Re: [KolinskyDC] I have a question
http://www.basejump.org/...les/differences.html Differences Between B.A.S.E. Jumping and Skydiving by Tom Begic
Differences Between B.A.S.E. Jumping and Skydiving.
Why A B.A.S.E. Jump is Not Just Another Skydive.
You Can't Skydive From a Cliff!
Everyone has seen pictures of the amazing 3000ft cliff in Norway, known as Kjerag. This inspires many skydivers to make the pilgrimage to what is perceived as a relatively safe B.A.S.E. jump. But is it really safe? And are skydivers adequately prepared for every scenario that they may encounter. As time goes by and the number of fatalities increases, it is being proven that skydivers are NOT adequately prepared.
How do you prepare for big wall B.A.S.E. jumping? What differences are there between high and low altitude jumps?
I use a technique called Potential Problem Analysis on each and every jump. To be able to use this technique effectively, you first need to be able to recognise and analyse all possible variables (scenarios) and then map out a plan of action prior to jumping.
For a skydiver wanting to attempt B.A.S.E. jumping, this means that they should:
know about all possible skydiving malfunctions and how to deal with them.
have an intimate knowledge of equipment.
have the right motivation for wanting to jump.
obtain the right training from the right people.
know about all possible B.A.S.E. malfunctions.
know the differences between skydiving and B.A.S.E. jumping.
The last point is especially relevant because many of the incidents in B.A.S.E. jumping involve skydivers who make the statement its 3000ft, hence its just like doing a hop’n’pop on a skydive – how easy and safe is that!”. This thought could not be further from the truth.
Let's split up a jump and analyse the differences between skydiving and B.A.S.E. jumping.
SITE ACCESS On a skydive, you just hop on an aircraft and away you go. On a B.A.S.E. jump, you may have to do hours of difficult hiking, technical climbing, and mountaineering. There is also the issue of legality and trespassing – are you allowed to walk to the exit point and jump off it?
EXIT On a skydive, all you need to do is hop out of the aircraft. There is plenty of airspeed for you to be able to fly into the correct body position. You also have a lot of free space around you.
On a B.A.S.E. jump, quite often the exit point is difficult to access, slippery, unstable, secured (i.e. security, refer to legal access issues), radiated, electrified, etc. There is no airspeed as you leave the object. This means that you have to put your body in the correct position. If you become unstable, you must use gymnastic &/or diving techniques to regain stability. You can’t “arch” into a stable position for a number of seconds. The exit point is usually precise, if you jump a few metres either side of defined exit point you may introduce further dangers (such as a protruding ledge).
FREEFALL Once you exit an aircraft, you have a lot of free space around you. It does not really matter what you do until you commence your deployment. On a B.A.S.E. jump, there is an object near you. Therefore you effectively lose half of your space. You must maintain separation from the object. Can you guarantee the you don’t backslide a few feet on every skydive?? On an underhung object, backsliding a few feet would probably lead to an ugly death. Your freefall time is finite. On lower objects you must be precise in calculating you delay. On a skydive, a few seconds either side of the planned opening altitude does not matter. On a B.A.S.E. jump, a few fractions of a second could mean the difference between life and death. As in the exit, you must use gymnastic &/or diving techniques to regain stability in the first few seconds of a jump if you become unstable.
DEPLOYMENT Stability is critical on deployment. Your shoulders must be parallel with the ground and your back must point up to provide a clear space for your pilot chute and canopy to deploy. This is true in both skydiving and B.A.S.E. jumping. However, most B.A.S.E. jumpers use single parachute systems. Hence, you must guarantee each and every opening. You would usually get away with an unstable skydiving deployment and you have a reserve to deal with the consequences.
Another critical factor is the height consumed during a deployment. It is very important that a B.A.S.E. jumper uses equipment that consistently consumes the same altitude with minimal variance on every jump. 100 feet here or there are not important on a skydive, yet on a B.A.S.E. jump, it could mean the difference between life and death.
