nwt

Interesting. So the 2:1 ratio you mention is the area of region B to area of region A in your diagram? Or the volumes? Do you have a source for this actually being a contributing factor for the worse accuracy in vertical?

$5/jump adds up to AAD money pretty quick!

Very cool projects! If this is the culprit, I bet it's the fact that the speed is so vertical. I don't think that's true but maybe there's some geometry and/or statistics thing I'm missing This is true though. I haven't found a great explanation for why, but I'm thinking it's because we get satellites in all directions horizontally but only across 180 degrees vertically? This answer from Garmin is pretty vague but it sort of hints at what I'm saying.

Everyone is entitled to their opinions, but some opinions are wrong and deserving of ridicule.

Ironically, if aircraft electrification does take over, my idea for building cheap tunnels with unwanted turbines may actually become feasible...

This is the kind of math I've been wanting to see and I've been pretty skeptical that it would come out favorable. The cost savings in fuel looks much more compelling without this context, and that seems to be the main driver of enthusiasm. Another really important point that is obvious now but hadn't occurred to me.

Speech is an action, not a thought. If you can't tell the difference between speech and thought, the medical term for that is hallucination.

Hi everyone! I got my A license October of last year and have mostly been lurking since then, but I've found myself posting more lately so I thought I'd say hi. I'm Nate (New Nate if you like) and I'm from a tiny Cessna DZ in the middle of nowhere, but I also jump at CSC and SDC. My main focus is 4-way FS, but lately I've also started playing with my canopy more now that I have one that's good for that, and I might start to dabble in free flying once I get a new rig that's better-suited. I plan to get my coach rating in 2021, hopefully get really good at FS, and who knows what else... I'll be at Paraclete in a couple weeks and then Invasion boogie at Sebastian if anyone wants to jump!

I'm new but I got a pair of these because they seem like the go-to and I wasn't disappointed. I wear them every jump and in the tunnel. White to get those points.

I agree CFR wouldn't be the right tool for looking at spread of the virus, but that isn't what we were doing. We were looking at which country is having better outcomes than the other in the metric of keeping COVID patients alive. CFR is the right tool for that job. Deaths / total infections isn't really used for anything to my knowledge. It feels like it wants to be CFR but it isn't. Well, that's what you're doing when you use metrics that are different from what others are using. I guess "inventing" would have been a better choice of words--"fabricating" has some negative connotations I wasn't going for. So what? Are you bent on showing that Canada's healthcare system is more cost-effective than the US's? You'd almost certainly be right, but it seems like a wide tangent from this thread, and I'm sure you could draw much stronger conclusions from other data.

Right. I don't mean to imply that the US is doing well--it clearly isn't. I was merely responding to the idea that Canada had a better CFR and maybe that meant it's healthcare system is doing a better job at treating the disease. I merely intend to point out that the US has a better CFR than Canada and stop there without any further interpretation.

The fact that you are calculating them the same way for both countries doesn't imply that it's a useful or meaningful metric, and it's not. Fabricating your own metrics is not a valid substitute for the real ones just because you haven't found them. The chart I showed you is from JHU data, visualized at http://91-divoc.com/pages/covid-visualization/

There's your problem--that isn't how you calculate case fatality rate or anything useful. Total cases includes a bunch of people who will die but haven't done so yet, which throws off the result.

What doesn't jive? Going off the numbers from your source, CFR = deaths / (deaths + recoveries) = 10,853 / (10,853 + 228,189) = 4.5% That's worse than the 3.8% depicted on the chart I posted.

Why now? Why not months ago? Why not approve every vaccine candidate that anyone dreams up, before it's even synthesized for the first time? I'm sure you'd agree that it's possible to approve something *too* early. The FDA is moving this along more quickly than they ever have moved anything along the past. They have all the information and they intend to approve it as soon as the time is right and not a moment later. They operate on all pertinent details, not just "so many people are dyeing every day so we'd better just approve it now". The FDA hasn't approved it yet, and so we can be sure that they think approving it now would be *too* early. Why do you think your information or judgement is superior than that of the FDA?

