B. Task:  
NAVIGATION SYSTEMS AND RADAR SERVICES
REFERENCES: AC 61-21, AC 61-23, navigational manuals

P 1. Knows uses and limitations of navigational aids and radar services.
P 2. Selects, identifies and uses appropriate aids and radar services
P 3. Uses facilities to confirm aircraft location.
P 4. Intercepts and tracks a given radial or bearing, if appropriate
P 5. Recognized and describes the indication of station passage, if appropriate.
P 6. Recognizes signal loss and takes appropriate action.
p 7. Uses correct communication procedures and acknowledgments with ATC.
P 8. Flies + 200' at all times of appropriate altitude. Uses CHECKLISTS

EX Use NAV radio and ident code compared with sectional; centers OBS from/to; turns plane to course; checkscompass, heading indicator, OBS readings; limits wind correction to 30 degrees with ever decreasing corrections; does not chase needle at station passage; watches for red flag; uses CHECKLISTS. Within + 200 feet of altitude, locates aircraft position using radials, intercepts and tracks a given radial. Recognizes signal loss and takes appropriate action. Describes station passage.

The initial selection of a VOR station is dependent upon your location relative to the station, altitude, the distance and the terrain. 40 miles is the usual general aviation distance limit for accurate usability. Since line-of-sight is a limiting factor the distance may be much less because of the terrain. It is essential that every VOR signal be identified and confirmed with the sectional for its code. Lack of identification is the way to tell if the VOR is unusable. If a service man is making adjustments it may appear to work but accuracy is not assured without the IDENT. Once identified be sure to turn the IDENT volume down.

Part of the AIM, called the Airports/Facility Directory available at all FSS, lists the terrain/directional limitations of VOR's. The latest available should be purchased shortly before you plan to take the flight test from a local FBO. The Concord VOR is unusable in a wide arc toward Mt. Diablo. The signal may operate the needle, the IDENT work, and you can fly into the mountain. You must know the terrain in order to use a VOR safely. Using an out of date A/F D is a no-no. Centering the needle with the OBS requires some degree of dexterity. The weaker the signal the more the needle waves.

Behind terrain or at maximum line-of-sight ranges for a given altitude the waving may make the VOR unusable. If this is the case learn to recognize it. Hold the OBS knob between two fingers and move it back and forth in ever decreasing amounts until the needle is centered. Read the TO/FROM window to confirm setting and heading to turn aircraft to. Don't delay-turn immediately.

After turning aircraft to initial heading check compass, heading indicator, and OBS for agreement. They must agree for you to avoid reverse sensing that causes the needle to work backwards. Any delay in turning the aircraft will cause the needle to swing excessively. In any event, re-center the needle and fly the corresponding heading. Watch the needle for movement caused by wind drift. This movement can only be determined if ACCURATE headings are flown. After a few minutes if the needle moves to one side, make a heading correction 30 degrees or less designed to re-center the needle keeping in mind a heading that will be required to keep the needle centered. This is a guessing game similar to finding a number between two other numbers on a computer. With practice and some knowledge of the forecast winds you can become quite accurate. The key to flying the VOR is the ability to fly headings while distinguishing between actual and transient movements of the needle.

Flying to a VOR is like flying into a 40-mile funnel. The closer you get to the station the more sensitive the needle becomes to 1 or 2 degree heading changes. Recognize that winds will change both with position and altitude. This means that the correction at one point will not necessarily apply further along. Be prepared to make heading adjustments as necessary, hopefully in ever decreasing amounts until one heading keeps the needle centered until station passage. Learn to recognize the rather rapid needle movement indicative of passage. Remember that the higher the crossing altitude the larger will be the cone of confusion. This means that the station passage heading must be held for periods of time, depending on altitude, before the needle will function properly on the other side of the VOR.

The VOR is frequently used as checkpoint backup indicator when map references may be limited. A VOR is selected that will give radials FROM at an angle 60 to 90 degrees to the course line. The closer to 90 the more accurate. Draw a line on the sectional from the VOR to the checkpoint. Find the VOR frequency, code, and OBS radial from and write them on a navigational log and on the sectional. As part of your checkpoint CHECKLIST you should have an item specifically for setting and re-setting your VOR.

