Hooknswoop

Right, but I think this was based on having a rangefinder and wanting to know the height of an object. Derek

I should have clarified it is easier to measure A and C to figure B than it is to measure A at a point exactly 45-degrees from the top of height B. How would you figure a 45-degree angle exactly? Also, you can measure the height of an A from the top without any math simply by pointing the rangefinder straight down. But if you at the bottom and need to use a rangefinder to find the height, the Pythagorean theorem is the easiest way to do it. My first post was in response to: Derek

If you have a laser rangefinder and measure the distance to the base of the object (A) and to the top(C), you can figure the actual height of the object (B). Derek

Exactly, and when USPA must chosse between it's members or Group Members, the GM's win every time. With the USPA it is GM's first, individual members second. Derek

If I had to guess, I would say most likely it was the slider not being against the slider stops on the stabilizers. Derek

This thread demonstrate the conflict of interest the GM program causes. Does USPA support jumpers or DZ's? If they support jumpers, then what does it matter if the DZ they work at is a GM DZ? If they are members, they should be able to hold a certification course at any DZ. What if every DZ in the country dropped their group membership? Would USPA members have to pay extra to hold a course at every DZ in the country? Is that fair to USPA members? No, it isn't.If a DZO does not want his DZ to be a GM DZ, why should jumpers be penalized for that decision? Forcing USPA members extra to become Instructors if they jump at a non-GM DZ encourages USPA members to simply Instruct without a rating, forcing them to operate outside of the USPA. The FAA imposes no regulations concerning AFF, S/L, or IAD Instructors, and only require initial certification for Tandem Instructors. (They do require a 'master parachutist license', but since USPA no longer calls the "D" license the 'Master Parachutist License', then technically there are no leagal TI's in the U.S) I think it is a conflict of interest for the USPA to require either Group Memebership to hold a rating course or an extra fee. FI everyone is a USPA member, they should recieve the benifits of said membership without extra fees or being penalized for where they jump. Almost seems like the USPA is trying to force DZO's into joining the USPA GM program. Derek

If you have standard risers, not mini risers, pulling the slider down to the 3-rings will be very difficult, if not impossible. You need mini risers in order to pull the slider down to the 3-rings. Derek

In the U.Ss, AAD's are only mandatory for tandem skydives. The FAA mandates AAD's for tandems, which is the only regulatory agency for skydiving in the U.S. Derek

My one bag lock, on a tandem, was becaue the rubber bands had been double wrapped. There is no need to make stows that tight. Small rubber bands or micro-line tube stows on micro line work great. Derek

It is currently 'sticky' so that it stays at the top. Eventually it wil be made an article in the archives. Derek

If the canopy is out of trim, all bets are off. Mostly, I've seen canopys open harder and off heading once they get out of trim. People are always amazed at how well a canopy opens and flys after being re-lined from out of trim. The difference from jump to jump is so small, but it adds up. Derek

'E' thread. Check Para gear catalog. Derek

Slider size, disgin of the canopy make a significant difference in how a canopy opens. Pulling the slider out the front, rolling the tail tight, etc can change how a canopy opens, but not too much, in my experience. I think a canopy tends to open a certain way and that can be affected by packing technique, but not drastically changed. Of course packing errors can definately change how a canoy opens. Derek

The no-stow D-bag operates the same way a free-bag does. The lines play out under very little resistance from a pouch with only the locking stows holding the bag closed until line stretch pulls them out and opens the d-bag. The free-bag was designed for a quick opening. The PC doesn't have to pull lines out of rubber bands every 14-18 inches, slowing deployment. It only has a locking stow to prevent bag dump. If I have 50 jumps or 5000 jumps makes zero difference on how the stows affect the opening. If I pack slider down and pull at terminal I will have a hard opening, jumpers numbers won't help. I have used the free bag on several canopies, from a Stiletto 97 up to a Safire 189 without the Velcro pouch-stowed lines causing any hard openings. As long as the bag stays closed until line stretch, it won't matter if the non-locking stows were held tight or loose in a pouch or free-stowed in the bottom of the main pack tray. Tight line stows are not necessary for soft openings. Only the locking stows are important. Derek

If loose stows cause hard openings, then why doesn't no-stow d-bags/free-bags cause hard openings? Derek

