In watching video footage of the recent collision between a hot-air balloon and some high-voltage power lines, I noticed that they appeared not to be firing the burner continuously in the moments prior to the collision. (Video here cued to 2:08; crash at 2:36) Were they deliberately attempting to fly at a dangerously low altitude, or is there some feature of the balloon and/or burner that prohibits long, continuous burns?
Also, how quickly can a balloon arrest its descent with that burner? Assuming “typical” balloon performance and “typical” passenger load, if they are descending at (for example) a half a foot per second, how long of a burn would it take to bring their descent rate to zero?
The only real control a pilot has with a hot air balloon is on the vertical axis, and there is a long lag time between a burn and a change in bouyancy, several seconds. This is the time for all the air in the envelope to heat. The pilot also has a second control, which is a long rope atached to a vent whereby he can dump the air.
You don’t burn continuously because the heat from doing so will damage the fabric near the flame. About ten second or so under normal conditions is the limit.
As far as your question about arresting descent, that depends on ambient air temp, weight in the basket, envelope size, and pilot skill. Since I never progressed beyond a student pilot, my skills were rather rudinmentary.
My wife was a professionally licensed hot-air balloonist, she got out of it about 8 years ago.
She could do long burns. I think maybe that guy ran out of fuel or was having problems with his burner. Descending in a area with that many obstructions doesn’t make any sense unless there were some other factors at play.
When you’re in the air, you are subject to the discretion of the winds and can only change direction by varying your altitude and catching different wind patterns if available. So, a lot of care has to be taken in looking at the current winds and deciding where to launch from, in order to ensure that your flight path carries you over terrain that offers ample space for landing.
Seems like that guy should have descended quickly, then collapsed the balloon, by pulling the top open, which my wife has done a couple of times when landing in tight spots.
Shortly before the collision, the passengers were talking to someone one the ground who was recording video of them; they (the passengers) were pointing to their house nearby, which is what made me think they were probably flying at such a low altitude on purpose. OTOH, I’m surprised that a balloon pilot would willingly do so.
Why were the passengers told to remain in the basket until the balloon deflated, against the wishes of the Firefighters? What’s wrong with the basket becoming airborne during the passengers scrambling egress?
I would imagine that they’re worried about people clinging to the outside of the basket as it becomes airborne, but I would imagine that your state relative to the basket is rather binary. Either you’re in it, or you’re not, and the transition between the two is about 1/2 of a second. Why risk people’s lives by keeping them in the basket after a harrowing ride rather than shedding all of the people you can to save them the risk of a repeated emergency landing?
If it’s neutrally-buoyant with 12 passengers on board, then when six get off, the balloon with the remaining six is going to shoot upward pretty damn fast. At that point, who knows if it’s going to get snagged on a tree, a powerline, or where will be their next safe opportunity to land (remember they had just made an emergency landing in turbulent weather into a cluttered residential area). If there’s no immediate threat to their lives (e.g. a fire), it’s safer to keep everyone in the basket until the pilot has released enough hot air from the envelope to assure that it will remain firmly grounded until the last person has exited the basket.
I know this is GQ but is it just me or did anyone else notice what ignorant, ah, idiots the people filming it were? They were all laughing & giggling like it was one big joke right up until the very second that the power lines exploded. What the hell did they think was gonna happen? Even without the power lines they were in danger of seriously crashing the whole time! The should have been calling 911 at the beginning of the video.
Tree topping is quite common, and one of the most popular altitudes at which to fly.
I’ve been flying since the infancy of the sport, when my father went to work for the world’s biggest hot air balloon manufacturer. We used to skim the tops of the lake, and perform 6-8 touch-and-go maneuvers in an hour flight. Flying low is nothing unusual.
Also, when it becomes clear that you are going hit power lines, the correct response is to open the vent and get the basket below the lines. Trying to go over them only gets you in hotter water.
When I took a hot air balloon ride the pilot was adamant that we were to absolutely stay inside the basket no matter what until he told us to get out. As noted, it’s because once you unload a couple people the balloon can shoot upward, with zero control on the part of the pilot, and quickly reach an altitude lethal for anyone else attempting to exit.
I wouldn’t say zero control. If the balloon shoots up, the pilot will lean on the vent to stop the ascent quickly. Otherwise, that’s pretty much right. The primary danger comes from the fact that people may be half out when the balloon goes back up, there may be trees and power lines in the way, etc.
How quickly does that vent decrease buoyancy though? I mean it already sounds like it’s not that fast, if he can’t dump lift fast enough to keep up with twelve passengers trying to make an orderly exit from the basket.
I’m not specifically talking about 12 people exiting at once. People usually exit one or two at a time. In general, though, the balloon reacts more quickly to venting than it does to the burner.
I just watched the video linked in the OP, and it just looked like an incredibly bad attempt at a landing in a tight spot. Why he didn’t dump all of his air when he was over that yard is a bit of a mystery to me. It was almost as if he couldn’t decide what to do, and his indecision caused the accident.
I just read a report from a Boston based tv news station. It named the pilot(who has 3000 hours balloon time). The article goes on to say the pilot missed his original landing, had to fly over a large lake, missed another landing at a school on the lake’s shore, then attempted a landing in the tiny area where the balloon caught the wires. The article also mentions that the pilot was “uninvited” to an upcoming balloon festival in Maine. I looked on Google Earth at the various terrain he had to fly over, and what was downwind. It seemed like he was running out of good places to land, maybe fuel was low as well.