polarbear

Haven't seen any of those (fortunately)...the ones I have seen have all been nicely executed. I will repeat, again, I HAVE NOT ADVOCATED DOING TOGGLE HOOKS. I HAVE EXPRESSELY STATED THEY ARE NOT AS SAFE, AND THAT THEY GIVE LESS BENEFIT, AND EXPLAINED WHY. I just pointed out that correctly done, they can improve the landing.

Yes, I know that, my point is just that there is some benefit from a correctly-performed toggle hook. Re-read my posts, no where have I said a toggle hook is as good or even close to a riser turn. In fact, I think I have said the opposite...TWICE...front riser turns give more benefit while being safer (now three times).

. I said the airspeed is low during a toggle turn. As far as "benefit", well, the pendulum effect does cause the wing to have a higher angle of attack after the pilot swings through the equilibrium point and is ahead of his canopy. This higher angle of attack creates more lift without the added drag of flaring the canopy (as deeply). EVERY toggle hook I have ever seen has created a longer surf than a straight-in, natural speed approach...so there must be some benefit. Having said that, I do agree they are very dangerous and are not as benefecial or "safe" as a front riser turn.

The understanding I have picked up is this - somebody correct me if I'm wrong: Toggle hooks generally slow the canopy down, meaning it can't flare as efficiently. The benefit from a toggle hook mainly comes from swinging way out from under the canopy, then swinging back under in a pendulum effect. As the pilot swings back under, he will actually swing forward of the canopy, increasing the angle of attack, providing some extra lift during landing. Since the advantage comes from the pendulum effect, you have to be swung out from under canopy to get the most benefit. Most toggle hooks I have seen have been with the pilot horizontal to the ground. While the pilot is swung out from under canopy, he can't flare. He has to wait until he is back under canopy. If he turned too low, he has few (if any) options. Since the toggle slowed the canopy, it actually has to speed back up to get over the head of the pilot, and to have flare energy...this takes time. With a front riser turn, the canopy actually speeds up...it gains airspeed, which is translated to more lift during the landing. This airspeed can be gained with a moderate bank angle, meaning the pilot isn't swung out very far from under the canopy. If the turn is executed too low, the low bank angle makes it easier for the pilot to flare and save himself. Also, the canopy "recovers" after a riser turn by slowing down(remember, it gained airspeed during the turn). It is easier for the canopy to "slow down" after a riser turn then to "speed up" after a toggle turn. All this translates into more options for the pilot if he turned low and has to save himself. Another issue is that the toggle hook generally has to be performed at a specific altitude. Too low, and the pilot crashes. Too high, and he pendulums under the canopy (planes out) above ground level, and then has to actually land with little airspeed. The front riser turn, however, can be contolled to a greater extenet, so the pilot can turn high and then lengthen the turn/dive to carry the speed all the way to landing altitude. Note that front riser turns can still be aggresive enough that the pilot is horizontal to the canopy, so until he swings back under he can't flare. Also, some canopies are not stable on front risers, so using them can invite a canopy collapse. Both front risers and toggle turns have killed, so be careful. It is generally agreed (at least in the US) that front riser turns give more benefit with fewer risks.

Good post. I have noticed that some kill line pilot chutes have a length of tape that is attached to the base of the pilot chute (not the kill line) and runs to the appex of the pilot chute. This serves as a sort of spacer; when you cock the pilot chute, this length of tape should be pulled tight. If the tape can't be pulled tight during normal cocking, the kill line is too short (assuming the spacer tape hasn't shrunk, which I don't think will happen). Interestingly, I had a pilot chute where the kill-line was too long(even after it had shrunk). It wouldn't collapse all the way. It won't cause a malfunction, but it pissed me off that I payed (extra) for a collapsible pilot chute and it wouldn't collapse all the way. I've since added a bi-monthly kill-line check to my rig maintenence.

My guess is that on double-sided RSL's (ie Racer) you would need to disconnest them...I think you might run the risk of choking off your reserve if you don't. It's probably something worth checking on your rigs to figure out if you need to do it or not.

I just had this happen on my samurai the other day...it was a new experience.

