The Boeing 747 is the most popular wide-body aircraft in the world. It was originally designed for commercial use, but it’s been used by militaries as well.
The main reason this airplane has lasted so long in such high demand is because of its size and capacity to carry people and cargo over great distances.
The original design of the Boeing 747 requires a minimum runway length of 7500 feet or 2200 meters. But this depends on a number of factors, including the aircraft weight, airport elevation, temperature, wind speed, and much more.
We’ll go through each one of these factors in this article. Then stay tuned for some more frequently asked questions about runways and runway length.
Aircraft Weight
Generally speaking, the heavier the aircraft, the longer the runway needs to be. It takes more time for heavier aircraft to come to a complete stop, so they need a longer runway.
Four factors make up most of an airplane’s weight: the plane itself, the passengers, the amount of fuel, and the baggage.
The Boeing 747 is one of the largest and heaviest commercial airplanes, which is why it requires so many feet of runway.
Each airplane has a maximum takeoff weight, or MTOW. The plane must weigh less than or equal to the MTOW to takeoff.
Learn more about airplane weight at this link.
Aircraft Type
Which aircraft land on the runway?
If multiple planes are landing on the same runway, it will have to accommodate the largest plane.
There’s no downside to smaller planes landing on longer runways. Long runways just give the plane more time to come to a complete stop. They can be especially helpful in wet or icy weather conditions.
How fast can the aircraft reach the speed necessary for takeoff?
Most planes take between 30 and 35 seconds to take off. But, again, weather and altitude need to be taken into consideration before take off.
Due to weather conditions, altitude, the type of aircraft, and other factors, a unique takeoff speed is calculated before every takeoff.
Flight instruments on today’s planes show pilots everything from the optimal range to the dangerous range of airspeed. The air traffic control crew further informs pilots, by making calculations and communicating the exact speed to the pilot.
As conditions change during flight, air traffic control can assign different speeds to the pilot to maintain fuel efficiency and safety standards.
How fast does the aircraft need to be to generate enough lift for takeoff?
A large airliner like a Boeing 747 requires about 180 miles per hour for takeoff, while most commercial aircraft require 150 miles per hour.
How much thrust does the aircraft need to take off?
Most aircraft do not need to use their maximum thrust to generate enough lift for takeoff. Even large aircraft like the Boeing 747 don’t need to use all their thrust to takeoff.
Instead they’ll use about 75% of their thrust (more or less depending on the temperature, altitude, and runway length, among other factors). This is fuel efficient and, over time, keeps the engine in good condition for longer.
On a shorter runway, a plane could use more of its thrust to get into the air sooner, if needed.
Airport Elevation
The higher the airport elevation, the longer the runway needs to be. The lower the airport elevation, the shorter the runway needs to be. This is because the air is much thinner at higher elevations.
Therefore, planes don’t encounter as much resistance as usual when landing. Similarly, when taking off, they need more time to get enough air under the wings. It takes longer to generate the necessary lift for takeoff.
Temperature and Humidity
In hotter temperatures, the air is less dense. Humid air is also less dense, which means that the runway length must be longer for the aircraft to take off.
Conversely, air is denser in colder, dry temperatures.
When dense air travels under the wings of a plane, it provides more lift than thinner air. So the runway length does not need to be as long to take off successfully.
Inclement Weather
Ice
In cold climates, there may be ice build-up on an airport’s runways. Ground crews typically take care of the ice and snow as best they can before the airplane arrives.
Mechanical sweepers, blowers, and snowplows are commonly used. Deicing compounds containing glycol and water are also popular, such as ethylene glycol and propylene glycol.
Salt-based compounds or anything with chlorine is not often used, because they can accelerate the corrosion of metals.
As a safety measure, in icy conditions, runways need to be 3-4 times longer than normal to land safely.
Note: Ice on a plane’s wings will increase its weight and drag, making it more difficult to land.
Slush or Standing Water
For runways with slush or standing water, you’ll need about twice the distance to take off and land safely.
Snow
Snowy runways need about 1.5 times as long for takeoff and landing.
Rain
Finally, wet runways need to be about 1.3 times longer than normal.
Wind Speed – Headwind, Crosswind, and Tailwind
When taking off and landing, planes may encounter headwind, tailwind, or crosswind.
Headwind
Headwind blows toward the front of the aircraft.
You might think that headwind slows down aircraft, just as headwind would slow down a runner or biker. However, planes work a little differently.
The air travels under the wings and actually helps generate more lift.
So, under ideal conditions, planes take off into the wind. This reduces the runway length necessary for a safe takeoff.
