What does "dead reckoning" mean?

Dead reckoning most likely derives from "deduced reckoning." You deduce your current position by calculating from a known starting point using heading, airspeed, and elapsed time - no external reference required.

Do I still need to know how to use an E6B if I have ForeFlight?

Yes. The FAA checkride requires you to demonstrate E6B proficiency, and your examiner can place one in front of you during the oral and ask you to solve a wind problem. More importantly, working through the E6B manually gives you a genuine understanding of what the numbers mean - which matters when something unexpected happens in flight.

What is wind correction angle?

Wind correction angle is the offset applied to your true course to compensate for wind drift. If a crosswind is pushing you to the right, you aim your nose slightly left into the wind; the amount of that correction is the wind correction angle.

How much fuel reserve does the FAA require for VFR flight?

The FAA requires at least **30 minutes** of fuel at cruise power for VFR day flights and **45 minutes** for VFR night flights. Most experienced pilots plan for an hour or more and add a fuel stop if the numbers require it.

How close to my planned ETA does the ACS require me to arrive?

The Airman Certification Standards for the private pilot certificate require arrival within **five minutes** of your planned estimated time of arrival.

Dead Reckoning, the E Six B Triangle, and the Navigation Foundation GPS Made Every Student Forget But the ACS Still Requires

Dead reckoning is not a backup navigation method - it is the primary skill, and GPS is the backup. The FAA Airman Certification Standards (ACS) for the private pilot certificate requires you to navigate by pilotage and dead reckoning, and your examiner will test it with or without a moving map in front of you.

What Is Dead Reckoning and Why Does It Still Matter?

The name likely derives from deduced reckoning, shortened over centuries of nautical use. You deduce your current position by calculation: you know where you started, your heading, your airspeed, and your elapsed time - therefore you can calculate where you are.

GPS tells you where you are. Dead reckoning tells you where you should be. When those two answers don’t match, the gap is telling you something important.

How Do I Measure True Course on a Sectional Chart?

Cross-country planning starts on the ground with a sectional chart and a plotter. Draw your route and measure your true course - the direction of your intended flight path measured from true north - from departure to your first checkpoint, then from there to destination.

On a sectional, true north runs along the meridian lines, top to bottom on the chart. If your true course measures 240 degrees, write it on your navigation log. That number is the starting point for every conversion that follows.

How Do I Use Winds Aloft for Flight Planning?

Pull up the winds aloft forecast, not the surface winds. Wind at cruise altitude can be completely different from what you feel on the ramp. The National Weather Service publishes winds aloft forecasts at standard altitudes: 3,000, 6,000, 9,000, and 12,000 feet, and higher. Pick the level closest to your planned cruise altitude.

That wind - direction and speed - is what you feed into the E6B to find out how far off course it will push you and how it will affect your groundspeed.

How Do I Use the E6B Wind Side to Find Wind Correction Angle and Groundspeed?

The E6B flight computer (the Whiz Wheel) has two sides: a calculator side for time, speed, distance, and fuel, and a wind side for wind correction angle and groundspeed. The wind side is the heart of cross-country planning.

Here is the process step by step:

Set the wind direction under the True Index at the top of the compass rose.
Mark a wind dot above the center of the grid at a distance equal to wind speed. For a 20-knot wind, move 20 spaces up from center.
Rotate the compass rose until your true course is under the True Index.
Slide the grid until the wind dot lands on the arc representing your true airspeed.

Once positioned, groundspeed reads at the center hole. The horizontal offset of the wind dot from the centerline is your wind correction angle - left offset means correct left, right offset means correct right.

True course ± wind correction angle = true heading.

How Do I Convert True Heading to Compass Heading?

Two more corrections apply after you have your true heading.

Magnetic variation accounts for the difference between true north and magnetic north. Your sectional shows isogonic lines - dashed magenta lines labeled with degree values. The memory aid is “East is least, West is best”: subtract east variation, add west variation. True heading ± variation = magnetic heading.

