Flight Simulator

Take off, race through rings or land over a generated island; the landing modes score sink rate, centre line and touchdown point.

How to play

You fly a small single-engine aircraft over an island that the page builds from a number: hills, mountains near the coast, a lake, towns, forests and an airfield. Pick a mode and a difficulty and press Start.

In Free flight you start in the air near the airfield, and the page records the distance you fly.
In Take-off & landing you start on the runway with the engine idling. Open the throttle, lift the nose at about 45 knots, climb above 200 ft, fly a circuit and land on the runway in either direction.
In Landing approach you start 3.2 km out, lined up on a 3° glide path.
In Ring course you fly through ten rings in order against the clock. The next ring is yellow, and an arrow points to it when it is off the screen.

A landing scores up to 100 points: 50 for a gentle touchdown (a sink rate of 0.6 m/s, about 120 ft/min, or less), 30 for staying within a metre of the centre line and 20 for touching down 150 to 500 m past the threshold. A bounce or a tail strike costs 10 points, leaving the runway 20. The score appears once you have stopped; best results are saved in this browser.

Easy switches on the assist: when you let go, the wings level and the climb or descent flattens out, the bank stops at about 60° and the wing cannot stall. Normal adds a light breeze from 25° off the runway heading, Hard a strong gusty crosswind from 55° off, turbulence and smaller rings.

Controls

Mouse: after you click Start (or the view), move the pointer into the circle in the middle; then it is your control column: below the centre raises the nose, above lowers it, sideways banks, and the farther from the centre, the stronger the input. The wheel sets the throttle.
Keyboard: ↓ or S raises the nose, ↑ or W lowers it. ← → or A D bank, Q E work the rudder, Shift or + adds power, Ctrl or − reduces it (5 % per tap) and B or Space brakes. Ctrl+W closes the tab in most browsers, so the minus key is safer. Settings can swap the pitch direction.
Touch: drag with your left thumb on the left part of the view to steer, slide the throttle on the right and hold BRAKE; Easy is preselected.
On the ground the bank and rudder controls steer the nose wheel. C switches between cockpit and chase view, M shows the map, P or Esc pauses, F is full screen.

How it works

Four forces act on the aircraft: thrust, lift, drag and weight. Lift comes from the wing:

L = ½ ρ v² S C_L(α)

ρ is the air density (1.225 kg/m³ at sea level, less higher up), v the airspeed, S the wing area (16.2 m²) and α the angle of attack between the wing and the oncoming air. The lift coefficient grows almost linearly, C_L = 0.25 + 4.9 α (α in radians), up to the critical angle of 15°, where it reaches about 1.53. Beyond it the airflow separates, lift collapses and drag rises: the wing stalls, often dropping one wing. For 1000 kg the stall speed in level flight is

v_s = √(2mg / (ρ S C_L,max)) ≈ 25 m/s (about 49 knots).

In a turn the wing must carry more than the weight, so the stall speed grows with the square root of the load factor: in a 60° bank (2 g) it is about 70 knots. Drag is D = ½ρv²S(0.031 + 0.054 C_L²), where the second term is the induced drag that lift creates. Thrust is 2.5 kN at a standstill and falls as speed rises; full power gives about 125 knots in level flight.

The page computes these forces 120 times a second and moves the aircraft with Newton’s second law. Rotation is simplified: the controls set roll, pitch and yaw rates that grow with airspeed, the nose turns into the airflow like a weathervane, and with the stick centred and the wings level the aircraft keeps its current climb or descent angle. On the ground rolling friction is 0.02 of the load on asphalt (0.05 on grass) and the brakes add 0.42. Touching down faster than 3.6 m/s (about 700 ft/min) is a crash, and so is hitting the ground with a wing tip or the nose, water, a building or a tree; a gentle landing on flat grass works but is not scored.

Tips

On take-off keep the nose down until about 45 knots, then raise it gently; pulling hard drags the tail on the runway.
On the approach the nose sets the speed and the throttle the height. If the four lights beside the runway show more red than white, you are too low: add power.
Cross the threshold at 60–65 knots and flare gently just above the runway.
If STALL appears, release the back pressure, lower the nose and add power.

Frequently asked questions

What do the four lights next to the runway mean?

Two white and two red lights mean you are on the 3° glide path; more white means too high, more red too low.

Why is my island different from a friend’s?

It is generated from a number. Settings can change it; the same number always builds the same island.

Is this a real flight simulator?

No. The forces use real formulas and numbers typical of a light aircraft, but rotation, the engine and the ground are simplified. Do not use it to learn to fly.

Sources

NASA Glenn Research Center (2024). Lift Equation. The lift formula above.
Federal Aviation Administration (2023). Pilot’s Handbook of Aeronautical Knowledge, chapter 5: Aerodynamics of Flight (FAA-H-8083-25C). A 60° bank means a load factor of 2 g, and the stall speed grows with the square root of the load factor.
Federal Aviation Administration (2026). Aeronautical Information Manual, chapter 2, section 1: Airport Lighting Aids. The four-light precision approach path indicator: two white and two red lights on a 3° glide path.