Man in Washington State struck by HPR. Ouch

[o1d_dude]

Having a boat air horn for the LCO to use is a good thing. Doesn't much matter if the PA system is weak or middle of the road in the volume department, the air horn WILL be heard.

Following our last club launch, I was tasked with obtaining a few air horns for the fall season. Thus far I've found the Walmart price of $15-16 for the horn and can of compressed air to be the best deal locally. Replacement cans of air run almost as much as the entire package...around $13-14.

A significant problem is when folks accompanying spouse or kids lose interest in the proceedings and sit in their vehicles with the windows rolled up, air conditioner on, motor running.

 

[CCotner]

A significant problem is when folks accompanying spouse or kids lose interest in the proceedings and sit in their vehicles with the windows rolled up, air conditioner on, motor running.

This is a problem at ROC also... like when the child was almost struck bu a falling nosecone that pierced the roof of a large SUV a few months ago; it came down over the center console in line with the front seats and went clean through into the console, while the child in question was sitting in the back seat...

It's frustrating, because there's clearly a general attitude that safety isn't important. I'm not immune to this, for instance; If I were, we wouldn't be flying a minimum diameter N at a family-friendly Black Rock launch...It's frustrating because there's no easy solution.

 

[EeebeeE]

When we start getting into rockets that require reinforced nose cones to handle the hypersonic speeds we have to realize that those same reinforced parts WILL go completely through a parked vehicle. 18 ga. sheet metal is no match for an aluminum-tipped nose cone coming in ballistic. For that matter, bunkers won't even help that much. We've all seen the core sample photos.

 

[CarVac]

When we start getting into rockets that require reinforced nose cones to handle the hypersonic speeds we have to realize that those same reinforced parts WILL go completely through a parked vehicle. 18 ga. sheet metal is no match for an aluminum-tipped nose cone coming in ballistic. For that matter, bunkers won't even help that much. We've all seen the core sample photos.

When things start out 100,000 feet up, whether it's reinforced for hypersonic speeds or not it's going to go through nearly anything. The material doesn't really matter, only the mass.

 

[DaveHein]

As I said in the other thread on a similar subject, the key is to reduce the chance of ballistic rockets hitting the flight line. This is accomplished by placing launch pads farther out than the NAR/TRI minimum distance, ensuring that the surface wind is parallel to the flight line, and angling rods/rails a few degrees away from the flight line.

Many people on the flight line/parking area are occupied with rocket and motor prep, or are just observers that may not be watching every single rocket launch. An air-horn or a heads-up announcement isn't really going to help people dodge a ballistic rocket coming straight at them. All they see is the front of the nosecone approaching them at 200 mph. It's virtually impossible for them to judge exactly where the rocket will hit. The key is to prevent rockets from crashing in that area.

 

[EeebeeE]

When things start out 100,000 feet up, whether it's reinforced for hypersonic speeds or not it's going to go through nearly anything. The material doesn't really matter, only the mass.

Beg to differ. Velocity and Acceleration have a lot to do with this as well.

Plus the shape of the nose cone and the hardness of the tip of it also come into play. The reason why a telephone book will stop a bullet is due in part because the lead bullet deforms and disintegrates as it penetrates the book. An arrow going at a slower speed, but with a razor sharp steel tip will keep its shape and go completely through the book. Due in part to the increased mass, but more importantly because it comes out the back of the book looking like it did when it went in.

 

[AHansom]

When things start out 100,000 feet up, whether it's reinforced for hypersonic speeds or not it's going to go through nearly anything. The material doesn't really matter, only the mass.

100.000 feet is a long way to fall but how much faster is a ballistic rocket from 100.000' going to be traveling compaired to one that had a flight to 4.000'?

 

[Pantherjon]

Terminal velocity is terminal velocity..Whether it is achieved from 4,000 feet or 100,000 feet..It is as fast as that object is going to go..Now, how quickly the object achieves terminal velocity is related to its mass and aerodynamics..

 

[luke strawwalker]

I deleted my original post because I did not want to start heated debate.

But this is not a one in a million occurrence. Within the last several months 2 other similar events have been posted here on TRF. There certainly have not been several million flights between these occurrences.

Perhaps in this case there was sufficient rail angle (~5 degrees) away from the flight line and there wasn't a strong wind coming from the flight line. But in general I have been to far too many launches where rockets are routinely flown over the flight line. There IS a safety attitude problem in this hobby. It is not pervasive but it is not rare either.

