Contents
VII. AREA OF OPERATION - NAVIGATION
Basic Navigation Goals
The basics of navigation is to avoid obstacles and get to the destination with required reserves of fuel. Preciseness in navigation is required by the FARs and ATC to provide separation and tracking when assigned electronic headings and related altitudes.
A. TASK:
PILOTAGE AND DEAD RECKONING
References AC 61-21, AC 61-23, AC 61-84
P 1. Knows application and distinction between pilotage and dead reckoning
P 2. Uses pilotage (landmarks and charts) to navigate plotted course line. Computes speed, times and ETA Compares with ETAs and fuel used.
P 3. Identifies landmarks by relating surface features to chart symbols.
P 4. Navigates by means of pre-computed headings, ground speeds and elapsed time.
P 5. Corrects for and records the differences between preflight fuel, ground speed, and heading calculations and those determined enroute.
P 6. Verifies the airplane's position within 3 nautical miles of the flight-planned route at all times. All courses maintained laterally + 3 miles.
P 7. Arrives at the en route checkpoints and destination ETAs + 5-minutes,
P 8. Maintains appropriate altitudes + 200' and headings + 15 degrees;
P 9. Completes appropriate checklists.
EX Plotting course, selecting checkpoints, computing data based on forecast data, how to establish course and stay on course, locating checkpoints, how to compute ground speed, ETA's, fuel use, correcting ETA's into arrival airports.
Destination and course to be within three nautical miles, altitude + 200 feet, arrival within +5 minutes, headings within + 15-degrees
Pilotage is flying a course line by charted reference to ground points. Dead reckoning is flying a route based upon course, time, and distance from a known point using estimated winds. Plotting the course begins with drawing the line on the sectional. Using a highliter pen or spaced multiple lines makes the course line easily discernible. Determine the True Course, determine the nearest variation (angle between the north and magnetic poles) and compute the Magnetic Course for entry on the course line. Since the Magnetic Course has no wind factor computed, it is a good reference for in flight wind correcting.
You are required to estimate a time of arrival (ETA) at a particular checkpoint. You are allowed + 5 minutes error in ETAs ATA, + 200' in altitude, + 10 degrees of heading, and + 3 nautical miles of course. If you cannot fly pilotage within half of these tolerances you will have difficulty passing the test. The examiner is allowed to create distractions to determine your ability to divide your attention.
Checkpoint selection is critical since a good checkpoint has three verifiable features, one of which may be a VOR radial. A day checkpoint may be invalid for night. There is some advantage in spacing checkpoints evenly from the destination. Keep points on the pilot's side as much as possible. Above 3000' don't use power lines or railroads. Lakes change during the year. Visibility conditions and altitude can greatly change the value of a checkpoint. Your skill in correlating a chart-symbol to the landmark seen from the airplane is essential.
The Compass Heading of the aircraft is the way the navigational computations say we should point the plane to allow for the wind, once we are established on course. Since these computations are based on forecasts they are at best estimates which must be adjusted in actual flight. The forecast winds are relative to True North in knots. We use the True Course line drawn on the sectional and True Air Speed in knots from the manual to compute the True Heading and Ground Speed. True heading is then corrected for variation and deviation to obtain Compass Heading, which is where the paragraph started. Fly to your first checkpoint and turn on course. Re-set your heading indicator and confirm your course. Sight on something as far ahead as you can see and start looking for your next checkpoint.
The computed Ground Speed is used to compute ETA's (estimated time of arrival) along the route. These times are in turn used to compute fuel consumption. Estimates of fuel consumption are based upon the manual the actual consumption at the end of the flight can be very educational indeed. The pilot who records fuel use on all flights gets insight into actual aircraft performance. Fly fuel use by time. Most aircraft are NOT topped off to full tanks because of fuel that may be wasted due to heat expansion.
Since wind conditions may vary the departure from an airport, it is vital that the aircraft be established on course as soon as possible. It is easily possible to depart incorrectly and exceed the 3-mile course error before reaching 1000'. By telling the tower that you plan to depart on course to your destination you solve a multitude of problems. Fly directly to your first checkpoint. Use the checkpoint CHECKLIST Carefully select a point as far ahead on course as you can see and fly to it. If possible reach your first checkpoint level at cruising altitude. This makes possible a time check at the second checkpoint and computation of an ETA. Destination ETA should be estimated at every checkpoint based on checkpoint ATA. The planning technique that makes ETA at destination very easy is to try to make your checkpoint distances the same measuring backwards from your destination. The only uneven distance should be from your departure to your first checkpoint. (see instructor)
See training material on use of checkpoint checklist.
Common Navigation Faults
1. Failing to use CHECKLIST for climb, leveling, checkpoints, and descent.
2. Failing to accelerate to cruise before fine trimming.
3. Being off course and not correcting.
4. Not setting Com/Nav radios ahead of time.
5. Holding head down while reading charts or using computer.
6. Failing to estimate heading required to correct wind and then flying that heading.
See instructional material related to cross country, checkpoints and radio.
The applicant must plan a cross-country to the maximum range of the airplane with required reserve. This is a test of judgment as well as computational accuracy. The major judgments involved are weather considerations, aircraft performance, airport requirements, navigational options, considered alternatives, and use of resources.
Dead Reckoning
A method of navigation without the use of checkpoints predicated on direction, time, and estimates of speed and wind. Contrary to popular opinion, it has nothing to do with 'ded' as in deduction. As 15th century sailing ships began a voyage a rope with evenly spaced knots was tied to a log. The log was placed 'dead' in the water and the rope was played out over a fixed amount of time as the passage of knots was counted. The result of this gave a time over distance that was calculated as knots per hour and recorded in a logbook. Lindbergh used dead reckoning while flying the Atlantic. The accuracy of this method depends on several factors:
1. Selection of the initial heading based on wind correction angle.
2. Estimation of ground speed based on true airspeed and wind effect.
3. Accurate timing.
4. Luck
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