relyon

Night jumps, CRW, and open water? What could possibly go wrong? Bob

The latest issue of Parachutist that I have (Sep '07) has a 15-way CRW formaton on the cover. I could be wrong, but I believe everyone on the load is American. Like many, I have problems with the content of USPA publications, but the nationality of those in the photos is of no concern at all. Bob

Two things I can think of: The "more fabric out" theory. With small round reserves, I'm inclined to agree. Round reserves are better if not cutting away - it won't fight the main (eg. downplane). They may also be better over tall, tight forests. Cutting away from a wrap/entanglement you can't get out of is likely to use valuable time and little else. As far as reserve size, I have no idea. I'd rather have something larger within reason. Bob

It's assumed that the canopy and/or suspended mass (eg. the jumper) is [close to] ideal as well. If the lines aren't exactly matched, the drag isn't balanced laterally, etc. the canopy could turn for reasons other than the wind. In those cases it won't stop turning either. Other than wind shear (for the reasons given), wind does not turn a canopy. Bob

stratostar and DSE: I certainly see both of your points and don't question either in any way. I very much agree with your views as to integrity and holding one's self (or being held to) to a higher standard, whether legally mandated or not. My point was that the risk to an underage child is the same, regardless of who is at the "helm", be it skydiving, motorcycling, or [insert high risk activity here]. I've been to every state except ND and currently live in Austin, TX. Since I've never rode any sort of motorcycle, I don't know what laws or regulations apply to them. I've seen the scenario I described many times in many places (notably in UT and TX, among others). I've seen police giving tickets for speeding a few miles over the speed limit completely ignore those on motorcycles. Bob

Thanks for the clarification. I see this issue has brought out some fairly strong emotions. I'm curious though. How does taking an underage individual for a tandem differ from putting them on the back of a motorcycle and blasting off down the highway? Many times I've seen kids with no helmet or other safety gear clinging on to a driver who's doing 70+ mph. Bob

As with many topics, I prefer to keep my opinion to myself on this one, but I've got to ask: What is illegal? I've gone over FAR section 105.45 several times and don't see anything regarding age in the regulations. Am I missing something? Bob

In CRW it's often important to have wingloadings that are generally close to what everyone else has and that are appropriate for the both the canopy (eg. Lightnings fly better at 1.3 and higher) and the application (competition, bigway, recreational, etc). Line length and trim play are important as well. For most other general use, I'd probably upsize to the 1.0 to 1.2 range, and maybe have an AAD and RSL as well. While I've been comfortable in the setup I've had for quite some time now, a little more margin of safety would be ok as well. Bob

While it may have been the first planned chuteless jump, but it was definitely not the first. My 84 year old uncle piloted a B-17G out Foggia, Italy during late 1944. During the time he spent in a prison camp in Barth, Germany (sometime between Dec 1944 and May 1945), he personally spoke with a bomb crewmember who had no chute at all. He has a autographed picture with him sitting next to the guy in the prison camp infirmary. Apparently, the guy's A/C (a B-24, IIRC) was hit by flak and he was thrown clear while it disintegrated. He didn't have his chute on at the time, since they were bulky and interfered with operating the guns (ball turret gunners didn't wear them in the turret at all, due to space constraints). He found himself in freefall at 24000', certain he was going to die. Amazingly, he didn't. At the time his A/C was hit, he was returning from a mission and was over the Bavarian Alps. He fell into deep snowdrifts near the top of a very steep mountain. He was seriously injured when the Germans found him, but they didn't shoot him. The guy was quite the celebrity, which may be why they spared him. Whether the incident was actually the first chuteless jump or not is anyone's guess. I do know my uncle has never been fond of skydiving. His first and only jump was over Poland in Dec 1944 under less than ideal circumstances. The whole crew got out ok, but his copilot's chute totaled and he bounced. Everyone else wound up in prison camps until the war ended. Bob

