pchapman

Anyone can become a dropzone bum. It takes more work to get a decent job / career.  Which can then pay for lots of skydiving. (Like TampaPete said.)

Everyone likes the "right" to do whatever they choose in life. But young adults often can use a boost / support from parents to get an advantage, and that financial power does give them some leeway to impose conditions. One can argue about those conditions, but one can't always avoid them...

Yes I meant "the whole point" in the context of skydivers using tunnels, as one of the reasons skydivers want to use tunnels. 

Rather than the obvious "The whole point of tunnels, which are commercial enterprises,  is to make money for their owners".

Even in skydiving I have seen waivers where one has to state that one is "fully recovered" from any injury.  Bad ankle, dodgy shoulder? Doesn't matter, you can't do the first jump course unless you claim to be perfectly healthy, as the DZ doesn't want to play the role of giving expert medical opinion. I think we agree on the liability thing.

It would seem silly to exclude people just because of prior injury. The whole point of the tunnel is to be able to check things out in a safer environment than in the sky. Obviously there are walls to smash into, but all sorts of people are advised to get tunnel --  like people with flexibility issues, physical disability, older age, returning from an injury, etc.  Often that's about doing basic skydiving things like staying stable, basic belly maneuvers, and being able to pull, not whether they can join a 4 way freefly style team in the tunnel.

Heck, one local jumper here in Ontario got free tunnel time from worker's compensation, because his  screwed up landing that broke a lot of stuff, was on a working camera jump. He still can't lift one arm much above his shoulder but flies ok.

To the OP:  Anyway, it sounds like general purpose legal disclaimer & warning stuff. Contact your local tunnel to find out what they really think about working with someone with a prior shoulder dislocation.

Tests have been done over the years but little by individual jumpers as opposed to companies.

Just whipping this post off:
While GPS data is easy to get these days, you would still need to do some analysis to get good data out of it. It is hard to find "no wind" conditions all the way up to altitude, so you are going to have to take data acquisition runs in different directions, ideally up and down wind, to help calculate out the wind's effect.

Plus, for any observed rates of descents and airspeeds,  you'll want to do all your tests in similar conditions to avoid density altitude effects messing up your numbers. At least if you measure on a similar temperature day (across the air mass and not just on the ground), and at similar altitudes, you could compare canopies, even if they are not the 'proper' numbers as one would have for an airplane. That is, airplane flight data is always adjusted to be what it would be at sea level, International Standard Atmosphere conditions (29.92"Hg, 15 deg C), that sort of thing.  So if measuring canopy speed and rate of descent at 6000' on a hot summer's day, it'll be faster than if measured at 3000' on a cooler day, in a predictable way.

If all this goes over one's head, then one isn't ready to do accurate comparisons of flight characteristics of different canopies.

... Still, it can be fun to go up and get a little data just for fun, comparing different canopies for some rough numbers.

Back 15-25 years ago I did a bit  of data collection on a few canopies of the era, using a calibrated anemometer, electronic variometer, and a whole bunch of data reduction (analysis) to take into account density altitude effects. So the canopy types are a bit old now! -- and I'm not including modern competition style swooping canopies like a Leia or Valkyrie.

This is a very quick summary that I used in a canopy flight course I have sometimes given, to give people some "rough numbers":

From my testing.

(These numbers have been adjusted to sea level standard conditions... because that's how it is done in aerospace engineering for comparing airplanes in a standardized way. On a typical summer day at a typical dropzone, at a typical height above sea level when flying one's canopy,  the air density will be somewhat less. The Glide Ratio won't really change, but the Airspeed and Rate of Descent will be a little higher.)

- Glide ratio typically:    (brakes off)

            3  student canopy

            2.5 medium modern ZP canopy

            2.1 small canopy

                        In partial brakes, my Icarus FX 88 at 1.9 loading went 2.1 to 2.8! (lowered the rate of descent a lot, while only moderately reducing the speed)

 (While big F-111 canopies might just get less glide angle with brakes, with less effect on their already slow descent rate)

(Sabre 1  135 when adding brake: got only bit better glide ratio with a bit of brake, then a lot worse as one got into heavy brake).

