24
E-flite Ascent PNP Assembly Manual
Minimum Sink Speed
In our discussion of thermals, we know sink is the cooler air
moving downward to replace the warm air that is rising.
Minimum sink speed is the speed at which a park glider loses
altitude most slowly. As the term then implies, minimum sink
speed gives the glider the maximum amount of time aloft from a
given altitude. This is the speed to fly at when you are circling in
thermals, or whenever you need the maximum lift the glider can
produce. The pitch attitude will appear to be more nose-up.
To determine what this speed is for your Ascent, fly it at a slow
speed, slowing down until it just stalls, then trim it to fly at a
speed just above where it begins to stall. Observe the pitch
attitude at this speed. You will need to practice flying at this speed
without stalling so you can come back to it whenever you want to
when you are in a thermal or trying to maintain maximum lift.
Maximum Lift/Drag (L/D) Speed
This is the speed at which you can fly the maximum distance
for a given altitude. It's used when you move from one thermal
to another, or when you need to cover the maximum distance
over ground. This will be a moderately faster airspeed than the
minimum sink speed. You will have to experiment by starting from
the minimum sink speed and add small amounts of down trim
to increase speed slightly. This is the speed the Ascent performs
the best for duration, and the speed at which you will do most
of your flying. It will take practice until you are familiar with
the Ascent's attitude at this speed. Remember you will be flying
slightly faster, at a lower pitch attitude as compared to minimum
sink speed.
Best Penetration Speed
This is the speed at which the Ascent will travel forward against
the wind or a thermal, as far and as quickly as possible. This
speed will vary with the conditions, such as windy situations or
very strong thermals. You will want to use this speed to escape
from very strong lift (or sink). This speed has a more pronounced
nose down appearance, which will vary with the conditions
encountered. It will also not be a consistent attitude, but vary with
the strength and direction of the lift/sink or wind.
Once you have learned to launch and control your Ascent in a
consistent manner, you will want to then proceed with practicing
these three speeds. Remember these are trim speeds, so you
will be using your trim lever to obtain them. For maximum
performance, remember to use trim sparingly, don't depend on
the stick, as you will only impart small movements that result in
drag and battery drain.
Practice Smooth Control Inputs and Use the Trim lever. (Remember
you trimmed the Ascent in the first flights, and then set the
mechanical linkages to reflect the trim imparted. You then set your
trim levers back to neutral. Now you know why we performed
that procedure, to allow you to use the trim lever for in-flight trim
to better control flight performance.)
There are other things that can be done to bring the performance
level of your Ascent to its absolute best. However, they should
not be attempted until you have become proficient in the launch,
control, and trim of your model.
The more you learn how to trim your Ascent for optimum
performance, the more fun you can have chasing thermals!
