Ever looked up and wondered how fast that airplane is actually moving? Airplanes might seem to glide slowly across the sky, but in reality, they are traveling much faster than you might think. Especially jet planes can cruise at speeds approaching the sound barrier!
Because of their high altitude, it’s difficult to truly grasp their speed. In this article, we will delve into the speeds of various types of aircraft and give you a glimpse into the future of flight.
Key Speed Insights
- Airspeed is the standard measurement for aircraft speed, not ground speed.
- The Mach scale is crucial for understanding speeds near the speed of sound.
- Commercial airliners fly close to Mach 1 but are typically subsonic for efficiency and to prevent structural stress, unless specifically designed for supersonic flight.
- Military jets utilize supersonic speeds for tactical advantages.
- General Aviation aircraft operate at lower, subsonic speeds.
- Supersonic passenger flight may be making a comeback, and hypersonic flight is on the horizon.
Airliner Speed Demystified
For commercial airliners, speed is a careful balance between flight duration and fuel consumption. Flying faster saves time but drastically increases fuel burn. Aircraft manufacturers determine the optimal cruising speed based on the intended flight routes and economic considerations.
The Airbus A320 family and the Boeing 737 family are the workhorses of short to medium-haul routes. These narrow-body jets typically cruise at around Mach 0.78, which is approximately 587 mph (945 km/h).
Larger, wide-body airliners like the Boeing 787 Dreamliner and the Airbus A380 are designed for long-haul flights. They are optimized for higher cruise speeds to minimize travel time on these longer routes. These aircraft typically cruise at Mach 0.85, or about 669 mph (1076 km/h). The faster cruise speed on long-haul flights translates to significant time savings compared to shorter routes.
Boeing 787 and Airbus A380 on the apron, showcasing wide-body commercial aircraft.
Private jets often prioritize speed even further. Operators are willing to accept higher fuel consumption for the benefit of saving valuable time for their passengers. Modern private jets also frequently fly at higher altitudes than commercial airliners, ranging from 45,000 to 51,000 feet. The thinner air at these altitudes reduces drag, allowing aircraft like Gulfstream GV series and Bombardier Global Express jets to achieve cruise speeds of Mach 0.90, around 715 mph (1150 km/h).
The Concorde remains the most iconic example of high-speed commercial flight. Introduced in 1976, this supersonic airliner was specifically engineered for speed. It cruised at an astonishing Mach 2.04 (1,559 mph or 2,509 km/h), cutting transatlantic journeys to under three hours – half the time of conventional jets.
The Concorde supersonic airliner in flight, highlighting its delta wing design.
However, the Concorde’s incredible speed came at a cost. High fuel consumption and maintenance expenses contributed to its eventual retirement in 2003, demonstrating the economic challenges of supersonic commercial flight.
Military Jet Speeds: Speed as a Tactical Advantage
Military jets exhibit a wide range of speeds, dictated by their specific roles and mission requirements.
Military transport, tanker, and cargo aircraft share similar operational profiles with commercial airliners. Consequently, their speeds are comparable.
For instance, cargo aircraft like the Boeing C-17 Globemaster and the Lockheed C-5 Galaxy typically cruise around Mach 0.77 (520 mph or 837 km/h). Interestingly, these are slightly slower than commercial jets, as their design emphasizes payload capacity and the ability to operate from shorter airfields over sheer speed.
Fighter jets represent the pinnacle of military aircraft speed. In aerial combat, speed provides crucial tactical and strategic advantages. Therefore, modern fighter jets are designed for supersonic flight capabilities.
Multi-role fighters such as the F-35 Lightning II and F/A-18E/F Super Hornet can reach speeds of Mach 1.6 (1,190 mph or 1,915 km/h). Interceptor aircraft, like the F-16 Fighting Falcon, prioritize speed above other considerations like stealth or aircraft carrier compatibility, achieving speeds up to Mach 2 (1,353 mph or 2,177 km/h).
F-35 and F-16 fighter jets in flight formation, showcasing modern military aircraft.
It’s worth noting that fighter jets often attain their maximum speeds using afterburners, which are fuel-intensive. In standard cruise flight, they typically fly at subsonic speeds, around Mach 0.9 (621 mph or 1,000 km/h).
Some advanced military jets possess “supercruise” capability. This allows them to sustain supersonic flight for extended periods without engaging afterburners, enhancing fuel efficiency and stealth. Examples include the F-22 Raptor, which supercruises at Mach 1.82 (1,220 mph or 1,963 km/h), and the Eurofighter Typhoon at Mach 1.5 (1,035 mph or 1,666 km/h). With afterburners, the F-22 can reach a maximum speed of Mach 2.25 (1,500 mph or 2,414 km/h).