Different designs could be more efficient…   e.g. a special experimental high glide ratio 11 cell 170 from PD over 20 years ago that I jumped = 4.5 glide ratio in slight brakes

- Airspeed: (Bit more than Forward speed horizontally)

            25 mph student canopy

            46 mph small crossbrace  @ 1.9 loading (Icarus FX)

                        But: Deep brakes only 25 mph

- Sink rate:   

            800-1000 fpm big canopy  (13-17 fps) for students or novices

                        (On the lower side of that for modern ZP student canopies compared to ones like F-111 Mantas)

            1300 fpm Sabre 1  135 @ 1.25

            1750 fpm (29 fps) small crossbrace @ 1.9 loading (Icarus FX)

In brakes any of those down to only 750 fpm

(So one can have the case of an instructor under a crossbraced canopy, maybe not a modern competition style one, being able to almost stay with a student or novice flying full speed under their rental canopy.) 

Even if the camera isn't a snag hazard:

a) national skydiving organizations often forbid cameras on less experienced jumpers (even if the person is strapped to an instructor)

and

b) there's no incentive for skydivers and dropzones to take away from their own revenues in providing video services to tandem students. 

It is what it is. Enjoy your jump. Hopefully you do get video. :-)

Curiously, their current Vortex / Decelerator manual has no mention of, or instructions about the number of reserve pack jobs or any porosity checks. 

Then one can get into the arguments about "What instructions from a manufacturer are the official instructions a rigger must follow?"   I'm sure many would argue that something printed on the reserve parachute itself constitutes an official instruction, even if "it's not in the instruction manual"....

Does Parachute Systems currently answer messages or are they now completely gone, despite the website being up?

For a while in the last couple years, various people around the web said they were still supposedly open for spare parts sales & manufacture but not whole rigs & canopies....

"Survey says...", I mean, my old ParaGear says:   Raider = 220 feet in their 9 cell range of canopies (unlike the Fury), supposedly 484 packing volume (although those numbers can be uncertain).

If your rig is a Vector II, then attached is a pack volume chart. Although modern canopies don't always have volumes listed any more, so it isn't necessarily a great help in figuring out what modern canopy will fit in the rig. What you should be flying, both initially and as you get experience with ZP canopies, is a whole other thing.
 

09101 (Vector II sizing chart).pdf

'Bill von's' checklist is an oldie that still makes a fair bit of sense.  Just checked and saw he first posted it in rec.skydiving in 2003, and on dropzone.com too, with more details: https://www.dropzone.com/articles/safety/downsizing-checklist-r32/

I'm sure plenty of jumpers haven't done most of the steps, so it isn't like the OP is the odd one out, but they are good things to consider. 

Mind you, just working on learning these sort of things have dangers of their own. (While not directly related, I recall a couple people breaking ankles at the local DZ while participating in basic Flight-1 canopy skills camps.)

But to re-emphasize: in the OP's particular case, the knotted brake line might lock that brake line into having 'some brakes on', to a variable amount. Landing on rears with one brake partially set, preventing a full speed approach to landing, can become a lot tougher than doing it brakes free. That starts to be a whole new ballgame, and changes the equations when considering whether to land vs. chop.

One certainly can also practice landing from a little bit of brake on approach, but that again adds risk in practice while trying to reduce risk in an emergency. The USPA SIM mentioned flaring from "slow (braked) flight" in a section on downsizing, or at least some years ago it did. Don't overdo it though, as it would be easy to run out of flare power if the canopy is slowed too much on the approach!
 

Ouch. Hope you can still find it. Kudos to anyone like you willing to educate others after a screwup -- even if it was just a tiny, momentary lapse in focus.

(I did something not quite the same but with similar effect once. Locked up one toggle but that side was still effectively at full flight -- So I was able to land the Icarus FX canopy with one toggle and one riser.  Not a big deal even if such 'mixed controls' is not typically recommended.  Was your canopy still braked a fair bit on one side, which would complicate any flare?   I assume your canopy was more ground hungry / twitchier / more highly loaded than my early generation crossbrace.) 

shredvideo.com   
AI based, automates the editing, processing is on the DZ's computer, provides a web page link for the customer to download pics & vids, integrates with Burble manifest software, etc.  Haven't tried it myself but saw it at a DZ I've been to.

