kallend 1,672 #51 September 27, 2009 QuoteOne bad spotter can hose a whole planeload of lemmings! So you'd suggest that on, say, a 120-way that each jumper stop in the door and check the spot for him/herself. I don't think you'll be invited on many big ways.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
MikeJD 0 #52 September 29, 2009 Quote Quote One bad spotter can hose a whole planeload of lemmings! So you'd suggest that on, say, a 120-way that each jumper stop in the door and check the spot for him/herself. I don't think you'll be invited on many big ways. On a 120-way, all the jumpers are part of the same group (at least that's the plan! ). Everyone clears the aircraft within a few seconds, and in any case the super floaters and the late divers - even though they'll be to some degree spread along the jump run on exit - are going to be converging on the base. Thus the entire plane(s) load gets the same spot. However there is a case, and an opportunity, for smaller separate groups and solos to check where the aircraft is by the time they come to climb out. Quote Share this post Link to post Share on other sites
Travman 6 #53 September 29, 2009 Some dropzones in Australia are allowed to punch cloud. There have been many many times when I have jumped without being able to see the ground, so you really have to trust the pilot. There have been a few times when I have come through the cloud base and looked at the ground and realised it was a bad spot. Quote Share this post Link to post Share on other sites
MikeJD 0 #54 October 1, 2009 QuoteSome dropzones in Australia are allowed to punch cloud. Are they actually allowed to, as in it being approved by the APF? Or do they just do it? There's a heck of a lot more cloudbusting than there used to be since GPS became so universal, but I'm curious as to the reasons why only some DZs would be exempt (assuming they all fall under one national governing body). Quote Share this post Link to post Share on other sites
muff528 3 #55 October 1, 2009 QuoteOne bad spotter can hose a whole planeload of lemmings! Sunset load a few years ago. Yep, it was a lemming jump. 10 or 12 of us and only one looked down during freefall. He opened high and landed only 2 miles out. Got an "Oh Crap!" feeling while looking at the sunset over the DZ on the horizon after opening. Quote Share this post Link to post Share on other sites
pchapman 262 #56 October 1, 2009 QuoteQuoteSome dropzones in Australia are allowed to punch cloud. Are they actually allowed to, as in it being approved by the APF? Or do they just do it? I don't jump there and haven't reviewed the Aussie rules in detail, but a CASA (Aussie civil aviation authority) document is out on the web. It specifies a bunch of responsibilities for the pilots, DZO, jumpers, manifest, local airspace authorities, and so on. A risk analysis has to be conducted. A DZ must specifically request to to do cloud jumping at a particular location, the parachuting federation must approve their application, and then the CASA has to consider and approve it too, with any modifications they deem necessary for reasonable safety. Approval must be renewed every few years. So it is much more than just "you can do it in such and such airspace class". Quote Share this post Link to post Share on other sites
Baksteen 84 #57 October 2, 2009 Quote Quote One bad spotter can hose a whole planeload of lemmings! Sunset load a few years ago. Yep, it was a lemming jump. 10 or 12 of us and only one looked down during freefall. He opened high and landed only 2 miles out. Got an "Oh Crap!" feeling while looking at the sunset over the DZ on the horizon after opening. Hah - that reminds me... "That formation-stuff in freefall is just fun and games but with an open parachute it's starting to sound like, you know, an extreme sport." ~mom Quote Share this post Link to post Share on other sites
brettski74 0 #58 October 2, 2009 QuoteAre they actually allowed to, as in it being approved by the APF? Or do they just do it? There's a heck of a lot more cloudbusting than there used to be since GPS became so universal, but I'm curious as to the reasons why only some DZs would be exempt (assuming they all fall under one national governing body). To be allowed to punch clouds in Oz, you need to come up with a set of rules and procedures which conform to CASA guidelines and have them approved. This is why some dropzones may be permitted to punch clouds but others are not. That's not to say that some of these other dropzones don't just do it, too, but if they're not approved, I guess they've done a different type of risk analysis. Having jumped at such a dropzone, among the paperwork I had to read and sign when I arrived was the cloud jumping procedures document, a copy of which I was to sign at the bottom indicating that I'd been informed of the rules, had the opportunity to ask questions and that I understood and was willing and able to comply with those procedures. Quote Share this post Link to post Share on other sites
erdnarob 1 #59 October 5, 2009 Yes bad spots exist and for many reasons such as : 1) pilot's mistake or GPS system temporarily out of service 2) poor visibility of the ground seen from 13500', clouds, haze... 3) first jump of the day and people taking a guess 4) winds aloft quite different than those on the ground level 5) first group too slow to exit 6) first group exiting way too early because of many other groups following including tandem ...etc Generally spots are OK but one bad spot could lead to disaster like dropping jumpers in the water, on a mountain slope, in town, in an industrial area... Not being able to get back to the DZ is in my opinion a source of potential hazards. Anything can wait for you at landing like moving vehicles, electrical or telephone lines, junk yard, trees or even alligators... I am at a DZ where we have a lot of place for landing even if we miss moderately the spot. I remember a couple of years ago when a VIP came for a tandem jump accompanied by wife and several employees. It was the first jump of the day and a warm weather front was coming for the South West. The person in charge of the spot took a guess according the winds at the ground. Unfortunately, winds aloft were up to 45 knots. First they drifted badly in freefall because of the winds above the opening altitude then the tandem and cameraman couldn't crab enough to come back in the landing area. They all landed in a field at 2 miles from the airport. I was at the ground trying my best to answer wife and employees questions about such a situation. That VIP was director of a hot air balloon festival and it was no wonder we have never been invited to do a parachute demo at this festival. That prompts me to think about a program to calculate the spot given the winds at different altitudes from the aviation forecast. A friend of mine mentioned he was going to design a computer program using EXCEL to do so. Since I have a HP 48GX graphing calculator I tried to do a program on this calculator and succeeded to get one working fine. My program is using 10 wind data (5 speeds and 5 directions). Winds are given every 3000 feet. I use the winds at 12000, 9000, 6000, 3000 and at ground level and enter the 10 data in a specific order. One push on the menu SPOT and I have for instance : 4700 feet at 245 degrees. I use a satellite picture of the airport and draw radials and 500 feet circles on it and it is easy to show people where to exit and for the pilot to show him the best direction to take on the jump run. Anybody interested to get my program is more than welcome. It is well explained.Learn from others mistakes, you will never live long enough to make them all. Quote Share this post Link to post Share on other sites
