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Everything posted by lasse

  1. You can deploy your main with your right arm. You can also deploy your reserve with your right arm and of course cut away your main with the left. I think there are examples of people that have done one armed emergency procedures for different reasons. If you're able to you could try to loose your right shoe and pull with your foot. Also you could try pulling with your hands anyway (if you broke lower arm pulling the RSL might be an idea). I don't say you're in an easily solved situation, but I don't think that there are other options for you to deploy something. Besides that is a situation where an AAD comes handy (I think that those who argue against the use of it will tell that if you break both your arms you sholdn't go skydiving...)
  2. Brakes do affect the angle of attack one way or another. If you fly at full brakes you will get a lower glide ratio yet you havn't changed the pitch of the wing (at least not matching the decrease of the glide ratio). You've got an higher angle of attack. Pilotdave - as far as I have understood lift and drag (as described at the lift at steady state certainly are different since the drag has a different vertical component (the sum of the vertical components of the forces must be zero).
  3. Doesn't sound safe, not safe at all. Pull, pull at right altitude, pull at right altitude with stability... Pulling your reserve two seconds after impact is not going to save you. A two out is not so bad seen from that perspective. Heres my idea: grab your handles - changes the airflow around your body - if that doesn't help (nothing happens) I'd cut and pull. Yes the main could start deploying and it could entangle with the reserve, but the result most likely is going to be better than before (and nothing will get much worse anyway even in case of a total on your reserve)
  4. Since most fatalities are caused by other problems than reserve problems the fatality frequency is not a good measure. Furthermore not all double malfunctions are related to the reserve packjob and those who are need not be related to the repack period. Actually eating breakfast could increase safety. Most accidents happens because the jumper does something wrong rather than there is something wrong with the equipment.
  5. Your solving of the differential equation is quite wrong which should be obvious if you consider the behaviour after reaching terminal velocity. The correct solution to the equation is a hyperbolic tangent function. Fitting the constants to the assumtion that initial acceleration is 32 feet per second squared and terminal velocity is 176 feet per second we get v=176*tanh(t/5.5). By this formula you should never reach terminal velocity (and cosequently never exceed it), 90% should be reached after about 8 seconds, 95% after about 10 seconds, 97.5% after about 12 seconds.
  6. So you really intended to hit a car or what??? Accident hasn't have to mean that someone wasn't at fault it only mean that noone intended the outcome. Regarding FAA's definition as applied to skydiving: would a cutaway be considered an incident? I think it's a bad idea that USPA doesn't require reporting accidents.
  7. Pulling has to be done if death is to be avoided. A head down pull has better survival chances than a nopull so pull has to be top priority.
  8. I don't think the difference is very significant. Most of the time the main function properly. And the few times it doesn't the reserve function properly and the student lands safely anyway. About education. You will need to have special education whatever choice of reserve you have done. If you use square reserves you will have to know how to handle two-out. For round reserve you have to know how to maneuver it. In both cases you will have to know your PLF anyway - you can have a hard landing with squares too you know. As for obstacles you should probably how to land with a square too, the use of radio is no excuse to not teach the students how to avoid and land in obstacles - radio as all other equipment can fail and the use of radio may in fact make the student neglect the nessecity to learn to land safely on his own from first jump. And no round reserves does not guarantee that the student lands in the right place given that he is dropped at the right place. A student may fly a long way under a low speed "malfunction" before he decides to cutaway. Again education is the key.
  9. However there has been fatalities like jumper has total malfunction, jumper pulls cutaway, jumper lands at 120mph... It may be that the jumper believed the RSL would pull the reserve (as explained in a sloppy manner), consequently it may not be a bad idea to tell the student exactly how the RSL works (and especially how it doesn't).
  10. You should probably check for other traffic too.
  11. It seem to be in the one per 100,000 jumps range. Makes me start wondering if this isn't based on very old information. I'd expect about one per 1,000 range (actually about one reserve ride per 1,000 jumps). Most fatalities is of other causes than double malfunctions. About one out of ten fatalities (that is 1 out of 1,000,000 jumps) is due to double malfunction. In addition there might be double malfunctions that doesn't result in fatalities.
  12. Yes, but if you want illustrations and more details, get the book mentioned above (The Skydiver's handbook by Dan Poynter). Where exactly? I read the SIM and couldn't find that information.
  13. In sweden normal rates seem to be about 950euros for AFF (incl 10 jumps). Jump tickets are about 12euros per jump.
  14. But then that leads to the question what "very" different size is. The PD website doesn't give any information on that. Assuming that people never make mistakes is a mistake when it comes to reserve considerations. If you've got your reserve out it means that you (or perhaps someone else have made a mistake). If you get your cypress to fire you either forgot to pull at right altitude (a mistake) or got knocked unconsious (you're not supposed to collide in free fall - a mistake).
  15. That depend on what you mean by "hell of a lot safer". Most injuries and incidents are NOT related to the static line system.