Navigation Log & Flight Planner

A navigation log (nav log) is a structured flight planning document that records all route, time, speed, wind, heading, and fuel data for a flight. Pilots use a navigation log to track each flight leg from departure to destination and to maintain safe and accurate navigation.

A navigation log contains flight legs, where each leg includes a waypoint, true course, wind correction angle, true heading, magnetic heading, compass heading, distance, groundspeed, and estimated time en route. It also includes fuel burn per leg and cumulative fuel remaining.

A navigation log uses inputs from the E6B flight computer, including wind triangle calculations and time-speed-distance calculations. The log converts these inputs into headings and timing values for real-world flight execution.

A navigation log supports dead reckoning navigation by allowing pilots to predict position based on heading, speed, and time. It also supports fuel planning by tracking consumption across each leg of the route.

A navigation log improves flight safety by ensuring pilots verify track, time, and fuel at every waypoint during a cross-country flight.

A navigation log contains the route, heading, wind, speed, time, altitude, and fuel information needed to plan and fly a cross-country flight. Each column records either pilot-entered flight data or values calculated from those inputs, allowing pilots to monitor navigation and fuel status throughout the flight.

The table below explains every field in a navigation log, including what it records, what it is used for, and where the value comes from.

The example below shows a completed navigation log for a VFR cross-country flight from Gloucester Airport (EGBJ) to Duxford (EGSU) via Coventry, Sywell, and Cambridge. It demonstrates how wind conditions change across flight legs and how the navigation log tracks heading, time, and fuel for each leg individually.

Waypoint names and ICAO codes are real. Distances, courses, and wind conditions are illustrative and do not represent actual charted values. Pilots must always compute headings, ground speed, time, and fuel using actual charts, weather forecasts, and aircraft performance data.

Leg 1 (EGBJ → Coventry): Wind from the right requires a +13° right crab. Ground speed is 3 kt below TAS — the crosswind component dominates with a slight headwind effect.

Leg 2 (Coventry → Sywell): Wind is nearly aligned with the track from behind. WCA is 0° and ground speed jumps to 140 kt — 30 kt above TAS. This is the shortest leg by time despite being 38 NM.

Leg 3 (Sywell → Cambridge): Wind is almost directly on the nose. Ground speed drops to 82 kt — 28 kt below TAS. Despite being only 44 NM, this is the longest leg by time (32 minutes) and burns the most fuel (4.3 gal).

Leg 4 (Cambridge → Duxford): Wind from the left requires a −10° left crab. Ground speed is 112 kt with a slight tailwind component.

A navigation log records detailed per-leg flight calculations, while a flight plan defines the overall route, timing, and intent of the flight for ATC and operational use.

A navigation log contains leg-level data such as waypoint, distance, true course, wind correction angle, true heading, magnetic heading, groundspeed, estimated time en route, and fuel per leg. Pilots use a navigation log to perform E6B-based calculations and track navigation accuracy during the flight.

A flight plan contains high-level information such as departure airport, destination airport, alternate airport, route of flight, total estimated time, and total fuel required. Pilots submit a flight plan to air traffic services for traffic management, search and rescue coverage, and airspace coordination.

A navigation log supports dead reckoning by converting wind, speed, and time into position estimates. A flight plan does not perform these calculations and does not track individual flight legs.

A navigation log is a cockpit navigation record used by the pilot to track headings, groundspeed, time, and fuel during flight. A flight plan is an operational document used by air traffic control (ATC), search and rescue services, and dispatch systems to manage and monitor the flight.

Pilots use a navigation log as follows:

1. Track heading and groundspeed in real time

Pilots use a navigation log to compare planned true heading and groundspeed with actual in-flight performance. This comparison helps pilots detect wind changes and navigation errors.

2. Monitor position using dead reckoning

Pilots use a navigation log to estimate aircraft position between waypoints. The pilot uses elapsed time and groundspeed to predict location along the planned track.

3. Verify waypoint timing using ETE

Pilots use a navigation log to compare estimated time en route (ETE) with actual flight time. At each waypoint, the pilot records the actual time of arrival alongside the estimated time. This check confirms correct progress toward each waypoint.

4. Manage fuel consumption during flight

Pilots use a navigation log to compare planned fuel burn per leg with actual fuel usage. This ensures fuel endurance and reserve requirements remain within limits.

