The glider relies on a combination of headwind and the pilot moving forward in combination to generate the required lift for takeoff. In true Flintstone fashion, the pilot essentially uses peddly power to work through a number of defined stages before a safe takeoff can be achieved. Tony was adamant that the takeoff is one of the most imperative parts of any glider flight and that a “successful takeoff is required for a successful flight”.
Unlike any conventional aircraft, the pilot is very sensitive to the effects of the various controls and responds accordingly. The lack of any power plant, instrumentation or airspeed indicator means that the pilot must remain mindful of the feel of the glider and the aerodynamics that contribute to a safe flight. In particular, I found myself referring back to the drag curve and, for the first time in my flying career, talking about the ‘region of reverse command‘ because of its serious importance during the takeoff or launch.
Most fixed wing pilots are familiar with the region of reverse command because of the effect it may have on a landing approach, particularly when flying near the bottom end of the drag curve on a short field approach. On a normal approach, a small increase in approach speed also increases drag which then tends to assist the pilot in maintaining a target airspeed. On a short field approach, however, the target airspeed can often be on the unhappy end of the drag curve which tends to reverse the expected effect of drag with an increase or decrease in airspeed.
When taking off with a glider, the pilot accelerates through the region of reverse command and then into the normal region of the drag curve that offers more predictable handling with an increase or decrease in speed.
Before I was allowed to run with the glider, considerable time was spent on the ground simply mastering the monkey grip on the down tubes which would lead to more stable handling both during the blastoff and while ground handing in wind. The training glider, an Airborne Fun, weighs only 23kg so it was surprisingly easy to hold and carry. Although typically regarded as a ‘training glider’, it is used widely by recreational and advanced pilots for soaring sand dunes or cross country expeditions. Like training on any smaller GA aircraft, the Fun was a logical first glider before purchasing one of its larger Airborne stable mates that could offer slightly better performance.
The advantage of training in hang gliders is that a location can be selected early morning to best take advantage of the conditions. Tony, a long term resident of the Stanwell Park area and well known surfing personality on the South Coast beaches, has any number of locations that can be utilised on a day-to-day basis. Most important was that I flew with a constant headwind. The headwind ensured directional control in the early stages of my launches but it also meant that less effort was required in the takeoff to achieve a safe flying speed.
With the glider in grip, the pilot should select a mild angle of attack that will allow the wing to start flying after a few steps without producing too much drag. If the nose is too high, the wing will want to fly up and back and inhibit the pilots ability to generate forward speed. Rather than simply start running with the glider as most of us lay general aviation types would assume, Tony had me take short controlled baby steps and then, rather than accelerate with a run, he had me increase the stroke of my stride which naturally translated to a faster pace. As the glider started to produce lift I could, by bending my elbow and raising my arms in a lateral manner (while keeping the bar close to my midsection), move to the ‘second grip’. With the second grip, I moved my hands around to the uprights and moved the bar back towards my chest so my body essentially sat inside the A-frame to reduce drag. At this point in the takeoff run, the glider was flying and the bar position was used to minimise the angle of attack so that I could positively accelerate without having to carry or fight the glider on the ground.
Just prior to launching myself off a three-foot sand hill, and after reaching a safe flying speed, I could then, and only then, ease forward on the uprights for some additional lift. It is in these early stages that you enjoy flying the shallow contour of a beach – if only for a few seconds. I found myself doing takeoff after takeoff until Tony was happy that my technique was consistent and suitably developed for more advanced sequences.
Next Time: Advanced techniques
This blog was initially published in a flying magazine in 2004. It has been reformatted for this blog.
Blog series: Learning to Fly Hang Gliders