When a spectator gets carried off a field by ambulance and has surgery because a rocket hit him that is a BIG problem. And if the reaction is PHEW lucky he didn't die and it was freak accident, that is also a big problem. And if the analysis is there is nothing we could have done differently, then you really shouldn't conduct anymore launches. Sorry if I am being harsh, but sometimes you need to be harsh to shake up things a bit.

I've avoided posting in this thread because of the inevitable backlash I constantly receive for it, but I will simply say that I agree completely with what JD is saying here... and is EXACTLY the reason I'm glad there's no HPR activities within a couple hours drive of me...

Later! OL JR

 

[luke strawwalker]

I think that goes without saying. So let's not try anything?

Make an umbrella to carry when you're not under the awning... sorta like the coyote used in all those cartoons to deflect boulders...

Wait, maybe that's not the best example... LOL

Later! OL JR

 

[bobkrech]

The minimum high power launch field is 162 acres, or 7,068,583 square feet. The cross-section of the average rocketman is about 3 square feet. If it rained rockets, the probability of getting hit by a falling rocket is about 2,356,194 to 1. If the event has 250 participants and spectators randomly walking around, the chance of some getting hit by a falling rocket is 9425 to 1. If 100 rockets were rained in, the probability of some one getting hit is approximately 94 to 1. Certainly more probable than 1 in a million.

The good news is that with a proper range safety practice in place, rockets don't randomly fall from the sky. Good range safety practice establish ballistic impact zones by angling the launch rails and rods away from the spectator areas so the 2 areas do not overlap by a large margin. Under this condition, the probability of some one getting hit from a falling rocket is vanishingly small, unless some one is out in the ballistic recovery area recovering a rocket.

There are many mechanisms that defeat good range safety practices.

3. Failure of the sponsoring organization to analyze the field layout and and the wind and proactively prevent launches towards or over the spectator area by instructing the launch crew and the owners on range rules and enforcing them.

2. Failure of the launch management personnel to monitor the rod angle and wind direction to proactively prevent launchs towards or over the spectator area.

1. Failure of the rocket owner to set and check the launch angle and the wind to proactively insure his rocket will not launch towards or over the spectator area.

Rockets don't simply fall from the sky. Someone assembled the rocket and put it on the pad, and adjusted the rod angle that determined the ballistic trajectory of the rocket. That person is directly responsible for the accident. If he had set up his rocket properly, the accident would not have happened.

The LCO and the launch crew also share responsiblity for the accident. They launched the rocket and did not adequately check to see that the ballistic rocket trajectory would not impact in the spectator area.

The launch organizers also share responsibility in failing to adequately train the launch crew and to instruct the rocket owners to properly angle the launch rods away from the spectator area.

Good PA systems and heads up alarms are fine, but should not be used as an excuse to permit unsafe launch practices.

Wake up folks. Stop making excuses for being sloppy. Launch safety is no accident.

Bob

 

[plano-doug]

18 ga. sheet metal is no match for an aluminum-tipped nose cone coming in ballistic.

It's no match for a plain old styrene or polyester nosecone whose tip is filled with lead shot and epoxy, either. That's why I like the idea of putting the stabilizing weight farther aft in the nosecone, at the expense of a little more weight, because then the nosecone will tend to be unstable and tumble in rather than coming in like a round shot out of a cannon.

Doug

.

 

[luke strawwalker]

(snip, for brevity, not because it's not absolute truth...)

IMO, there is no difference between a ballistic return that hits dirt near a flight line and one that hits flesh or property of value. Both are still failure, and it was luck, not safety controls, that prevented injury.

And I agree, we don't want government trying to do it for us, so we better always do our best.

Couldn't agree more... that's the point I've tried to make over and over again and constantly get shot down for... hope you guys have better luck! OL JR

 

[shrox]

Make an umbrella to carry when you're not under the awning... sorta like the coyote used in all those cartoons to deflect boulders...

Wait, maybe that's not the best example... LOL

Later! OL JR

Nevermind.

 

[CarVac]

100.000 feet is a long way to fall but how much faster is a ballistic rocket from 100.000' going to be traveling compaired to one that had a flight to 4.000'?