Somebody else mentioned using the main closing pin to pry the broken rubber band loose, I find that to be a quick and easy method

I don't think tighter stows can really slow a jumper down much. Really tight line stows would require maybe 10 pounds to unstow them; this 10 pounds is the force transmitted to the jumper. 10 pounds of unstowing force in the "up" direction isn't much to the 200 lbs (average) in the "down" direction that the jumper weighs. 10 lbs is significant to the weight of the bag+canopy+ pilot chute, and a figure I heard for pilot chute drag at terminal is ~70 lbs. 10 lbs. is a much higher percentage of 70lbs. then 200 lbs. Now, smaller pilot chutes typically have less drag, meaning they accelerate the bag away from the jumper less. They don't really affect the jumper at all...no matter what drag force the pilot chute produces, the jumper only feels the force required to unstow the lines, which is the same no matter what the pilot chute drag. If the bag is accelerated less by a smaller pilot chute, there will be a smaller velocity difference between the bag+canopy+pilot chute and the jumper at line extension. The exception is that a too-high drag pilot chute will cause line dump, which means there will be no unstowing force at all on either the bag or jumper. It does tend to stand the jumper up, but it happens so fast there is no time for the jumper to accelerate to a higher freefal speed. As it turns out, snatch force is defined as I said earlier...when the mass of the bag+(uninflated) canopy + pilot chute is suddenly accelerated to the jumper's freefall speed. Once this occurs, snatch force is done. Inflation force takes over. Now is where my (presumed)understanding of it all starts getting foggy. What I think happens is (in a normal opening) the bottom skin of the center cells (and maybe the center cells themselves) and the slider inflate, which starts the inflation force. If the center cells haven't inflated yet, they then do so. At this point the center of the canopy has its airfoil shape and begins flying forward (albeit very slowly). It is still descending fast. The primary inflation force slows the jumper down, which lessens the force holding the slider up. Air pressure through the crossports and at the nose of the canopy starts to inflate the cells adjacent to the center cells. The spanwise inflation forces overcome the slider forces and push the slider down, alowing the canopy to spread and fully inflate. On my old heatwave, the right end cell does not inflate and the canopy begins to turn to the right, making polarbear grab his rear risers and flare, while hoping his tracking was good enough to get away from everyone. The primary inflation force (I think) depends mostly on the area of the slider and the area of canopy first exposed to the airstream. I don't really know. Inflation forces are mainly a function of airspeed and canopy design. The rest of the inflation has to do with how slowly it takes the canopy to spread and the slider to come down. I would appreciate some knowledgeable canopy designer (cobaltdan? brian germain?) explaining the rest of it.

Yeah, that all makes sense. I can dig it. I don't really go with "quad-cell" or "tri-cell" either...but I don't know what else to call it. I guess I'll use quad-cell so people know what I am talking about.

It is hard to explain over the internet...the instructions in a package of tube stows shows how to do it. Basically, you are using the same larks head knot you normally would, but are looping the free end through more than once.

Don't forget. Many riggers use a Molar Strap; I know of no cases where one was left on and killed somebody. If you can't remember to untie the pull up cord from the lines every time, how can you remember to cock a pilot chute every time? To set your brakes every time? To unstow the slider every time? The whole point is to establish a routine. If tying the lines as mentioned above is part of the routine, why is it more likely you will forget it?

Its good you recognize your problems...while repeated mistakes are an indication of something wrong, the fact that you recognize them (and the potential seriousness of them) and want to fix them is a good mentality. You should know that in the instances you landed downwind, if you had whipped a toggle turn to try and get back around, you would have done far worse. Your decision to land downwind was probably a good one. If you are really worried about getting hurt, it could be prudent to stop jumping...but we all don't want to see you do that

. About the time I bought my old Heatwave 170, another jumper on my DZ bought a Stiletto 150. He was about my size and was downsizing from another Heatwave 170. He was really surprised by the difference...he kept telling me how much more responsive it was, how much faster it was, and so on. I became very cautious of going on to a 150 design. 100 jumps later, I worked up the nerve to fly a Stiletto 150, and it was no big deal. The reason is because I had been led to believe it would rock my world and kick my ass. I was expecting a lot more; while the 150 was more responsive, it wasn't a kick in the ass. I suspect that may have happened here. As for the "SOME" of us who recommended you not take such a big step, I am glad we have been wrong (thus far ). I don't believe it is ever prudent to recommend to a low time jumper to make such an aggressive change. While it is certainly true it can be safely done, many low time (even many high-time) jumpers simply haven't learned the skills necessary, and/or they don't have a safe mentality. I would feel terrible if I blindly told a 100-time jumper to by a Stiletto at 1.3 and he promptly broke himself. Oh, yeah, I still contend that a pilot with less skill will get better landings from a PD 190 than from a Stiletto 170. The Stiletto has more potential, but the pilot has to know how to use it correctly.

