Icarus Tandem mod

Making things better

Almost all tandem canopies in use in Australia are Icarus Tandem. They are good canopies, carrying the weight of the tandem operations. Despite that, statistic has shown that 30 % of the Tandem malfunctions are line twists. Along with that, it is well known that these canopies do not really perform well in turbulence. Understandably, these are generalisations as they depend on what the canopies are compared to, who flies them, in what conditions and what is their condition.

“Can something be done, to the existing Icarus Tandem canopy design that can make canopies to perform better”?

Well, before starting to repair your car you need to know exactly – what a car is, how is it built and how it works, and can you repair it? Let’s see what we know about the canopies.
Icarus Tandem canopies are nine cell, non-cross braced, slightly semi elliptical/tempered trailing edge/. The trim is flat so they can open well with the brakes unset. All this makes them canopies that open ok, have predictable stall characteristics and long recovery arc. As already mentioned, they flare well in normal conditions with induced speed/toggle turn/. The most popular Icarus Tandem sizes in use are- 364, 330, 300 and 270 sq ft. It is a fact that some of the deployment issues are contributed by the size reduction happening on the field. The reason for that is the increased wing loading makes symmetrical canopy inflation more susceptible to body position mistakes, packing errors and harness adjustments irregularities. Originally the canopies were designed for 8 upper control lines attached to 2 lowers on each side. Nowadays, Most of the Icarus Tandem canopies are equipped with 6 control lines per side on the trailing edge, connected to a single lower line and the brakes are not set for opening. This makes them easier to operate- easy packing with still adequate flare in good conditions. For landing, additional speed is usually gained with a turn to ensure good flare. On the field, in turbulence and low speed, Icarus Tandem canopies behave more like square rather than elliptical canopies- slow recovery with significant loss of altitude. The reason is- their design is closer to square canopies than to the high-performance eliptical canopies.

It is useful to know that with every 10 degrees Celsius, any canopy loses on average 3-4% of its performance, in turbulence at least another 3-4% /depending on the turbulence/. So, if we have 30 + degrees temperature day with some turbulence, the canopy has lost at least 10% of its performance. Equipment age, humidity, wing loading etc incur additional loss of performance.
Taking all that into consideration, we redesigned the Icarus Tandem control lines with the idea to make openings more predictable and improve the flare on landing. To achieve that, we designed 8 upper control lines with new dimensions. These 8 control lines on each side of the trailing edge are attached to a single lower control line.
The result achieved on the field testing was even better than expected. The inflation on opening is more predictable and symmetrical which reduced the risk of line twists. Another important result is the increased speed and lift produced in flight that provides longer and more powerful flare on landing.
At first, the new 8 control lines configuration was tested on an old canopy, designated to be retired soon. The new control lines design improved this canopies openings and flare on landing to such an extent, that this “retired” canopy was now preferred to be used by the instructors even more than the new tandem canopies. Consequently, all Icarus Tandem fleet, all sizes for “Australian Skydive” and “12 Apostles” drop zones were equipped with this brake lines configuration with excellent result.

“The brake lines modification by GLH Systems is the best thing to happen to tandem canopies since tandem canopies” – Mike Tibbits, CI.

Well, this might be a bit of overstatement. However, the target was achieved- safety is significantly improved, level of fun- increased!

GLH Systems- driven by innovation!
Stay safe!

📷 Vova Otomas

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