Terminal velocity at high altitudes is dramatically higher than at low altitudes... if its ballistic coefficient is fairly high, it will have a much higher ground strike velocity than terminal velocity, since it would be continually slowing down as the air density increases, always lagging the changing terminal velocity.

I just ran the sims: if Bare Necessities came in ballistic from ~100k, it would strike the ground at a little under 1200 ft/s. If it fell from ~6k, it would strike the ground at 600 ft/s. At 1200 ft/s, the rocket had about 50 pounds of drag on a 21 pound rocket, so it hit the ground at about 1.5x terminal velocity.

 

[3stoogesrocketry]

What this situation boils down to is , people are lazy . Thank god he wasn't hurt worse then he was . We can sit here and throw out stats and numbers all we want , but that will not help . How many times have you been at a launch where the LCO calls a heads up flight , and requests people to stand and watch ? How many people are still sitting in their chairs ? How many times have you seen people working on a part of there rocket under a EZ-up when the air horn is blasted and not come out to look ? LDRS 22 , a 29mm fiberglass rocket punched right thru a ez-up canapy and a section of 3/4 inch plywood less then 2 feet from a man working on his rocket. Lets all be safe and watch our neighbors at a launch . The LCO has a lot on his plate. The RSO should also be in charge of keeping the range safe and clear.

Eric

 

[TheSamurai]

What this situation boils down to is , people are lazy . Thank god he wasn't hurt worse then he was . We can sit here and throw out stats and numbers all we want , but that will not help . How many times have you been at a launch where the LCO calls a heads up flight , and requests people to stand and watch ? How many people are still sitting in their chairs ? How many times have you seen people working on a part of there rocket under a EZ-up when the air horn is blasted and not come out to look ? LDRS 22 , a 29mm fiberglass rocket punched right thru a ez-up canapy and a section of 3/4 inch plywood less then 2 feet from a man working on his rocket. Lets all be safe and watch our neighbors at a launch . The LCO has a lot on his plate. The RSO should also be in charge of keeping the range safe and clear.

Eric

Yeah, you can't fix stupid. We do everything we can as a club and if someone doesn't watch and do what they are told there isn't much else to do. Darwin's theory will take its rightful place in the universe at that point.

 

[DaveHein]

The minimum high power launch field is 162 acres, or 7,068,583 square feet. The cross-section of the average rocketman is about 3 square feet. If it rained rockets, the probability of getting hit by a falling rocket is about 2,356,194 to 1. If the event has 250 participants and spectators randomly walking around, the chance of some getting hit by a falling rocket is 9425 to 1. If 100 rockets were rained in, the probability of some one getting hit is approximately 94 to 1. Certainly more probable than 1 in a million.

Bob, I know your calculations were based on hypothetical values, but I would suggest changes to a few of the numbers. If the average rocketman had a cross-section of 3 square feet he would have a waistline of 73 inches. That's probably a bit on the high end of the bell curve. A more reasonable value would be 1 square foot, which corresponds to a circumference of 43 inches. Also, even though the launch field may be 163 acres, a ballistic rocket would most likely hit within a much smaller area, such as 10 acres. So I would adjust your number by a factor of (162/10)*(1/3) = 5.4. So the probability of someone getting hit would be 17 to 1. A more reasonable number of ballistic rockets may be 2 per launch, so a more realistic number would be 1 injury per 750 launch events.

 

[shrox]

Bob, I know your calculations were based on hypothetical values, but I would suggest changes to a few of the numbers. If the average rocketman had a cross-section of 3 square feet he would have a waistline of 73 inches. That's probably a bit on the high end of the bell curve. A more reasonable value would be 1 square foot, which corresponds to a circumference of 43 inches. Also, even though the launch field may be 163 acres, a ballistic rocket would most likely hit within a much smaller area, such as 10 acres. So I would adjust your number by a factor of (162/10)*(1/3) = 5.4. So the probability of someone getting hit would be 17 to 1. A more reasonable number of ballistic rockets may be 2 per launch, so a more realistic number would be 1 injury per 750 launch events.

Did you factor in the movement and of clustering of people?

 

[DaveHein]

Movement and clustering don't really change the probabilities. What matters is whether your 1 to 3 square-foot of area coincides with the rocket's location at the time it hits the ground. One important thing that isn't included is the fact that the probability of hitting a certain distance from the pad drops off quickly. I assumed a uniform distribution, but the actual distribution would probably be more like a Gaussian.

