2 ms·

You can actually find Incident Reports on USPA website https://www.uspa.org/searchincidentreports https://www.uspa.org/searchincidentreports > ~1/1000 chance t

You can actually find Incident Reports on USPA website https://www.uspa.org/searchincidentreports https://www.uspa.org/searchincidentreports > ~1/1000 chance that your main chute doesn't deploy Yes > times a ~1/1000 chance that the reserve doesn't deploy No. There is way smaller chance that your reserve would not deploy, not even to M, but MM. I think there were some stories about fatalities caused by this. The one issue I remember - there was a gear issue in a condition, when a skydiver is passed out and on his back - AAD (Automatic Activation Device) fired at 1000 feet, and the reserve did not open in time. I am not sure if that was a fatality or not. But all the containers of this type went through modification. Main does not open because they are packed by skydivers or packers in 5–10 minutes (or 30-60 if you are new). So you can skip the step, or do it not correctly, or forget something. Reserves are packed by FAA certified riggers and it takes at least an hour to pack the reserve. Reserves are packed similar to BASE canopies (where there is only one canopy, and it has to open). > a small factor because people (especially beginners) do dumb stuff That is a big factor. Similar to car drivers, some skydivers just feel too confident at the beginning of their career and start doing low, high-performance turns. And obviously, there are some other various factors - weather, other skydivers, other people, and own mistakes.

jessriedel 3y ago
> No. There is way smaller chance that your reserve would not deploy, not even to M, but MM. Thanks. Do you have a cite on this? I am pretty skeptical of any complicated mechanical system (including not just the packed suit, but also the calibrated altimeter, etc) having a 10^-6 malfunction rate. Like, I would consider having the altimeter mistakenly calibrated to lower elevation a case of “the reserve failing to deploy” even if it was packed perfectly or whatever. Likewise if your main deploys wonky, you cut it and get into a spin, and then reserve gets tangled as it comes out.
- outcoldman 3y ago
  I mean maybe I overshoot a little with millions. But it is a known to have one cutaway (main malfunction) in around 1000 jumps. But giving the same for reserves is just not fair. BASE canopies are packed the same way as Reserve canopies. And there are people with over 4500 BASE jumps in their lifetime. Reserve canopies are not the same as main, with different characteristics. Even opening them in a spin gets you a flying canopy that is hard to control, but probably will save your life. And there are also all depends on the type of your main canopy, if we talk about Tandem or Student canopies - those spins aren’t going to affect that much reserve opening. The high performance canopies will, but a lot of jumpers don’t jump with anything that can deploy their reserves automatically, preventing this issue of high spins and deployment of the reserve. And instead trying to stabilize the body position. Unfortunately nobody has a data about how many reserve rides there are, and how many were unsuccessful. I mean it is possible to find recently unsuccessful, if there are any, guess how many jumps are there in general, and guess that every 1000 jumps there were at least one reserve ride. So some stats can be done on that. But based on your logic out of 3M jumps a year in USA we should have seen 3 fatalities caused by not opened reserve. Also seems like you are combining reserve and aad into one system, which is not correct. The idea behind the reserves, that in most cases it will be manually deployed. And for the cases when the pilot is unconscious there is AAD the purpose of which purely try to save a life, with just one manufacturer it is known that it saved more than 5000 lives https://www.cypres.aero/info/saves/ https://www.cypres.aero/info/saves/

jessriedel 3y ago

> No. There is way smaller chance that your reserve would not deploy, not even to M, but MM. Thanks. Do you have a cite on this? I am pretty skeptical of any complicated mechanical system (including not just the packed suit, but also the calibrated altimeter, etc) having a 10^-6 malfunction rate. Like, I would consider having the altimeter mistakenly calibrated to lower elevation a case of “the reserve failing to deploy” even if it was packed perfectly or whatever. Likewise if your main deploys wonky, you cut it and get into a spin, and then reserve gets tangled as it comes out.

outcoldman 3y ago
I mean maybe I overshoot a little with millions. But it is a known to have one cutaway (main malfunction) in around 1000 jumps. But giving the same for reserves is just not fair. BASE canopies are packed the same way as Reserve canopies. And there are people with over 4500 BASE jumps in their lifetime. Reserve canopies are not the same as main, with different characteristics. Even opening them in a spin gets you a flying canopy that is hard to control, but probably will save your life. And there are also all depends on the type of your main canopy, if we talk about Tandem or Student canopies - those spins aren’t going to affect that much reserve opening. The high performance canopies will, but a lot of jumpers don’t jump with anything that can deploy their reserves automatically, preventing this issue of high spins and deployment of the reserve. And instead trying to stabilize the body position. Unfortunately nobody has a data about how many reserve rides there are, and how many were unsuccessful. I mean it is possible to find recently unsuccessful, if there are any, guess how many jumps are there in general, and guess that every 1000 jumps there were at least one reserve ride. So some stats can be done on that. But based on your logic out of 3M jumps a year in USA we should have seen 3 fatalities caused by not opened reserve. Also seems like you are combining reserve and aad into one system, which is not correct. The idea behind the reserves, that in most cases it will be manually deployed. And for the cases when the pilot is unconscious there is AAD the purpose of which purely try to save a life, with just one manufacturer it is known that it saved more than 5000 lives https://www.cypres.aero/info/saves/ https://www.cypres.aero/info/saves/