Planes have come a long, long way since the  Wright brothers. Propellers, then jet engines, breaking the sound barrier, and supersonic flight. Today, not even the sky is the limit as aviators race toward the development of hybrid airplane-spaceships. 

Speed - as in how fast airplanes go and how fast the fastest plane is has always piqued the imagination of children interested in flying. And now wonder - planes are, after all, the pinnacle of human-speed.

If you’re a parent or educator introducing your kids to flying, it’s likely questions about speed will come up.

• “How fast can planes go?”

• “How fast is the fastest plane?”

And other variations are to be expected. Here are some answers and cool facts about the world’s fastest planes that you can share and explore with your little aviators.

The fastest plane ever

The world’s fastest military planes take flight at impressive speeds that often break boundaries, including the sound barrier.

The  Lockheed SR-71 Blackbird is the fastest plane ever built with a top speed of Mach 3.3 or 2,200 miles per hour (3,539 km/h). Wow! This remarkable feat was accomplished in 1976 and no other airplane has been able to break its record since then

The fastest commercial plane

The fastest current commercial aircraft is the Boeing 787 Dreamliner, which can travel at speeds of up to 955 kilometers or 593 miles per hour.

Note that commercial planes are  designed to fly at subsonic speeds and are limited by international aviation regulations, such as the Convention on International Civil Aviation.

What is "Mach"?

Mach is a unit of measure for speed. It measures the ratio between the speed of an object and that of sound in the same medium - air, for example.

The “speed of sound” - also known as Mach 1 - is around 343 m/s or 767 mph (1,233 km/h). Anything faster than this is considered supersonic, and anything slower than it is subsonic…So if someone says they flew at Mach 3, that means they were going three times faster than the speed of sound! 

How fast is the speed of sound? 

The speed of sound is approximately 767 mph (1,233 km/h). It varies according to altitude, temperature, and humidity.

At sea level, the speed of sound is roughly 750 miles per hour (1,207 kilometers per hour). This means that a plane flying at Mach 1 is traveling at 1,207 kilometers an hour.

What it means to go faster than sound.

What does supersonic mean?

Supersonic flight is defined as any speed faster than the speed of sound. This means speeds greater than 1,207 kilometers per hour (750 miles per hour). Currently, no commercial planes can go supersonic - but plenty of military planes do.

Other really fast planes include the MiG-25 Foxbat, which is the fastest military airplane still in active service. And then there's the fastest-ever jet fighter, the X-15.

How fast was the first plane?

In 1903, the Wright Brothers made history with their first powered flight. Their plane had a top speed of about 35 miles per hour (56 km/h) - pretty slow by today’s standards! But it was revolutionary for its time and set the stage for modern aviation and faster planes to come.

Today’s planes can fly more than 20 times that speed! We've definitely come a long way since those early days of flying.

The world's fastest planes | POWERUP for kids

Learning about these amazing planes is just one way to inspire your kids to explore their love for flight and spark an interest in science and technology. So get ready for takeoff - with some cool airplane facts!