How Fast Do Helicopters Fly?

The average cruising speed of a helicopter is generally less than 160 knots (184 MPH, 296 km/h). An airliner, by comparison, cruises nearer 450 knots.

You see a helicopter spinning on the spot and dropping into a parking lot, and it is easy to assume that anything that nimble must also be fast. 

Well, let’s take a look at how fast real helicopter models actually fly. We’ll discuss which machines hold the speed records, and the ceiling that keeps them from flying any faster.

Key Takeaways

• Helicopters usually top out around 100 to 190 knots, roughly 115 to 218 mph.
• The top speed you see quoted is usually V_NE, the never-exceed placard limit.
• A helicopter’s V_NE can still change depending on weight and density altitude.
• The Westland Lynx has held the official helicopter speed record since 1986.

Popular Helicopters and Their Maximum Speeds

Most civil and military helicopters you’ll likely recognize have a helicopter top speed somewhere between roughly 100 and 190 knots. That works out to about 115 to 218 mph, or around 185 to 350 km/h.

The maximum speed quoted to you for a given model is usually its V_NE, short for never exceed speed. It’s a placard limit, set for reasons like retreating blade stall and structural loads.

In other words, a helicopter’s top speed on a spec sheet is a line the manufacturer tells you not to cross. It’s not necessarily a physical limit that the aircraft can’t pass. That’s a big part of why helicopter top speeds look so modest next to fixed-wing aircraft.

The table below shows the maximum speeds for a selection of well-known helicopters.

Helicopter	VNE (knots)	VNE (MPH)	VNE (km/h)
Robinson R22	102	117	189
Robinson R44	130	150	241
Bell 206	130	150	241
Airbus Eurocopter EC120	150	173	278
Airbus H175 / Eurocopter EC175	175	201	324
AgustaWestland AW109 Power	168	193	311
AgustaWestland AW139	167	192	309
Sikorsky H92 / S-92	165	190	306
AgustaWestland AW189	169	194	313
Airbus H155 / Eurocopter EC155	175	201	324
Airbus H225 / Eurocopter EC225	175	201	324
Airbus H125 (AS350)	155	178	287
Bell 407	140	161	259
Sikorsky UH-60 Black Hawk	193	222	357
Boeing CH-47 Chinook	170	196	315

But firstly – a word of warning. It should be noted that details of their actual maximum speeds do tend to differ slightly depending on the source of the information. So it is hard to say exactly which helicopter is the fastest.

Cruise Speed vs. Never-Exceed Speed (VNE)

Cruise speed is what your helicopter flies at on a normal trip. V_NE, or never exceed speed, is the red line on the airspeed indicator you must not pass. Helicopter cruise speed usually sits well below it. 

But helicopter V_NE isn’t a single number. In the Robinson R44 II, it’s 130 KIAS at or below 2,200 pounds. Above that weight, the V_NE is 120 KIAS. In autorotation, it drops to 100 KIAS.

The placard trims it even more as altitude and temperature climb. That’s because the higher you go, retreating blade stall arrives at a lower airspeed. That’s why manufacturers publish V_NE charts that drop with altitude.

The World’s Fastest Helicopters

The fastest helicopter on the official books is a conventional machine from 1986, and nothing has beaten it since. Everything quicker cheats a little, bolting on an extra propeller or tilting its rotors forward, which is exactly why the FAI won’t count it as a helicopter.

1. Westland Lynx

The Westland Lynx was long known as the fastest rotary aircraft in the world. In 1986, a specially modified version of this helicopter, registered G-LYNX, set a world rotary speed record of 400.87 km/h (216 knots, 249 MPH) on 11 August. The FAI still recognizes that mark as the absolute speed record for helicopters.

Test pilot Trevor Egginton flew it along a 15 km course over the Somerset Levels. The flight used BERP rotor blades and uprated Gem 60 engines. No helicopter has beaten it since.

2. Eurocopter X3

If you consider the Eurocopter X3 a helicopter, it is the fastest in the world, as it can reach 255 knots (293 MPH). It set that speed in level flight on 7 June 2013. 

But it should be noted that it is actually a compound helicopter, which is a hybrid between a helicopter and an airplane. It keeps a conventional main rotor for lift. But, it also adds short wings and two tractor propellers for forward thrust.

