When only Space is higher: How high do planes fly?16th Jan 2023
The history of aviation dates back to 1900. It was then that the Wright brothers built their first glider, and three years later, they took the first Flyer 1 into the sky. It was built from wood and had a top speed of only 43 km/h. Since then, the “iron birds” have evolved greatly and are now widely used for civil, commercial, and military purposes. In this article, we will list specific examples of how high planes can fly, what their altitude depends on, and take a quick look into the future of aviation.
What determines how high planes fly
Every aircraft has a height it can reach, but it cannot fly there for a long time. This is the so-called limit. There may be several reasons that determine this limit, but the main one is restrictions on engine operation time at their maximum capacity.
As a rule, airplanes operate at the flight levels at which the best range or flight duration mode is achieved. Flight Level is set at standard atmospheric pressure hundreds of feet above sea level and is determined by the technical capabilities and safety requirements of the aircraft.
From a technical point of view, flight altitude depends on the balance of engine thrust, drag, weight and lift of the aircraft. As the aircraft rises to an altitude, its thrust reserve, drag and lift decrease. Engines in a rarefied atmosphere do not produce full power, and less dense air does not provide enough lift. But let’s take a better, point-by-point look at the factors determining how high planes fly.
In aviation, fuel efficiency is achieved by choosing the optimal altitude (and speed) of flight. This is the altitude at which the engines are most efficient; that is, they produce the required power to maintain the specified flight parameters with minimal fuel consumption. Logically, the higher the aircraft rises, the less air resistance it needs to overcome, making it easier to fly. But in practice, it’s not so.
An airplane needs lift, which doesn’t increase when the air density is too low. The engine works better with cold air, but it needs a lot of it to keep the kerosene burning. At high altitudes, air may not be enough. The correct ratio of all parameters is important, which is why pilots choose to cruise.
The sky today is extremely busy, so to eliminate the possibility of aircraft collision, they are “separated” in height. Planes moving east occupy odd echelons, and those flying in the opposite direction occupy even echelons. But what does this have to do with the question, how high do planes fly in miles? Some echelons may be fully occupied, so your airliner pilot may simply not be allowed to set out for some time.
Modern aircraft can fly in tough weather conditions, but there are limitations. Facing the so-called dangerous weather phenomena in the sky does not bode well. That is why pilots try to bypass thunderclouds and navigate heights where there is less turbulence, no icing or strong oncoming jet streams.
As a rule, all this “unpleasantness” does not go beyond the troposphere, so you can fly quite safely and comfortably at an altitude of 36,000 feet or just under 7 miles. As long as the traction reserve allows, of course. If not, then a lower free echelon is selected.
Pilots love altitude reserve because it gives them time to correct mistakes and make decisions in emergency situations. If the engines fail, the aircraft can keep gliding to cover a large distance and make an emergency landing at the nearest airport.
On the other hand, should a cabin fire or rapid depressurisation occur, pilots would have to descend very quickly to reach an altitude where a person can breathe without oxygen masks (below 10,000 feet). How high do planes fly in metres in such cases? At 3,000 metres. So, when developing routes, airlines take these factors into account.
Solar radiation increases with altitude. However, Japanese scientists claim that high doses of radiation can only be obtained during a period of very strong solar activity, and solar storms of such strength occur once every 17 years. But radiation is only one of the factors that can threaten the lives of passengers and aircrew.
At high altitudes, liners experience severe overloads, so they must have reduced windows to maintain the strength of the fuselage and reduce air loss should a hull break occur. The aircraft must also have a redundant cabin air supply system and a rapid descent procedure. Unfortunately, such systems are complicated and expensive, which makes them unfeasible.
Now that we’ve got some basic details covered, let’s see how high different types of planes fly.
How High Do Commercial Planes Fly
According to ICAO, commercial passenger and cargo aircraft flights are allowed at flight levels from 10 to 510, although not all of them can climb that high. For most aircraft today, the cruising flight level is between 330 and 360.
So how high do passenger planes fly in km? Usually, up to 12km. Theoretically, they can fly higher, but pilots try not to take advantage of such opportunities. Although, when it comes to business, there are exceptions.
Almost all such aircraft are distinguished by high flight performance and excellent equipment. For them, cruising at an altitude of 12-13km is not a problem at all. This is your answer to how high commercial planes fly in km. They quickly gain altitude thanks to powerful jet engines with a relatively small flight weight.
