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How Safe are Hot Air Balloons?

Hot air balloons at dawn on the west bank of the Nile in Egypt.Richard Bryant/Arcaid/Corbis

In the worst hot air balloon accident in at least 20 years, 19 tourists died in a hot air balloon explosion in Egypt on Tuesday.

While there are conflicting reports of how the accident happened, a look at safety regulations and past accidents provide a glimpse into the risks of the oldest form of human flight.

“A balloon is a very simple thing,” said Glen Moyer, editor of Ballooning Magazine, the Journal of The Balloon Federation of America. “You’ve got the protection of the wicker basket and a little rubber padding. It’s generally very safe, but when something bad happens there are not a lot of options.”

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The primary dangers, he said, are hitting power lines and hard landings.

The balloon's operating company said a gas cylinder exploded on board, according to the BBC. But it’s unclear what caused it to explode.

Some element of pilot error usually plays into an accident, such as not seeing a power line, Moyer said.

Fires are not common, but often lead to explosions because of the close access to propane. A fire would almost certainly be caused by a mechanical failure, Moyer said, such as a leak in a hose or a loose valve connection. Then any sort of spark, even from a nylon jacket, could cause a fire and explosion, he said. The only escape at that point is jumping to the ground, as the pilot and one passenger apparently did in the Egypt explosion.

"People were jumping out of the balloon from about the height of a seven-story building," Cherry Tohamy, an Egyptian living in Kuwait who was in a nearby balloon, told the BBC.

Balloon flights in the area have been suspended.

In the U.S., the Federal Aviation Administration regulates ballooning. According to the National Transportation Safety Board's aviation accident database, there have been 67 fatal incidents involving hot air balloons since 1964 in the U.S.

How Safe are Hot Air Balloons?

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The key to safety, Moyer said, is good judgment in knowing when to fly. One of the FAA’s rules and regulations requires pilots to check all available weather information before flying, including the FAA’s readings of conditions at different levels of the atmosphere. Pilots also have to be certified.

The F.A.A. also requires a yearly inspection of balloons; commercial balloons have to be inspected after every 100 hours of flight time.

“In over 30 years the worst I’ve ever done is bruise a knee,” Moyer said.

But part of the romance of ballooning is a certain lack of control. On board, a pilot usually has access to an altimeter, a barometer, and a pyrometer, Moyer said. Still, the only real control is adjusting the heat in the balloon to change altitude. Depending on the wind, there is a certain level of steering involved as well.

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“You’re able to steer the balloon left and right, but only to the extent it’s available in wind patterns,” he said.

Mornings are more conducive to flying because there is typically slightly more steering control  in calmer winds. Hard landings usually occur when a pilot gets caught in tricky wind conditions -- but while those accidents can cause broken arms or legs, they rarely result in fatalities.

Other recent accidents include an explosion in New Zealand that killed 11 people last year after hitting a power line on landing, and a crash in Australia that killed 13 when two balloons bumped into each other in 1989. At the same site in Egypt, 16 tourists were injured when their balloon struck a cellphone tower in 2009.

The area is popular for balloon rides, because tourists can get aerial views of the Nile River and ancient temples.

Aviation safety expert Todd Curtis, founder of airsafe.com, has never ridden in a hot air balloon, but says he would -- under certain conditions.

Think twice about riding in a balloon in a country with looser regulation than the FAA, he said. And if it’s windy or gusty, he said, don’t do it.

“It’s a judgement call,” he said. “There’s no radar, and you’re operating far away from an airport where there would be more professional eyes and ears from a tower. It’s just like flying any other aircraft: it’s up to the pilot to make the judgement about whether flying conditions are acceptable or unacceptable.”