Barrel roll to check for clear airspace?

[chuckakers 406]

danielcroft

Very importantly your flattest track is not the track that'll get you the most horizontal separation.

I'd like to see some evidence on that. A flat track may not generate as much forward speed as one with some angle to it, it definitely burns altitude significantly slower, allowing the jumper to track for more time.

Any brainiacs in here want to opine? Dr. Kallend, perhaps?

Chuck Akers
D-10855
Houston, TX

[Hooknswoop 19]

Quote

I'd like to see some evidence on that. A flat track may not generate as much forward speed as one with some angle to it, it definitely burns altitude significantly slower, allowing the jumper to track for more time.

The track that will give you the most horizontal distance from other jumpers is the flattest track. By the flattest track, I mean the least amount of altitude lost per horizontal distance moved.

I don't mean the angle of the jumper's bodt relative to the ground. I mean the angle the jumper describes as they move through the air relative to the ground.

Speed is not relevant, just the angle.

Think about getting back from a long spot of a no-wind day. Airspeed doesn't matter, just maxing out the glide ratio of the wing matters.

Derek V

[daffes 4]

proof by definition haha

[chuckakers 406]

Hooknswoop

Quote

I'd like to see some evidence on that. A flat track may not generate as much forward speed as one with some angle to it, it definitely burns altitude significantly slower, allowing the jumper to track for more time.

The track that will give you the most horizontal distance from other jumpers is the flattest track. By the flattest track, I mean the least amount of altitude lost per horizontal distance moved.

I don't mean the angle of the jumper's bodt relative to the ground. I mean the angle the jumper describes as they move through the air relative to the ground.

Speed is not relevant, just the angle.

Think about getting back from a long spot of a no-wind day. Airspeed doesn't matter, just maxing out the glide ratio of the wing matters.

Derek V

That is obvious. I'm asking for data on something different.

The person I was responding to claims that a slightly "steeper" track (body position relative to the ground and thus a faster fall rate) produces greater forward speed to the degree that it results in what you described - a shallower glide angle (least amount of altitude loss for the horizontal distance covered). That's what I'd like to see some evidence of.

I'd like to see a comparison between the flat tracker vs the slightly diving tracker.

Chuck Akers
D-10855
Houston, TX

[danielcroft 2]

I really don't know what data to give you, I was looking through my jump videos from the event I was thinking it was on but the only one I came up with wasn't particularly convincing.

After thinking about it for a while, I realized I'm only really objecting to the terminology "flattest". I think that describes the angle relative to the ground. That doesn't mean it's going to be the best angle to gain distance.

[Hooknswoop 19]

Ya, I tried to clarify what I meant by flattest.

Derek V

[JohnMitchell 16]

Hooknswoop

-At beak-off altitude, LEAVE! Do not hesitate, do not delay leaving by wave-offing to indicate to the group that it is break-off altitude. Leave now. Every second is valuable and the best indication you can give the group that it is break-off altitude it to break off and leave.

Everything you said in your whole post is spot on, IMHO. I tell people my break off signal is the bottoms of my feet tracking away from them as fast and flat as I can.

And people, quit this "break off, track, then stop and stare at my altimeter until pull altitude." Like he said above, track until you're clear, then wave and pull. I always say you can look at your alti after opening and see if you're about where you thought you'd be. But I see too much wasted time of alti gazing.

[JohnMitchell 16]

danielcroft

After thinking about it for a while, I realized I'm only really objecting to the terminology "flattest". I think that describes the angle relative to the ground. That doesn't mean it's going to be the best angle to gain distance.

You're talking about "angle of attack" vs. "angle of glide". I usually think of glide angle when I hear "flat tracking."

[JohnMitchell 16]

chuckakers

I'd like to see a comparison between the flat tracker vs the slightly diving tracker.

