The most common question asked of a Balloon Pilot is: How do you steer a hot air balloon and where are we going to land? The answer is not always as simple as giving a specific location. The best answer is, we have several landing sites we use where the land owner has graciously given us permission to land and access with our Crew for retrieval of the passengers and equipment.
The method we will use to steer is to choose a variety of altitudes over the flight duration to steer to a predetermined safe landing site. What makes a good landing site? From the Pilots perspective, a good landing site is a location with good access from the air using wind conditions to navigate safely into without jeopardizing passengers, crops or animals, large enough to fly into in variable wind conditions, with safe terrain features for passengers, crew and vehicle to move about and importantly a place where our landing is welcomed and does not interfere with landowners privacy or fear of risk.
Hot air balloons have no built-in mechanism for steering or propulsion. It uses the speed and direction in which the wind travels to move. However, that does not mean that pilots let the balloon amble anywhere. At different altitudes, the wind speed and direction are different.
Pilots place the balloon at different altitudes at certain times in the flight to change the direction of the flight path.
We aren't pushed around by this pressure because the forces on all sides of us balance one another out. For example, The chair doesn't feel substantially greater pressure from any particular angle. So, with no other forces at work, everything would be completely balanced in a mass of air, with equal pressure from all sides. But on Earth, there are other forces to consider, chiefly gravity.
While air particles are extremely small, they do have mass, and so they are pulled toward the Earth. At any particular level of the Earth's atmosphere, this pull is very slight -- the air particles seem to move in straight lines, without noticeably falling toward the ground.
So, pressure is fairly balanced on the small scale. Overall, however, gravity pulls particles down, which causes a gradual increase in pressure as you move toward the earth's surface. All air particles in the atmosphere are drawn by the downward force of gravity. But the pressure in the air creates an upward force working opposite gravity's pull. Air density builds to whatever level balances the force of gravity, because at this point gravity isn't strong enough to pull down a greater number of particles.
This pressure level is highest right at the surface of the Earth because the air at this level is supporting the weight of all the air above it -- more weight above means a greater downward gravitational force. As you move up through levels of the atmosphere, the air has less air mass above it, and so the balancing pressure decreases.
This is why pressure drops as you rise in altitude. This difference in air pressure causes an upward buoyant force in the air all around us. Essentially, the air pressure is greater below things than it is above things, so air pushes up more than it pushes down.
But this buoyant force is weak compared to the force of gravity -- it is only as strong as the weight of the air displaced by an object. Obviously, most any solid object is going to be heavier than the air it displaces, so buoyant force doesn't move it at all.
The buoyant force can only move things that are lighter than the air around them. For buoyancy to push something up in the air, the thing has to be lighter than an equal volume of the air around it. The most obvious thing that is lighter than air is nothing at all. A vacuum can have volume but does not have mass, and so, it would seem, a balloon with a vacuum inside should be lifted by the buoyancy of the air around it.
This doesn't work, however, because of the force of surrounding air pressure. Air pressure doesn't crush an inflated balloon, because the air inside the balloon pushes out with the same force as the outside air pushing in. A vacuum, on the other hand, doesn't have any outward pressure, since it has no particles bouncing against anything. Without equal pressure balancing it out, the outside air pressure will easily crush the balloon.
And any container strong enough to hold up to the air pressure at the earth's surface will be much too heavy to be lifted by the buoyant force. Another option would be to fill the balloon with air that is less dense than the surrounding air.
Because the air in the balloon has less mass per unit of volume than the air in the atmosphere, it would be lighter than the air it was displacing, so the buoyant force would lift the balloon up. But again, fewer air particles per volume means lower air pressure, so the surrounding air pressure would squeeze the balloon until the air density inside was equal to the air density outside.
All of this is assuming that the air in the balloon and the air outside the balloon exist under exactly the same conditions. If we change the conditions of the air inside the balloon, we can decrease density, while keeping air pressure the same. As we saw in the last section, the force of air pressure on an object depends on how often air particles collide with that object, as well as the force of each collision.
We saw that we can increase overall pressure in two ways:. So, to lower air density in a balloon without losing air pressure, you simply need to increase the speed of the air particles. You can do this very easily by heating the air. The air particles absorb the heat energy and become more excited. This makes them move faster, which means they collide with a surface more often, and with greater force. For this reason, hot air exerts greater air pressure per particle than cold air, so you don't need as many air particles to build to the same pressure level.
So a hot air balloon rises because it is filled with hot, less dense air and is surrounded by colder, more dense air. The basic idea behind hot air balloons has been around for a long time.
Archemedes, one of the greatest mathematicians in Ancient Greece, figured out the principle of buoyancy more than 2, years ago, and may have conceived of flying machines lifted by the force.
In the 13th century, the English scientist Roger Bacon and the German philosopher Albertus Magnus both proposed hypothetical flying machines based on the principle. But nothing really got off the ground until the summer of , when the Montgolfier brothers sent a sheep, a duck and a chicken on an eight-minute flight over France. The two brothers, Joseph and Etienne, worked for their family's prestigious paper company.
As a side project, they began experimenting with paper vessels elevated by heated air. Over the course of a couple years, they developed a hot air balloon very similar in design to the ones used today.
But instead of using propane, they powered their model by burning straw, manure and other material in an attached fire pit. The sheep, duck and chicken became the first balloon passengers on Sept. They all survived the trip, giving the King some assurance that human beings could breath the atmosphere at the higher elevation. Two months later, the Marquis Francois d'Arlandes, a major in the infantry, and Pilatre de Rozier, a physics professor, became the first human beings to fly.
Other hot air balloon designs and ambitious flights followed, but by , the hot air balloon had been largely overshadowed by gas balloons. One factor in this popularity decline was the death of Pilatre de Rozier in an attempted flight over the English Channel.
The new balloon he built for the flight included a smaller hydrogen balloon in addition to the hot air balloon envelope. The fire ignited the hydrogen early in the flight, and the entire balloon burst into flames. But the main reason hot air balloons fell out of fashion was that new gas balloon dirigible designs were superior in a number of ways -- chiefly, they had longer flight times and could be steered.
Another popular balloon type was the smoke balloon. These balloons were lifted by a fire on the ground, and did not have any attached heat source. They simply shot up in the air, and then sank back to the ground. Asked 3 years, 3 months ago. Active 3 years, 3 months ago. Viewed 6k times. Improve this question. Monty Wild Monty Wild 4 4 silver badges 7 7 bronze badges. I've been lurking here for years though. Most of the time online info is better Show 1 more comment.
Active Oldest Votes. Improve this answer. John K John K That is the physical reason for the changing wind directions, and as your answer stands, it just claims how they change without presenting proof. I thought that would be a nice addition. If so, perhaps you should specify whether you're answering for North or South half of the world?
Your profile has no location, so I can't even guess. Add a comment. This is a very limited way to steer left or right. Near ground level, the air in the Northern hemisphere of the Earth tends to move to the left near the ground, and to the right in the Southern hemisphere.
This means that when landing, the balloon could turn left, but uneven terrain can cancel this effect. Steering up and down is a straightforward process. The canopy of the hot air balloon is filled with hot air that lifts the balloon up.
Firing the burner heats more hot air and causes the balloon to rise further. As the hot air cools, the balloon will descend.
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