A properly set OBS (FROM the VOR) for a checkpoint will cause the needle to start moving within 10 degrees of the radial. The needle will be on the side toward the VOR. As you proceed toward the checkpoint the needle will move closer toward the center. It will center at the radial set on the OBS and then move to the side away from the station. If the station is very close to the course line it is possible for this swing to occur so fast that it will not noticed. Be sure to observe the side the needle is on since this is the best clue as to the position of the checkpoint.

While it is necessary to demonstrate pilotage as the basic form of navigation, it is also expected that the pilot be able to perform using radio aids. Over dependence upon radio aids to navigation seems to be a common training error. The fact is that when weather and flight conditions are the poorest the practical use of the VOR decreases. The VOR range is a function of line of sight, which is in turn dependent upon altitude. If flight must proceed within 700/1200 feet of the surface due to ceilings the VOR range becomes less than 20 miles in level terrain and even less if terrain intervenes.

Flying to VOR's tends to put you in the major flyways with heavier traffic. Undue reliance on the VOR reduces pilotage skills and gives a false sense of navigational skill. Use the VOR only when it is honestly the best route since its limitations become greatest when you need them most.

See instructional material related to checkpoints.

C. TASK:
DIVERSION
REFERENCES: AC 61-21, AC 61-23

P 1. Knows the problems and solutions related to a diversion.
P 2. Selects an appropriate alternate airport and route.
P 3. diverts promptly toward the alternate airport.
P 4. Makes an accurate estimate of heading, ground speed, arrival time, and fuel consumption to the alternate airport.
P 5. Maintains the appropriate altitude, _200' and + 15 degrees

EX Factors of selection, present position, location of alternate, sectional use for distance and direction, altitude for visibility and insurance, communication procedures, decision making capability, division of attention, priorities. Arrival procedure are determined by communications. Accurate estimate to heading, ground speed figured, estimated time of arrival, fuel consumption, altitude -+ 200 feet and course held within + 15 degrees.

Reasons for diversion can be numerous such as a kidney stop, airsickness, weather, fuel, mechanical, turbulence, and precautionary. Every flight should be planned with the possibility of a diversion in mind. This flexibility should be part of the mental set as an antidote for get-there-itis. Along the route, possibly as part of your checkpoint CHECKLIST you should have noted diversionary airports and their radial from the nearest VOR. On the sectional write pattern altitudes, frequencies, and other pertinent data. KEEP YOUR CHECKLIST OUT.

If the pre-planning has been done correctly a number of the elements of this task are in place. First you will know where you are. Visually triangulate your position by using references to sides and front. This means that while flying up a valley covered with fog, with Mt. Diablo on your right and Grizzley Peak in the Oakland hills to your left, you should approximate your position as Walnut Creek. This skill can be developed with practice and conscious effort. Try to keep oriented along your route and have in mind the direction and location of airports. Practice locating private fields that may not be on the sectional. Keep an eye out for wind indicators and learn to relate what you see with the winds you find on the ground. Learn the terrain altitudes, power line locations, and obstructions so that you can make reasonable judgments as to emergency choices.

When required to divert, for whatever reason, turn immediately, maintain altitude as much as possible, fly the airspeed for best range. Use more power against the wind and less with the wind. Tell the examiner why you are doing this. Once headed in the selected direction start using the sectional to locate yourself and the emergency destination. Fold the sectional for your course line or make a line. Altitude is insurance. Use the plotter and VOR rose to determine course. Be sure to correct for variation if using plotter only. Fly estimated heading. Estimate time, distance and fuel. Keep attention divided.

Keep altitude until sure of arrival procedure. Set radios. Listen on COM while setting VOR radial for intercept. Maintain altitude until alternate is located. If contact is established an arrival can be planned, otherwise maintain altitude of at least twice pattern altitude. Use wind and runway indicators to determine arrival sequence.

Have the manual available but be familiar with the glide range to altitude ratio and short field performance of your plane. Know the effects of stopping the propeller on glide. Remember the first item in any emergency is CHECKLIST.

The element of judgment is more difficult to explain. Your choice of where to go and what to do may differ from that of the examiner. Don't try to second guess, make a considered decision and stay with it if possible. You would do well to explain the what and why of your actions. If task requires partial or no power be sure to trim for best glide. Don't let the wind blow you away from your field. There are far more corrective alternatives for being high than low. Keep your priorities in order. Fly the plane (airspeed), navigate (to arrive at a pattern altitude abeam numbers on downwind), and

then communicate (121.5 or advisory). Use your CHECKLIST. See instructional material on emergencies

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