How Fast Can an Aeroplane Go? Work It Out in This Order

An aeroplane has four speeds at once, and the question has no single answer until one of them is named. A modern narrow-body airliner carries two certificated limits simultaneously: the Federal Aviation Administration's type certificate data sheet A16WE lists the Boeing 737-800's maximum operating speed as 340 knots calibrated airspeed and Mach 0.82, while the European Union Aviation Safety Agency's data sheet EASA.A.064 gives the Airbus A320 350 knots and the same Mach 0.82. Normal cruise runs below both. EUROCONTROL's Aircraft Performance Database lists the 737-800 at an indicative 460 knots true airspeed and Mach 0.79 — roughly 529 mph, or 852 km/h — and the A320 at 450 knots. The number on the seat-back map is none of these. That is ground speed, which is true airspeed adjusted for wind, and in February 2024 it reached 838 mph on a United Boeing 787 over the Atlantic.

1. Decide which speed the question is asking about

The Pilot's Handbook of Aeronautical Knowledge, FAA-H-8083-25C, published by the FAA's Flight Standards Service in 2023, defines four quantities that ordinary usage collapses into one word.

Indicated airspeed is "the direct instrument reading obtained from the ASI, uncorrected for variations in atmospheric density, installation error, or instrument error." The handbook adds a detail that decides most arguments: manufacturers use indicated airspeed as the basis for determining aircraft performance. Calibrated airspeed is that reading corrected for installation and instrument error. True airspeed is calibrated airspeed corrected for altitude and non-standard temperature — in the handbook's performance chapter, "the speed of the aircraft in relation to the air mass in which it is flying."

Ground speed is the fourth. The handbook is blunt about it: "the actual speed of the airplane over the ground. It is TAS adjusted for wind. GS decreases with a headwind and increases with a tailwind."

A figure quoted without one of those four labels attached cannot be checked. Take "600 mph": a plausible true airspeed in the cruise, an impossible indicated airspeed for an airliner at 521 knots against a certificated limit of 340, and an unremarkable ground speed on a winter crossing to Europe. One number, three incompatible claims.

2. Separate the speed through the air from the speed over the ground

Paul D Williams, Professor of Atmospheric Science in the Department of Meteorology at the University of Reading and a Royal Society University Research Fellow, set out the relationship in a single line in Environmental Research Letters in 2016: "the velocity of the aircraft relative to the ground is equal to the velocity of the aircraft relative to the air plus the velocity of the air relative to the ground."

His study held the aircraft's air speed fixed at 250 metres per second — 486 knots, or 900 km/h — and let only the wind vary across twenty simulated years of daily North Atlantic weather. The results are the clearest available demonstration that speed and journey time are different questions. Mean eastbound crossings from New York to London took 5 hours 38 minutes. Westbound, at identical air speed, they took 6 hours 40 minutes. In still air the great-circle route would have taken 6 hours 09 minutes. The average along-track tailwind component Williams calculated on that route was 21.4 metres per second, about 42 knots.

Williams also noted an asymmetry most passengers never see: "the amount by which the westbound journey is lengthened by the headwind exceeds the amount by which the eastbound journey is shortened by the tailwind." Wind is not a wash over a return trip. It costs.

3. Read cruise as a Mach number, not a mile-per-hour figure

The most common wrong answer to this question is a fixed mph value for airliner cruise — 550, 575, 600, depending on the source. Cruise is not managed that way, and the handbook explains why.

Mach number is the ratio of true airspeed to the speed of sound in the same atmospheric conditions, and the speed of sound falls as air gets colder. Under the International Standard Atmosphere it is 661.5 knots at sea level at 15°C, about 576 knots at 35,000 feet, and 573.6 knots from the tropopause at 36,089 feet upward, where the temperature stops falling at −56.5°C. The same Mach number therefore means a different true airspeed at every altitude.

Which limit governs also changes with height. FAA-H-8083-25C works an example: an early civilian jet had a maximum operating speed of 306 knots calibrated airspeed up to roughly FL310, where Mach 0.82 happened to equal 306 knots. Above that altitude Mach 0.82 corresponded to a lower calibrated airspeed and took over as the binding limit — at FL380, the handbook notes, Mach 0.82 equals 261 knots calibrated. One aircraft, one certificate, two different numbers depending on where it is flying. The handbook places civilian jet cruise in the range of Mach 0.7 to Mach 0.90.

4. Treat takeoff speed as a per-flight calculation

There is no takeoff speed for a model of aeroplane. There is a takeoff speed for a departure.