Several factors or combinations of these factors can cause hard openings. 1) Slider not up against the stops. If the slider is not completely against the stops o opening, the canopy is not reefed in as much as it should be allowing the bottom skin to inflate too much, overpowering the slider. 2) Initial pressurization of the canopy is too high, expanding the canopy too much, exposing too much bottom skin while still falling at terminal. 3) Deployment speed. Very few people actually flat track, or slow their vertical speed while tracking. If the jumper does not take the time to slow down after their diving track, their deployment speed can cause a hard opening. Also for free flyers, if they do not allow enough time to slow down from free fly speeds they can experience a hard opening. 4) Bag dump. It is possible, but rare, for the canopy to be pulled from the D-bag prior to line stretch, resulting in a hard opening. I have seen lots of videos of deployments, but I have never seen video of bag dump. If loose stows or line dump (not locking stows), caused hard openings, then every deployment with a 'no-stow' D-bag or coiling the lines in the bottom of the main pack tray would result in a hard opening. It doesn't. I have deployed several main canopies from free-bag style D-bag (with a pouch for all the lines except the locking stows) and except for intentional line-overs, have not experienced a hard opening with loose line stows. As long as the locking stows remain in place until they are pulled out at line stretch, the canopy will open normally. I have seen lots and lots of videos of deploying canopies. Some of them were very hard openings. I have never seen video of bag dump. Bag Dump What is it? Bag dump is when the pilot chute pulls hard enough on the bad and/or the line stows that hold the bag closed are loose and or small enough that the canopy is yanked out of the bag before the lines are taut. The canopy begins to inflate and then the jumper falls to the ends of the lines, resulting in an extremely hard opening. The opening could result in injury and/or equipment damage (broken lines, torn fabric, etc) For this to happen, the line stows that hold the deployment bag shut must be released before the line tension would release them normally. If the other, non-locking stows released early, the only difference should be a faster, not harder opening. How loose would the locking stows have to be? That depends. Size of the deployment bag, distance between the locking stows, weight of the bag, amount of force the pilot chute delivers at your opening speed are all factors. The heavier the line, the bigger the PC, and the farther apart the stows are, the bigger the problem. Taking some measurements on an old Sun Path Javelin J3 main deployment bag, the locking stows are 5 inches apart. If you make 2 inch stows, there is 8 inches of line outside the stows and 5 inches between the stows. The line outside the stows is heavier and high acceleration of the deployment bag does not tend to create bag dump. Acceleration tends to hold the stows in place until line tension pulls them out. Only if the locking stows were to break allowing the canopy to come out of the bag could the canopy open hard. Looking at a Sun Path Javelin J3 reserve free-bag, the locking stows are only 4 inches apart. With 2 inch locking stows, there is 8 inches of line outboard of each stow and 4 inches of line between stows. There an less weight inboard of the stows. So even loose stows shouldn't result in line dump and a hard opening. Looking at reserve packing instructions, I found the Dolphin manual says 2-3 inch locking stows, the Mirage manual says 2 inches for micro-line and up to 3 inches foe Dacron line, and the Reflex manual says 1 ½ inch locking stows." I believe canopies inflate in 3 "stages" Stage 1- once he canopy is out of the bag, it will "snivel" until the nose catches a bit of air and it begins to pressurize, making the bottom skin slightly larger than the slider. (I removed the ribs and top skin from a canopy and jumped it in a free-bag style D-bag. The bottom skin never inflated.) Stage 2- The bottom skin begins to inflate, out-pacing the pressurization of the canopy. The slider slides down the lines. Stage 3- Canopy pressurization. This happens last and accounts for closed end cells. Derek

If you measure the distance between the 2 locking stow grommets, it is usually between 4 and 6 inches. If you make 2 inch stows, then there is 8 inches of line outside the stows and only 4 to 6 inches of lines between the stows. This makes it difficult for the lines to fall out of the stows. Incidents where the canopy comes out of the d-bag before line stratch are rare and Dacron lines, loose stows and a big PC are usually at fault. Derek

I hear this often, but it isn't true. As long as the locking stows remain in place until line stretch, the rest of the lines don't matter. Take a look at reserve free-bags or the new no rubber-band main d-bags that are being developed. The only lines that are held in place are the locking stows, the rest are coilled in a pouch. Tight stows lead to bag locks, not better openings. Derek

Containers are sized to fit canopies and harnesses are desinged to fit people. To find out what size harness you would need, download the order form and it should tell you exactly where to measure yourself (or be measured). Send this information to Sun Path and they can tell you what size harness would fit you best. Derek

Open the door and dive out. Looks just like a Cherokee, which I've jumped. Actually did a 2-way out of one. Make sure the pilot understands you'll be destroying a lot of lift and adding drag to the right side. http://www.fotoimages.com/images/aircraft/BE7901.jpg Derek

Never thought otherwise, the 1 instructor side discussion got started in response to: Derek

Be careful here. If your Fox 265 was a 9-cell air locked ZP, it could land you softer than your 150-sq. ft. 9-cell ZP air locked canopy. A smaller canopy does not necessarily land you more softly than a larger canopy. In fact I would argue that the opposite is true, all other things being equal. What would land softer, a 100-sq. ft. F-111 square 7-cell or a 200-sq. ft. ZP 9 cell? Fabric type, aspect ratio, and canopy design play critical roles in how a canopy performs and lands. Derek

Not sure if this qualifies, but I've seen a main pin get pulled by someone giving a gear check. Derek

Bill Booth posted about Ace Pure Silicone Lubricant back in Oct, 2002. I got the idea from him. He gets the credit. Derek

I have seen a tandem passenger open the reserve flap of en experienced jumper. I asked him what he was doing and he said he didn't know, but everyone else was doing it. A gear check from someone that doesn't know what to look for or how to properly re-close flaps is worse than no gear check at all. I have seen numerous people re-close a newer Javelin reserve flap without tucking it into the bottom flap. I have had to reclose Kelli's reserve flap in the aircraft because someone opened it (without her permission) and couldn't get it re-closed. Some main tuck tabs are more secure tucked between the side flaps instead of under the top main flap. A proper gear check is a good thing. Asking before you give a gear check is appropriate, Giving a gear check before asking or being asked is not. Always be careful moving around in the aircraft and be conscious of your and others gear. Derek