 

[jadebox]

Did you factor in the movement and of clustering of people?

That number also doesn't factor in that we generally launch our rockets so that the impact area for ballistic trajectories is away from the observers. So, the real odds of injury are much less. As Bob said, "The good news is that with a proper range safety practice in place, rockets don't randomly fall from the sky."

-- Roger

 

[Davidtmp]

I look at all these responses, and I can get down to one thing that "could" have prevented this. WAIT for the rockets that launch to come down first. IF this was done, instead of this guy watching another rocket come down under chute to see where it landed, he could have had his eyes on the rocket with the problem and gotten out of the way. Some may say this will slow operations down, why wait for a rocket that pops a chute in the desert from 12,000ft to land?, etc. I'd personally rather slow down and be safe than to have something bad happen.
We also need to try and keep flights from coming over the crowds....I know sometimes it will happen, but the more we get people educated on doing the right things, we minimize our chances of something bad happening.
The real issue is this story gets printed in the media and then all hell breaks loose because the general public don't know what a high power rocket is.

 

[paul.nortness]

What this situation boils down to is , people are lazy . Thank god he wasn't hurt worse then he was . We can sit here and throw out stats and numbers all we want , but that will not help . How many times have you been at a launch where the LCO calls a heads up flight , and requests people to stand and watch ? How many people are still sitting in their chairs ? How many times have you seen people working on a part of there rocket under a EZ-up when the air horn is blasted and not come out to look ? LDRS 22 , a 29mm fiberglass rocket punched right thru a ez-up canapy and a section of 3/4 inch plywood less then 2 feet from a man working on his rocket. Lets all be safe and watch our neighbors at a launch . The LCO has a lot on his plate. The RSO should also be in charge of keeping the range safe and clear.

Eric

While I was on the other side of camp when it happened and didn't actually see the accident, there was rumor that this gentleman was the one who brought out a lazy boy and set it up right on the other side of the rope from the flight line.

It's hard enough to get out of one of those folding lawn chairs quickly.....but a lazy boy?

 

[thobin]

I have had two recent recovery failures, no chute deployment but both the rockets separated due to a back up. First both rockets survived, falling much slower than total separation failure, easier to see and move out of the way. I don't have one 38mm + rocket that does not DD backup, a few extra pennies more is worth the safety and survival of the rocket.



TA

 

[TheSamurai]

While I was on the other side of camp when it happened and didn't actually see the accident, there was rumor that this gentleman was the one who brought out a lazy boy and set it up right on the other side of the rope from the flight line.

It's hard enough to get out of one of those folding lawn chairs quickly.....but a lazy boy?

If that's true then the RSO and LCO might need to clean things up a bit. But rumors are like....

 

[TheSamurai]

I have had two recent recovery failures, no chute deployment but both the rockets seperated due to a back up. First both rockets survived, falling much slower than total seperation failure, easier to see and move out of the way. I don't have one 38mm + rocket that does not DD backup, a few extra pennies more is worth the safety and survival of the rocket.



TA

Good on you and I agree. If it is only going to run you a couple extra bucks for backup safety then it should be done.

 

[CZ Brat]

I look at all these responses, and I can get down to one thing that "could" have prevented this. WAIT for the rockets that launch to come down first. IF this was done, instead of this guy watching another rocket come down under chute to see where it landed, he could have had his eyes on the rocket with the problem and gotten out of the way. Some may say this will slow operations down, why wait for a rocket that pops a chute in the desert from 12,000ft to land?, etc. I'd personally rather slow down and be safe than to have something bad happen.
We also need to try and keep flights from coming over the crowds....I know sometimes it will happen, but the more we get people educated on doing the right things, we minimize our chances of something bad happening.
The real issue is this story gets printed in the media and then all hell breaks loose because the general public don't know what a high power rocket is.

I agree that more time is needed, but there are more distractions to address than just another rocket floating down. Like people focussed on rocket prepping, wrangling kids, or even talking Bologna Sandwiches (BS) with others. It's like banning cell phones while driving, but not addressing Mr. DigInTheGloveBox or Mrs. PutOnMyMakeup

 

[CCotner]

The minimum high power launch field is 162 acres, or 7,068,583 square feet. The cross-section of the average rocketman is about 3 square feet. If it rained rockets, the probability of getting hit by a falling rocket is about 2,356,194 to 1. If the event has 250 participants and spectators randomly walking around, the chance of some getting hit by a falling rocket is 9425 to 1. If 100 rockets were rained in, the probability of some one getting hit is approximately 94 to 1. Certainly more probable than 1 in a million.