Title 14 of the US Code of Federal Regulations, section 25.107, defines the takeoff speeds as multiples of other speeds rather than as constants. Rotation speed VR may not be less than V1 and not less than 105 percent of the minimum control speed VMC. The takeoff safety speed V2 may not be less than 1.13 times the reference stall speed VSR for most two- and three-engine turboprops and turbojets, 1.08 VSR for aircraft with qualifying stall-reduction provisions, and 1.10 times VMC.

Stall reference speed depends on weight, and weight moves a great deal. Boeing's 737 MAX Airplane Characteristics for Airport Planning, document D6-38A004 Revision K of July 2025, lists maximum design takeoff weights for the 737-8 alone ranging from 159,400 to 182,200 pounds across the offered configurations. The same publication prints its takeoff runway length requirements not as one chart but as four temperature cases — standard day, and standard plus 15°C, 25°C and 35°C — plotted across pressure altitudes from sea level to 15,500 feet.

EUROCONTROL's indicative V2 for a 737-800 is 145 knots, about 167 mph. That figure is a reasonable expectation, not a specification, and the database says so itself: "All data presented is only indicative and should not be used operationally."

5. Apply the same rule to the landing speed

Section 25.125 of the same regulations ties the landing reference speed to the stall in the same way. In non-icing conditions, VREF "may not be less than: 1.23 VSR0" — 23 percent above the stall reference speed in the landing configuration.

Because VSR0 varies with weight, so does the approach. A 737-800's maximum landing weight is 146,300 pounds under FAA data sheet A16WE, while its maximum zero-fuel weight is 138,300 pounds; an aircraft arriving with reserves only and one arriving heavy do not fly the same approach speed. Boeing accordingly publishes landing runway length "for different airplane weights and airport altitudes" rather than a single figure.

Indicative landing speeds from EUROCONTROL run 147 knots for the 737-800 (169 mph), 137 knots for the A320 (158 mph) and 121 knots for a Bombardier Dash 8 Q400 (139 mph).

6. Compare aircraft that operate under the same constraints

Certificated limits and indicative cruise figures answer different questions, so a comparison has to keep them in separate columns.

| Aircraft | Certificated limit (VMO/MMO) | Indicative cruise | Max operating altitude | Indicative landing speed | |---|---|---|---|---| | Cessna 172 | not applicable | 115 kt TAS (132 mph) | FL130 | 65 kt (75 mph) | | Dash 8 Q400 | not listed | 360 kt TAS (414 mph), no Mach listed | FL250 | 121 kt (139 mph) | | Airbus A320 | 350 kt / Mach 0.82 | 450 kt TAS, Mach 0.79 | 39,100 ft | 137 kt (158 mph) | | Boeing 737-800 | 340 KCAS / Mach 0.82 | 460 kt TAS, Mach 0.79 | 41,000 ft | 147 kt (169 mph) | | Boeing 787 | 360 KIAS / Mach 0.90 | about Mach 0.85 | 43,100 ft | not listed | | Concorde | 530 kt CAS / Mach 2.04 | 1,176 kt TAS (2,179 km/h) | about 60,000 ft | not listed |

Certificated limits come from FAA data sheets A16WE and T00021SE and EASA data sheet EASA.A.064; cruise and landing figures from EUROCONTROL; Concorde figures from Heritage Concorde's published performance data, drawn from the aircraft's flight manual. "Not listed" marks a figure absent from those sources rather than one that does not exist. VMO and MMO are transport-category limits, which is why the Cessna 172 has none; a light aircraft is governed by a never-exceed speed instead.

Two of these entries disagree with other published sources, and the disagreement is worth stating rather than smoothing over. EASA's data sheet gives the A320 a maximum operating altitude of 39,100 feet as standard, 39,800 feet with modification 30748 embodied and 41,000 feet with modification 162744; EUROCONTROL lists a flat FL390. Both are defensible, and neither supports a single sentence beginning "the A320's ceiling is". On Concorde, Heritage Concorde converts 1,176 knots to 2,179 km/h and 1,345 mph, but that same knot figure works out to about 1,353 mph — a rounding that survives in secondary coverage as a hard number.

A maximum operating altitude is also not a service ceiling. FAA-H-8083-25C defines the service ceiling as the altitude at which an aircraft can no longer climb faster than 100 feet per minute; the altitudes above are certificate limits, which is a different thing measured a different way.

One comparison the numbers above will not support is a fighter's maximum Mach against an airliner's cruise. Mission, altitude band, propulsion, structural margin and the regulations each type is certificated under all differ. A transport-category limit under 14 CFR Part 25 and a military design point are not values on the same scale.

