0
kallend

Collisions - two in a week

Recommended Posts

Ok, here's something I'd like input on: reading the thread, I see quite a few people saying that turning 45* off jump run upon exit is a way to reduce collisions in the event of an unstable exit by jumpers later on in the order. This weekend I was doing 4 way WS jumps, and we were just flying straight up jump run on exit. 2 different times, 2 different jumpers had unstable exits that put them into very steep dives at almost exactly 45* off of jump run, which was just fine, since we hadn't turned. And in my experience, this isn't uncommon. Is 45 the most widely used pattern, or would it be better to go say 90 immediately or something? Just trying to up my knowledge of organizing, since I'm the most experienced WS jumper at my dz and in turn the de facto jump organizer everytime.

Share this post


Link to post
Share on other sites
skydave89

Ok, here's something I'd like input on: reading the thread, I see quite a few people saying that turning 45* off jump run upon exit is a way to reduce collisions in the event of an unstable exit by jumpers later on in the order. This weekend I was doing 4 way WS jumps, and we were just flying straight up jump run on exit. 2 different times, 2 different jumpers had unstable exits that put them into very steep dives at almost exactly 45* off of jump run, which was just fine, since we hadn't turned. And in my experience, this isn't uncommon. Is 45 the most widely used pattern, or would it be better to go say 90 immediately or something? Just trying to up my knowledge of organizing, since I'm the most experienced WS jumper at my dz and in turn the de facto jump organizer everytime.



I like a solid 90. The reason a 45 could be justified in some cases is if the plane doesn't want to give you a long spot you might need to start on a 45 and carve it around. It isn't ideal but sometimes we have to work with what we get. You might want to avoid putting newbies or unknowns in that scenario.

Trying to build a group up jump run really makes it harder for the guys getting out towards the back as the formation is below and behind them. It's much easier to just angle and dive on a formation than put on brakes.

The goal is to get away from jump run and the next folks exiting. I have seen plenty of unstable exists and they all went down and with the throw of the plane, not very far either side of jump run.

Since it is skydiving shit could still go wrong but I think it sets the jump up for lower risk in the approach phase.
Summer Rental special, 5 weeks for the price of 4! That is $160 a month.

Try before You Buy with Wicked Wingsuits - WingsuitRental.com

Share this post


Link to post
Share on other sites
Solid reply from Wicked.

90 is best with different groups. If you have one big group you can exit, move horizontally away from jump run, then even back up with it again (or go 90 for a few seconds then bring it back to 45), that way you only have to close side to side distance and not front to back distance, but gives some buffer for tumblers. Also, put the groups or people likely to tumble out first (hard to do, I've seen people much better than myself take a roll on exit, just seems to be infrequent but random even with highly experienced jumpers).

With big suits people can start flying pretty quickly out of the plane and just slide away while watching everyone else exit (and outside of the tumble zone). Not something I've been very successful with, I was paranoid about hitting the tail for a long time and developed a habit of dropping rather quickly and then flying. One of my ongoing projects is exiting without losing much altitude.

Also don't pile out of the plane like belly and freefly jumpers, give it a couple seconds between each person. If you can't get together with your group by doing that, it just means you need to get better.

When dealing with new jumpers or guys who have rapidly upsized, sometimes they get a hard turn on exit that they can't fix right away, which could bring them into others even if they have a lot of separation. The only fix there is putting them out first. Just be wary of anyone with a "sweet new Freak" if they are coming from something smaller, and those without a lot of WS jumps or who are barely/uncurrent.

But ultimately you have to work with what you've got, there is no way to eliminate all risk from any discipline.

Share this post


Link to post
Share on other sites
WickedWingsuits



That makes sense, I was focused on being unconscious but a spin that you are fighting makes for a valid scenario.

Thanks.



The individual in the incident in Switzerland was not likely conscious. He forgot to zip up one of his Arm wings and apparently made no attempt to resolve the situation from airplane exit to ground (likely he died midair from the high G forces).

Given that he was unlikely to be conscious, there is at least one scenario where an unconscious skydiver in a wingsuit did not have enough vertical speed to trigger his AAD.

Share this post


Link to post
Share on other sites
A buddy of mine got clobbered hard on a WS flock exit recently "saw stars".

In a group not all are transitioning to full flight consistently. First exiting jumper transitions after a brief delay and reduces their vertical velocity, second jumper transitions to full flight lower than the first jumper so there's a collision with high difference in vertical component of velocity. In this case exit was a group exit. They did not see each other during exit.

Something strategy that mitigates the proximity or relative vertical speeds, or helps with visibility & avoidance of fellow flockers is needed.

Share this post


Link to post
Share on other sites
dorbie

A buddy of mine got clobbered hard on a WS flock exit recently "saw stars".

