Speeds and limits
The Su-27's slowest and fastest speeds, how much G it can pull, and where it turns best, measured in FlightOut.
All figures were measured in FlightOut with the jet you start with: about 24,800 kg, with 5,200 kg of fuel and the default missiles, no wind. A lighter jet does better; a heavier one, worse.
The limits
| Limit | Value | Past it |
|---|---|---|
| Speed | 1,400 km/h (756 kt) indicated | The nose, fins and tailplanes are damaged, faster the further past |
| Mach | 2.35 | The intakes and engines are damaged |
| G | +9 / -3 G up to 21,400 kg; the structure takes about 7.8 G at the starting weight, and in practice the flight controls stop you at about 7 G | The flight controls hold you inside it. Overridden, the wings bend and then break. See Flight controls |
| Angle of attack | 26° (less at high speed) | The limiter holds it |
| Landing gear | 500 km/h (270 kt) | Damaged from about 575 km/h (310 kt), and it jams |
| Canopy open | 250 km/h (136 kt) | Torn off |
Slow flight
The slowest speed at which the jet can hold its height, with the limiter on (at 1,500 m):
| Configuration | Slowest level flight |
|---|---|
| Gear down, flaps up | about 190 km/h (103 kt) |
| Gear and flaps down | about 175 km/h (94 kt) |
At these speeds you are at full angle of attack, with the nose high and the engines working hard. Normal approaches are flown much faster, at 280 km/h (152 kt). See Approach and landing.
Top speed
Level flight at full afterburner:
| Altitude | Top speed |
|---|---|
| 1,000 m (3,300 ft) | Reaches the 1,400 km/h indicated limit, about Mach 1.2. Throttle back before it |
| 5,000 m (16,400 ft) | about 1,500 km/h true (1,160 km/h indicated), Mach 1.3 |
| 10,000 m (32,800 ft) | about 1,530 km/h true (885 km/h indicated), Mach 1.4 |
Indicated speed falls with height for the same true speed, because the air gets thinner: the HUD speed box shows the indicated speed. The afterburner burns fuel very quickly: at full afterburner low down, the starting fuel lasts about 11 minutes. See Engines and fuel.
How hard it can turn
Full aft stick at 1,500 m (4,900 ft), limiter on:
| Starting speed | Most G reached | Pitch rate |
|---|---|---|
| 360 km/h (195 kt) | 2.4 G | 27°/s |
| 500 km/h (270 kt) | 4.2 G | 28°/s |
| 650 km/h (350 kt) | 6.4 G | 25°/s |
| 830 km/h (450 kt) | 7.0 G | 19°/s |
| 1,080 km/h (580 kt) | 7.0 G | 14°/s |
- Below about 600 km/h the jet runs out of lift before it reaches its G limit: the angle of attack limiter stops you.
- Above about 800 km/h you reach the most the flight controls allow (about 7 G here) and can't pull harder, so the turn gets wider as you go faster.
- In between, around 650 to 800 km/h (350 to 430 kt), is where the starting jet turns best. A lighter jet can pull more G.
- Every hard turn bleeds speed. Pulling hard from 650 km/h for 4 seconds loses about 150 km/h.
Altitude
There is no fixed ceiling: the engines and wings lose power and lift as the air thins, so climbing gets slower and slower. The autopilot's altitude window goes up to 20,000 m (65,600 ft). Above about 15,000 m (49,000 ft), stay in afterburner and keep your speed up.
Checked against FlightOut 0.5.2.