3. Sikorsky X2

In 2010, the Sikorsky X2 reached 250 knots (288 MPH) in level flight, and 262 knots in a shallow 2 to 3 degree dive. That makes it almost as fast as the Eurocopter X3. Its rigid, coaxial counter-rotating rotors cancel out the dissymmetry of lift that limits an ordinary helicopter’s speed. A pusher propeller supplies the thrust.

4. Bell/Boeing V-22 Osprey

Some people would describe this as the fastest helicopter in the world, while others would argue that it is not technically a helicopter. 

The V-22 uses tilt-rotors to transform itself from a helicopter to a fixed-wing aircraft, and back again. Unlike the Eurocopter X3 and Sikorsky X2, which keep their rotors lifting and add separate propellers for thrust, the V-22 tilts its whole rotors forward until they act as propellers.

The Osprey has a maximum recorded speed of about 275 knots (316 MPH), but only in airplane mode, when it’s flying as a fixed-wing aircraft rather than a helicopter. It is used mostly by the US Military.

In true helicopter mode, though, it comes nowhere close. That’s a large part of why many would not call it a helicopter at all.

Other new types of helicopters are on the way, so the answer to the question “How fast do helicopters fly?” is ever-changing. Conventional helicopters simply cannot fly fast, and most likely never will be able to.

So why is this the case?

Helicopter aerodynamics is somewhat different from that of fixed-wing aircraft. To put it simply, the lift is generated in a slightly different manner, and this will only work up to a certain speed.

We first need to look at exactly how helicopters fly.

So Which Helicopter Actually Holds the Record?

The fastest helicopter in the world on record is the Westland Lynx. It’s held the helicopter speed record since 1986. Its G-LYNX run of 400.87 km/h (216 knots) remains the FAI helicopter record holder, unbeaten for nearly four decades. 

Take note, we’re talking about the fastest helicopter ever officially recorded. Plenty of machines fly faster, like the other models we discussed earlier. But each one either bolts on an extra propeller or tilts its rotors forward until they act as propellers. Hence, the FAI won’t count any of them as a “pure” helicopter.

How Do Helicopters Fly?

A helicopter’s rotor blades are wings that rotate. Spinning them drives air over the blades and produces lift in the same way forward motion does for a fixed wing. That raises the aircraft into the air.

This works until the helicopter moves forward. From then on, the air flows faster over the advancing blade, the one turning into the direction of flight, than over the retreating blade turning away from it.

So, the advancing blade makes more lift than the retreating one. If you leave this uncorrected, that dissymmetry of lift would simply roll the helicopter over. And this is precisely what wrecked the earliest helicopters.

The solution was the autogyro, which was invented by Spaniard Juan de la Cierva in the 1920s. He found that letting the blades flap up and down as they rotate evens out the lift across the disc. Helicopter designers borrowed the idea, which became known as flapping to equality.

Flapping to equality only holds up to a certain speed, which is where a helicopter’s speed ceiling begins. Now, let’s look at what happens beyond it. 

Why Helicopters Cannot Fly Fast

It’s because as a helicopter picks up speed, its rotor gets squeezed from both ends.

On the retreating side, the blade moving away from the direction of flight keeps losing airflow. When you reach a certain speed, part of it just stalls.

On the advancing side, the blade tip is already moving fast. Adding forward speed pushes it toward the speed of sound, where shock waves begin to form.

Neither problem leaves you with much room. That’s why manufacturers set a helicopter’s V_NE well below the point where speed becomes an issue. You can’t just keep going faster in a helicopter the way you might in a fixed-wing aircraft. 

Now, let’s take the speed problem apart, one effect at a time.

The Phenomenon Of Flapback

A side effect of flapping is that when the cyclic (joystick) is moved forward to increase speed, the rotor disc (the hypothetical disc made by the spinning rotor blades) tilts forward initially but then flaps back. Further forward movement is required in order for the helicopter to continue to accelerate, and this phenomenon is known as ‘Flapback’.

Flapback occurs throughout the whole speed range of the helicopter. So, if you want to increase our speed, the cyclic has to be moved progressively further and further forward while flying. 