Tailwind and Crosswind
Tailwind blows in the direction of the aircraft, while crosswind moves in multiple directions.
If a plane has a tailwind or crosswind, this reduces the amount of lift generated during takeoff. So planes will need more runway. How much runway do they need? Well, this depends on the aircraft. Each aircraft has specific limits for crosswinds and tailwinds.
If the crosswind or tailwind is too strong, the plane cannot take off or land. Typically, a crosswind of around 40 miles per hour and a tailwind of 10 miles per hour are the upper limits for a safe takeoff and landing.
Runway Slope Angle
A runway’s slope angle is the upward or downward angle of a runway. More specifically, the slope angle is the total change in height of the runway over the total length of the runway.
Planes on runways with a downward slope (negative) will take off more quickly. On the other hand, planes taking off of runways with an upward slope (positive) will take more time to take off.
When landing, the reverse is true: planes landing on a runway with an upward slope will land more quickly. The uphill climb will slow the plane down gradually as it lands. But on a downward slope, the plane will take longer to land.
Runway Material
Concrete or Asphalt
The best material for runways is concrete. It is hard and smooth, and doesn’t have a lot of give. This helps the tires roll with little to no resistance. It’s also the most durable option for a runway. Concrete is what you’ll see in the busiest airports that might see dozens or even hundreds of flights per day.
Asphalt is also popular, although it’s a little less durable.
Gravel or Grass
At smaller airports, you might see gravel or grass on runways. But, the tires can sink into the surface on grassy runways, slowing takeoff speed. Or they can get torn up by the gravel which isn’t good for the plane’s longevity.
Because of the weight of larger commercial planes, grass or gravel simply wouldn’t do. But it works fine for smaller planes.
Grooved Runways
Some runways have grooves, by design. Grooved runways are ideal in icy or wet weather where there’s little to no friction on the runway surface. Also, the water sinks into the grooves, too. This makes it easier for pilots to take off since they don’t have to deal with any standing water on the runway.
A Note on Runway Durability
Over time, a runway experiences wear and tear and may accumulate some holes or divots. These can keep the tires from gliding smoothly and interfere with takeoff.
The tires also can get pretty beat up, as the rubber sheds off onto the runway surface. Ideally, this is cleaned off before takeoff and landing but not all airport runways are maintained as best as possible.
If the tires are not cleared from the runway, they can sink into the grooves, allowing standing water to accumulate. This may prevent planes from having a smooth takeoff.
Minimum Runway Length for a Private Jet
Some private jets require as little as 2800 feet of runway. They have compact designs, which make them more versatile than other long-range jets. Comparably, commercial aircraft require significant runway space to take off or land, typically a minimum of 4,500 feet and a max of up to 13,000 feet or more. The harsher the weather and thinner the air, the longer the runway needs to be for a safe take off and landing.
Private jets can land pretty much anywhere, even on unimproved grass, gravel runways, deserts, or mountainsides. This is possible thanks to additional undercarriage and landing gear protection.
How long is the average airport runway in miles?
For large commercial airplanes, runways are usually between 7,000 and 12,000 feet long. The minimum runway size for aircraft under 200,000 pounds is 6,000 feet or about 1,800 meters. Airplanes over that weight will need approximately 8,000 feet (about 2000 meters) of runway if they take off near sea level. The higher the altitude, the longer the runway needs to be.
Frequently Asked Questions
Which airport has the longest runway?
The Qamdo Bamda Airport has the longest runway, which is 5,500 meters or 18,045 feet. It’s located in China, specifically in the Tibetan Autonomous Region in the village of Bamda.
The air is so thin at incredibly high altitude that the runway needs to be over three miles long. The airport is the second highest altitude airport in the world (4,334 meters) , behind Daocheng Yading Airport (4,411 meters)
What aircraft requires the longest runway?
The commercial aircraft that requires the longest runway is the Airbus 380. It requires a runway of about 9000 feet. This makes sense, since the Airbus 380 is one of the heaviest active commercial aircraft, at 1,265,000 pounds.
What plane needs the shortest runway?
The jet aircraft with the shortest runway is the Airbus A220-100, which only requires a runway of 4,800 feet (1,463 meters). Some smaller airplanes require only about 1,000 meters of runway or less to take off.
What is the best paving material for runways?
Concrete is the best material for runways thanks to its incredible durability, but it’s quite expensive. Asphalt is a great alternative since it’s much cheaper and relatively durable.
Thanks for checking out our guide on the minimum runway length for the Boeing 747. We hope you learned valuable information about what determines runway length and why runway length is important.
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