Speed, wind & trig
1 knot = 1 nautical mile an hour; 1 nm = 1.852 km. time = distance ÷ speed. Reciprocal heading: add or subtract 180°. Wind and airspeed at right angles: use Pythagoras.
Crosswind = wind × sin θ; headwind = wind × cos θ (calculator in degrees). A 3° glide slope drops about 318 ft per nm. Avgas ≈ 0.72 kg per litre.
One step
Speed, headings, scale and temperature.Trip time
A plane flies 250 nm at 125 kt over the ground. How long does it take? What is 125 kt in km/h?
Other end
Runway 07 points about 070°. What heading is the other end, and what is its runway number?
Chart scale
A line on a 1 : 500,000 chart is 9 cm long. How far is that on the ground?
Colder up high
It is 12 °C at sea level. Using 2 °C per 1,000 ft, about how warm is it at 4,000 ft?
Two or three steps
Sketch the triangle before you calculate.Dog-leg
A route goes 60 km north, then 80 km east. How long is the direct line? How much shorter is it?
Wind triangle
Airspeed 90 kt north; the wind pushes 30 kt east. Find the ground speed and the drift angle east of north.
Crosswind check
Wind 25 kt blows at 40° to the runway. Find the crosswind and headwind. Is it within a 15 kt crosswind limit?
Coming down
On a 3° slope, about how high should a plane be 5 nm out? A plane that glides 10 : 1 is 800 m up: how far can it reach?
Fuel load
What is the mass of 120 L of avgas? A plane can carry 320 kg of people, bags and fuel. Two adults weigh 150 kg and bags 30 kg. How many litres can it take?
Square law
Lift grows with speed². By what factor does lift change if speed rises 20%? If it drops 20%?
Equations
A1–A2 (pp.17–18).Reserve
A plane starts with 180 L and burns 36 L/h (made-up): F = 180 − 36t. When does it reach a 30-minute reserve of 18 L?
Same height
Plane A: h = 2,000 + 400t. Plane B: h = 8,000 − 600t (ft, t in minutes). When are they at the same height, and what height?
Takeoff roll
A plane accelerates at 2.5 m/s² from rest: d = 1.25t². How long does a 500 m roll take?
Hangar
A hangar is 8 m longer than it is wide, with an area of 240 m². Solve w(w + 8) = 240.
Your turn to be the flight planner
- Pick two Alberta airports or towns on a map.
- Write a question about distance, time, wind or fuel for the trip.
- Solve it, and add a reserve: what could change on the day?
My problem, and my worked answer:
Try every problem first, then check here. Wrong answers are useful: find the step where your work and the key split apart.
The key never prints with Print my work or Print blank. Open it to get its own Print the answer key button.
Answer key
Worked solutions. Aircraft numbers are made-up examples, not for real flight planning.