⚠️This fact has been debunked
This is a common myth. The statement is false because it lumps all 'modern jets' together. While most modern military fighter jets CAN break the sound barrier (go supersonic), commercial passenger jets absolutely cannot and are not designed to do so. All commercial airliners in service today (Boeing 737, 787, Airbus A320, A350, etc.) operate at subsonic speeds, typically cruising around Mach 0.85 (about 560 mph). The Concorde, which retired in 2003, was the last commercial supersonic aircraft. Even among military jets, not all are supersonic-capable - many trainer aircraft, cargo planes, and specialized military aircraft are subsonic. The term 'jet' simply refers to jet engine propulsion, which doesn't inherently mean supersonic capability.
Any modern jet is capable of breaking the sound barrier.
Can Modern Jets Break the Sound Barrier? Busting the Myth
You've probably heard jet engines roar overhead and wondered if that plane just broke the sound barrier. Here's the truth: the vast majority of jets you'll ever see cannot break the sound barrier, and that's completely by design.
The myth likely stems from confusing "jet" with "supersonic aircraft." A jet is simply any aircraft powered by jet engines - that includes everything from massive cargo planes to tiny business jets. Breaking the sound barrier (going faster than Mach 1, roughly 767 mph at sea level) requires specialized design, enormous power, and creates challenges most aircraft are never meant to handle.
Why Your Flight to Vegas Isn't Going Supersonic
Every commercial airliner currently flying - your Boeing 737s, 787s, Airbus A320s, A350s - cruises at subsonic speeds around Mach 0.85 (about 560 mph). They're aerodynamically optimized for fuel efficiency and passenger comfort at these speeds, not for punching through the sound barrier.
The only commercial jet that ever broke the sound barrier in regular service was the legendary Concorde, which retired in 2003. For over 20 years since, there hasn't been a single supersonic passenger jet in operation. In January 2025, Boom Supersonic's XB-1 test aircraft broke the sound barrier, reviving hopes for future commercial supersonic travel - but that's still years away from carrying passengers.
The Military Side of the Story
Now, modern military fighter jets? That's a different ballgame. Most air superiority fighters are indeed supersonic-capable:
- F-22 Raptor: Can supercruise above Mach 1.5 without afterburners
- F-35 Lightning II: Tops out around Mach 1.6
- Eurofighter Typhoon: Capable of Mach 2+
- Su-57: Russia's answer, also Mach 2-class
But here's the kicker: even though these fighters can go supersonic, they rarely do in actual combat. Air-to-air engagements typically happen at subsonic speeds because supersonic flight guzzles fuel and reduces maneuverability. There's likely never been a true supersonic dogfight in aviation history.
And Even Military Has Subsonic Jets
Not every military jet is built for speed. Plenty of military aircraft are subsonic by design: cargo transports like the C-130 Hercules, attack aircraft like the A-10 Warthog, trainer jets, reconnaissance planes, and aerial refueling tankers. The U.S. military operates hundreds of jet aircraft that will never break the sound barrier.
The bottom line? "Jet" just means jet-powered. Supersonic capability requires specific engineering, mission requirements, and operational costs that most aircraft - military or civilian - simply don't need or can't justify. Next time you see a contrail overhead, odds are overwhelming that plane is cruising comfortably below the speed of sound.