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E-flite Ascent 450 Brushless PNP User Manual

Page 24

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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!