sacex250

Ouch, this is going to hurt! I WAS WRONG! My apologies to: Zlew davelepka pchapman strop45 DaVinciflies rehmwa Martini Remster and billvon Crap, what a list! I remember when I was taking my original flying lessons 20 years ago, and our flight school had a poster on the wall with the 10 rules for cadet airman from 1920 or something. One of the rules was a warning about the downwind turn. I laughed and told my instructor that was funny, and he glared at me and said, "No, that's true." I said, "Uh uh, the airplane's flying with the wind it doesn't matter." He then proceeded to explain to me how I was wrong until I believed him. Like I said, "quality of instruction." So, pretty much everything I said was wrong. That is all. -- It's all been said before, no sense repeating it here.

My original point was about airplanes, skydivers don't have enough mass for it to become a factor, so you're probably safe. -- It's all been said before, no sense repeating it here.

Oh please, do you really not understand that the part of the tire that is in contact with the road has to come to a complete stop each revolution and the top of the tire is moving twice as fast as the car is? If the car is going 60 mph, the bottom of the tire that's going the same speed as the ground is physically stopped and the top of the tire is moving forward at 120 mph. What a brilliant idea, if you can't feel motion if your inside a different medium, let's fill the cockpit of a fighter jet with water, give the pilot some SCUBA gear, and that way he won't feel the G-forces. Brilliant! The goldfish, the pilot, or a skydiver will feel a force of acceleration if there is a change in speed or direction no matter what medium he, or it, happens to be in. -- It's all been said before, no sense repeating it here.

No, the turns won't be perfectly circular, they will only look perfectly circular from your vantage point. Your ground track will look like something made with Spirograph. Let's say the clouds are moving at 20 knots, and you are orbiting above them with 20kts of airspeed. On the downwind leg, your groundspeed is 40kts, but on the upwind leg, you come to a complete stop hovering in the air while the clouds go by you at 20 kts. It looks like you're flying past them, put you're really stopped in mid-air while they go by you. Then as you turn downwind, your parachute (flying at 20kts airspeed) accelerates from 0 to 40kts in the turn until you're outracing the clouds; they're travelling at 20kts, you're doing 40kts. Then you turn upwind again and come to a complete stop while the clouds pass you by again. Your airspeed may be constant, but you are physically accelerating and decelerating each time you fly around the circle. That is a real force that you and your parachute will feel, it doesn't matter whether you're hanging in mid-air or riding in a car. -- It's all been said before, no sense repeating it here.

Have you ever flown a parachute in 40kt winds? I was using Bill's example. So, if you took a fish up in an F-16 and did a 9G turn, you don't think that the fish would feel the force of the change in direction? I guarantee that the fish would feel the 9G's. If you took the fish up in the parachute experiment, the fish would also be able to feel not just the steady turn, but also that it was speeding up and slowing down during the turn. How about a valve stem on a car's tire? As the car is going down the road at 60 mph, the tire rotates at a constant speed but the valve stem comes to a complete stop when it's at the bottom of the wheel, and then rapidly accelerates to almost 120 mph when it is at the top of the wheel. Going from 0 to 120 to 0 again with each rotation of the wheel is quite an acceleration/deceleration. A skydiver flying in circles in a strong breeze is just like the valve stem on the car. Speeding up and slowing down with each turn. -- It's all been said before, no sense repeating it here.

3) The accelerational forces of physically speeding up and slowing down during the turn. Check out the following video: The riders are going around in a circular steady turn, but are being rapidly accelerated and decelerated by the overall rotation of the ride. http://www.youtube.com/watch?v=q8sSALDUCtE It's the same situation a skydiver would feel while doing flat turns in a strong wind. You seem to think that because the riders are going around in steady circles in their cars then they cannot possibly feel the effect of their total motion on the ride as a whole. Yes, they can! -- It's all been said before, no sense repeating it here.

It is time to move past DaVinci to Newton! A flying airplane is just as connected to the Earth as the moon is. The physical mass/inertia/motion/momentum/energy/hurtling speed of an airplane has NOTHING to do with the airmass! The airmass exerts a force on an airplane, or bullet, which can affect its inertia, but the physical forces at play have to do with its speed through space, not the air! An airplane in flight is bound by the same physical laws of motion and gravity whether sitting on the ground, floating in water, or orbiting the planet. Here's a skydiver flying into the side of a hangar: 20kt airspeed, 10kt headwind = 10kt collision 20kt airspeed, 10kt tailwind = 30kt collision 20kt airspeed, 20 kt headwind = impossible to collide with immovable object if you're not moving! The airspeed has nothing to do with the inertia of the skydiver, the inertia is completely dependent on the object's relative motion through space, and our main reference point of motion here on Earth, or in orbit, is the Earth, not the airmass. -- It's all been said before, no sense repeating it here.