More expensive tech like the Gulfstream G650, Falcon 5X, and some others can reach 15,500m. The ability to fly higher than scheduled airlines allows pilots to choose more direct (fuel-efficient and shorter) routes.
Can commercial planes fly at 50,000 feet?
In the upper layers of the troposphere, the air is so rarefied that not every airliner can ensure a stable flight. It just doesn’t have enough lift to balance the mass.
Pilots have to increase the engine power to increase aircraft speed and lift. This leads to excessive fuel consumption and an increase in the cost of tickets for passengers, which in most cases is unviable, which is why passenger aircraft fly at levels no higher than 40,000 feet. The only liner that climbed above 50,000 feet was the Concorde.
This supersonic aircraft, which started regular commercial flights back in 1976, was certified (cleared) to fly at flight level 600. How high do Concorde planes fly in metres? 18,300!
Up until now, no other passenger liner has flown so high. However, despite its advantage in flight altitude, the Concorde turned out to have more important disadvantages. These are high fuel consumption and ticket prices already mentioned above, low comfort, short flight range (6-7 thousand km) and rapid wear of aluminium skin due to heating. The planes turned out to be economically unprofitable and dangerous, so in 2003 they were decommissioned.
Sadly, you will not be able to enjoy seeing the highest mountain in the world from a plane window. The thing is, these are vast mountainous regions with very high elevations. Airplanes have to fly at high altitudes, but should a depressurization take place, they will not be able to descend to a height where passengers can breathe the surrounding air.
For flights over mountain ranges to be safe, aircraft will have to carry an additional supply of oxygen on board. This would require changes in aircraft designs. In addition, there are few means of navigation and radar control, as well as airports suitable for emergency landing of large aircraft.
There are always strong winds and turbulence over the mountains, and the limited altitude manoeuvre poses a danger. The aircraft can hit mountains if it descends or fall into a tailspin if it climbs too high. To eliminate these risks, the Chinese authorities simply do not allow flights in these regions.
How High Do Small Planes Fly
They cannot fly as high as passenger liners. Their weak piston engines operate erratically in a rarefied atmosphere (above 15,000 feet).
As a rule, they are not even furnished with oxygen equipment, so they rarely climb above 10,000 feet. In addition, they usually fly short distances off-routes, which does not require high altitude climbs to save time and fuel.
How high do skydiving planes fly?
Skydiving usually requires a small but reliable aircraft like the Cessna 182, which typically climbs to no more than 12,000 feet. This is quite enough to enjoy free fall for a minute and have the time to open a reserve parachute if necessary. However, sports jumps can also be performed from high altitudes (up to 18,000 feet), but only when using oxygen equipment.
The military is focused on solving specific problems, so they fly on routes that usually pass much higher than passenger airlines. The answer to how high military planes fly in feet will depend on the aircraft’s purpose and its power plant type. A combat vehicle with a turbojet engine can gain 90,000 feet; for a ramjet, the limit will be around 150,000. Most modern fighters, such as the F22, F35 or Eurofighter, can fly at altitudes around 65,000 feet.
Only aircraft with rocket engines, or so-called rocket planes, can fly higher than military aircraft. For example, in 1963, the experimental North American X-15 reached an altitude of 107,700m. And 41 years later, this record was broken by Virgin SpaceShipOne, which climbed 112,000m. However, we should clarify that both rocket planes were part of the air-launch system. Both had carrier aircraft that took them to an altitude of 50,000 feet. At this altitude, the ship was undocked to continue flying into suborbital space, after which it made a manned landing.
In 2021, Virgin used a modified SpaceShipTwo for the world’s first suborbital tourist flight at an altitude of 80km. This was enough for passengers to experience weightlessness and enjoy the space views through the panoramic windows. This flight actually marked the beginning of the space tourism era.
In addition, Virgin Orbit successfully uses its air launch system to send payloads to LEO. However, unlike classical vertical launch vehicles, the payload capacity of such a rocket is limited by the carrying capacity of the parent aircraft.
Now you know how high planes fly and what determines their flight attitude. Only space is above now, and the era of space suborbital flights has already begun. This means that, soon enough, we will fly from London to Sydney 10 times faster, and in the porthole window, we will see the bewitching beauty of the Universe instead of the habitual clouds. However, conventional aircraft will not lose their relevance for a long time, as they remain one of the fastest modes of transport.