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Fall Rates Theory
After we exit an aircraft we accelerate towards the earth until we reach terminal velocity.
You might remember Galileo’s famous experiment in which he dropped two different
sized objects from the leaning tower of Pisa and both made impact at the same time. We all
accelerate at the same speed regardless of our size or mass but because of air resistance and
our mass, terminal velocities will vary.
Since FS (relative work) is about falling relative to each other we must learn to change our
fall rates. The conventional method was simply to arch more. The most effective way to do
this is to change our mass by using and adjusting weight belts. However if we need to
adjust rates once we are in freefall, then all we can do is change the air resistance. The
amount of air resistance depends on the amount of our surface area. The more surface area,
the more air resistance, the less surface area, the less air resistance as shown in fig 9 and 10.
Fig. 9
Fig. 10
Coaching Lesson
23
The aim of this lesson is to teach:
Fall Rate Control
Training Aids: Coach, DVD, Video, Mirror, Bean Bag, Jumpsuit, Altimeter.
Revision: Study the theory on how fall rate is achieved. Also, emergency procedures
where appropriate.
Explanation: Explain theory to fall rate control.
Demonstration: Using an assistant or a freeze frame of the video, demonstrate the
position as a whole. Break the position into parts and demonstrate
the move.
Imitation: Student to practice.
Practice: Practice the skill in reps of 5.
Practice with corrections until proficient.
Practice eyes closed.
Confirmation: Go through the whole dive sequence from exit to track off. Confirm
in air coaching signals and emergencies. Re-emphasize altitude
awareness and break off at 5000 feet.
Coaches notes:
For slow fall, ask the student to lie on their back with their arms and legs out straight and
apart. Ask them to lift their arms and legs off the ground 6-8 inches. Tell them the
resistance they can feel is similar to the resistance of the air when a slow fall position is
applied.
In Air Coaching
24
Fall Rate Control
Exit
Ask the student which exit they would like to practice next.
Vary the exits from jump to jump.
Give the student time to adjust into the neutral position, ensure the student is in a neutral
position before attempting a new skill, they should be ready by the time you reach
terminal.
In Air Coaching
From a position in front of the student but not too close demonstrate the fast fall position.
For the first few demonstrations only drop a short distance. When static provide a good
reference for the student. For the slow fall turn 90 degrees and only go a short distance.
Whenever on level and static give corrective signals if necessary. If time and altitude
allows increase the distance in levels.
The balance between the amount of demonstrations you do to the students attempts is up to
you, but if the student is performing well then just stay static and allow maximum student
practice of the new skill.
5000 Feet
Observe the students altitude awareness during the entire skydive. At break off ensure
there is a safe distance between you and the student but continue to observe their track and
deployment making a note of the altitude.
25
Theory to Transitional and Rotational Moves
As you know, all moves start from the neutral flying position. Before we make a move we
should be in a position of balance. The resistance, which holds us in place, is this same
force that we use to move. Forces come in pairs and forces always seek to stay in a state of
balance so when we try to change the balance by applying force, a force equal will try and
resist that change. The good news is that the resistance to change is short lived because
once we start to move, the forces are once again balanced until we decide to stop. So as far
as physical effort goes, the amount of input to create a move is at its greatest when starting
and stopping. Whatever input we use to initiate a move, we have to use the same amount of
input to stop it.
Generally, an FS transitional move takes longer to complete than rotational moves because
the translation involves a move from point A to point B. Transitional moves are normally
quite small, but if there were a big distance to cover a track may be a more efficient method
to close the distance.
It’s better to translate to close distance to a target before making the rotation. Backwards
movement is used in FS but usually as a fix to a problem. If you need to present your leg
grips to another skydiver then it should be as part of a turn in place. Flying backwards and
　
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