5. Maintain overall situational awareness

Pilots use a navigation log together with visual references and navigation aids to confirm route integrity and detect deviations early.

Dead reckoning is a navigation method that estimates current aircraft position by advancing from a previously known starting point, called a fix, using heading, groundspeed, and elapsed time.

The navigation log is the operational worksheet that makes dead reckoning possible in flight. It organises each leg of the route into calculated inputs and measured outputs that pilots use to maintain position awareness without GPS.

Pre-flight calculations

Before departure, the pilot divides the route into legs and calculates the expected True Heading, Groundspeed, and Estimated Time En Route for each leg. Wind correction angle is applied to True Course to derive True Heading. Groundspeed is derived from the wind triangle. Estimated Time En Route is calculated using:

ETE = Distance ÷ Groundspeed

In-flight tracking

During flight, the pilot flies the pre-calculated Magnetic Heading and records the actual time of departure from each waypoint. Elapsed time is tracked against the planned ETE for each leg.

Position estimation

The pilot estimates current aircraft position by applying elapsed time and groundspeed to the last known fix. If 15 minutes have elapsed at a groundspeed of 100 knots, the aircraft is estimated to be 25 nautical miles from the last waypoint along the planned track.

Adjustments

When the pilot reaches a waypoint, the actual arrival time is compared against the planned ETA. A consistent difference between actual and planned times indicates a groundspeed error, typically caused by forecast wind variations. The pilot adjusts heading or recalculates fuel endurance for the remaining legs.

Pilotage complements a navigation log by providing the vital real-world visual confirmation needed to validate pre-flight mathematical calculations. While the navigation log provides the expected headings, times, and fuel burns, pilotage allows the pilot to look outside the cockpit, identify visible landmarks, and physically confirm the aircraft's progress along the planned route.

A navigation log lays out a mathematically precise plan based on forecasted winds and aircraft performance. However, because atmospheric conditions and actual aircraft performance rarely match forecasts exactly, pilotage acts as the necessary checks-and-balances system.

The relationship between the two works as follows:

1. Confirming groundspeed and time

The navigation log: Calculates the estimated time en route (ETE) and arrival time over a checkpoint based on a predetermined groundspeed.

How pilotage complements it: By spotting an exact landmark — such as a distinct highway intersection or a large bend in a river — the exact time of passage is noted. Comparing this actual time to the planned nav log time immediately reveals whether the aircraft is flying faster or slower than expected.

2. Identifying heading errors

The navigation log: Provides the predetermined magnetic heading and wind correction angle.

How pilotage complements it: When looking outside, if landmarks on the chart are observed drifting to the left or right of the nose, the actual track is diverging from the planned course. Pilotage exposes wind shifts or compass inaccuracies, allowing heading to be altered to return to track.

3. Cross-checking fuel estimates

The navigation log: Predicts exact fuel consumption rates for each leg based on expected power settings.

How pilotage complements it: By using pilotage to track actual progress, it can be accurately determined whether headwind is causing fuel to be burned faster than planned. Knowing the exact position and groundspeed ensures situational awareness regarding fuel reserves is maintained.

Electronic Flight Bags (EFBs) and GPS systems digitize and automate navigation logs by seamlessly integrating pilot-planned route data, wind forecasts, and real-time aircraft performance to calculate precise headings, fuel burn, and waypoint arrival times.

How the data interacts

Route and waypoint tracking: An EFB hosts flight planning applications such as ForeFlight where the pilot creates a navigation log consisting of a series of waypoints. The EFB syncs these coordinates to the aircraft's GPS, creating an active flight plan.

Wind and heading corrections: Traditional navigation logs require pilots to manually calculate True Course, Magnetic Heading, and Wind Correction Angles using an E6B. An EFB automates this by pulling real-time winds-aloft forecasts, applying those variables to the specific aircraft's performance numbers, and instantly producing a corrected magnetic heading for each leg of the flight.

Time and fuel calculations: The EFB's digital log constantly monitors ground speed and fuel flow provided by the GPS and engine monitors. It continuously updates the Estimated Time of Arrival (ETA) and remaining fuel for subsequent waypoints.

Situational awareness and execution

Moving maps: The EFB digitally overlays the planned navigation log — tracks, radials, and waypoints — onto moving aeronautical charts. As the GPS updates the aircraft's exact position, the EFB shows where the aircraft is in real time relative to the intended flight path.

