative radar.” You will not be surrounded by armed MPs but will be allowed to taxi out and take off just like any other kind of Class D airspace.

Special Use Airspace

There are several types of special use airspace, but they are almost all indicated on charts with blue hatching. Look just to the right of the Olympia airport at the lower left corner of the chart excerpt. The most restrictive is a Prohibited Area, such as that above the White House (Figure 9-24 is an example). There is no way to get permission to fly in a Prohibited Area and getting caught in one is painful for both your pocketbook and pilot certificate.

The next step down is a Restricted Area (Figure 9-25). They are designated and controlled by the military and usually involve firing ranges, etc. A table on each sectional chart gives the operating hours and altitudes for each Restricted Area. The operating hours are not engraved in stone, however. During your preflight briefing, ask the FSS if a Restricted Area along your route is “hot,” or give the controlling agency a call (at Navy Whidbey, the status of their Restricted Area is on the ATIS). Do not just blunder into the area, however, because the hazards you are being protected from are invisible.

Temporary Flight Restrictions. Because of the increased emphasis on security where large groups of people (or government big-wigs) are congregated, the FAA is issuing Notices to Airmen implementing Temporary Flight Restrictions (TFRs) over sporting events, political gatherings, etc. These areas do not appear on aeronautical charts, but their dimensions and locations are included in the NOTAM. It is incumbent on every pilot to make a last-minute check for such restrictions before taking off.

Check for TFRs during flight planning by going to www.aopa.org and clicking on Temporary Flight Restrictions on the right side. Check again with Flight Service by radio after takeoff to be sure that nothing new has come up.

National Security Areas. The FAA has converted some TFRs to National Security Areas, which are permanent but voluntary (pilots should avoid flying through NSAs, though). When it is deemed necessary, an NSA can be changed to prohibited airspace by NOTAM.

Warning Areas and Alert Areas (Figures 9-26 and 9-27) also involve the military. Warning Areas have the same kinds of hazards as Restricted Areas, but are offshore in International waters. No clearance required, but keep your eyes open. Check their status with the flight service station. Alert Areas involve a high volume of military training activity; again, no clearance is required but extreme vigilance (or avoidance) is.

Military Operating Areas (MOAs, Figure 9-28) are shown on charts with magenta hatching; again, look at the areas surrounding R-6703A, B, C, and D east of Olympia (that’s the Army’s Fort Lewis firing range, if you’re curious). You do not need a clearance to fly in a MOA, but military airplanes operate in them without restriction—the regulations don’t apply to them while flying in a MOA. Military pilots are not only flying at high speed, but they are not spending much time looking for traffic. Your FSS can tell you the status of a MOA, of course, but the ARTCC in whose airspace the MOA exists will be in direct contact with the military flights and can advise them of your presence. Your preflight planning should include getting Center frequencies from the A/FD. MOAs can be overflown if too big to circumnavigate; the ceiling of each MOA is given in a table on the back of the sectional.

Military Training Routes (MTRs) create the most hazard for general aviation airplanes. The good news is that they are charted: see the gray lines that run from the top to the bottom of the chart excerpt west of Ellensburg? IR and VR mean instrument and visual routes, but there is more to it than that. Routes with 4-digit numbers are flown at or below 1,500 feet agl, while routes with 3-number identifiers are flown above 1,500 feet agl. Nothing like flying along at 2,500 feet and seeing a flight of C-130s go under you.

“Hot” times for MTRs are available from the FSS, and you are foolish if you do not check on the status of any MTR that will cross your flight path. The military might schedule a route for several hours and only use it for a portion of that time, but you can’t afford to gamble. Military jet pilots fly very fast, with their heads in their cockpits, and they are painted with camouflage colors for a reason. Never fly parallel to an MTR—the military is allowed to be as much as eight miles off the centerline. Cross military training routes at right angles to reduce your time of exposure to a minimum.

Air Defense Identification Zones

Air Defense Identification Zones exist along the Pacific, Gulf, and Atlantic coasts, and aircraft inbound to the United States from outside of the ADIZ whose place and time of arrival within the zone are unknown will be intercepted by armed military aircraft. If you will be returning to the United States (from the Bahamas, for example) and will penetrate an ADIZ you must have a DVFR (Defense Visual Flight Rules) flight plan on file giving your point of penetration and estimated time of penetration. If you are simply operating within 10 miles of the coast you are exempt from this requirement. This discussion does not include the ADIZ that surrounds Washington, DC. Special regulations apply in that area. Go to www.aopa.org and click on ADIZ procedures on the right side. Membership is not required.

