Mach Numbers for Commercial Flights

I’m new to FlightAware (very cool site, by the way). I’m following my wife’s Lufthansa flight across the Atlantic right now. She’s in an Airbus A340-600 between Chicago and Munich, and FlightAware says the plane’s doing exactly 600kts at 37k feet altitude. By my calculations (pls check my math), that works out to about Mach 1.05.

Is that even possible in a big people hauler like the A340? Disregarding planes like the Concorde, what’s the fastest you would expect to see a commercial airliner flying these days, and what airframe would it be?



That would be the ground speed the aircraft is doing. That’s a combination of the aircraft’s actual speed plus the wind factor. Going east there’s usually a tail wind so it is possible that the aircraft *appears *to be going faster than the speed of sound.

If you’d like more information, use the search link above and look for ground speed.

Of course–makes perfect sense now. Airbus’ site says Mach 0.85 is about the max for the A340 with its four big turbofans. So at least another 100kts or so is coming from the wind.

Like Inspector Holmes once said, “Watson, you have an INCREDIBLE grasp of the obvious!” Thanks for pointing it out to me.

Make sure you type Ground speed in and not Glide speed :smiling_imp:

The Cessna Citation X is the fastest commercial aircraft, it is capable of Mach .92. It only holds 8-9 people though. Most airliners are capable of .82-.85 although you hear them on the radio at around .78 to .80 for fuel savings.

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