Automated diversion: If a diversion is required due to weather or airspace issues, the EFB's navigation log instantly recalculates distance, heading, and time to the nearest suitable airport, communicating these updates directly to the GPS for direct-to routing.

Legal and operational limitations

Primary vs supplementary: While EFBs utilise GPS data for highly accurate flight planning and situational awareness, consumer-grade tablets and their internal GPS are not approved as primary navigation under IFR operations. For VFR operations, EFBs may be used as a supplementary navigation tool alongside approved equipment.

Backups: Aircraft must rely on permanently installed, certified avionics — such as a Garmin G1000 or an aviation-certified WAAS GPS — for primary navigation, treating the EFB and its digital navigation log as supplementary tools.

Winds aloft alter a navigation log by changing the aircraft's groundspeed and heading. They determine how much the aircraft must crab into the wind to stay on course, dictate the exact time en route, and directly impact fuel burn projections.

The relationship between wind and navigation is calculated using specific flight parameters and formulas as listed below.

1. The wind triangle

To maintain a straight True Course (TC), the aircraft nose must point into the wind. The angle difference between the True Course and the direction the aircraft is actually pointed is the Wind Correction Angle (WCA).

True Heading (TH) = TC ± WCA   (+ for right crosswind, − for left)

2. Groundspeed

Winds pushing the aircraft from behind (tailwinds) increase speed over the ground, while winds blowing against the aircraft (headwinds) decrease it.

Groundspeed (GS) = True Airspeed (TAS) ± Headwind/Tailwind component

3. Time en route

Because winds affect groundspeed, they directly alter leg times, which in turn determines the required fuel.

Time = Distance ÷ Groundspeed

4. Fuel burn

A headwind extends the time spent airborne, increasing the total fuel required to reach the destination. Conversely, a tailwind reduces total flight time and conserves fuel.

Fuel Required = Time En Route × Fuel Burn Rate

Winds aloft forecast data must be sourced from official meteorological briefings or flight planning applications for the specific cruising altitude before the True Heading, Groundspeed, and ETE columns of the navigation log can be completed.

Fuel planning fits into a navigation log as a structured, column-by-column breakdown of expected fuel consumption. It ties the aircraft's performance metrics to the specific route and timeline, allowing fuel remaining to be verified at each checkpoint.

The fuel planning process integrates into the navigation log in three primary ways:

1. Pre-flight planning

Using the aircraft's performance tables from the Pilot's Operating Handbook (POH), the exact fuel used for each leg is calculated. The navigation log records:

• •Start fuel: total usable fuel onboard at engine start.
• •Taxi fuel: fuel allocated for startup, run-up, and taxi, typically a fixed amount.
• •Leg-by-leg burn: the exact fuel used in gallons, pounds, or kilograms for the climb, cruise, and descent phases of each leg.

2. The running fuel column

A navigation log features a fuel remaining column that begins with total fuel minus taxi fuel and acts as a countdown.

• •At each waypoint, the planned fuel burn for that leg is subtracted from the running total.
• •This provides a continuous forecast of how much fuel should remain at the destination.

3. Minimum and reserve fuel

This column tracks legal minimum fuel limits. Total fuel at takeoff is the sum of:

• •Trip fuel: fuel required to fly from departure to destination.
• •Contingency fuel: extra fuel to account for unexpected winds or routing changes.
• •Alternate fuel: fuel needed to fly to a backup airport if weather goes below minimums.
• •Reserve fuel: final buffer required by aviation regulations — 30 minutes for day VFR, 45 minutes for IFR and night VFR.

In-flight application

During the flight, the navigation log serves as the primary fuel monitoring tool. Actual time en route is tracked continuously and actual fuel gauge readings are compared against the planned figures in the log. This allows unexpected trends — such as a higher-than-forecast headwind increasing fuel burn — to be identified early so the flight strategy can be adjusted before fuel reserves are compromised.

A VFR navigation log focuses on pilot-calculated, manual calculations for visual checkpoints, dead reckoning, and magnetic headings. In contrast, an IFR navigation log is highly structured around pre-defined routes (airways, fixes, and SIDs/STARs), ATC assigned altitudes, radio navigation frequencies, and instrument approaches.

The table below summarises the key differences between a VFR and an IFR navigation log.