Wildlife Refuge Area

Along the bottom edge of the sectional chart excerpt you will see Mount Rainier National Park. Note the line of dots that marks the boundary. Wherever you see those dots they surround a wildlife refuge area, and you are asked, not required, to stay at least 2,000 feet above the terrain to minimize the effect of aircraft noise on wildlife. If you are a seaplane pilot, check with local authorities before you fly into a state or national park; seaplane operations are severely restricted in parks.

Lesson 9

Enroute Flight Review Questions

1. What is the magnetic course from Cedar Rapids (airport A in Figure Q9-1) to Fairfield (airport E)? The magnetic variation is 5°E.

A—013°

B—193°

C—198°

2. While flying from Cedar Rapids to Fairfield, you cross Interstate 80 at 1015, and the highway west of Wellman at 1022. What is your estimated time of arrival at Fairfield if your ground speed remains constant?

A—1028

B—1035

C—1040

3. Your airplane uses 8.6 gallons of fuel per hour. You plan a 250 nautical mile flight at an average ground speed of 115 knots. What is the minimum fuel required for the trip (allow a 30 minute reserve)?

A—18.7 gallons

B—23.0 gallons

C—15.6 gallons

4. Your ground speed between Cedar Rapids and Fairfield (52 nm) is 111 knots. At an average fuel consumption rate of 7.2 gallons per hour, how much fuel will you use en route?

A—3.4 gallons

B—2.5 gallons

C—4.2 gallons

5. Your true course is 270°, your true airspeed is 110 knots, the wind is from 330° at 18 knots, and the magnetic variation is 6° W. What is your ground speed and magnetic heading?

A—119 knots; 278°

B—100 knots; 264°

C—100 knots; 284°

6. Upon refueling at your destination after a 345 nautical mile flight, you take 32 gallons of fuel (tanks were full on departure). During the flight, your ground speed averaged 136 knots. What was the fuel consumption rate for this flight?

A—11.0 gallons per hour

B—14.0 gallons per hour

C—12.6 gallons per hour

Refer to the full-color Seattle sectional chart excerpt in Appendix D for questions 7 through 11.

7. What kind of lighting is available at the Cashmere-Dryden airport (47° 30' 45"N, 120° 29' 15"W)?

A—No runway lighting is available.

B—Rotating beacon only.

C—Pilot-controlled runway lighting (or on request).

8. How tall is the antenna for radio station KPQ, 8 miles northwest of the Wenatchee airport, (H)?

A—560 feet

B—943 feet

C—313 feet

9. Where would you look for information on how to activate pilot-controlled lighting?

A—Sectional chart legend.

B—Aeronautical Information Manual.

C—Airport/Facility Directory

10. How would you apply magnetic variation when planning a flight from Ellensburg (I) to Seattle (C)?

A—Subtract 47° 30' from the true course.

B—Add 18.3 degrees to the true course.

C—Subtract 18.3 degrees from the true course.

11. You are flying over Lake Kachess (near A) in the central Cascade Mountains. What sectional chart feature tells you the minimum safe altitude in that area?

A—Terrain with an elevation of 6,680 feet at the north end of the lake.

B—Maximum elevation number 7⁹.

C—Contour lines on the mountains.

12. You are approaching an airport within Class C airspace. Which of these statements is true?

A—You must have a clearance from ATC before entering the Class C airspace.

B—You must be in two-way communication with ATC before entering the Class C airspace.

C—Your airplane must be equipped with a transponder, two-way radio, and VOR to enter Class C airspace.

13. Under what conditions, if any, may civil pilots enter a restricted area?

A—With the controlling agency’s authorization.

B—On airways with ATC clearance.

C—Under no condition.

14. Under what condition may an aircraft operate from a satellite airport within Class C airspace?

A—The pilot must monitor ATC until clear of the Class C airspace.

B—The pilot must contact ATC as soon as practicable after takeoff.

C—The pilot must secure prior approval from ATC before takeoff from the satellite airport.

15. What is the upper limit of Class D airspace?

A—18,500 msl.

B—The base of Class A airspace.

C—Usually 2,500 feet above the surface.

16. What are the horizontal limits of Class D airspace?

A—5 nm from the airport boundary.

B—As indicated with blue dashed lines.