29 minutes ago, gowlerk said:

 Several large DZs that I have been to, including SDAZ forbid standing them up unless there is enough wind.

Yeah, I've been at a big Ontario DZ that mandates sliding landing (although accepts standups in high winds). But it does depend on the canopy a lot too -- Sigma canopies tend to be suited to sliding landings rather than standups.

3 hours ago, BIGUN said:

Seriously? 

I'm really not sure what to say about this.

Fair enough if it was implied that the airbag was to be used for normal civilian application. But it looks like it is being marketed more to the military, for heavy loads / night / crappy landing areas. Some of the pics show a military tandem, trailing a kit bag on a line.

Looks like the airbag is like a paragliding airbag, which have been around for a long time, self inflating from an opening at the front, but with the added design feature to be held closed in freefall.

30 minutes ago, sfzombie13 said:

i am pretty sure i would plf every time, even the one you described,

In any case I think we agree that one shouldn't forget to be ready to PLF, even if one moved on to also using sliding landings, a landing technique considered to be 'more advanced' (due to it being learned later, and being associated with cool canopies).

Quote

i have heard folks say plf's are not designed for high speed canopies and the higher horizontal speed, but this is simply not true.

Yes and no. I'm not going against you here but am putting it in a different way:  I would say sliding is superior for high speed landings in a general sense-- but as you would agree, there are limitations, where PLF's are better. I'd far rather slide a fast downwinder under a crossbraced canopy, than PLF and go tumbling along. But there are those limitations:  High vertical speed requires a PLF, and a PLF is good in rough terrain where you don't want to pile into a rock hard clump of dirt or whatever, while sliding with one's body down low.

A lot of people slide in landings without any special jumpsuit additions.

Things to note:

- Certainly some landing areas get very hard or are bumpy, making the situation trickier.

- Normally one tries to slide while twisted a bit to the side, trying to slide on one butt cheek. (Pretty much the 'baseball slide' if I have the terminology right.) Thus if you drop down suddenly a bit, or you hit a bump, you don't smack down straight on your tailbone or compress the spine as suddenly. It might still hurt, but the shock to the spine will be less.

- Some jumpsuits actually have padding and not just heavy duty cordura or ballistic cloth on the butt area. But that tends to be pants for tandem instructors. And if the instructor slides or sits down, it tends to be without that twist I mentioned, due to having the student there.

- Part of the sliding landing is to gradually transfer weight from the canopy to the ground. So if coming it at speed, some of the slide will be with legs out in front, sliding with one's shoes, without one's butt actually being on the ground yet. Eventually yes as one slows down, the side of the leg and butt will be sliding on the ground too. But one tries to delay that. 

- So padding can help, but it is more about technique than padding!

24 minutes ago, dudeman17 said:

Why was talking with the manufacturer not the first thing you did?

To educate oneself more and try to understand the source of the issues better, to be a better informed consumer, before discussing it with the manufacturer?

To piss off those who cry "Won't somebody think of the children?", I mean "Why didn't you contact the manufacturer first?" ?

A tight yoke & shoulder area on the rig could make it harder to move your shoulder blade area back, which in turn restricts how easily one can reach in behind one's back.

But that's just guessing so getting a buddy to watch & record pulls on the ground is clearly the way to go.

I don't expect riggers to start adding Collins lanyards. I'm wondering if some companies will add Collins lanyards to their MARD rigs.

The rigs with MARDs that didn't have or license the Skyhook have always been without the safety feature of the Collins lanyard.
(Although it also adds complexities that in rare cases add to the danger, the issue of 'back loading causing a partial cutaway if the reserve bag falls out'.)

Not having a Collins lanyard didn't stop companies from marketing their MARDs, or indeed even RSLs in general.

Some might say that riser breakage issues are not a serious problem nowadays with reinforced mini risers and better understanding of packing zero P canopies. Or a company might have an RSL that is less susceptible to activating the reserve in case of riser breakage, by placing the RSL ring lower down on the riser compared to the old days. (E.g. Mirage says in their manual that if using their TRAP MARD, to always use Mirage main risers that are built that way.)

So will they choose to reconfigure their rigs for Collins lanyards (and have the RSL on the appropriate side for that)?  Will be interesting to see where the industry goes with it.
 

