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SIGMA TANDEM SYSTEM OWNER’S MANUAL
11301 - 00.00.0000 Section 3: Instructor Techniques • Chapter 1 - Preparation
1) Weather assessment:
a) Wind speeds:
For Tandem jumping, the optimum range for winds is 5 - 20 mph. All jumpers should realize that very high winds are
unsafe to jump in. In the case of Tandem jumping, we need to realize that it may be equally unwise to jump in
extremely low winds. It is a hard point to realize since sport jumping goes on in no wind conditions all the time, but it
is a fact that Tandem jumping with heavy students in no wind conditions can produce final approach ground speeds
which can make landings more difficult.
Heavy students with any physical malady which can prevent them from running or supporting their own weight
should not be jumped in no-wind conditions.
b) Temperatures:
As the seasons change, the canopy's performance will vary as the air becomes cooler or warmer. Cooler air is always
more stable and dense so the canopy's decent rate and flare performance is good. Warmer air is thinner and you may
find that landings become harder. This can be noticeable even during the course of a day as the temperature rises on
a hot summer day. The warmer air actually provides an effect in which the field elevation can be thought of as being
barometrically higher than its geographical elevation. This effect is referred to as “density altitude”. The hotter the
day, the thinner the air, and the higher the density altitude, in other words, on a hot humid day, the canopy may land
as if the field is at perhaps 6,000' rather than sea level - a BIG difference! On a very hot day, with a heavy student,
density altitude is a factor you must take into account. Common sense, good judgment, and caution is often called
for.
2) Terrain assessment:
a) Landing area selection:
If you are planning a Tandem jump at an unfamiliar spot, check the area before you jump. Note where the obstacles
are, and keep track of other large open alternate landing areas. Turbulence can effect canopy flight as much as 1/4
mile away from tall obstacles. Keep these things in mind when making a note of wind direction and spotting. Think
ahead and plan carefully!
b) Altitude:
When jumping at locations well above sea level, you must also take into account that the higher the ground elevation,
the less effective your flare will be. If you find yourself making Tandem jumps at high field altitudes, choose lighter
students till you have a good feel for the different flare characteristics the canopy will have at that location.
OVERVIEW OF THE JUMP
A) synopsis of the jump
B) video and assumption of risk agreement
A) Synopsis of the jump:
Before the first jump, it is important that the student understand what the jump will be like, and what is expected of
him or her. Before the first jump, the student should have the Tandem concept explained by video, still photos, or
direct observation. Inform them of the entire sequence and what to expect at each stage of the jump. Information
such as exit altitude, length of freefall delay, and length of canopy ride are all motivating points of interest.
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