Sorry, wasn't referring to a spiraling turn there. I was refering to the flat turn. Let's say a 40 knot wind from the north and a parachute doing a 15 knot flat turn to the left. The diver starts out with 25 knots of southbound inertia (backwards). As the diver turns to the south he begins to accelerate to 55 knots southbound but the parachute accelerates faster than he does causing the parachute to descend/pitch down to accelerate the diver. Once facing south, the diver will have a groundspeed of 55 knots and an airspeed of 15 knots, of course, discounting any recovery arc or pitch up to make up for the pitch down. Continuing the turn back to the north, the parachute starts to slow down but quicker than the diver does, causing a climb/pitch-up as the diver swings forward of the parachute as his speed begins to slow from 55 to 35. Even though the diver is basically flying at a constant airspeed of 15 knots, his body is constantly being accelerated and decelerated as he's basically being whipped around on the downwind side of the turn, and slowed down on the upwind side. The diver would definitely feel this force. -- It's all been said before, no sense repeating it here.

Which is why I mentioned "quality of training." An airplane's inertia is its energy through space not through the air. Airspeed is the combination of the airplane's physical inertia combined with any independent movement of the air. "Quality training" would go a step further than just flying a plane in reference in the ground to illustrate how an airplane flies is still determined by how it's moving in relation to Earth not just to the wind. A change in wind speed is not an instantaneous change in the airplanes physical inertia; an airplane has more mass than the air does and therefore will not change inertia as quickly. The physical speed of an airplane in level flight is its groundspeed no matter how strong the wind is or what direction it's coming from, just as an airplane tied down on the ramp is always stopped no matter how hard the wind may blow even though the airspeed indicator may be showing that the airplane has airspeed. If a pilot of an airplane with a stall speed of 30 knots is flying into a headwind of 40 knots at an airpspeed of 40 knots then the groundspeed is zero because the airplane is hovering in mid-air. If the headwind suddenly dies down to nothing, the airplane will still have a physical speed of zero and will instantly stall and start falling until it can regain it's speed by descending and/or powering out of it, which is what is happening in the F-22 video above, The F-22 can maintain control even though it's fully stalled because of its thrust vectoring and fly-by-wire control system, but even it can't stay in the air when stalled. It is entirely possible to turn a light airplane flying at a slow speed faster than its engine is capable of accelerating it in level flight. If the airplane turns away from a headwind in a level turn and the airplane doesn't have the power to accelerate the mass of the airplane to make up the difference then the airplane will lose airspeed, and, it may stall if it loses enough airspeed. Imagine a helicopter hovering into 25 knot headwind, airspeed is 25 knots, groundspeed is zero. If the pilot does a 180 pedal turn, the airspeed drops to -25 knots (flying backwards), but the groundspeed is still zero. In order for the pilot to regain his 25 knots of (forward) airspeed, the helicopter will have to, completely under its own power, accelerate from a groundspeed of 0 to 50 knots. That will take longer than the pedal turn did. So, if the pilot wanted to maintain his 25 knots of airspeed, and turn downwind, he would have to be patient and turn slowly to allow the helicopter to accelerate away from the hover to a groundspeed of 50 knots all while maintaining an airspeed of 25 knots. It's not as easy as it sounds. -- It's all been said before, no sense repeating it here.

Momentum is inertia not G-forces. Speed has everything to do with momentum. It is acceleration that causes G-forces. In training pilots do ground-reference maneuvers like "turns around a point" and "S-turns across a road". This training demonstrates that the downwind and upwind turns are in fact quite different. The downwind turn is flown with a steeper bank angle because the airplane has a higher ground speed on the downwind side of the turn; it's the ground-reference part that illustrates this point, or hides it depending on the quality of instruction. You have quite a bit of inertia/momentum but if there's no acceleration taking place then there won't be any force. A change in inertia requires force. The airspeed has nothing to do with the airplane's mass. The airspeed can change much faster than the airplanes physical speed through space can. This is the underlying concept of windshear. If an airplane is flying into a headwind and the wind suddenly changes direction then the airplane can suddenly lose airspeed without the airplane's groundspeed changing. The point here is that an airplane can turn quicker than it can accelerate in a straight line. If the turn causes a significant change in wind direction it can cause a rapid change in airspeed. --- It's all been said before, no sense repeating it here.