I'm also a jumper familiar with F-111 style 7 cells.  I'll give a stab at the issue of reserve flaring, without being any kind of expert:

Reserves tend to not have a lot of energy to convert into a long duration flare, which is both because they are high drag compared to modern main canopies, and may fly flatter than more ground hungry canopies.

(Earlier reserves like the original Ravens, perhaps the most popular of the late 1980s, are especially flat trimmed and if at higher loadings,  tend to lack much flare power, and have high stall points on the toggles. But you don't see them around much any more.)

I have seen a jumper on his first reserve ride, who wasn't familiar with 7 cell F-111, have a terrible landing. On a small modern reserve like a PD126, he started to feed in his flare gradually and progressively, from higher up, as one might do while casually planing out a main. He ran out of airspeed and flare power while still some ways from the ground and thumped in, only avoiding injury by landing in muddy ground. 

That being said, it isn't like all the jumpers trained in the last decades under ZP student canopies are all smashing in when they first land a small reserve. Even a ZP student canopy, at typical low wing loadings, is going to need a shorter sharper flare than one will use later in one's skydiving career.

One does want to think about one's reserve flare & hopefully practice it higher up. A shorter, sharper flare, started closer to the ground, will be what is needed. It can still be so-called 2-stage to evaluate how it is going and finish it off, but the total duration of the flare isn't going to be very long!

(Would I go as far as Riggerrob saying a reserve is similar to a Sabre 1 of similar size?      Hmm, I don't think I'd go that far. I think my Sabre 1 135 does plane out way better than a PD reserve of similar size. But still, I see the point:  As long as you treat the reserve like a canopy that isn't by modern standards a ground hungry super-swooper, and start the flare closer to the ground and quicker, that will help.)
 

PD has some useful info in their documents on their canopies' flight characteristics. A couple relevant quotes:

For the PD Reserve:

Quote

Many people will find it easier to land a zero-p main than a canopy of the same size made from
“F-111” type fabric.  Most zero-p main canopies can create more lift during the flare than an “F-111” canopy, and
a zero-p main may be more forgiving if you don’t time your flare correctly. Smaller canopies generally require
more skill to land than larger ones, so the difference between landing a small zero-p main and landing a small
“F-111” reserve will be even more noticeable than the differences between larger ones.

For the PD Optimum, which is supposed to be easier to land:

Quote

The canopy responds immediately to proper flare input, providing ample feedback to the jumper.
The “sweet spot” in the flare is easy to find, starting around mid stroke, and is well above the stall
point. A properly timed flaring will cause the Optimum to plane out easily, better than other
reserves and similar to many main canopies.

With the long control range and powerful response, it is relatively easy to land well, with timing of
the input being less critical than for other reserve parachutes of similar size.

However, these great
landings are not automatic.  You must have the skill and technique that is appropriate for the
Optimum size you have selected. Any small canopy will have a high descent rate on final, so
flaring must be timed well. Regardless of how great the flare potential is with the Optimum, a hard
landing will be the likely result from a poorly timed flare.

9 hours ago, nwt said:

I use the VOG audible as my primary. It's different from most audibles in that it speaks your altitude to you in increments. So you're always altitude aware without having to think about it, and if it quits working you'll notice. I recommend it highly.

Good point. And to clarify, the real point is that it doesn't just make noise when you're supposed to break off, but is saying things all the way down. That's why one would notice early if there's a problem with it. 

1. In the old days, nobody worried about exactly what altitude to make turns at.  Guidelines on downwind / base / final turns are just rough numbers to help people get used to what is reasonable. And always make your turns to conform to other parachute traffic, and by your actual flightpath over the ground, with the aim of getting into the landing zone. Never robotically make a turn just because your altimeter says a particular number.

 200 to 400 feet is fine for turning final and over time you'll get a visual feel for whether you are on the low or high end, and get a feel for what works for you.

That being said, most jumpers have gone digital and many also have audible alarms for under canopy altitude checkpoints. That's for regular folks too, and not just competition canopy pilots.

2. Used to looking at your wrist for altitude? Great! That's what you are supposed to do.  An audible altimeter is supposed to be an aid only, not your primary way of deciding when to deploy. 