In a group not all are transitioning to full flight consistently. First exiting jumper transitions after a brief delay and reduces their vertical velocity, second jumper transitions to full flight lower than the first jumper so there's a collision with high difference in vertical component of velocity. In this case exit was a group exit. They did not see each other during exit.

Something strategy that mitigates the proximity or relative vertical speeds, or helps with visibility & avoidance of fellow flockers is needed.



As was discovered in RW and vRW a number of years ago, vertical separation cannot be relied upon to avoid collisions. I see no reason that WS is any different.
...

The only sure way to survive a canopy collision is not to have one.

Share this post


Link to post
Share on other sites
kallend

***A buddy of mine got clobbered hard on a WS flock exit recently "saw stars".

In a group not all are transitioning to full flight consistently. First exiting jumper transitions after a brief delay and reduces their vertical velocity, second jumper transitions to full flight lower than the first jumper so there's a collision with high difference in vertical component of velocity. In this case exit was a group exit. They did not see each other during exit.

Something strategy that mitigates the proximity or relative vertical speeds, or helps with visibility & avoidance of fellow flockers is needed.



As was discovered in RW and vRW a number of years ago, vertical separation cannot be relied upon to avoid collisions. I see no reason that WS is any different.

Vertical component relative velocity is not vertical separation. I'm talking about group that exits together, in fact lack of vertical separation is desirable in this situation as it takes vertical separation to build the vertical component of relative velocity.

Share this post


Link to post
Share on other sites
dorbie

******A buddy of mine got clobbered hard on a WS flock exit recently "saw stars".

In a group not all are transitioning to full flight consistently. First exiting jumper transitions after a brief delay and reduces their vertical velocity, second jumper transitions to full flight lower than the first jumper so there's a collision with high difference in vertical component of velocity. In this case exit was a group exit. They did not see each other during exit.

Something strategy that mitigates the proximity or relative vertical speeds, or helps with visibility & avoidance of fellow flockers is needed.



As was discovered in RW and vRW a number of years ago, vertical separation cannot be relied upon to avoid collisions. I see no reason that WS is any different.

Vertical component relative velocity is not vertical separation. I'm talking about group that exits together, in fact lack of vertical separation is desirable in this situation as it takes vertical separation to build the vertical component of relative velocity.

If they exit together how come there's a "first jumper" and a "second jumper" who don't see each other?
...

The only sure way to survive a canopy collision is not to have one.

Share this post


Link to post
Share on other sites
kallend

*********A buddy of mine got clobbered hard on a WS flock exit recently "saw stars".

In a group not all are transitioning to full flight consistently. First exiting jumper transitions after a brief delay and reduces their vertical velocity, second jumper transitions to full flight lower than the first jumper so there's a collision with high difference in vertical component of velocity. In this case exit was a group exit. They did not see each other during exit.

Something strategy that mitigates the proximity or relative vertical speeds, or helps with visibility & avoidance of fellow flockers is needed.



As was discovered in RW and vRW a number of years ago, vertical separation cannot be relied upon to avoid collisions. I see no reason that WS is any different.

Vertical component relative velocity is not vertical separation. I'm talking about group that exits together, in fact lack of vertical separation is desirable in this situation as it takes vertical separation to build the vertical component of relative velocity.

If they exit together how come there's a "first jumper" and a "second jumper" who don't see each other?

It was a group exit with typical small delays between those in the door and those diving, sorry for any confusion. There were more than two jumpers in the group. They all knew they were in a group and knew of each other, but they did not maintain visual contact with each other during exit, built significant vertical relative velocity after building vertical separation and ended up colliding hard. If anything (from memory) the later jumper's exit was poor and he "fell" onto the lower jumper. I will try to get the video to share.

Share this post


Link to post
Share on other sites
dorbie

************A buddy of mine got clobbered hard on a WS flock exit recently "saw stars".

In a group not all are transitioning to full flight consistently. First exiting jumper transitions after a brief delay and reduces their vertical velocity, second jumper transitions to full flight lower than the first jumper so there's a collision with high difference in vertical component of velocity. In this case exit was a group exit. They did not see each other during exit.

Something strategy that mitigates the proximity or relative vertical speeds, or helps with visibility & avoidance of fellow flockers is needed.



As was discovered in RW and vRW a number of years ago, vertical separation cannot be relied upon to avoid collisions. I see no reason that WS is any different.

Vertical component relative velocity is not vertical separation. I'm talking about group that exits together, in fact lack of vertical separation is desirable in this situation as it takes vertical separation to build the vertical component of relative velocity.

If they exit together how come there's a "first jumper" and a "second jumper" who don't see each other?

It was a group exit with typical small delays between those in the door and those diving, sorry for any confusion. There were more than two jumpers in the group. They all knew they were in a group and knew of each other, but they did not maintain visual contact with each other during exit, built significant vertical relative velocity after building vertical separation and ended up colliding hard. If anything (from memory) the later jumper's exit was poor and he "fell" onto the lower jumper. I will try to get the video to share.

