Even at low speed, flying balloons over Bagan is a task that requires skill from pilots. From takeoff to landing, understand step by step how these vehicles fly.
Filling with air
At the takeoff location, the balloon is inflated with ambient air by a large gasoline-powered fan. When the air has already occupied about 60% of the envelope’s volume – the name given to the balloon’s fabric bag – the torch is lit.
Warm up and take off
The torch heats the air in the envelope, which expands and becomes less dense than the air outside the balloon. Takeoff occurs when this air exceeds the outside temperature by about 60ºC. It is as if the hot air balloon (less dense) floats in the cold air (denser), just as a ship floats on water.
The direction and horizontal speed are determined by the wind currents. The balloon is slow, like a ferris wheel ride. Above 18 km / h, only experienced pilots should fly, and without passengers. You must not fly faster than 30 km / h. The pilot controls the height and is guided by map, compass, altimeter, variometer (measures the speed of climb) and thermometer.
The balloon and basic equipment weigh 670 kilos. The set is 30 meters high and the envelope, capacity of 5,000 cubic meters (5 million liters), the volume of two Olympic swimming pools.
Crew and equipment
A large balloon can carry 1 ton and carries an average of 8 passengers, a pilot and a navigator. Below the envelope is a two-burner torch, propane cylinders (each kilogram of gas allows 1 to 2 minutes of flight) and the guidance instruments. The basket is made of wicker, which is light, durable and absorbs the impact of landing. Steel cables support the structure.
The envelope is made of nylon-stop (material that holds tears) and waterproofed with an anti-fire resin. The part closest to the torch is made of nomex, the same fabric as the overalls of firefighters and pilots of F-1, which withstands 400 ° C.
Part of the team goes by land to collect equipment and passengers at the end of the trip. The teams communicate by radio and those in the air inform their location, if the ground personnel cannot follow the balloon route.
Never at noon
Flights are made in the early morning or late afternoon, when the winds are milder. It is dangerous to fly with the sun high because the ground is very hot, as well as the air immediately above it. This generates upward currents of hot air – they decrease the difference between the density of the internal and external air in the balloon, which loses fluctuation. It is similar to what happens with an airplane in turbulence.
A parachute-shaped lid can be opened to release hot air. Cold air enters the mouth of the balloon and increases the density of the indoor air – making the balloon go down. To ascend, the pilot turns on the torch (heating and decreasing the density of the indoor air).