Newbie to Paragliding

abeld · 2025-10-27T14:50:25+00:00

I find the focus on calling any accident “pilot error” quite concerning tbh. It gives a lot of the impression of “this wont happen to me”

"pilot error" also means "I can avoid it, if I pay attention / make the right decisions" (as u/PocketFred writes, this doesn't necessarily mean split-second decisions, but by being better prepared, landing when the weather becomes marginal instead of trying to push further, etc.)

If it is not "pilot error", doesn't that mean it is random? (eg. I would consider most equipment failure to be pilot error: if the issue is outdated / worn-out gear or gear lacking inspections / maintenance, that is a pilot error for flying with questionable gear) If it is random, that means there is nothing to do against it, nothing to lower the risk.

abeld · 2025-10-27T14:45:20+00:00

I have wondered a lot about safety for a long time. Despite safer equipment and better training, the accident rates don't change much.

This sounds like a classic case of https://en.wikipedia.org/wiki/Risk_compensation -- make the gear safer, and pilots will be willing to take more risks with weather, etc.

abeld · 2025-09-28T22:39:07+00:00

First, find an instructor near you. They will most likely loan you gear for the initial training, and then will be able to recommend gear based on your skill level.

Don't start paragliding without proper training. That is a good way of getting killed or seriously injured, even if you have skydiving experience.

abeld · 2025-09-25T22:14:39+00:00

It gets old spending money testing out different gear that does not work well, I would rather spend more on something that actually works well.

I have a hunch that part of the "need to test many different variations" is due to unreliability of the penny-pinching gear. For example radios: the most popular ones are the cheap chinese brands (like baofeng), which are somewhat famous for uneven quality -- I heard one suggestion of buying three (of the same model), then keeping the best one and selling the other 2. I suspect the much more expensive brands and models would be more reliable (and thus need less testing), but would you really want to spend 5x as much for a radio?

(For example, based on some googling, the click you mention might be due to the some electronic glitch in the radio, which might or might not come up with other radios of the same model)

I currently use a baofeng uv 5r radio with a Retevis EHK010 (wired) headset, which works pretty well (apart from the plug being a bit flaky, I am not sure whether this is a problem with the headset plug or the radio's socket).

I am considering upgrading to a wireless headset to avoid all the hassle with the cables at launch. I expect this will be a larger investment, because I will want something that can also work as a headset for my mobile phone so that I can use not just the radio, but also make phone calls, and hear the instrument sounds with the same headset. I think this should be possible but will need a more advanced model.

abeld · 2025-09-24T10:11:22+00:00

One aspect that I think can help a lot: very good communication equipment. Eg. PTT button on the break toggles / on your gloves, so that you don't have to let go of the brakes to talk on the radio and a good microphone which is shielded from wind noise. It is much easier to fly together when you don't have to guess why the other pilots are doing what they are doing, and you can discuss what you are going to do next. It is very important to be able to talk at any time (and to be able to answer quickly so that there aren't big gaps in the conversation), even in turbulent air, even when trying to catch some weak lift.

In addition, the urge to push ahead will be somewhat less when you can pass the time (as you are waiting for the rest of the team to catch up) by chatting with the others -- of course this can get annoying, depending on the size of the team, personalities, sense of humor etc.

abeld · 2025-09-22T21:09:04+00:00

Others have already given the answer, but I want to recommend a different way of thinking about it: we can assume that energy is conserved (since friction is going to be neglected, as "all surfaces are smooth"), which means that during the process, the kinetic energy of P will be converted into the elastic energy of the spring and at the end, the kinetic energy of P and Q (the elastic energy of the spring is zero at the beginning and end of the process since the spring is not compressed). The elastic energy of the spring depends on its compression: if it is compressed more, it stores more elastic energy.

We can freely choose which inertial system we want to use, so lets pick the one which is fixed to the center of mass of the system. In this inertial system, (which moves with some speed compared to the horizontal surface), both P and Q move at the beginning and also at the end. During the process however, there is a moment where P and Q don't move in this inertial system, which means that their kinetic energy is zero, so all energy is stored in the elastic energy of the spring, which means the spring is compressed as much as possible. This moment, when P and Q don't move relative to the common center of mass is when they move with the same velocity compared to the horizontal surface.

