Why does the aircraft climb worse at altitude?

Air density falls with height, so a normally aspirated engine makes less power and the wing makes less lift at the same speed. This simulator models both with the standard atmosphere density lapse, which is why the Hellcat feels sluggish above about 6,000 metres.

What were the real F6F Hellcat's specifications?

The Grumman F6F-5 had a 334 square foot wing, a loaded weight near 12,600 pounds, and a Pratt & Whitney R-2800 Double Wasp making about 2,000 horsepower. Top speed was roughly 330 knots and the stall speed with flaps down was around 70 knots. Those numbers drive the flight model here.

Hellcat — WWII Carrier Flight Simulator

Hellcat — a browser flight simulator with real aerodynamics

This is a Grumman F6F-5 Hellcat, the carrier fighter that flew from American decks from 1943 onward, in a flight model built from the actual equations rather than from arcade feel. Lift and drag come from the standard coefficients, air density falls off with altitude the way the standard atmosphere says it does, and the wing stalls when it exceeds its critical angle of attack — not when a speed number is crossed.

Controls

Key	Action
W / S, or ↑ ↓	Pitch down / up
A / D, or ← →	Roll left / right
Q / E	Rudder
Shift / Ctrl	Throttle up / down
G	Landing gear
F	Flaps
H	Tailhook
C	Chase / cockpit view
R / Esc	Restart mission / mission menu

On a phone or tablet the on-screen pads appear automatically: throttle and rudder on the left, pitch and roll on the right, and the configuration switches down the right-hand edge.

The aeroplane

Quantity	Value	In the model
Wing area	334 ft² (31.0 m²)	Sets lift and drag directly
Span / aspect ratio	42 ft 10 in / 5.5	Drives induced drag
Loaded weight	12,600 lb (5,714 kg)	Wing loading, and therefore turn radius
Engine	R-2800, 2,000 hp	Thrust from shaft power, scaled by air density
Stall angle	16°	Lift falls away past this, not at a fixed speed

What the flight model actually computes

Each physics step resolves the velocity vector into body axes to get the angle of attack, then builds the coefficients and the forces:

Dynamic pressure q = ½ρV², with ρ from the standard-atmosphere lapse. This is also what scales your control authority — at 60 knots on final the controls are genuinely mushy, because q is small.
Lift L = qSC_L, with C_L = C_L0 + C_Lαα. Past the critical angle C_L falls rather than flattening, which is why a stall here breaks rather than mushes.
Drag C_D = C_D0 + kC_L², the drag polar, with k = 1/(π·AR·e). Gear, flaps and hook each add their own parasite penalty.
Thrust T = ηP/V, capped at static thrust so it does not go to infinity at rest, and multiplied by the density ratio because the R-2800 is normally aspirated.

Two consequences fall out of this rather than being scripted. Turning hard raises the load factor, which raises the required lift coefficient, which can stall you well above the published stall speed — a genuine accelerated stall. And the aircraft climbs noticeably worse above 6,000 metres, because both the wing and the engine are working in thinner air.

Flying the carrier approach

The landing mission puts you two miles astern at 500 feet, dirty and on speed. The technique that works is the real one:

Hold about 75 knots and a steady 500 feet per minute down. Trade throttle for glidepath and attitude for speed, not the other way round.
Gear, flaps and hook all down. The tailhook is the one people forget; without it you touch down, roll, and go off the bow.
Do not flare. A carrier landing is a controlled arrival. Flaring floats you long and you sail over all four wires — that is what a bolter is.
Aim for the third wire. The first is uncomfortably close to the ramp; the fourth means you were fast or high.
The deck tolerates about 1,200 feet per minute at touchdown. More than that and the gear folds.

The ship is under way at 15 knots, so the deck is moving away from you the whole time — the aim point drifts, and that is part of the problem.

Frequently asked questions

How do you land on an aircraft carrier?

A stable approach around 75 knots with gear, flaps and hook down, holding roughly 500 fpm of descent, and no flare. You fly the aircraft onto the deck and let the hook find a wire. Aim for the third of the four.

What is an accelerated stall?

A stall above the published stall speed, caused by pulling hard enough to raise the load factor. Because stall is a function of angle of attack, pulling 2 g raises the stall speed by √2 — about 41 percent. It is modelled here rather than scripted: pull hard enough at any speed and the angle of attack crosses 16 degrees.

Why does it climb so badly high up?

Density lapse. The standard atmosphere loses about half its density by 6,700 metres, so the wing makes less lift at the same speed and the normally aspirated R-2800 makes less power. Both are in the model, so the service ceiling emerges rather than being imposed.

What were the real Hellcat's numbers?

334 ft² of wing, about 12,600 lb loaded, a 2,000 hp Pratt & Whitney R-2800 Double Wasp, roughly 330 knots flat out and a stall around 70 knots dirty. Those are the values driving this simulation.

Why does the aircraft feel unresponsive on approach?

Because it should. Control authority scales with dynamic pressure, which is proportional to the square of airspeed. At 75 knots you have roughly a quarter of the control power you have at 150, which is exactly why a slow approach is a demanding one.

Related simulations

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Bonneville Spillway Operator — run a real dam on the Columbia.
Floodline — California flood defence under a rising hydrograph.
Biosphere Blue — planetary climate and ecology, coupled.

HELLCAT

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