The Lockheed SR-71 Blackbird holds the record as the fastest jet aircraft ever built. This high-altitude, long-range reconnaissance aircraft operated during the Cold War. The Blackbird could reach an incredible Mach 3.32 (2,193 mph or 3,529 km/h), outrunning any contemporary interceptor aircraft or surface-to-air missiles. Its unmatched speed allowed it to operate unchallenged for over 24 years, until satellite reconnaissance technology led to its retirement in the 1990s.
Small Airplane Speeds: Slower and Closer to the Ground
At the lower end of the speed spectrum are small general aviation aircraft. These airplanes typically fly at speeds below 300 knots (Mach 0.45) and at altitudes under 25,000 feet. At these lower speeds, the Mach scale is less relevant, and pilots primarily use indicated airspeed (IAS).
General Aviation airplanes encompass four-seater aircraft like the Cessna 172 Skyhawk, Piper Cherokee, and Diamond DA40. These commonly cruise around 125 knots (143 mph or 230 km/h) with maximum speeds around 160 knots (184 mph or 296 km/h). Newer single-engine aircraft, such as the Cirrus SR22 and Columbia 350, can achieve higher speeds, reaching up to 200 knots (230 mph or 370 km/h).
Diamond DA40 general aviation aircraft on the tarmac, illustrating a typical light airplane.
The slower speeds of these aircraft compared to jets are primarily due to their use of piston engines, which produce significantly less power than jet engines. Piston engines also become less efficient in the thinner air at higher altitudes.
To improve performance at higher altitudes (above 15,000 feet), manufacturers often equip aircraft with turbochargers. These devices compress the incoming air, boosting engine power and performance. Turbocharged variants of general aviation aircraft offer noticeable improvements in both top speed and cruise altitude.
For example, the Mooney M20 Bravo Turbo can fly approximately 35 knots (41 mph or 66 km/h) faster than its non-turbocharged counterpart and can cruise at altitudes up to 25,000 feet compared to the standard model’s 18,500 feet.
However, the focus in modern general aviation aircraft development has shifted towards enhancing comfort, safety features, and fuel efficiency rather than dramatically increasing speed. Speed is not typically the primary design priority in this segment.
The Future of Airplane Speed: Supersonic and Hypersonic Horizons
Given the challenges associated with transonic flight (speeds near Mach 1), it’s unlikely that conventional airliners will significantly exceed current speeds. Achieving substantial reductions in travel time will require the introduction of entirely new aircraft designs.
Excitingly, supersonic passenger aircraft development is experiencing a resurgence, with potential first flights as early as 2024. NASA and Lockheed Martin’s X-59 Quiet SuperSonic Technology (QueSST) demonstrator and Boom Supersonic’s Overture airliner are leading contenders in the revival of supersonic commercial flight.
Why did supersonic passenger flight fade away after the Concorde?
The decline of supersonic aircraft development after the Concorde’s retirement was due to more than just high operating costs. A major obstacle was the intense sonic boom generated by supersonic flight.
When an aircraft exceeds the speed of sound, it creates shockwaves that coalesce into a loud, thunderclap-like sonic boom. This noise pollution generated significant public opposition in areas overflown by the Concorde, particularly over land.
In response, aviation authorities like the FAA imposed bans on civil supersonic flight over land. These restrictions severely limited viable routes for the Concorde and discouraged further supersonic aircraft development.
The NASA X-59 QueSST program aims to overcome the sonic boom problem. The X-59’s unique elongated shape is designed to minimize the sonic boom, reducing it to a much quieter “sonic thump” during supersonic cruise at Mach 1.4 (937 mph or 1,508 km/h).
With its first flight anticipated in 2024, NASA hopes that this technology will persuade regulators to reconsider the ban on overland supersonic flight.
Boom Supersonic’s Overture is an 80-passenger airliner designed to cruise at Mach 1.7 (1,100 mph or 1,770 km/h). The aircraft is currently in active development and is projected to enter service by 2026. Despite past failed attempts at Concorde successors like the Aerion AS2 and Boeing Sonic Cruiser, the Boom Overture appears promising, with firm orders from major airlines like United and American Airlines, totaling 130 aircraft, suggesting a positive outlook for its future.
Beyond supersonic, hypersonic flight – speeds exceeding five times the speed of sound – represents the next frontier.
The North American X-15 holds the record for the fastest speed achieved by a crewed, powered aircraft, reaching Mach 6.7 (4,520 mph or 7,274 km/h) in 1967. Much of hypersonic research since then has focused on missile and rocket technology.
However, in June 2023, Boeing unveiled a concept for a hypersonic passenger aircraft that could potentially cross the Atlantic in a mere two hours. This futuristic design would utilize a combination of jet engines and ramjet engines to achieve blistering cruise speeds of Mach 5. While still in the conceptual stage, hypersonic passenger flight could become a reality within the next 20 to 30 years, promising to revolutionize long-distance travel.
Conclusion
Intrigued by the different speed measurements mentioned? Explore our comprehensive guide to the six types of airspeed for a deeper dive into aircraft speed terminology.
