General navigation
Connect positions, charts, time, speed and wind in general navigation. Use worked examples to check units, reference directions and small-angle estimates.
General navigation explains where you are, where you intend to go and how movement through the air becomes movement over the ground. Identify the reference, draw the situation, then calculate. A correct number attached to the wrong north reference still answers the wrong question.
This guide is organised for Airline Transport Pilot Licence aeroplane, or ATPL(A), study. Its themes draw on European Union Aviation Safety Agency (EASA) Subject 061 in AMC1 FCL.310; FCL.515(b); FCL.615(b); FCL.835(d), October 2026 consolidation. They are our study map, not an exhaustive syllabus or official endorsement. EASA lists General Navigation and Radio Navigation separately; radio aids belong to the latter.
A topic map for general navigation
| Theme | Connections to understand |
|---|---|
| Position, direction and distance | Latitude and longitude locate a position. True, magnetic and compass directions use different north references; distances need explicit units. |
| Earth geometry and charts | Great circles, rhumb lines, convergence, scale and projections explain why a line on a chart needs interpretation. |
| Time, speed and distance | Groundspeed connects distance with elapsed time. Coordinated Universal Time (UTC), local time and date changes add a separate reference problem. |
| Air movement and ground movement | True airspeed and heading describe motion through air; wind completes the triangle that determines track and groundspeed. |
| Planning and monitoring | Dead reckoning predicts a position. A fix lets you compare prediction with observation and revise timing or track estimates. |
Position, charts, wind triangles and progress checks also appear in the separate EASA Private Pilot Licence aeroplane (PPL(A)) syllabus, AMC1 FCL.210; FCL.215, section 9.1. They are useful foundations for PPL readers; that does not make PPL and ATPL examination requirements identical. UK candidates should check their training organisation’s current UK Civil Aviation Authority (CAA) syllabus rather than assume this EU reference defines their examination.
A recommended study sequence
Begin with units and reference directions. Practise converting minutes to hours and marking every direction as true (T), magnetic (M) or compass (C) before adding wind.
Next, locate positions and measure routes on the appropriate chart. Study Earth geometry alongside projections so you can explain what the chart preserves and what it distorts.
Then work through time, speed and distance; add wind triangles only when the distinction between airspeed and groundspeed is clear. Finish with monitoring exercises: compare a predicted position with a fix, explain the difference and update the estimate. This is our editorial sequence, not a mandatory official order.
Four ways to check a calculation
1. Turn knots into nautical miles per minute
One knot is one nautical mile per hour, so divide by 60. At a constant groundspeed of 120 kt, you cover 2 NM/min. An 18 NM ground leg therefore takes 18 ÷ 2 = 9 minutes. Using hours gives the same answer: 18 ÷ 120 = 0.15 hours.
Use groundspeed for ground distance. Substituting true airspeed silently assumes the wind has no effect on the required groundspeed. If speed changes along the leg, split it into suitable parts or use an appropriate average.
2. Separate track error from the correction to regain track
Assume the ground track since departure has been straight. In an original flat-plane sketch, a fix lies 2 NM right of the planned line, 40 NM along from departure. A waypoint lies another 20 NM along that line. The 1-in-60 estimate gives:
- Track error from departure: 60 × 2 ÷ 40 = 3° right.
- Closing angle from the fix to the waypoint: 60 × 2 ÷ 20 = 6° left of the planned line.
The desired ground-track change from the old track towards the waypoint is about 9° left. Correcting only the 3° error would leave you parallel to the planned line, still displaced from it. This is geometry, not a complete new heading solution: wind must still be accounted for.
The exact angles are arctan(2/40) = 2.86° and arctan(2/20) = 5.71°. The shortcut replaces these with small-angle estimates. Do not extend it to large offsets or treat its rounded results as exact; curved-Earth and chart effects are also outside this sketch.
3. Draw where the wind goes
With a heading of 000°T, true airspeed 100 kt and wind from 270°T at 20 kt, draw the wind arrow towards the east. In a steady horizontal model, the ground velocity has 100 kt north and 20 kt east components. The track is therefore east of north. A drawing that produces westward drift has reversed the wind.
To maintain a northward track you would need a westward air-velocity component. This direction check comes before solving the wind triangle; it does not supply the correction angle by itself.
4. Give magnetic variation a sign
Define east variation as positive and use true = magnetic + variation, reducing the result to 000–359°. With true track 074°T and variation +6°, magnetic track is 068°M: 74 − 6 = 68. Reverse the calculation to check it. Compass deviation is a separate conversion; variation alone does not give a compass heading.
Check your understanding
At 90 kt groundspeed, how long does 15 NM take? Ten minutes: 90 ÷ 60 = 1.5 NM/min, then 15 ÷ 1.5 = 10.
Does a 3° track error mean a 3° turn will reach the next waypoint? No. Removing the error and closing the existing lateral offset are different tasks. The remaining distance affects the closing angle.
Can you combine a magnetic course with a true wind direction directly? First convert them to a common north reference. Otherwise the angle between them is wrong before the arithmetic starts.