FWIW, I've used the one hand per handle method and never had any problems with cables clearing in 9 cutaways. The one time I wanted to cutaway but couldn't, my teammate's cutaway canopy was fouling my left three ring and I doubt it would have released. I had bigger problems the time, being cocooned from the neck down with no access to either the cutaway or the reserve handles, the altimeter, or any hook knives. Fortunately, I had a good canopy and minimal access to the toggles. I posted some related thoughts here a while back. Bob

You did ... I think LloydDobbler's point was that the term "professional" means he was paid for it, and I tend to agree. I'm a professional offshore helicopter pilot - I get paid for doing that sort of work. I'm not a professional CRWdog even though I'm highly experienced at it - no one pays me to do CRW. YMMV. Bob

Perhaps you were. When I compare the risks of instructing helicopter students to putting out jumpers, I come to a different conclusion. At least with students, I know who is trying to kill me and have some idea as to how. I'd love to have my fixed wing commercial and put out jumpers on weekends for fun, but easy or without risks it's not. Perhaps because as the final authority with respect to all aspects of a given flight operation that responsibility is ultimately the PIC's? Bob

With A/Rs generally between 2 and 3, they're not very high or very low. Similar results would be seen if observing an SR-71 or the Shuttle during landing. In every case the subject aircraft has an very low A/R (less than 1.0), is experiencing significant ground effect, has power on engine thrust (except the Shuttle - and it shows), and is under dynamic conditions. The same aircraft gliding steady state power off appears to drop out of the sky. Those do have very low A/Rs (below 1.0). Take a look at the L/D ratios at 30 degrees - they're around 1.3. I don't about you, but I'm not a big fan of my steady state flight path on final being around 40 degrees to the surface ... Bob PS - I'm guessing the NASA ram air wing study was not using ZP, either. I'm fairly certain that would have affected the results.

I checked other. Not being trained or certified, I know I'd be more in the way than anything, so I'd probably move along and encouage others to do likewise unless I was specifically being asked to do something by someone who was. If I was the only one there at the time, I'd do the minimum necessary - pull their head out of water, compression to prevent arterial bleeding, move the person if they're in any further immediate danger, etc. - until more qualified help arrived. Such a thing happened in front of my teammates and I while we were waiting for the plane. In the early days of swooping before swoop ponds ("turf surfing"), a guy hammered in and compound fractured his left femur in front of us. Fortunately, one of my teammates was an EMT and went right to his aid. While I didn't interfere, I did notice it was blowing pretty hard. So I cutaway the main ASAP, then helped my teammate get the guy out if his rig. Since I couldn't be of any more direct aid, I got out of the way and encuraged others to do the same. Bob

Turbine airplanes must have a approved terrain awarness and warning system. Other turbine aircraft are not mentioned in 91.233. Bob

My point was that the statement that F111 7 cell reserves were "not designed for having several hundreds of jumps" is misleading. There is nothing about the basic canopy design (airfoil, planform, lines, material, etc.) that cannot accomodate that many jumps. I gave the PD main/PD reserve canopies as an example; there are others. Whether one wants to jump that kind of canopy that much is very different than whether or not it can be. How a canopy is wingloaded in practice is an entirely different issue from what the canopy as a whole was designed for. All the F111 mains (and the reserves mentioned) beyond student status I'm aware of were loaded above 1.0 but below 1.5. All flew and landed just fine - repeatably. As has been the topic of numerous posts, this could be a problem. While admittedly, reserve wingloadings less than 1.0 may be unnecessarily low, they can easily get too high as well. Trade a 79 sq ft 9 cell ZP pocket rocket loaded at 2.0 for a 99 sq ft 7 cell F111 reserve loaded at 1.6? A broken femur (or worse) following a "sucessful" save is embarassing ... at best. I'll pass. Bob

This appears to be in contradiction. To my knowledge, the design (7 cell), airfoil, planform, material (F111), lines, and even trim for the PD reserve canopy series was identical to the PD main canopy series while the main series was still being manufactured. PD mains were used for hundreds of jumps, and while the reserves were/are used decidedly less, it's not that they couldn't be because of a basic design limitation. I know plenty of CRWdogs who have 30-40 reserve rides on the same reserve who notice no difference whatsoever in flight characteristics or flare from the first jump to the most recent. Bob