The first part of the deployment (from throwing the pilot chute to line stretch) is the most important on a B.A.S.E. jump. The slightest pilot chute hesitation on a low or underhung object could mean the difference between life and death. As an example: you are on a low jump (250ft), and have a hesitation such that the distance consumed during deployment is greater than usual. Most jumpers will begin to panic and undermine their body position. This could lead to off headings or entanglements. The hesitation may mean that you could impact the ground prior to full canopy deployment. The hesitation may be caused by: incorrect pilot chute selection (material, geometry, size, construction, etc), incorrect bridle length, incorrect stowage or holding methods, incorrect usage technique, downward wind rotors, air density/pressure/ temperature, plus many other factors.
Would you consider any of these on a skydive? You have to on a B.A.S.E. jump.
CANOPY FLIGHT You MUST pre-plan your flight path and allow for all deployment eventualities on most B.A.S.E. jumps. Most sites have obstructions from exit to landing and may have very tight landing areas. Often there are no out landing options. You have to use all your control inputs (front and rear risers, toggles) to control the flight of your canopy. Due to the greater time and space available on most skydives, this is not usually a problem.
LANDING Landing areas in Australia are often tight with no outs, steep, and covered in sharp rocks or other "injurious" objects. In case of injury, they are also not easily accessible to medical and rescue personnel. In contrast, most skydivers land in open fields. Hence your canopy choice, flight path planning, accuracy skills, personal protective equipment (ankle protecting and shock absorbing boots, knee pads, elbow pads, helmet, etc) must all be of a high standard.
EQUIPMENT As long as your skydiving equipment is maintained, packed, and used correctly, you can use the same gear on every jump (notwithstanding the discipline specific equipment that is available nowadays such has CRW and accuracy gear).
In B.A.S.E. jumping every component of your gear and its configuration must be taken into account on each and every jump. This can best be explained using two contrasting examples.
Example 1: a 1500ft bridge onto a large grass landing area. You could use virtually any sort of B.A.S.E. equipment in any configuration. Example 2: a 200ft cliff onto a tight, sloped, and rocky landing area.
You need the following specific equipment:
large reinforced pilot chute (> 45 in) for extra drag and faster extraction.
longer bridle (~ 9 ft long) with NO collapsing system to avoid the burble zone.
multiple bridle attachment point preferred to minimise centre cell stripping.
brakes set appropriately (this is dependant on wing loading and characteristics of the particular canopy you are jumping).
appropriate wing loading - 0.7 lbs per square foot preferred.
bottom skin vents or pac valves to enhance early pressurisation.
a secure (but quick release) toggle system to prevent premature toggle release.
slider removed or down.
brake lines stowed outside the keeper ring.
unobstructed (i.e. cover flaps lifted) & primed pins or velcro.
pilot chute folded / stowed and used correctly (poor technique can lead to minor hesitations which at very low altitudes translates to higher potential for death).
good body position. At this altitude, head high position is preferred.
single parachute systems since there is no time for an alternate parachute.
appropriate PPE (personal protective equipment) such as shock absorbing ankle protecting boots, knee pads, elbow pads, helmet, etc. Other equipment such as back braces, abrasion resistant pants, etc could also be used.
knowledge of weather conditions & the affect wind has on deploying, flying, and landing canopies. Rotors, downdrafts, venturi affects, etc need to be considered.
the ability to say NO to a jump and to reject, peer or ego pressure.
ability to determine what skills are required for a jump & whether or not you have the appropriate skill set to perform the jump safely.
As you can see, to maximise safety on a B.A.S.E. jump you have to take into account many complexities that most skydivers would not consider. This lack on consideration is the root cause of most of today's incidents and fatalities. Take a few moments to learn about an activity before you participate. This time could save you a lifetime.
Tom Begic
October 2001
But if not, get to Lysebotn and you can't miss the cliff from there. 
hell im not even sure if i dare to jump the place... it involves a slider
unless you want to be under canopy for a looooooooooooonge ride...