VFR navigation log

Purpose: To help the pilot calculate headings, drift, and groundspeed using manual calculations such as the E6B, while maintaining visual reference to the ground.

Key entries: True Course, Magnetic Variation, Wind Correction Angle, Magnetic Heading, and checkpoints mapped out via visual cues.

Contingency: Involves diverting to a visual alternate airport if weather degrades.

IFR navigation log

Purpose: To manage highly structured IFR procedures, radio frequency changes, minimum altitudes, and legal requirements such as alternate airport planning.

Key entries: Route SIDs/STARs, MEAs, MOCAs, NAVAID frequencies for VORs and localizers, and specific fix names.

Contingency: Requires strict adherence to an alternate airport calculated under the 1-2-3 rule (ceiling and visibility parameters).

A navigation log is universally required for commercial (Air Transport) operations, international flights, and Instrument Flight Rules (IFR). For VFR private flights, authorities require a navlog as a practical tool for safe cross-country planning, though the physical document is only explicitly mandated during practical pilot checkrides and examinations.

ICAO

The International Civil Aviation Organization (ICAO) outlines standards that require member states to ensure a flight plan contains necessary navigation details (Annex 2). For International General Aviation (IGA) and Commercial Air Transport (CAT), a Journey Logbook is legally mandated to be carried on board, which must contain comprehensive route and navigational tracking details (ICAO Annex 6).

USA (FAA)

• •Commercial / Part 121 & 135: Legally mandated. Operators must complete a comprehensive operational flight plan (navlog).
• •IFR (Part 91): Required to ensure sufficient fuel and alternate airports have been calculated.
• •VFR cross-country (Part 91): The FAA does not explicitly mandate a hard-copy document in the cockpit for purely personal VFR flights. However, the completion of a navlog is required during pre-flight planning and serves as the pilot's mechanism to comply with fuel requirements and cruising altitude regulations.

UK (CAA)

• •The UK Civil Aviation Authority operates under Standardised European Rules of the Air (SERA) and its own CAP series.
• •IFR/Commercial: Detailed navigation logs are strictly required.
• •VFR: While not prescribing a specific form, the CAA recommends — and emphasises during training — that a navigational plan is needed to stay clear of controlled airspace and track position. Filing a flight plan or logging flight data is advised for sea crossings over 10 nm from the coastline.

EASA

• •The European Union Aviation Safety Agency requires an operational flight plan (navlog) for all Commercial Air Transport (CAT) flights.
• •Private / General Aviation: Under EASA Standardised European Rules of the Air (SERA), pilots operating IFR or flying outside the vicinity of an aerodrome must have compiled a comprehensive operational flight plan. For VFR, detailed navigation logs are heavily relied upon to satisfy EASA training and competency standards.

The most common navigation log mistakes involve incorrect headings, wind data, fuel calculations, and time estimates. These errors can produce inaccurate navigation, fuel shortages, and missed waypoints.

Using true and magnetic headings incorrectly

Pilots sometimes confuse True Course, True Heading, and Magnetic Heading. Applying magnetic variation in the wrong direction produces an incorrect heading for every flight leg.

Using incorrect wind information

Pilots sometimes enter surface wind instead of winds aloft or use wind direction referenced to Magnetic North instead of True North. Incorrect wind data produces inaccurate wind correction angles and groundspeeds.

Using indicated airspeed instead of true airspeed

The navigation log requires True Airspeed (TAS) for wind and time calculations. Using Indicated Airspeed (IAS) or Calibrated Airspeed (CAS) without conversion produces incorrect groundspeed and estimated time en route (ETE).

Measuring route distance incorrectly

Pilots should measure each leg along the planned route using an aeronautical chart. Measuring a straight-line distance when the route avoids controlled airspace or terrain results in incorrect time and fuel calculations.

Calculating time using true airspeed instead of groundspeed

Estimated Time En Route (ETE) should be calculated using Ground Speed (GS), not True Airspeed (TAS). Headwinds and tailwinds change groundspeed and directly affect flight time.

Mixing fuel units

Pilots should use the same fuel units throughout the navigation log. Mixing US gallons, Imperial gallons, litres, kilograms, or pounds can produce significant fuel planning errors.

Failing to update the navigation log during flight

Pilots should record actual waypoint crossing times and compare them with planned values. Updating the navigation log during flight helps detect wind changes, heading errors, and unexpected fuel consumption before they become safety issues.