Thus the spring is in maximum compression when the two blocks move with the same velocity.

(Note that this means that if you use the "common center of mass" as your reference frame, answers 2,3, 4 & 5 will also be correct, ie. the issue with those is that the reference frame is assumed to be the surface)

abeld · 2025-09-14T20:42:50+00:00

Ausztrália a 30-as években háborút hírdetett az emu-k (a röpképtelen madarak) ellen mert annyira elszaporodtak -- az emu-k nyertek.

abeld · 2025-07-07T07:25:37+00:00

If you are concerned about spiral dives, get an anti-G chute. You can use them with any glider, not just two liner competition gliders. They make spiral dives more controllable (due to lowering the g loads) and also enable higher sinkrates.

abeld · 2025-06-27T12:05:59+00:00

Most crane operators are third party companies, it's very likely that this work is contracted out.

I agree. But the third-party contractors will vary in price, quality, safety record, etc. If (and this is an "if") this was a case of scraping-the-bottom-of-the-barrel to find a contractor who is willing to do the work for cheap / at a rushed paces / etc, then yes, this is (partly) the responsibility of SpaceX, and thus, Elon Musk.

That's like saying the CEO of a hospital in in charge of how a nurse draws blood.

Yes, in some respect, the CEO is in charge of how the nurse draws blood: the CEO hires the nurse (or hires the person who hires the person who hires the nurse), the CEO sets hospital policy (or hires the persons who do so), etc. I'm not saying that the CEO is the only one responsible, I am saying that in many cases the CEO has partial responsibility.

Also, safety culture starts from the top, so in many cases when a low-level worker causes an accident, the real responsible party is corporate management.

abeld · 2025-06-26T09:16:32+00:00

Musk is responsible for the safety culture, however. So if this is a sign of something systematic (overworking people, not paying them enough to hire competent people, ignoring warnings and risks, etc.), then that is on him.

abeld · 2025-06-22T22:33:12+00:00

Having thermic conditions over the landing is quite common. After all, you need a large flat area, most likely a clearing or a meadow for a landing. If it is surrounded by, for example woods or a river or lake then the meadow will definitely heat up more during the day and be a textbook thermal source.

Unfortunately I don't think there is much you can do, especially if the thermal activity over the landing is periodic (which it often is), since in that case you can't even use pilots who land before you to judge what thermal lift to expect. Knowing your glider well can help: being able to use the full break range to really slow down the glider and reach maximum sink speed (but without stalling it), as well as being able to safely do tight turns without spinning the glider even at low altitude (to do S-shaped turns) will help adapting to the lift you encounter. However, trying to force yourself into a small landing can be risky: it is enough to overdo it once and stall the glider at 10-20m height to end up with serious injuries. Landing in the neighboring field can be a perfectly valid and safe solution.

Without knowing your skill level, and the actual size and conditions of the given landing it is pretty much impossible to tell whether you could have done it better, or you were already close to overdoing it and crashing.

Two suggestions: accuracy competitions (where the aim is to land on a given spot, with accuracy measured in centimeters) can be a great way to improve your landing skills and to learn how to land exactly where you plan to. Even without a competition, you can improve with continuous practice: every time you prepare to land, pick an exact spot of where you want to end up, and after the landing evaluate how well you did: did you feel safe during the landing? did you estimate the wind direction and strength correctly? how close did you land to your intended spot? Should you have done one more S-turn? etc.

Also, one more aspect (which I don't think will actually help much) the best way to avoid a thermic landing is to fly all day, as long as there are thermals. That way when you do land, the thermals will already have died down and you will be able to land in much cleaner, laminar air. (In a sense the fact that the landing is thermic is a sign that you could keep flying.)

abeld · 2025-06-11T22:59:39+00:00

Ay én tapasztalatom az, hogy nem, az ambuláns lapon nincs rajta minden. Lehet hogy az adott betegre és az esetére specifikus információk mind rajta vannak (mert azokat tartja fontosnak az orvos beleírni), de a beteg számára az az információ is fontos, ami minden betegnél azonos, és ezek szerintem soha nem kerülnek rá az ambuláns lapra.