Strictly speaking, there will come a point at which the cyclic is at its forward limit, and the helicopter cannot fly any faster. In practice, there are other factors apart from flapback that are likely to play a part in limiting the helicopter’s forward speed before the cyclic reaches its limit.

Airflow Reversal

As the helicopter flies gradually faster and faster, the difference between the relative speed of the advancing and retreating blades increases.

Confused? Don’t worry; it makes more sense if we put in some actual numbers.

Suppose the helicopter is moving forward at 20 knots, and the blades are rotating at X  knots. Assuming no wind, the advancing blade is moving at X + 20 knots, and the retreating blade is at X – 20 knots. So the difference between the airspeed of the advancing blade and the retreating one is 40 knots. But if the helicopter is moving at 100 knots, this difference becomes 200 knots!

Now, there will come a point at which the root of the retreating blade, which is the slowest part, has zero airspeed since the helicopter is moving forward at a faster speed than that section of the blade is rotating. When that occurs, this particular section of the rotor blade cannot produce any lift at all.

At first, this inability to produce any lift only occurs over only a small area of the blade.  But, as the helicopter speeds up, this ‘airflow reversal’ takes place over a larger and larger area of the retreating blade. The only way the rotor system can compensate for this is for the outer part of the retreating blade to work harder and harder.

So the outer section of the blade has to produce more lift, and it does this by operating at a higher and higher angle of attack, which is achieved through more flapping.

It is not a terribly efficient way for the helicopter to operate, but it works. At the speeds reached in fast forward flight, though, this reverse flow spreads across a large inboard stretch of the retreating blade, leaving less and less of the blade doing useful work.

But, there is a limit to how far this can go while the helicopter still is able to fly effectively. There comes a limiting point at which lift is no longer produced, and the retreating blade enters a stall. As you might expect, this phenomenon is called Retreating Blade Stall.

Retreating Blade Stall

As with any aerofoil in any type of aircraft, if the angle of attack increases beyond a certain point, the blade will stall. This is known as a “retreating blade stall.”

A retreating blade stall starts at the tip of the blade since this is the area that has the highest angle of attack, and spreads inwards to the root. And, basically, the retreating blade ceases to produce any more lift, as would occur with any stalled ‘wing’. When this happens, the helicopter first pitches its nose up and then rolls toward the retreating side.

This sounds rather scary, and it sure is. But, as with any stall, there are definite symptoms that occur before the full stall actually occurs. The Helicopter Flying Handbook lists three warning signs. Watch out for a low-frequency vibration, a pitch-up of the nose, and a roll in the direction of the retreating blade. Because few pilots have ever felt a retreating blade stall, these signs can go unrecognized.

Also, as the retreating blade starts to stall and the helicopter pitches its nose up, this in itself will slow the helicopter down, and it may correct the problem before the result becomes catastrophic. Therefore, a retreating blade stall can be self-correcting.

If a pilot does actually recognize what is happening, the first step is to lower the collective, which reduces the blade pitch angle and eases the angle of attack across the disc. Again, collective, not cyclic. Aft cyclic creates a flare effect that raises the angle of attack and only worsens the stall. Forward cyclic increases the angle on the retreating blade, which makes it worse as well. 

Now, with the collective lowered, the pilot then works on the actual cause. They ease off speed and, for example, roll out of a steep turn or restore rotor RPM to its normal range.

A retreating blade stall is actually very rare. That’s because it lies at the high end of the speed range, beyond the never-exceed speed pilots are trained to respect. It’s a high-airspeed condition. But the FAA does note that high gross weight, low rotor RPM, high density altitude, turbulence, and steep or abrupt turns all make it more likely at those speeds. 

So, for this reason, it is a good idea for pilots to be aware of it and know how to recognize the symptoms, but that’s about all.

A retreating blade stall is certainly unlikely to happen just because you decide to fly a bit faster than is recommended. But it is still a reason why helicopters cannot just fly a conventional helicopter faster and faster.

Air Compressibility

There is one more aerodynamic factor that can limit high-speed helicopter flight, and this is air compressibility. At high airspeeds approaching the speed of sound, the character of the airflow is changed, and compressibility must be taken into account.