A couple problems with this: 1) A spiral is forward movement vertically in a column of air. The winds would be nullified. Try it in a flat braked turn though. 2) A parachute is not capable of a sustained constant airspeed level turn. 3) A skydiver has very little mass and would accelerate and decelerate very rapidly by pitching up and down during the 360's. It would be a wild ride, and the skydiver would definitely notice the G-forces as the parachute's energy increased and decreased during the turns. -- It's all been said before, no sense repeating it here.

Yes, there are many airplanes both certified and homebuilts that can fly at 30 knots, not to mention ultralights wihich are required to have stall speeds of 24 knots or less. How long does an airplane take to accelerate its mass on a runway from 5 knots to 55 knots? And that's without induced drag. An airplane with an airspeed of 30 knots and a vector momentum of 5 knots can basically turn as fast as a shopping cart. Bottom line: Airplane's mass has to accelerate from 5 knots to 55 knots, while airspeed is falling from 30 knots to -20 knots. -- It's all been said before, no sense repeating it here.

Actually, that is a true phenomenon, but the airplane has to be flying slowly in a strong wind. Imagine this: You're flying along at 30 knots into a 25 knot headwind, groundspeed and the airplane's physical momentum are both 5 knots. The pilot then does a quick 180 in a matter of seconds whch isn't too difficult to do with 5 knots of momentum. So, the airplane is turning downwind to a tailwind of 25 knots, AND has to accelerate its physical mass from 5 knots to 55 knots but at an airspeed of negative 20 knots. The airplane will stall at some point in the turn! -- It's all been said before, no sense repeating it here.

And of course, the one everyone missed, don't forget the ATC notification. It's all been said before, no sense repeating it here.

That may be true for parachutes, but it's not true for airplanes. A lighter airplane will have a lower rate of descent, but best glide speed will remain constant at any weight. The pilot has absolute control over the speed of an airplane with or without engine power. -- It's all been said before, no sense repeating it here.

Isn't that what I just said? Wouldn't it be easier to get the "site picture"[sic] if there is some consistent way of knowing what altitude you're actually at? What I find laughable is that you and the OP think that a simple altitude beep will somehow turn someone into a blithering idiot. Skydivers were turning into *beep*ing idiots long before anything started beeping. -- It's all been said before, no sense repeating it here.

No, it isn't what the sport has come to; it's where the sport is going! I don't know of many skydivers who are cyborg "Terminators" with built in laser-ranging eyes, built-in altimeters, or built-in GPS receivers. Using an audible with canopy alarms merely provides a reference point so that jumpers can fine-tune their visual perception of altitude and do it far more accurately with less workload. How can that hurt? -- It's all been said before, no sense repeating it here.

Love the signature, but I've got a suggestion: The probability of survival is inversely proportional to the angle of arrival. -- It's all been said before, no sense repeating it here.

It was actually K-mart that stopped selling ammo because of Michael Moore and Bowling for Columbine. - It's all been said before, no sense repeating it here.

In this case, they don't need a warrant because of a specific exigent circumstance of protection of life. They received a phone call from the guy threatening to kill himself; a warrant is no longer necessary to protect someone in imminent danger. It could also be argued that this could be a consent search due to his having "invited" the police to his home to help him. An another note, what it is about this freaking country that prohibits us from seeing nudity as anything other than perverted, dangerous, and obscene? - - It's all been said before, no sense repeating it here.

How about Blind Pilot Collisions? For example: "Did you hear there was another BPC at Perris? I guess they never saw it coming!" - It's all been said before, no sense repeating it here.