That being said, people do get very used to relying on their audibles to signal breakoff and pull altitudes. That's just the way it is, but people should still be using their eyes and altimeters to help confirm their altitudes, even if much of the time their eyes are focused on the formation work they are doing.

3. A good digital alti to get?  Sorry I can't help, I'm old school....

Cypres has had bulletins and recalls too. Yet Vigil had quite a few more bulletins and issues. But bulletins have been pretty much non existent for quite a few years.

Cypres still seems to have the best firing logic and algorithms, based on the little info that's out there. Vigil's were a little simplistic based on info that came out during some of the incidents. Both companies have been arrogant about their capabilities, although both provide great user service. 

But in any case, both have performed very well in recent years in practice.

I personally still trust Cypres a little more, but none of the big 3 brands now are frowned on.

I tried what I guess are some skateboard shoes (DC's) but don't like them --- Seemed to have very little padding to absorb any vertical shock. Just the harder rubber outer sole & an insole. Maybe that's something about keeping feet close to the skateboard without thick shock absorption?  So running out a landing on hard ground.

Maybe someone with more experience with either skate shoes or using them in skydiving can comment.

A bunch of people do use them, but didn't work for me. Maybe I'm just more sensitive to that. Running shoes with flatter soles and no big chunky treads, that worked for me for sliding in, both for Sigma tandems and for swoops.

4 hours ago, tstar said:

Stupid idea??  What am I missing??

 

Yeah not very practical. It just gets complex.   (Just like this reply did for me...)

In theory if there were a DZ with tons of funding (eg military) you could be lent a reserve canopy set up to use as a main. "You have a Smart 150 in your rig? Well, we have a PD 143 set up here, that would at least be similar."  There would be complexities because a reserve doesn't normally have the deployment bag attached. (So you need a specially built reserve, or static lining the jump, or removable deployment system, or someone else chasing the d-bag.)

Sometimes there are big boogies where manufacturers bring reserves set up to be tried out as mains, but then you need to be around such a big skydiving event.

But if you want to actually cut away from a parachute, then you need a 3rd canopy, a reserve, on the system. You can have the reserve to test in its proper place on your back -- which makes putting a real reserve on your belly more complex, especially to have it fully legal. Or you could have the reserve to test on you belly, which keeps your 'last reserve' in your rig as normal, but then the deployment for the test canopy won't be like a real reserve.

Either way, having 3 canopies makes the gear and handles and procedures and crap that your wearing more complex and less suited to a newbie. Maybe more dangerous than a real cutaway after a mal!

(There was even a World Champion doing a stunt jump for a commercial about 25 years ago, with 3 canopies, who screwed up the order he pulled stuff and died.  An unusual case but 3 canopies does get complex.)

And even if you set up everything to cutaway to a reserve to test flying it, there won't be nearly the same stress level as if you were having an actual malfunction. So then ideally you'd at least do something like pop one toggle on the main to get yourself spinning around before cutting away.

Reserves do fly a little different than the ZP canopies people are used to today. A small F-111 style canopy will tend to have a shorter, sharper flare motion, not a long gradual flare motion. It used to be that people were used to F-111 style canopies from their student days, but now they don't get that. So I do get a little concerned about newer jumpers these days knowing how to properly flare their reserve. At least people learn that they should do practice flares under their reserve when actually flying it after a malfunction.

All in all, it gets complex. So in the sport it is considered reasonable to just spend one's time practicing on the ground. Hanging harnesses are good, handle checks on all jumps are good. And you don't buy a reserve that is way smaller than what you are used to jumping as a main.

On 2/12/2021 at 9:00 PM, 20kN said:

 Changing the wingloading absolutely does change the glide ratio. If you increase the loading high enough, there comes a point where the canopy becomes overloaded and it's vertical decent rate increases substantially with little increase in horizontal speed. This is very apparent in XRW where canopy pilots will hook wingsuiters on their feet and suspend their weight, after which their canopy falls out of the sky with no noticeable increase in forward speed.

You're also adding the drag of the wingsuiter (at what body position?), and it is way down low on the whole canopy & pilot system, which also tends to angle the canopy more nose down. So I think that's a different situation overall; it is about more than just more weight   There are unmanned military canopy systems that fly just fine at wing loadings of 5 or 10 without dropping out of the sky.

"And now back to your regularly scheduled novice wing loading arguments."