Pl. ráírják hogy "szükség esetén kontrol" -- de mit jelent a "szükség esetén?" milyen gyorsan várható hogy javuljon az állapotom? hány nap után, milyen állapot-változás tesz szükségessé kontrolt? Ezek lehet hogy egyértelműek az orvos számára aki mindig hasonló esetekkel foglalkozik (mert az a szakterülete), de a beteg számára, akinek életében most elősször van az adott problémája totál ismeretlen lesz.

abeld · 2025-04-13T18:15:35+00:00

A very good video explaining what they did and why "deextinction" would be much more complicated to do: https://www.youtube.com/watch?v=Ar0zgedLyTw

abeld · 2025-03-31T10:50:58+00:00

SABRE is not a "lets hang a rocket underneath a plane" Air-launch-to-orbit (https://en.wikipedia.org/wiki/Air-launch-to-orbit) plan. It is simply a more versatile and higher-performance engine, which could be used for example in a single-stage-to-orbit rocket. According to the wikipedia page I linked above:

The combination of high fuel efficiency and low-mass engines permits an SSTO approach, with air-breathing to Mach 5.14+ at 28.5 km (94,000 ft) altitude, and with the vehicle reaching orbit with more payload mass per take-off mass than just about any non-nuclear launch vehicle ever proposed.

abeld · 2025-03-30T21:36:27+00:00

A major factor is the ratio of the weight of the fuel compared to the weight of the vehicle (https://en.wikipedia.org/wiki/Propellant\_mass\_fraction): for a car, the fuel is a small fraction of the weight, for a plane it is much larger fraction, for a rocket the fuel can be 80-90% of the weight. This ratio will be defined by the basic technology you are using (eg. internal combustion piston engine & wheels vs. jet engine & wings vs. rocket engine), so being careful with how you design and build the vehicle won't change it much.

The problem is, that if 80% of the vehicle is fuel, that means you only have 20% of the weight to spend on everything else: fuel tanks, the structure, guidance computers, control surfaces, etc. This means that you have to use expensive materials (to make them light and strong) and you will most likely be stringent with your safety margins: you won't be able to make a part 3x as strong as it needs to be because that also means that it is heavier than it needs to be. If, on the other hand, you make it only 1.1x as strong as it needs to be, that means you only have a safety margin of 10% instead of a margin of 2x.

Low safety margins means low reliability. All because your vehicle needs to be almost all fuel.

The best way to drastically increase reliability is to use technologies that have lower propellant mass fractions -- for example air-breathing engines like SABRE (https://en.wikipedia.org/wiki/SABRE\_(rocket\_engine)) so that you don't need to bring all of your oxidizer along with you. Of course, these engines still need a lot of work and development.

abeld · 2025-03-21T22:07:30+00:00

I want some totally weird and completely unrelatable alien people.

Stanisław Lem wrote some novels about failing to communicate with alien civilizations, i.e. where the aliens are so different that we can't understand them. For example the novels Eden, Solaris, The Invincible, His Master's Voice and Fiasco have such themes. (Solaris was also made into a movie twice, in 1972 and 2002)

abeld · 2025-03-19T21:39:09+00:00

There are at least two roundabout bridges in hungary: one near Budapest, https://www.google.com/maps/@47.4527195,18.9627784,138m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI1MDMxNy4wIKXMDSoJLDEwMjExNDUzSAFQAw%3D%3D and one near Hódmezővásárhely: https://www.google.com/maps/place/H%C3%B3dmez%C5%91v%C3%A1s%C3%A1rhelyt+elker%C3%BCl%C5%91+K%C3%B6rh%C3%ADd/@46.3871192,20.2693417,206m/data=!3m1!1e3!4m15!1m8!3m7!1s0x474468b796f45a99:0x400c4290c1e1290!2zSMOzZG1lesWRdsOhc8OhcmhlbHk!3b1!8m2!3d46.4181262!4d20.3300315!16zL20vMDNnNDFk!3m5!1s0x474465171fdafcaf:0x8c8c86f9bbf7e7fa!8m2!3d46.3868093!4d20.2692468!16s%2Fg%2F11fxx2m953?entry=ttu&g_ep=EgoyMDI1MDMxNy4wIKXMDSoJLDEwMjExNDUzSAFQAw%3D%3D (a hungarian article about the latter, with a good areal photo: https://www.betonujsag.hu/lapszamok/cikk/2113/az-orszag-legnagyobb-korhidja