1) Require a fairly extensive canopy training course for the A license. Someone who doesn't have an A license isn't the problem. A student on a lightly loaded canopy is going to be flying, or trying to fly, a slow, normal basic pattern anyway. That's what they should be trying to learn, and if they can't do that then more advanced canopy training becomes irrelevant. 2) Implement Brian Germain's downsizing chart as a BSR. While Brian Germain's chart is useful as a reference, it has some serious shortcomings that make it unrealistic to use as an enforced rule. The chart only combines three factors: exit weight, canopy size, and number of jumps. It doesn't take into account the design and performance differences between canopy models, it doesn't differentiate between how the canopy is intended to be used, and it doesn't account for a skydiver's skills, training, and attitude. Compare this to paragliders, where wings are uniformly rated according to skill level and safety. 3) Implement a NO passing rule, lower canopy has the “right of way” and you must not over take them. This isn't realistic. In every other facet of aviation, there are right-of-way rules for converging, overtaking, and sequencing to a landing area. How do you outlaw overtaking or "over-descending"? It doesn't matter if one canopy is faster than another if they're both flying a logical pattern and the faster canopy is practicing "see-and-avoid" which a no-passing rule would require anyway. It's the lack of "see-and-avoid" and therefore yielding to another canopy that's the problem. Not to mention, a traffic jam behind a slow canopy doesn't work in the air anymore than it works behind a slow car on the road. 4) Segregate canopy landing areas by wing loading. Split landing areas into two, fast canopies land over here slower canopies land over here. Again, one canopy overtaking another canopy isn't the problem; it's people not seeing each other and failing to properly yield to each other. "Circle of Awareness" is such a big deal during freefall training, but it needs to be an even bigger deal under canopy. Having a "head-on-a-swivel" looking for traffic and not just focusing on the landing area is what's going to make "see-and-avoid" work. I've seen very view videos of camera flyers thoroughly looking all-around them while under canopy. 5) Ban all HP landings (AKA swooping) on normal skydives and put into place rules that minimize any turns (must fly a standard pattern). Require a separate isolated pass for any type of HP landing. Separate landing areas, sure, like DZO's are supposed to be doing all ready, but removing traffic and giving individual swoopers priority use of airspace, as restrictive as it seems, only builds bad habits by taking away the reason to be looking for traffic in the first place. It's not the airspace environment that's causing collisions, it's pilots not proactively trying to see-and-avoid other jumpers. Allowing swoopers to become complacent in their own protected airspace bubble isn't going to make them any safer when they do end up having to play nice with others. Recommendations: 1) Better analysis of what exactly causes a collision or near-miss. 2) Having an observer on the ground, or video equipment, that monitors landing traffic looking for situations that could lead to conflicts and immediately providing feedback to a jumper who did something that encroached on another canopy. Or, bringing a dangerous situation to the attention of a jumper who may not have been aware of it. 3) Creating an affirmative way for jumpers to bring their concerns about specific actions or behavior from certain jumpers to the attention of the DZO. - It's all been said before, no sense repeating it here.

Dog repellent, or possibly shark repellent, depending on which way the wind is blowing. It's all been said before, no sense repeating it here.

Here's an idea, let's simplify this whole argument with a new hypothetical poll: Do you consider a pilot chute-in-tow to be a high-speed parachute malfunction along the lines of a bag lock or horseshoe, or is it a high-speed container malfunction along the lines of a hard pull or lost handle? It seems to me that your personal answer to that question would determine which EP is used. (1) Obviously, the most immediate risk during a pilot chute-in-tow, whether or not there is a cutaway, is that the reserve pilot chute might get entangled with the main pilot chute fouling the reserve deployment - a bad, bad situation. There is no advantage to having cutaway the risers at this point. (2) Having avoided (1), the next biggest risk is that during or after deployment of the reserve, the pilot chute-in-tow spontaneously clears causing the main to deploy resulting in a two-out situation with three possibilities: both parachutes operate normally, one or both parachutes malfunctions, or they become entangled. During the reserve deployment, there is only a small window of opportunity for the main to foul the reserve prior to opening shock, reserves are required to be open in three seconds, so entanglement can only occur within about a two second window. Again, there is no advantage to having already cut-away a perfectly good parachute that hasn't malfunctioned yet. If they don't entangle, it's now a two-square situation with its own EP's based on the situation. If one of the parachutes malfunctions, preferably the main, it can still be cut-away if necessary. If it's the reserve that malfunctions then there is no advantage to having already cut-away a perfectly good main parachute. If the parachutes entangle then there is no advantage to only hanging from one entangled parachute instead of two. What if the main suddenly inflates and gets ripped away from the reserve and you're not attached to it? Is the reserve going to untangle and reinflate in time, i.e. before ground contact? Why cut-away a parachute that hasn't malfunctioned yet, especially, if cutting it away has no immediate effect on improving the odds of a successful reserve deployment? To me, it's a high-speed container malfunction with an appropriate EP, the same as a lost handle, in this case an extremely lost handle. Don't cutaway, pull reserve, but be ready to cut-away the main at any time if it should suddenly deploy before you're on the ground. It's all been said before, no sense repeating it here.

I think you're going to need 600 bags, double-bagging for those heavy items. It's all been said before, no sense repeating it here.