The helicopter may not be moving at anything approaching this sort of speed, but its rotor blades certainly are. In this case, it is the speed of the advancing blade that can cause problems, as the rotation tip speed must be added to the forward airspeed.

Let’s use the R44 II as an example. Per its Pilot’s Operating Handbook (POH), it has a rotor tip speed of around 215 meters per second (705 feet per second) at 102% RPM. Now, if you were to fly it at V_NE of 130 knots or roughly 67 meters per second, its advancing blade would reach a speed of 282 meters per second. That’s dangerously close to the speed of sound at sea level, which is 340 meters per second.

This means that compressibility is significant, which means that more power is required for the same rotor thrust, and shock waves may be produced with increasing vibration and noise. So again, this will limit your speed.

What Changes a Helicopter’s Speed on Any Given Day?

Your helicopter’s published top speed is a best-case number. The real number on any given day is usually lower. Gross weight, density altitude, temperature, and your aircraft’s configuration could all pull it down. This is what affects helicopter speed in actuality.

Gross Weight

The heavier you load a helicopter, the harder its rotor works, and the sooner the retreating blade runs into trouble.

Again, take the R44 II, for example. According to its POH, crossing 2,200 pounds drops V_NE from 130 to 120 KIAS. And altitude hasn’t even entered the picture yet.

Density Altitude and Temperature

The air gets thinner on a hot day, or as you climb higher, and in those conditions, the rotor will need higher blade angles to hold you up.

That brings you closer to a retreating blade stall at a lower speed. This is why, as density altitude and temperature rise, the R44 II’s V_NE gets lower.

Turbulence

Rough air throws sudden gusts at the rotor. When that happens, the retreating blade’s angle of attack could briefly and suddenly spike.

The FAA mentions turbulence as one of the conditions that cause retreating blade stall. When in bumpy air, slow down to be safe.

Frequently Asked Questions

How Fast Do Helicopters Fly in MPH?

Most helicopters you’ll see fly at top speeds between roughly 115 and 218 mph, which is about 100 to 190 knots.

A Robinson R44, for instance, has a never-exceed speed of 130 KIAS, or around 150 mph.

What Is the Fastest Helicopter in the World?

The Westland Lynx holds the official FAI record at 400.87 km/h (216 knots, 249 mph). This record was set in 1986 and has never been beaten.

The compound Eurocopter X3 was quicker at 255 knots (293 mph), but the FAI doesn’t qualify it as a helicopter.

Why Can’t Helicopters Fly as Fast as Airplanes?

There are two factors that limit your main rotor’s capability. When you push the speed too far up, the retreating blade could run out of airflow, and it stalls.

On the other side, as you go faster, the advancing blade tip also approaches the speed of sound, which could form shock waves.

Retreating blade stall is no issue for the fixed wing of an airplane, and its compressibility limit also sits far higher.

What Does VNE Mean on a Helicopter?

V_NE stands for never exceed speed. It’s the airspeed you must never fly past as determined by your aircraft’s manufacturer. 

Take note that it isn’t a fixed number. On the Robinson R44 II, V_NE falls from 130 to 120 KIAS as weight increases. It drops even further as altitude and temperature increase.

How Fast Does a Black Hawk Helicopter Fly?

Sikorsky lists the UH-60 Black Hawk with a top speed of about 183 mph (roughly 160 knots) in level flight, and it cruises at around 150 knots. Its V_NE is higher at 193 knots. But again, this is the limit, and not the speed it normally flies.

Can a Helicopter Break the Sound Barrier?

No. Long before the airframe could approach the speed of sound, the advancing blade tip would get there first. Remember, you’ll have to add the blade’s rotational speed on top of the helicopter’s forward speed.

Before the rest of the helicopter could even break the sound barrier, shock waves and violent vibration would have long set in on the advancing blade.

Conclusion

How fast do helicopters fly? Well, while they can zip quickly through the air, they’re unlikely to be as fast as the airliner overhead. While they can hover and land almost anywhere, they still have a hard helicopter speed limit.

If you try to push faster than the V_NE, one side will stall while the other approaches the speed of sound. That’s why 40 years on, the 1986 record still stands to be beaten.

But if none of that deters you from learning to fly a helicopter, then nothing will!