The good news is that with a proper range safety practice in place, rockets don't randomly fall from the sky. Good range safety practice establish ballistic impact zones by angling the launch rails and rods away from the spectator areas so the 2 areas do not overlap by a large margin. Under this condition, the probability of some one getting hit from a falling rocket is vanishingly small, unless some one is out in the ballistic recovery area recovering a rocket.

There are many mechanisms that defeat good range safety practices.

3. Failure of the sponsoring organization to analyze the field layout and and the wind and proactively prevent launches towards or over the spectator area by instructing the launch crew and the owners on range rules and enforcing them.

2. Failure of the launch management personnel to monitor the rod angle and wind direction to proactively prevent launchs towards or over the spectator area.

1. Failure of the rocket owner to set and check the launch angle and the wind to proactively insure his rocket will not launch towards or over the spectator area.

Rockets don't simply fall from the sky. Someone assembled the rocket and put it on the pad, and adjusted the rod angle that determined the ballistic trajectory of the rocket. That person is directly responsible for the accident. If he had set up his rocket properly, the accident would not have happened.

The LCO and the launch crew also share responsiblity for the accident. They launched the rocket and did not adequately check to see that the ballistic rocket trajectory would not impact in the spectator area.

The launch organizers also share responsibility in failing to adequately train the launch crew and to instruct the rocket owners to properly angle the launch rods away from the spectator area.

Good PA systems and heads up alarms are fine, but should not be used as an excuse to permit unsafe launch practices.

Wake up folks. Stop making excuses for being sloppy. Launch safety is no accident.

Bob

Yeah, pretty much all of this. One problem is that the way the legal codes are written right now, the launching clubs are largely liable for damages; they don't inspect individuals at the pads, an as a result, we all will get penalized for someone's unsafe practices at some point. At the same time, how many of us would actually fly our rockets at all if we were %100 liable for damages? probably not many, the risk from that is just too large.

 

[Sully]

Bob, I know your calculations were based on hypothetical values, but I would suggest changes to a few of the numbers. If the average rocketman had a cross-section of 3 square feet he would have a waistline of 73 inches. That's probably a bit on the high end of the bell curve. A more reasonable value would be 1 square foot, which corresponds to a circumference of 43 inches. Also, even though the launch field may be 163 acres, a ballistic rocket would most likely hit within a much smaller area, such as 10 acres. So I would adjust your number by a factor of (162/10)*(1/3) = 5.4. So the probability of someone getting hit would be 17 to 1. A more reasonable number of ballistic rockets may be 2 per launch, so a more realistic number would be 1 injury per 750 launch events.

Assuming rocketeers are circular when seen from above (and I for one am more circular than I would like), 1 square foot gives a circumference of 37. That's not a very big waistline. And since we are at 3-dimensional, a rocket that passes through our bodies may very well hit the ground outside of our "footprint." So 3 square feet strikes me as a reasonable approximation.

Leaving aside the fun with math, I agree with Bob's (and other's) point that rockets don't fall randomly, and rocketeers are mobile, so with a well-designed rocket with redundant/reliable recovery, thoughtful pad and rod angle setup, an appropriately cautious and attentive flightline, and a careful LCO, the incidence of injury from falling rockets can be reduced quite a bit, although clearly not to zero.

Any safety lapse in the chain of events from rocket assembly to safe recovery worsens our odds, and a reversion to the mean, whether it is 1/94 or 1/750, or even 1/10,000 is too frequent given the large number of launches we do, from low to high power (a ballistic Estes Alpha could do some real damage in the wrong circumstances).

So I don't see any problem with being too careful. The fact that I really, really, want to launch something should never trump a safety measure, and I would have no problem with being turned away from an RSO table or launch pad out of a safety concern, even if I disagree with the rationale or assessment. (even if I really, really, really wanted to launch it!)

 

[shrox]

Assuming rocketeers are circular when seen from above (and I for one am more circular than I would like), 1 square foot gives a circumference of 37...

Now I am thinking about how rockets fly in Flatland...a straight line towards your head I guess with no wind.