Stalls and Turns — Why Pulling Harder Doesn't Turn You

“I’m pulling and it won’t turn.” “It fell out of the sky the moment I rolled in.” This is the most common way to fail in this game — and the real aircraft does exactly the same thing.

What follows is what is actually happening, in the flight model’s own numbers. All of them come from the aircraft constants.

1. Bank raises your stall speed

Turns here are not auto-coordinated. They are bank-and-pull, the way the real thing works.

To hold altitude at bank angle φ, the vertical component of lift has to balance weight. That takes more lift than level flight does — it takes load factor n.

n = 1 / cos φ
stall speed Vs(φ) = Vs × √n

At sea level the 1g stall speed is about 216 km/h. By bank angle:

The lift curve peaks at 25° — a full pull never loses lift

Lift grows with angle of attack and tops out at 25° (the same shape as the F-16’s wind-tunnel data). It is proportional to angle of attack up to 12°, then rounds over gently toward the peak.

Like the real FBW, this model has an angle-of-attack limiter that holds you at the 25° peak. So stick fully back is maximum lift. Pulling past the peak and having the lift fall away is not something you can do from the stick.

What you pay instead is speed. Near the peak the induced drag is large, and the longer you hold the pull, the more speed you lose. Past 22° of angle of attack the HUD speed bar turns amber — that is the sign that you are pulling on the peak of the lift curve.

The stall line on the HUD speed tape moves with bank angle and with altitude. It is Vs(alt)/√|cos φ| shown directly. Nothing flies the aircraft for you, but in exchange the display is honest about the danger. Whenever you are turning, that is the line to watch.

2. Slowing down doesn’t tighten the turn

“Slow down to be safe” buys you nothing here. Working out the available G, turn rate and turn radius by speed (sea level, 12.7 t, full afterburner):

Three things fall out of that.

① From 300 to 650 km/h the radius barely moves — 330 to 355 m. That is a 7% spread. Lift (∝V²) and centrifugal force (∝V²) cancel each other, so flying slower does not make the turn any tighter. All you lose is turn rate — how quickly the nose comes round — and the g you have in hand. At 300 km/h you turn at half the rate you get at 650.

② 500–650 km/h is the working range. The radius is still at the bottom, and the rate is 23°/s or better. The fastest turn you can hold without bleeding speed — a sustained turn in full afterburner — is also here: 24°/s at about 525 km/h. In an F-2, 300 km/h is approach speed, not a speed you maneuver at.

③ Past 650 km/h the radius opens up. That speed is corner speed — where aerodynamic lift first reaches the structural 9 g limit (sea level, reference weight). Above it the available g is pinned at 9, so radius grows with the square of speed: about 415 m at 700 km/h, about 700 m at 900 km/h, about 1,050 m at 1,100 km/h. §8 has the details.

So slowing down gains you nothing, and the penalty for too much speed arrives all at once at corner speed. When in doubt, take the faster option — with 650 km/h as the ceiling on “faster”.

3. At low speed the controls themselves stop working

There is a second trap sitting just short of the stall. Control authority is proportional to dynamic pressure.

authority = (speed[km/h] / 396)²

Halve your speed and you have a quarter of the authority. Control response also carries a time constant of 0.3 seconds.

Down at the bottom of the speed range, “the input does nothing” and “the input arrives late” happen at once. Grabbing at the controls once you are already near the stall is too late — and that is not a problem with your hands.

4. Recovering from a stall

The order matters.

The problem is that down low you cannot do this. There is no altitude to give away. So in the valleys the question is never whether you can recover: not getting slow in the first place is the only defense you have.

5. Flying it in the valley

The low-level courses — Kurobe Gorge, the Southern Alps, Kamikōchi and the rest — are meant to be flown along the river. Give up on the straight-line shortcut and follow the terrain.

There is one rule.

Get the speed first, then a steep bank and a firm pull.

Building speed and changing direction in one committed movement is safer than easing around in a shallow bank. A shallow bank spends time without producing turn rate, and the valley wall keeps coming. When you pull, you can pull all the way — the limiter stops angle of attack at 25°, so the lift does not fall away.