I don't have any empirical data, but my money is on the flatter of the two. The human body as an airfoil works at a high angle of attack. More sophisticated flying machines have Vy, Vx, and other speeds. Ours is too "blunt" of an instrument. Talking to some very sharp wingsuit designers, I've heard that max distance is usually at the flattest, slowest speeds, within reason. A tracking body is probably a similar situation. But I'd love to get "instrumented up" and experiment with it. Maybe this summer.

[rehmwa 2]

I have nothing to add beyond Derek's (Hooknswoop) original post.

If I'm in a situation where I'm concerned about the tracking abilities of my teammates (noticed before or during the dive), I might just focus even more on out-tracking the field (general dives) or being even more diligent if it's an organized track pattern. I'll look over my shoulder before squaring up, but that's an old habit and not always friendly to on heading openings with today's canopies. Barrel roll would have to be a very unique situation (very high, small group, I 'sense' an idiot right behind/above me)

Track your best, clear below, wave off big to help those above clear below them.

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[rehmwa 2]

Hooknswoop

The track that will give you the most horizontal distance from other jumpers is the flattest track.

You want the track that will give you the most horizontal distance from your starting point - if everyone does that and the lines are separated evenly, then that gives the most separation on average from the rest of the team. (exceptions for organized tracking groups where you pretty much want to just go to your targetted opening region)

And since we choose an opening 'altitude', not a 'duration of tracking time' - then that means your shallowest glide angle relative to the planet. (take into account that we are all drifting en masse in the same air column, so just visualize that on a no wind day)

Think of it in these terms - breakoff at 5000 ft, open set at 3000 feet - you want to travel as far from the center point in 2000 feet. That's a purely distance based metric.

Whatever it takes to get as far as you can horizontally by the time you reach pull altitude..

Frankly, the best trackers I know 'appear' to the rest of the group to do both - they go faster horizontally AND appear to also rise and track up and away (slower fallrate) relative the rest of the team.....

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[kuai43 7]

'Flattest track' is simply falling straight down on your belly.
Think about it.

Every fight is a food fight if you're a cannibal

Goodness is something to be chosen. When a man cannot choose, he ceases to be a man. - Anthony Burgess

[JohnMitchell 16]

rehmwa

Frankly, the best trackers I know 'appear' to the rest of the group to do both - they go faster horizontally AND appear to also rise and track up and away (slower fallrate) relative the rest of the team.....

When you track, you're developing lift. If you do that well enough, you'll develop enough lift to slow your rate of descent, as well as move horizontally across the sky. I've heard of some trackers in RW suits, nothing special, log descent speeds in the mid-80s while tracking. Prof. Kallend comes to mind.

I'm a bit proud to say I had a friend express amazement after one jump of how I "flew up and disappeared" when I tracked on breakoff.

[rehmwa 2]

kuai43

'Flattest track' is simply falling straight down on your belly.
Think about it.

no, not even close

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[rehmwa 2]

JohnMitchell

When you track, you're developing lift. If you do that well enough, you'll develop enough lift to slow your rate of descent, as well as move horizontally across the sky. I've heard of some trackers in RW suits, nothing special, log descent speeds in the mid-80s while tracking. Prof. Kallend comes to mind.

I'm a bit proud to say I had a friend express amazement after one jump of how I "flew up and disappeared" when I tracked on breakoff.

I'm not a big fan of calling that "lift". But I know what you are trying to convey and agree with your intent.

Kallend is an excellent tracker, Whitey, and a few others I remember from Couch when I was learning had it figured out and I learned a bunch watching.

My best experience was local. We had a few bigger loads and someone on the ground pointed at one flyer simply screaming away from the rest of the group at breakoff. A local packer said "oh, that's probably Bill (me)". That made me proud that he assumed it was me.. (it was, on that jump).

Be careful assessing from the ground though, angles can hurt or help one's impression of how someone is tracking.

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[JohnMitchell 16]

Lift is any aerodynamic force created at an angle to the airflow. A physicist will tell you it is indeed "Lift". But the human body is NOT as efficient, obviously, as a regular wing. The lift vector that drives us across the sky also slows our rate of descent.