Compass deviation is specific to your aircraft. Find the correction card posted on the instrument panel - usually only a degree or two in either direction. Magnetic heading ± deviation = compass heading. That is the number you actually fly.

The full mnemonic is “Can Dead Men Vote Twice”: Compass, Deviation, Magnetic, Variation, True. Work right to left - from true course all the way to compass heading.

How Do I Calculate True Airspeed, Time En Route, and Fuel on the E6B?

The calculator side of the E6B works as a circular slide rule for time, speed, distance, and fuel.

True airspeed: At altitude, thinner air means your actual speed through the air is higher than your indicated airspeed. Line up your pressure altitude with outside air temperature on the calculator side, then read true airspeed opposite your indicated value. Cruising at indicated 90 knots at 4,000 feet on a warm day might yield a true airspeed closer to 100 knots - that corrected number is what goes into the wind side.

Time en route: Set your groundspeed under the speed index (the 60 mark on the inner scale), then read time opposite your leg distance. A 45-mile leg at 90 knots groundspeed gives you 30 minutes. Do this for every leg and every checkpoint.

Fuel burn: Apply your aircraft’s cruise fuel burn rate to the time on each leg. The FAA requires at least 30 minutes of fuel at cruise power for VFR day flights and 45 minutes for VFR night operations. Plan for an hour or more - do not fly to legal minimums.

Every leg of your route gets its own row: checkpoint, true course, wind correction angle, true heading, magnetic heading, compass heading, true airspeed, groundspeed, estimated time en route, and fuel burned.

Fill it in completely before you leave the ground. It is not paperwork - it is the baseline you will check against reality throughout the entire flight.

How Do I Use Dead Reckoning in Flight?

Note your departure time. When you reach each checkpoint, record the actual time and compare it to your estimate.

Running consistently behind? Your groundspeed is lower than calculated - the wind is stronger than forecast, or something else is slowing you down. Your fuel calculation is now off. Adjust.

Running ahead? Your groundspeed is better than expected and your fuel buffer just grew.

Time checks at checkpoints are live calibration, not note-taking. If you are on time but the landmark below you does not match what you circled on the sectional, something is wrong. A time check that is right with a position that is wrong is information - use it.

The Airman Certification Standards for the private pilot certificate requires you to navigate by pilotage and dead reckoning, determine your aircraft’s position, recognize when you are off course, identify landmarks, and make appropriate corrections.

It also requires you to arrive at your destination within five minutes of your planned estimated time of arrival. That window is tighter than most students expect. You have to actively manage navigation throughout the flight - not glance at the chart occasionally while following the magenta line.

During the oral exam, your examiner will ask about your nav log and expect you to explain how you built it. They may ask how you derived your wind correction angle, what you would do if the wind differed from forecast, and during the flight they may cover the GPS and ask you to navigate a leg by dead reckoning alone.

How Do I Practice Dead Reckoning Without GPS?

On a clear day with good visibility, turn off the moving map for one leg. Fly the compass heading you calculated, at the speed you planned, for the time you computed.

What you will find: the math works. You will arrive close to where you expected. Find the landmark, confirm your position, update your estimate, and continue. That process - looking at the chart, looking at the ground, checking the clock, running the math - is also what keeps you actively engaged with the terrain in a way that passive GPS following does not. That engagement is what catches a drift toward wrong airspace or a wrong river valley followed one too many miles.

Use both dead reckoning and GPS. Understand both. Trust both.

Key Takeaways

Dead reckoning is the primary navigation skill; GPS is the backup - the ACS requires you to demonstrate it on checkride, with or without a moving map.
The E6B wind side solves for wind correction angle and groundspeed; the calculator side handles true airspeed, time en route, and fuel burn - both sides are testable.
The full heading chain runs true course → wind correction → true heading → magnetic variation → magnetic heading → compass deviation → compass heading. Mnemonic: Can Dead Men Vote Twice.
Time checks at every checkpoint are active calibration - they tell you in real time whether your fuel and timing calculations still hold.
The ACS requires arriving within five minutes of your planned ETA, which demands active navigation management throughout the flight, not passive GPS monitoring.