In practice it becomes throttle back just before a bend, throttle up on the straights — because too much speed makes the radar ceiling hard to manage, and every km/h past corner speed widens the turn.

6. How this differs from the real aircraft

Work backwards from this model’s lift coefficient and you get a mass of about 12.7 t — roughly the real aircraft’s landing weight. The 216 km/h stall and the 280 km/h approach were both measured there, and thrust is set against the same figure: the published F110 numbers divided by 12.7 t are exactly what the model carries.

Every number in this section is at that 12.7 t. Actual launch weight depends on what is aboard and how much fuel is left, so the Matsushima circuits and the formation missions — which carry two external tanks — fly at 15.1 t, where the stall sits at 236 km/h. Burn fuel off and the aircraft moves back toward the figures below (see The F-2 §4).

Wing area, weight and thrust are the F-2’s own; only the shape of the lift curve is borrowed from the F-16. The F-2’s wing is 25% larger than the F-16’s, so on the same curve it turns as well as an F-16 or slightly better, and accelerates and climbs worse — a difference that comes straight out of the physics.

What caps the top speed is not parasitic drag but transonic wave drag, which is zero below Mach 0.78 — so the band you actually fly in passes through untouched. Past the sound barrier the wave drag eases off again and afterburner thrust grows with speed, so up high a clean aircraft reaches Mach 2.0. Every store adds its own supersonic drag; in the anti-ship fit the ceiling is Mach 1.04.

7. High up, it is a different world

The atmosphere is the real ISA standard model, and thrust, lift, drag and Mach number all read the same air. Sea level passes through untouched (density ratio 1.000), so none of this reaches carrier landings or low-level ingress. It reaches you when you climb.

In thin air you have to fly faster for the same lift. Meanwhile the speed of sound falls with temperature, so the drag wall comes down to meet you. The higher you go, the more the band you can fly in closes from both sides.

The ceiling comes out of the physics too. Minimum drag is a constant that does not depend on altitude, while thrust falls away with the thinning air; above the single point where those two cross, no choice of speed will sustain level flight. Accelerating to top speed down low and zooming does not get you past it either. Afterburner is the one exception: past the sound barrier its thrust grows, so pushing up while supersonic reaches about 20,000 m.

8. The structural g limit — +9 / −3 g

The FBW in the real F-16 and F-2 will not accept a pull that would break the airframe, and neither will this model: load factor is capped at +9 g and −3 g.

It stops you by tightening the rate at which angle of attack may change, in proportion to the g margin left — not by killing the elevator. The pull therefore settles onto the limit rather than bouncing off it or punching through: a full pull from 1,134 km/h peaks at 8.95 g and sits there for five seconds with no spike. Holding a high-g turn takes very nearly full authority, which is why the command is not faded out at the edge.

Below corner speed — 650 km/h at sea level and reference weight — it never engages at all, because the lift peak (the 25° angle-of-attack limiter) binds first. Carrier landings, air-to-air refuelling and the procedure stages fly well below it. It bites only above 650 km/h: flying a valley on the fast side, or pulling up after a full-throttle run down low.

With tanks and missiles aboard, the real aircraft’s limit load is set well below 9 g (see F-2 armament §5), but this model holds 9 g whatever is on the wings. What tanks take away is the g you can generate — the extra weight means less load factor at the same speed — not the structural ceiling.

Both of the limits the real FBW puts on the stick are in place: angle of attack stops at 25°, load factor at 9 g. The flip side is that as long as you keep your speed up, it flies like the real aircraft.

Summary

1. Stall speed rises the moment you bank. 257 km/h at 45°, 306 km/h at 60°.
2. The HUD stall line moves. In a turn, that is the line to watch.
3. A full pull never loses lift. Angle of attack stops at 25°; what you pay is speed.
4. Slowing down doesn’t tighten the turn. From 300 to 650 km/h the radius stays at 330–355 m; slower just means less turn rate and less g in hand.
5. Past 650 km/h — corner speed — the 9 g limit opens the turn up.
6. Wings level comes first in a recovery. But down low there is no second chance.