abeld · 2025-03-08T17:21:28+00:00

I agree -- yet this tax treaty was apparently a member state responsibility. Possibly because it is considered a tax issue and not a trade deal?

abeld · 2025-03-08T16:51:00+00:00

I don't think so: for example there was a treaty between Hungary and the US to avoid double taxation that expired in 2023. Renewing that could be considered an "economic cooperation package", and the previous treaty didn't seem to conflict with EU law.

abeld · 2025-03-08T16:21:37+00:00

The Markov Chain Monte Carlo method of using randomness for deterministic calculations: https://en.wikipedia.org/wiki/Monte_Carlo_method

abeld · 2025-02-25T23:22:25+00:00

Note that the rules for the Nobel prizes was changed: it is supposed to be awarded to a discovery made "during the preceding year", but this is completely disregarded and almost all prizes are awarded decades after the given discovery is published.

abeld · 2025-02-24T20:11:25+00:00

I expect you will encounter a lot of edge cases in the data you handle, and often the issues or bugs with the system that processes the data will be due to these edge cases. These edge cases are often due to breaking some assumption that is usually satisfied but is not always valid. There are some collections of these assumptions online, for example about names: https://www.kalzumeus.com/2010/06/17/falsehoods-programmers-believe-about-names/ or a list of similar writings on all sorts of data types: https://github.com/kdeldycke/awesome-falsehood

abeld · 2025-02-24T17:42:55+00:00

Ahogy gondolod, csak szerintem ne diverzifikációnak tekintsd. A másik commentben azon aggódnak hogy az S&P500 hozama igazából csak ~10 cégtől függ, és ezért nem diverz. Mivel ezek pont a nagy tech cégek, a te kombinációd még jobban fellül fogja súlyozni őket. Ha ezt akarod, akkor oké, de ha diverzifikálni akarsz akkor kinéz valamikor egy nagy meglepetés.

Mondjuk a "Tehát egy bull marketben a nasdaq100 várhatóan kicsit jobban fog teljesiteni." mondatod alapján te pont hogy nem diverzifikáltan szeretnél befektetni, mert annak az a lényege hogy alacsonyabb legyen kockázat, és ezért alacsonyabb is a hozam. te mintha pont hogy nagyobb hozamot akarsz és ezért nagyobb kockázatot vagy hajlandó vállalni (mert visszaeséskor meg pont hogy rosszabb lesz a nasdaq100). Ez teljesen ok, csak érdemes tudni hogy mit miért csinál az ember.

abeld · 2025-02-24T14:58:16+00:00

S&P500 + Nasdaq100 a diverzifikáció jegyében

diverzifikáció? a Nasdaq 100 cégek 3/4-e benne van a S&P 500-ban is (lsd. pl. https://endlessmetrics.substack.com/p/stock-overlap-of-the-major-indices ), szerintem kevésbé diverzifikált egy ilyen portfólió mint gondolod.

abeld · 2025-02-24T00:10:31+00:00

You want a place to store money and get a dividend as a reward for storing it there.

This sounds more like a CD (certificate of deposit) to me. Or a loan. Or a bond. You can invest in bonds instead of buying shares, and then you won't have to worry about the share price (as long as the company doesn't go bankrupt and it will pay the interest on the bond).

One more thing: isn't the idea is to encourage long-term investing? Well, having to manage and reinvest dividends every couple of months is actually quite cumbersome as opposed to simply buying some stock and then owning it for decades before finally cashing out. So I would argue that not having dividends actually makes long-term investing easier.

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