7. Read a flight tracker against what the flight deck sees

A flight tracker's speed display is derived from ADS-B position reports broadcast by the aircraft itself. It shows ground speed. The flight deck manages indicated or calibrated airspeed at low altitude and Mach number at high altitude, and neither of those is what the tracker is showing. A passenger comparing a 529 mph published cruise figure with a 690 mph tracker readout is comparing true airspeed with ground speed and finding, correctly, that they do not match.

February 2024 made the gap unmissable. A weather balloon released by the National Weather Service office serving Baltimore and Washington on the evening of 17 February measured winds peaking near 265 mph — about 230 knots — around 35,000 feet, the second-highest reading in that region since records began in 1948, behind 267 mph on 6 December 2002. A United Boeing 787 from Newark to Lisbon logged a peak ground speed of 838 mph on FlightAware and landed 20 minutes early. A Virgin Atlantic 787 from Washington Dulles to London peaked at 802 mph and arrived 45 minutes early.

Neither aircraft went supersonic. Subtracting a tailwind component of that order from 838 mph leaves an air speed in the high 500s in mph — normal for a 787, whose certificated maximum is Mach 0.90 under FAA data sheet T00021SE. The air was moving; the aeroplane was not moving through it any faster than usual.

One certificate limit is expressly a ground speed, which shows the distinction matters to engineers as much as to passengers. EASA's A320 data sheet sets a tyre limit speed of 195.5 knots — 225 mph — and specifies it in ground speed, because it is the runway the tyre has to survive.

8. Verify a speed claim for one specific model

The sequence below turns a disputed figure into a checkable one.

1. Name the exact type and variant. A 737-800 and a 737-8 are different certificates with different limits.
2. Read the maximum operating speed and maximum operating altitude from the type certificate data sheet, published by the FAA or EASA for that variant.
3. Fix an altitude and a temperature, then convert Mach to true airspeed using the speed of sound at that temperature — 576 knots at 35,000 feet in standard conditions.
4. If the figure came from a flight tracker, subtract the wind component along the aircraft's track before treating it as an aircraft performance number.
5. Discard any figure that does not state whether it is indicated, calibrated, true or ground speed. It cannot be verified.

That last step disqualifies most of what circulates. The FAA's data sheet for the 737 series, EASA's for the A320 family and Boeing's airport planning document each attach a speed type, a weight or an altitude to every number they print. The round mph figures that dominate search results attach none of the three.

Frequently asked questions

Can planes go 500 mph?

Yes, in true airspeed at cruising altitude. EUROCONTROL's Aircraft Performance Database gives the Boeing 737-800 an indicative 460 knots true airspeed, roughly 529 mph, and the Airbus A320 450 knots, about 518 mph. Measured over the ground, wind pushes the figure well above or below that.

Can any plane fly 1,000 mph?

Yes. Concorde's maximum cruise was Mach 2.04 or 530 knots calibrated airspeed, whichever was lower, at 51,000 feet — equal to 1,176 knots true airspeed, about 2,179 km/h or roughly 1,350 mph. No aircraft in scheduled airline service has flown supersonically since Concorde was withdrawn in October 2003.

How slow can a plane go and still fly?

Down to its stall speed, which rises with weight. FAA-H-8083-25C works an example of a 550,000-pound jet transport stalling near 152 knots calibrated airspeed in clean configuration, at sea level and at FL380 alike. EUROCONTROL lists a Cessna 172 landing reference speed of 65 knots, about 75 mph.

Can an airplane go 2,000 miles an hour?

One has. The Fédération Aéronautique Internationale still recognises 3,529.56 km/h — 2,193.167 mph — set on 28 July 1976 by Captain Eldon W. Joersz and Major George T. Morgan Jr. in a Lockheed SR-71A. No aeroplane taking off under its own power has bettered it in fifty years.

How fast do passenger planes go in km/h?

EUROCONTROL's indicative cruise figures convert to about 852 km/h for the Boeing 737-800 and 833 km/h for the Airbus A320, both in true airspeed. A Bombardier Dash 8 Q400 turboprop cruises near 667 km/h. Ground speed shown on a tracker will differ from all three, depending on the wind.

How fast does a plane go at takeoff?

It depends on the departure. Section 25.107 of 14 CFR ties the takeoff safety speed V2 to a multiple of the stall reference speed — 1.13 VSR for most twin-engine jets — so weight, flap setting, temperature, elevation and wind all move it. EUROCONTROL's indicative V2 for a 737-800 is 145 knots.

How fast do planes go when landing?

Section 25.125 requires the reference landing speed VREF to be at least 1.23 times VSR0, the stall reference speed in landing configuration. EUROCONTROL lists indicative landing speeds of 147 knots for the Boeing 737-800, 137 knots for the Airbus A320 and 121 knots for a Dash 8 Q400 turboprop.