C—As indicated with magenta dashed lines.

17. Class D airspace is automatically in effect when

A—its associated control tower is in operation.

B—the weather is below VFR minimums.

C—radar service is available.

18. What is the purpose of Class D airspace?

A—To provide for the control of aircraft landing and taking off from an airport with an operating control tower.

B—To provide for the control of all aircraft operating in the vicinity of an airport with an operating control tower.

C—To restrict aircraft without radios from operating in the vicinity of an airport with an operating control tower.

19. Unless otherwise specified, Federal airways extend from

A—1,200 feet above the surface upward to 14,500 feet msl and are 16 nm wide.

B—1,200 feet above the surface upward to 18,000 feet msl and are 8 nm wide.

C—the surface upward to 18,000 feet msl and are 4 nm wide.

20. What type airspace is associated with VOR Federal airways?

A—Class B, C, D, or E airspace.

B—Class E airspace.

C—Class D airspace.

21. Class E airspace in the conterminous United States extends to, but not including

A—the base of Class B airspace.

B—3,000 feet msl.

C—18,000 feet msl.

22. What is the minimum weather condition required for airplanes operating under Special VFR in Class B, C, D or E airspace?

A—1 mile flight visibility.

B—1 mile flight visibility and 1,000 foot ceiling.

C—3 mile flight visibility and 1,000 foot ceiling.

23. For VFR flight operations above 10,000 feet msl and more than 1,200 feet agl, the minimum horizontal distance from clouds required is

A—1,000 feet.

B—2,000 feet.

C—1 mile.

24. No person may operate an airplane within Class B, C, D or E airspace associated with an airport at night under special VFR unless

A—the flight can be conducted 500 feet below the clouds.

B—the airplane is equipped for instrument flight.

C—the flight visibility is at least 3 miles.

25. The minimum ceiling and visibility required to operate under basic visual flight rules in Class C, D or E airspace are

A—500 feet and 1 mile.

B—1,000 feet and 3 mile.

C—1,400 feet and 2 mile.

26. In which type of airspace is VFR flight prohibited?

A—Class B.

B—Class D.

C—Class A.

27. What minimum pilot certification is required for operating to or from the airports within the 12 restricted Class B airspaces?

A—Student pilot certificate with appropriate logbook endorsements.

B—Private pilot certificate.

C—Private pilot certificate with an instrument rating.

28. What procedure is recommended when climbing or descending VFR on an airway?

A—Offset 4 miles or more from centerline of the airway before changing altitude.

B—Advise the nearest FSS of the desired altitude change.

C—Execute gentle banks, left and right for continuous visual scanning of the airspace.

Refer to Figure Q9-2 for questions 29 and 30.

29. You plan to fly under VFR from Airport A to Airport B. Regarding this flight, which of the following statements is true?

A—Flights below 7,000 feet must be operating on IFR flight plans.

B—Extreme caution should be exercised while flying through this area.

C—VFR flights are not permitted above 7,000 feet msl.

30. Which statement is true regarding the Chippewa MOA?

A—The military services conduct low altitude navigation flights at or below 1,500 feet agl at speeds exceeding 250 knots within this area.

B—Some training activities may necessitate acrobatic maneuvers by military aircraft within this area.

C—VFR flights between 7,000 feet and Flight Level 180 are prohibited within this area.

31. What are the visibility and cloud clearance requirements for VFR flight in Class G airspace below 10,000 feet at night?

A—One mile visibility and remain clear of clouds.

B—One mile visibility, 500 feet below, 1,000 feet above, and 2,000 horizontally from all clouds.

C—Three miles visibility, 500 feet below, 1,000 feet above, 2,000 feet horizontally from all clouds.

32. Just north of Kachess Lake your courseline crosses two Military Training Routes, VR1355 and IR313-314. From these route numbers you determine that

A—military airplanes will be flying VFR more than 1,500 feet agl.

B—military airplanes will be flying IFR less than 1,500 feet agl.

C—military airplanes will be flying VFR less than 1,500 feet agl.

Answers:

1-B, 2-B, 3-B, 4-A, 5-C, 6-C, 7-C, 8-C, 9-C, 10-C, 11-B, 12-B, 13-A, 14-B, 15-C, 16-B, 17-A, 18-B, 19-B, 20-A, 21-C, 22-A, 23-C, 24-B, 25-B, 26-C, 27-B, 28-C, 29-B, 30-B, 31-C, 32-C.