C-130 Hercules stall speed is about 100 knots, with C-130J references near 95. See how weight, flaps, bank and airspeed units change the figure.
The C-130 Hercules stall speed is commonly quoted at about 100 knots (115 mph or 185 km/h); C-130J summaries often quote about 95 knots. Neither is a universal cockpit limit. Actual indicated stall speed varies with variant, gross weight, flap setting, power, bank angle, centre of gravity and airframe condition.
For Aviation & Real-World Flying readers, we treat those numbers as orientation figures, not operating data. A generic specification rarely states whether it represents a clean or landing configuration, or the exact test weight. Our guide to VS, VS0, VS1 and other V-speeds explains why that missing context matters.
Is 100 knots correct for every C-130?
No; 100 knots is a useful headline number, not a stall speed shared by every Hercules. C-130H, C-130J, AC-130 and MC-130 variants have different weights, equipment and aerodynamic details, while each individual flight may carry a substantially different fuel and payload load.
| Condition | Effect on stall speed | Reason |
|---|---|---|
| Higher gross weight | Higher | The wing must produce more lift at the same load factor. |
| Landing flaps extended | Lower | Flaps increase maximum lift compared with the clean configuration. |
| Bank while maintaining altitude | Higher | The increased load factor requires more lift. |
| Power applied | Different from power-off data | Propeller slipstream and thrust alter low-speed behaviour. |
| Ice, damage or contamination | Higher and potentially less predictable | The wing reaches its critical angle of attack sooner and may stall less benignly. |
At an unchanged configuration and load factor, stall speed changes approximately with the square root of weight: new VS = reference VS × √(new weight ÷ reference weight). A 10% weight increase therefore raises stall speed by about 5%, not 10%.
Bank has an equally important effect. In a coordinated level turn, 30 degrees of bank raises stall speed by roughly 7%, 45 degrees by about 19%, and 60 degrees by approximately 41%. That is why a Hercules can stall well above the familiar 95–100-knot figure during an accelerated turn.
Is C-130 stall speed measured in KIAS or true airspeed?
Use the airspeed basis specified by the applicable performance data; a bare figure expressed only in “knots” is incomplete. Flight manuals may present calibrated airspeed in KCAS, while the cockpit normally displays KIAS, with a small difference caused by instrument and position error.
For the same weight and configuration, indicated stall speed remains broadly similar as altitude changes. True airspeed at the stall rises as air density falls, and groundspeed also includes wind. Comparing a simulator's GPS groundspeed with a published indicated or calibrated stall speed is a common source of apparently incorrect results.
What approach speed should a C-130 use?
A C-130 approach speed must come from the approved speed schedule for its model, weight, flap setting and operating condition—not directly from the generic stall-speed figure. Wind corrections, manoeuvring margin and, during abnormal operations, minimum control speed may also govern the selected speed.
As a mathematical illustration only, applying a generic 1.3 multiplier gives 130 knots from a 100-knot stall speed, or about 124 knots from 95 knots. That does not mean every Hercules should cross the threshold between 124 and 130 KIAS; the underlying stall reference may describe a different configuration from the one being flown.
If stall warning, buffet or an uncommanded roll develops, reducing angle of attack takes priority. Our practical stall-recognition and recovery explanation covers the general sequence, but real C-130 operations require the aircraft's approved manual, operator procedures and qualified instruction.
Why does my simulated C-130 stall at a different speed?
A simulated C-130 can stall above or below 100 knots because its loading, configuration, airspeed display or flight model does not match the reference case. Add-ons also vary in how accurately they model propeller slipstream, flap lift, stall warning and asymmetric wing behaviour.
- Set a known baseline. Record fuel, payload, gross weight and centre of gravity. Use calm conditions without icing.
- Match the configuration. Select the documented flap and gear positions, and check whether the reference is power-on or power-off.
- Stabilise the aircraft. Hand-fly straight and wings-level with calibrated controls; an unnoticed bank raises the measured stall speed.
- Decelerate gradually. Slow by roughly one knot per second. Pulling abruptly creates extra load factor and can produce an accelerated stall at a higher speed.
- Record the correct cue. Note the first repeatable stall warning or aerodynamic break. A descent at idle is not automatically a stall; the aircraft may simply lack enough power to maintain level flight at that speed.
- Compare like with like. Check KIAS against KIAS or KCAS against KCAS, using the same weight and configuration as the reference.
Our FSX C-130 Hercules aircraft provides a relevant simulator model for exploring these effects, but its behaviour should be assessed against its accompanying documentation rather than a single internet specification. A model that always stalls at exactly the same indicated speed regardless of weight, flaps or bank is probably using simplified stall logic.