The cumulative case fatality rate is actually worse in Canada than the US:

I agree that the apparent savings is quite significant. However, I don't think it's as simple as you present it: Yes, maybe you can take fewer jumpers up and still profit on the load. However, that ignores other factors I have already mentioned and simply being revenue-positive on the load is not enough. For example: how many additional planes would a DZ need to buy, house, and maintain in order to meet their current jump capacity requirements? Maybe with such dramatic savings on fuel it will make sense to work around these factors. However, that doesn't go without saying--you need to show it.

That doesn't sound so bad

Right, but we were already both in agreement that the batteries will continue to lighten over time, which will bring us closer to feasibility. I don't think a single person in this thread would refute that. What I'm refuting is the significance you ascribe to this arbitrary threshold of batteries required for jump ops being equal to or less than the weight of a full load of fuel. It's equally irrelevant whether you say "equal to" or "less than" or "equal to or less than". A relevant statement would be "batteries required for a single jump flight weigh X, and if you replace the fuel in a typically configured jump plane with X, turn time will change from Y to Z." For all we know, from what has been presented in this thread so far, an aircraft with battery weight equal to or less than a full fuel load may not even be within max takeoff weight. So why is this information useful? Again, we all agree batteries will become smaller and lighter over time, improving feasibility. The fact that this will also mean they will become a smaller percentage of a full fuel load is tangential at best. They will also become a smaller percentage of any other thing that has mass. You continue to hand-wave away the significance of weight on climb performance. This is so important that I think it is irresponsible to keep making such statements without any support. I think it goes without saying that there needs to be redundancy, but I imagine it would be similar to redundancy in fuel tanks--you have multiple of them but they all may see use in normal ops. No real need to have a completely separate module only for use in emergencies. Not to mention "getting down" won't really be the problem if your batteries go out lol I don't think this is any different from how aircraft are currently designed, anyway. Weight already matters a lot. If any new tech comes along to make airframes even lighter, electric airplanes will still have to compete with lighter-weight traditionally-powered airplanes using this tech. It's at least mostly orthogonal. It's one thing that always bothered me about how hybrid cars are marketed: I want to see their fuel economy compared to the same vehicle but traditionally-powered. This condition is necessary but insufficient. When fuel is on fire in an aircraft, there is almost always a firewall between the fire and the fuel tank. You can usually turn off fuel flow and extinguish the fire. A battery fire would be analogous to a fire in the fuel tank, a much more dangerous and rare scenario.

This is an inconsequential semantic difference that doesn't change anything about the discussion we've been having. Performance of today's Otters at the weights anticipated would be useful information.

I'll save my response for the new thread

Maybe that will happen someday, but it's orthogonal to the electric aircraft question.

So what exactly are you advocating for? We've been working on vaccines, but we don't have one ready yet. Are you advocating we take no precautions instead of wearing cloth masks? Because cloth masks are less effective than respirators and vaccines? That doesn't make much sense to me.

Interesting. Lower energy density by weight, volume, or both?

That's true, and it's important, but what you seem to keep glossing over is the fact that the batteries weigh much more than the fuel they will be replacing. You posited that when the amount of batteries required for jump ops weighs the same as a full load of fuel that this would be a clear inflection point. You stated it as if it should be obvious on it's face that it's true and requires no justification because there would be no drawback. I've been refuting this because the plane would clearly be heavier, therefore there is a drawback and you need to show your work for how you've determined the advantages to so clearly outweigh this drawback. That's really all I mean to refute and the rest of the discussion between us has felt circumferential. Again, please show your work. You seem to be in the habit of just spouting out numbers, in this case 1%, without any indication of where these numbers come from. How much fuel does an Otter burn on a typical jump load? How much does an Otter weigh at the start of a typical jump load? This is very straightforward. If you know this information, why don't you tell us and show your work? If you don't know it, why should anyone believe your conclusions?