How do you figure? As long as the locking stows hold, you won't have CANOPY DUMP. The rest of the lines can still dump. If all of your lines are stowed tightly, it requires more force to unstow them. As the lines unstow, this higher unstowing force keeps the bag from slowing down as much. When you reach line extension, you suddenly accelerate the canopy+bag+pilot chute to your freefall velocity-this is called snatch force and is the first force you feel during opening. A bigger difference in velocity between you and the bag+canopy+pilot chute creates a higher snatch force. Thus, if the bag slows down less, the snatch force is lower. Also, the snatch force is input to the canopy through the lines at the bottom and the bridle at the top...thus it "racks" the pack job, which can help to disorganize it. A more disorganized canopy has the potential to inflate violently/unevenly. When I actually tightened my stows (all of them) to the point of needing 8-12 pounds of unstowing force, my openings (and particularly the snatch force) got much lower. I have accomplished this on two completly different parachute systems. Another jumper at my DZ was jumping a brand new Velocity 90 that was seriously spanking him on opening. He had one so hard he actually ruptured his lymph glands and hurt his neck. After tightening his bands the way I do, he gets smooth openings EVERY time. I disagree. I think it happens more than people realize. Almost every time I pack a rig, I find it has very loose line stows. After tightening them, I have on several occasions had people tell me "that was a softer opening than I am accustomed to". I would agree that canopy dump probably doesn't occur with high frequency. Now, I will reiterate for the final time, USE WHAT WORKS. If you are happy with your openings, than that's it. If your openings are hard, I have found that it is almost always one of two things 1)the slider isn't in the right place 2)the lines are stowed too loose.

First off, as I said in my previous post, I know that many, many people have used tube stows with success. Second, my opinions are based on experiments I did on the ground. I used different stow bands and tightened them until I got the PD-recommended 8-12 pounds of force necessary to unstow the lines. With tube stows, I found that even when they were very tight, they still had a tendency to roll off very easily due to their round profile. Flat band shaped stows have to flip; they seem to get a better grip. It was easiest for me to get the 8-12 ponds with bands. I used to use tube stows because they lasted longer, but frankly, I have since gotten better openings with bands. It works for me, I have no desire to change. As far as baglocks go, there is more than one way for this to occur. One is that the band is so tight the lines can't come out. I HAVE NEVER SEEN THIS WITH ANY STOW BAND. In this instance, a band made of latex will be harder to break then a gum rubber band. Two is that a loop of line from one stow goes over a neighboring stow...this is the most common explanation for a baglock I have heard. In this case, it may be the case that a breaking band won't help. It may also be the case that if a band breaks, it will help...it just depends on the geometery. It is possible that a band may not hold the lines very tightly, but unless it breaks, a bag lock will occur. Again, it just depends on geometry. Three is that the band is tight enough that on a closing stow, the lines are sucked into the grommet, preventing them from unstowing. I have heard of this happening. In this case, the band will have to break if the lines are going to unstow. As previousy mentioned, because of the rolling phenomenon, I have found tube stows have to be tighter to provide 8-12 pounds, thus they are more likely to pull lines into the grommet. Since they are made of latex, they are harder to break. Now after having said all of that, I will reiterate what I have already said many other times in this and other threads. USE WHAT WORKS FOR YOU. If tube stows work, fine. I have better luck with rubber bands so I use them.

FX/VX and Velocity each have a square shaped cell in between the triangular ones. Again, the square will not have much rigidity compared to the triangle shape. My idea was to have NO quadrilateral sub-cells; all of them were triangular. I agree that 1 cell should be defined to be between two load-bearing ribs. I use the term "tri-cell" and "quad-cell" to designate different construction methods, and I ONLY use them becasue they are terms everyone recognizes. Extremes and Velocitys are not "21" or "27" cells, they are 7- and 9- cell canopies with tri-cell construction. The Onyx is a 9-cell canopy with quad-cell construction.