I've had a reasonable amount of gear, but only a couple types of each. Different sizes of the same main canopy type are counted separately. Close to 1200 jumps were on PD Lightnings (mostly the 126 and 143 sizes). Mains (4): Aerodyne Triathlon 170 PD Lightning 126, 143, 160 Harness-container/reserve (2): NLE Infinity I2.3/Tempo 170 (2 systems) NLE Northern Lite III/Tempo 210

While a stall does produce a loss of lift, not every loss of lift is due to a stall. While a canopy lying on the ground uninflated or one experiencing a net downward force in flight can produce insufficient lift (or no lift), there is no flow separation and it's not a stalled. Bob

Airfoils don't stall because of lack of airspeed, but rather exceeding the stall AOA. The result you describe is still a gift wrap (as is good CRW gone bad), but it isn't due to a stall. Bob

Assuming that the pilot was flying more or less straight with minimal inputs, there are a number of things that can cause a whirlie/wrap in that situation. From the person docking's perspective: coming up too fast, coming inboard (toward the pilot) too fast, and coming forward too fast. From the pilot's perspective: hardpointing the grip, putting more than minimal brake inputs, or twisting in the harness if hands are being used to take the grip. It's often one or more of the above in combination that produces the result you saw. There are several schools of thought, but most nowadays involve approaching largely in front risers with minimal use of brakes (usually in a "stabbing fashion"), most often from an approach point that is on the same or slightly higher level than the docked position. I prefer using both front risers, or a combination of inside front riser countered by outside rear riser as necessary. Brakes only in small, stabbing motions and as little as possible. One of the best drills you can do for offsets is no contact CRW. Fly the wedge or stairstep in as tight a formation a you can without actually picking up grips. Six inches to a foot from an A line attachment point to the target foot that takes the grip is ideal. The canopy should never make contact at any point; the pilot's job is to fly straight with a little input as possible. Bob

As Frank pointed out, both degrade performance, particularly the nose reinforcement. They are over-engineered (as is the tail pocket option) and while that isn't a bad thing in and of itself, it does add significantly to pack volume when the same end could be achieved with far less material and/or more careful packing.

No nose reinforcement. "Mesh" entered for the slider color - they are all white. 9' lines (for a 143). No topskin buffers. You may want to get in touch with Rusty Vest at PD as soon as the order is placed. He can ensure that your order is handled properly and answer any additonal questions you may have. 'skies, Bob

This is how CRWdogs take care of their own: The person under the reserve's job is to get down safely, preferably back to the DZ if possible. Ideally, another person makes sure they're okay and accompanies them. At least one or more follow the gear and bring what they can home. During the 2003 world record at Lake Wales, there was a 44-way (building toward the 70-way) that funneled. There were 6 cutaways, with lots of gear and people to chase. In the end, all six reserve rides landed at the dropzone and all gear was accounted for. I've been on 2-ways where the other guy had to cutaway and after checking on them, I followed their gear down and retreived it, and caught up with them later at the DZ. Bob

This sounds like a case of the the stagnation point moving onto the top skin. The stagnation point is the point where an air molecule comes to a stop. Those above it go over the topskin; those below under the bottom skin. Usually, it is in front of the nose, but if it moves onto the topskin, it will [partially] collapse the canopy. When that occurs, lift is lost, the canopy drops/dives, the stagnation point moves back to a lower point, the canopy reinflates, lift is restored, then the process starts again. The result feels like the bucking you describe. It is entirely possible to induce this by pulling one or both front risers far enough such that the stagnation point moves significantly higher. I've done it many times myself. Line trim may be the problem, but I doubt that given the number on jumps on the canopy. Wind/turbulence may also be part of the problem, but it's more likely from pulling too much front riser for the particular canopy and trim. Bob