Nav Logs

Navigation Logs, or Nav Logs, are a tool that pilots learn how to make and use during private pilot training. In "the olden days" where GPS or Foreflight didn't exist, pilots had to use the skills of dead reckoning and pilotage to navigate to where they planned to go. In this article, I'll list my steps for creating a successful paper nav log! This is not to substitute a ground lesson with your CFI, but can be a refresher if you have forgotten which step to do first, or when to do it.

Picture from https://www.mikepetrucci.com/blog/2021/6/12/navigation-and-flight-planning-using-foreflight-and-a-paper-navlog

NWKRAFT

• Before even attempting to make your Nav Log, go through and familiarize yourself with all the required preflight action items per 91.103.

  • N- NOTAMs

  • W- Weather

    • Get a weather briefing from a FSS (1-800-WXBRIEF) or 1800wxbrief.com

    • Check the METAR and TAFs for the airport

    • Utilize charts on aviationweather.gov such as the Surface Analysis Chart to see what weather will be affecting your route.

  • K- Known ATC delays

  • R- Runway Lengths at Origin, Destination, and Alternates (and conditions)

  • A- Alternates

  • F- Fuel Requirements

    • Day VFR: 30 minutes reserve

    • Night VFR: 45 minutes reserve

  • T- Takeoff and Landing Distance Data

After going through NWKRAFT, then get out a sectional (paper or digital), your E6B (manual or digital: https://e6bx.com/e6b/), a spare sheet of paper, a pencil, and a lot of patience. I like to write out all my. NWKRAFT items at the top of my nav log, along with the date it is intended for, the airports and the distance.

1. Start on the left side of the Nav Log under the "Check Points" box.

   1. In the first box: list your departure airport

   2. In the second box: list TOC (Top of Climb)

      1. This will be the point at which you reach your desired cruise altitude. I like to pair this point with a landmark on the ground (if able).

   3. In the second to last box: list TOD (Top of Descent)

      1. This is where you will begin your descent to your airport

   4. In the last box: list your destination airport

2. Draw a straight line from the airport of your departure to your destination airport.

3. Determine the course using the manual E6B by placing the E6B "compass" oriented north on the sectional and see wehre your line between airports falls. Write this in all boxes under "Course (Route)"

   1. Example: a course of 090 heading

4. Next, use the E6B like a ruler and measure the distance from airport to airport. Place this number at the top of your Nav Log in the notes section at the top.

5. Calculate TOC and TOD

   1. TOC will be comprised of 3 values: time, fuel, and distance to climb. These can be found under the Performance section of your POH for your aircraft. For example, it may take 5 minutes, 1 gallon, and 5 miles to climb to 3,500 feet from the ground. Input these numbers into the right side of the Nav Log under the applicable columns.

   2. TOD can be calculated using the 3:1 method. As a rule of thumb, for every 1,000 feet we plan to lose, we want to fly 3 miles. To find the distance from the airport in which we commence our TOD, you take the difference between the cruise altitude and pattern altitude at the airport, multiply it by 3, and then divide that answer by 1000. For example: 3,500 feet (cruise) - 1,500 feet (pattern) = 2,000 feet. 2,000 feet multiplied by 3 equals 6,000. 6,000/1000= 6. 6

      1. 6 miles from the airport, we should start the TOD.

6. Next, plot each check point and list them in the left column.

   1. Try to not make your points less than 5 miles, but no more than 15 miles apart.

   2. Pick recognizable items: highway intersections, other airports, towns, big lakes along your route.

      1. Avoid powerlines, towers, small roads, a single house, or small ponds since those may be hard to see from above.

   3. Once you have plotted your points on the sectional, make sure to measure and list the distance between TOC, each of your points in between, and TOD on the Nav Log.

7. Pick an altitude to fly along your route

   1. When flying above 3,000 AGL, we have to comply with the VFR cruising altitudes

      1. When flying a magnetic course of 0-179, fly at odd thousands of feet + 500

         1. 3,500, 5,500, 7,500, etc.

      2. When flying 180-359, even thoudsands + 500

         1. 4,500, 6,500, 8,500, etc.

   2. Consider the MEF (Maximum Elevation Figure) and obstacles in the area

   3. 

8. Plot the altitudes on your Nav Log

   1. However, in the box between your depature airport and TOC, put an up arrow, symbolizing a climb. Put a down arrow in the box between TOD and destination.

9. Winds: use the winds aloft in ForeFlight under "Weather" or get a weather briefing from Foreflight to see the winds aloft

   1. Note temperature, direction, and speed (velocity).

   2. If winds aloft at departure airport and different from destination winds, then for the first half of the boxes, put the winds at the departure airport aloft. For the last half of the boxes, put the winds aloft at your destination airport.

10. Before we move to computing our heading, we must figure out our CAS and then TAS for climb, cruise, and descent.

    1. For the Cessna 172, we can determine our CAS on the climb by using the IAS to CAS chart in the performance section. To determine TAS on the climb, then we have to use our E6B. Make sure to calculate pressure altitude and take note of the temperature (and list these items on your scratch sheet of paper).

    2. For TAS in cruise, the C172 has a handy table in the POH called "Cruise Performance". Note the pressure altitude you are cruising at and temperature, determine the %HP setting you want to cruise at, and then derive the TAS and GPH (gallons per hour). Plot the TAS on the Nav Log and put the GPH on the right side under GPH.

11. For the true course (TC) box, write down the same heading we got from the E6B plotter in the beginning.

12. Determine wind correction angle (WCA) using the E6B. If the wind dot from the E6B plotter falls on the right side, add the WCA. If left, subtract. This will give you your True Heading (TH).

13. True Heading must be adjusted by Magnetic Variation to obtain Magnetic Heading

    1. To determine the effects of magnetic variation, look at your sectional and search for the isogonic lines (pink dotted line shown below). If it is westerly variation, as shown below with the "W" next to the 4, add it. If it is easterly variation, subtract it.

13. Finally, to determine the Compass Heading (CH), we have to adjust for Magnetic Deviation caused by our plane. This value will be specific to each plane and will be indicated by the compass card.

14. Determine the ground speed by using the E6B. This number should have been provided when you determined WCA.

15. Determine ETE (estimated time enroute)

    1. This can be done by using the E6B or by using the equation:

       1. Time = (distance / ground speed) x 60

16. Determine fuel burned per leg. Either use the E6B or use this equation:

    1. Fuel burned = (distance x gallons per hour) / 60.

17. Then, add up all the leg distances, fuel burned, and time enroute at the bottom of each column. And voila, you have completed a Nav Log.