Wills Wing Alpha 180, Owner'S Service Manual

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Laying the glider down flat
The Alpha is not designed to be laid flat on the ground with the crossbar tensioned, nor is
it designed to be set up flat on the ground.
Launching And Flying The Alpha
1. If the wind is more than 10 mph or gusty you should have an assistant on your nose wires on
launch, and, if necessary, an assistant on one or both side wires. Make sure all signals are clearly
understood. Do a hang check immediately prior to launch. The angle at which you hold the glider
should depend on the wind speed and slope of the terrain at launch; you want to achieve a slight
positive angle of attack at the start of your run.
2. Run aggressively on launch and ease the bar out for lift off.
3. The flying characteristics of the Alpha are typical of a single surface flex wing. Make your first
flights from a familiar site in mellow conditions to give you time to become accustomed to the
glider.
4. We recommend that you hang as close as possible to the basetube in the glider - this will give you
lighter control pressures and better control.
Using Wing Tufts
Your Wills Wing glider has been equipped from the factory with short yarn tufts on the top surface of
each wing. The shadow of these tufts will be visible through the sail. The tufts are useful for indicat-
ing the local reversal of the airflow which is associated with the onset of the stall in that portion of the
wing. You can use these tufts, as described below, to help determine when you are flying at minimum
sink airspeed.
There are two important airspeeds with which all hang glider pilots should be intimately familiar;
minimum sink airspeed (hereinafter referred to as VMS) and minimum controllable airspeed (MCA).
The most important of these two is MCA . Minimum sink airspeed is that speed at which your de-
scent rate is the slowest possible. It is the speed to fly when you want to maximize your climb rate in
lift, or slow your rate of descent to a minimum in non lifting air. (You would normally not fly at VMS
in sinking air; the strategy there is normally to speed up and fly quickly out of the sink. By minimiz-
ing your time spent in the sinking air you minimize altitude lost, even though you have momentarily
increased your sink rate by speeding up.)
Minimum controllable airspeed is that speed below which you begin to rapidly lose effective lateral
control of the glider. Recognition of this speed and its implications is a more subtle problem than
many pilots realize. We have seen several instances of pilots who were having a lot of trouble flying
their gliders simply because they were unknowingly trying to fly them too slowly; below the speed at
which the glider responded effectively to lateral control inputs. It is our opinion that a great percent-
age of hang gliding accidents are caused by inadvertent flight below MCA, and subsequent loss of
control of the glider with impact preceding recovery. Such incidents are usually attributed to “stalls,”
but it is not the stall per se that causes the problem, indeed the glider need not even be “stalled” in the
traditional sense.