Re: [themotherfuckingcaptain] first skydiving rig
themotherfuckingcaptain wrote:
If I intend on using my first skydiving rig to practice my canopy skills for B.A.S.E. jumping, does it matter whether I buy a ZP or F-111 canopy?
Design and size make huge differences. You really need a big F111 seven cell.
Many (if not most) F111 seven cell designs with fat airfoils have a significant (from over 2:1 to below 1:1), progressive decrease in glide ratio as brakes are applied which provides the basis for classic accuracy. Such approaches get you into tight unfamiliar landing areas most consistently and therefore need to be in your BASE toolkit when you don't want to limit yourself to objects with relatively large and uninteresting landing areas. It's not hard - EIFF claims 100 jumps are enough to achieve USPA pro-rating accuracy levels.
Every modern skydiving canopy I've jumped had a glide ratio which increases with some brake application and then remains fairly constant until just short of its stall point. Without wind you have no ability to change your glide ratio and accuracy becomes a function of accurate guesses on where you are (which works best when you've made a lot of jumps in an area and know what it looks like to be in the right place), the length of approach legs, and shape of the corners connecting them. Some people argue that this is enough for BASE jumping, although having become a tree-hugger over shooting and watched professional skydivers with over 10,000 jumps do the same I strongly disagree.
BASE and classic accuracy canopies also have a stable sink regime where forward speed can decrease to zero. This can be used to stop you short of obstacles, although since the canopy is no longer producing lift you only have its drag slowing you down. That means you need a big parachute.
At pleasant BASE or classic accuracy wing loadings around .7 pounds per square foot (40% bigger than the accepted size for skydivers' first canopies) you can fly in 3/4 brakes until you flare and still have a comfortable stand-up landing. Short sinks over hard ground still produce comfortable landings. That's not going to be the case at contemporary skydiving wing loadings.
Flying modern ZP skydiving canopies will teach you to react to winds (which change with altitude, especially once you get into interesting geography like canyons joined together) and to make flat turns, but otherwise isn't too applicable to progressing as a BASE jumper.