Wow, if indeed he "fell", that makes 3 serious such accidents this year. I have been trying to raise awareness of this risk around our DZ for the past few weeks. I think we need to look hard and long at our exit skills when we plan our jumps. This has always been a concern but not such a deadly one as lately.
Instructor quote, “What's weird is that you're older than my dad!”

Share this post


Link to post
Share on other sites
dthames

***
It was a group exit with typical small delays between those in the door and those diving, sorry for any confusion. There were more than two jumpers in the group. They all knew they were in a group and knew of each other, but they did not maintain visual contact with each other during exit, built significant vertical relative velocity after building vertical separation and ended up colliding hard. If anything (from memory) the later jumper's exit was poor and he "fell" onto the lower jumper. I will try to get the video to share.



Wow, if indeed he "fell", that makes 3 serious such accidents this year. I have been trying to raise awareness of this risk around our DZ for the past few weeks. I think we need to look hard and long at our exit skills when we plan our jumps. This has always been a concern but not such a deadly one as lately.

Lots of events are potentially serious, this did not have a serious outcome beyond a bruised arm. When I say he fell I'm talking about before the collision when he dropped onto the other jumper. You can be sure there are a great many more incidents similar to this if you have two LOC fatalities.

Share this post


Link to post
Share on other sites
A quick safety vid we made last month for end of day viewing to highlight some of the day's dodgy ws flights. The first clip is as close as I ever want to come to being hit. Guy trying to exit on his back hasn't seen me yet.

http://vimeo.com/170911192
Ian Purvis
http://www.loadupsoftware.com
LoadUp DZ Management App
admin@loadupsoftware.com

Share this post


Link to post
Share on other sites
bucketlistpilot

Absolutely, but I'm not sure 30deg is enough. I'm tending to go with Wicked's 90deg now



I have exited rear float a lot and have a lot of video where someone has a bad exit. They tend to go shooting off in just about every direction but forward. I have not looked at all of the video in a scientific way, but it appears people can go any number of directions in unpredictable ways.

If those outside the aircraft start turning 90, then those that get out late on a larger group will be turning more than 90 to go back toward the formation. That is a common flight profile for a bigway, and there is nothing wrong with it as long as everyone has the skills.

I have seen some people present to the wind in a terrible fashion, trying a diving exit when they were not skilled for it. I agree with turning off of the flight line. I want to be careful not to do it too sharply and make things more difficult for those that follow. Surely there is a good balance in there somewhere. We need to find it.
Instructor quote, “What's weird is that you're older than my dad!”

Share this post


Link to post
Share on other sites
bucketlistpilot

A quick safety vid we made last month for end of day viewing to highlight some of the day's dodgy ws flights. The first clip is as close as I ever want to come to being hit. Guy trying to exit on his back hasn't seen me yet.

http://vimeo.com/170911192



That looks similar to the video I saw although the exit was not intentionally inverted in the other one. Those closing speeds right after exit can be very high in WS, I think because of the ability of the WS to suddenly deliver a lot of lift.

Share this post


Link to post
Share on other sites
dthames

***Absolutely, but I'm not sure 30deg is enough. I'm tending to go with Wicked's 90deg now



I have exited rear float a lot and have a lot of video where someone has a bad exit. They tend to go shooting off in just about every direction but forward. I have not looked at all of the video in a scientific way, but it appears people can go any number of directions in unpredictable ways.

If those outside the aircraft start turning 90, then those that get out late on a larger group will be turning more than 90 to go back toward the formation. That is a common flight profile for a bigway, and there is nothing wrong with it as long as everyone has the skills.

I have seen some people present to the wind in a terrible fashion, trying a diving exit when they were not skilled for it. I agree with turning off of the flight line. I want to be careful not to do it too sharply and make things more difficult for those that follow. Surely there is a good balance in there somewhere. We need to find it.

I think we are agreeing but just to clarify that "forward" isn't really where the formation is when existing on the line of flight. The group is below and behind. It's true that they could be spat out in any direction but one way or another they are going down at a high rate of speed. If the others already exited and flew a 90 then there is very little chance that a spinner out the door can hit them since the should be moving away from jump run in a hurry. Unless they also had a bad exit...then all bets are off!

I can say that in all exits I have seen with a solid turn out the door I never saw a spinner come close to the formation at all. For those staying on jump run I have seen some close calls that scared the bejesus out of me.

I have made the personal decision not to participate in any groups that don't make at least a 45 out the door, but preferably a 90. It is a bad setup for a formation flight anyways...let alone the dangers.

If enough people refuse to jump a "line of flight" formation then we should reduce that part of the issue.
Summer Rental special, 5 weeks for the price of 4! That is $160 a month.

Try before You Buy with Wicked Wingsuits - WingsuitRental.com

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

0