OK, I'll buy that. By the way, I didn't mean that YOUR drawing was bad, I meant my depiction of the front of the cell in my previous post was bad. Your drawing was very nice!

Interesting... I have a question. The front of the quad-cell looks kind of like [/ I \] - Figure 1 - Very bad computer drawing The two outer sub-cells are triangular, while the two center sub-cells are quadrilaterals. Quadrilaterals don't have much torisonal rigidity. Would you have better luck attaching the cross-bracing at the top of the non-load bearing rib, rather than outboard of the top of the non-load bearing rib, sort of like [/I\] - Figure 2- Another bad computer drawing In this case, all four of the sub-cells are triangular, which should have better rigidity then the quadrilateral case. Any thoughts? Note to canopy designers...if you use my idea, I expect credit - you heard it from polarbear on DZ.com!

Hi, Clay. Glad the Stiletto is going well. I wanted to respond to two points: Am I right in thinking that you have not flown a PD 170? If so,it is impossible for you to decide how much of the difference is due to size. I think most people would agree that size does make a difference; one size smaller OF A GIVEN DESIGN will fly faster and respond quicker. If you downsize and change design, there is no real way of telling which differences are due to design. I must press that "forgiving" is not the correct word to use here. The Stiletto is more efficient, so if something isn't quite right, the pilot has a better "tool" with which to fix the problem and still get a graceful landing. However, it requires that the pilot use that tool correctly-he must recognize the problem, decide on the correct control input to fix it, and then execute that input. I would contend that if you flare a PD 190 a little too high, and ride it in, it will give you a softer landing than would a Stiletto 170 flared too high. Thus, the PD 190 is more forgiving. By no means am I trying to bash you, I just think that an unprepared canopy pilot might get the wrong idea from your post and decide that they need a "more efficient" (ie smaller, higher performance) wing to fix their lack of landing skill. I would agree, though, that provided you know what you are doing, more lift makes it easier to land. After I started swooping, it seemed harder to make a natural speed landing. However, the same amount of screw-up on a natural speed landing will likely hurt less then on a high-speed approach.

Using light brakes before initiating a riser turn lowers the speed of the canopy, which lowers the riser pressure AT THE BEGINNING OF THE TURN. As the speed is built up, the riser pressure will retun to normal. The difference is that the riser is already down, you just have to hold it there. You don't have to fight against that pressure to get the riser down. Unless you do a very short duration dive, the speed lost during the brake application will be regained. With any speed-inducing maneuver, you have to let the canopy dive for a while to build up speed. No dive time=little (if any) gained speed. By the time you are going a billion miles an hour

I guess the question is, would they have done better on a smaller "more efficient" canopy? My feeling is no. Generally, the higher performance it is, the more skill it takes to fly/land. If you can't land a huge skytruck, getting a smaller canopy won't help. The abilities of the canopy may be greater with a higher performance design, but the abilities of the pilot are not. It takes more then a "better" parachute. It may be true that knowledge about flying higher performance canopies is more abundant these days, and canopy designs have progressed a great deal, but a Stiletto is still a Stiletto. They have not magically gotten easier to fly.

On some rigs (like Strong tandems and my mirage) the excess brake line gets tucked into a loop of fabric on the riser. I use a pull up cord to help pull the brake line into the loop. Vector and Mirage free-bags have a sort of "split bag" design. On other freebags, the grommet through which the closing loop goes is through both the upper and lower surface of the free-bag. On vector and mirage bags, the upper and lower surfaces each have their own grommet. I use a knotted pull up cord through the two grommets to hold them together, until the propper removal time. The pull up cord also serves to pull the closing loop through both grommets.

I'll see that and raise "Bottle of favorite liquor for rigger who saved your ass" and "Cutaway, baglocked main is hard to find in a corn field"

I was just saying in another thread that I have found that out of all the stow bands, I have found it the hardest to get tight line stows with tube stows (yes I know how to tighten them). I use rubber bands; they work the best for me. Check out the thread entitled "Line Dump" in the safety and training forum. Bottom line is if tube stows work for you, then they work for you. Many people use them with success.