Vit Hrusa is called the Marketing Director at Galaxy High Technology s. r. o. , but it’s a title that doesn’t cover the range of his activities there.
Galaxy manufactures the Galaxy Recovery Systems – whole plane ballistic parachutes – that are installed in every Sting, and has been creating cutting edge products since 1984. Vit has been with the company most of the way, doing what needs to be done, whether it was packing parachutes in the early days or telling the story of a superior ballistic recovery system today.
Galaxy is an innovator in the field, holding some of the seminal patents for designs that are mimicked today by its competitors. Even before the Czech Republic emerged from behind the Iron Curtain, Galaxy was sharpening its competitive skills and preparing for its leadership role in the global marketplace.
We recently talked with Vit to learn more about what makes the GRS ballistic recovery system tick.
Sting Notes: What are the most important features of the GRS system?
Vit: Very quick opening at stall speeds and low heights. The parachute opens in 5.8 seconds, which corresponds to the distance traveled of 120 meters (400 feet). That can be 120 meters vertically or 120 meters horizontally. Unlike the competition, we can tell you the lowest possible height of rescue.
Another feature is the small dynamic shock even at max weight and max speed. The maximum load an occupant would feel is 3.8 g.
Rapid opening is enabled due to the new, patented technology of the parachute canopy. The technology was patented by GRS in the year 1994, and now is used by Cirrus, too. It propels the whole system out to 18 meters above the aircraft in a compact inner container and safely opens the canopy there, away from the airplane and any debris or air currents that might foul the parachute.
Sting Notes: Can you walk us step by step through what happens when I activate the system?
Vit: You pull the activation handle, for which you need some elbowroom, so that the launching peg gets to the horizontal position. The required force is about 9 kg (20 lbs).
The peg engages a spring and the peg springs up, activating a hammer that hits two strikers, which ignite two starting cartridges. The two starters are redundant, as one cartridge is sufficient. Three grams of black powder are fired, which ignites the solid rocket fuel. The fuel is smokeless nitroglycerin powder. The fumes of this fuel, unlike the American fuel, are not poisonous.
The rocket starts, cuts three rivets on the plastic head, breaks through the airplane canopy and after the 2 meter long bridle is drawn, the inner container is taken 18 meters above the aircraft. At about 2m above the aircraft the two parts of the container separate. The upper part with the canopy continues to deploy away from the lower one with parachute lines and the main belt. When the whole system is drawn to its limits the bridle cables are ripped out of their hidden channels. At the same time, the force of 200kg (440 lbs) unlocks the canopy in the inner container and the canopy is drawn out.
This whole procedure takes only 0.7 seconds.
After the canopy opens above the aircraft, the rocket engine continues its own flight with its remaining energy and separates from the main canopy. It then free falls with its own braking inner chute.
Sting Notes: What happens to the rocket exhaust? Why doesn’t it fill the cabin with fumes or start a fire?
Vit: The whole volume of gas produced in 1 second by the rocket engine is 1 cubic meter. Since the rocket leaves the fuselage in 0.01 second, the amount of fumes is very small and is quickly exhausted out of the opening in the airplane canopy. Such an extremely short exposure to the blaze cannot ignite anything; it has been tested.
Sting Notes: Where are the GRS systems sold?
Vit: All around the world except South America and Japan.
Sting Notes: For the Sting: what is the maximum airspeed to activate the chute?
Vit: The GRS system is certified for the LSA category. It was tested at different speeds and loads:
• 250 km/h (135 kts), 750 kg (1,650 lbs), 5.0 seconds to open
• 90 km/h (49 kts) and 600 kg (1.320 lbs), 5.8 seconds to open
• 250 km/h (135 kts), and 600 kg (1.320 lbs), 5–5.5 seconds to open
• Max dynamic shock was 22. 6 kN corresponding to 3.8 g.
• Maximum speed in which the parachute was tested is 290 km/h (157 kts) and 600 kg (1,320 lbs), full opening in 5.0 seconds.
It is difficult to design a chute that works well at both slow and fast speeds (like an athlete good at both sprints and the marathon) and GRS outperforms the competition in this respect.
Sting Notes: For the Sting: what is the minimum height to activate the chute?
Vit: We estimate that at 120 meters (400 feet), in a vertical fall at stall speed. If there is a forward trajectory the height above ground can be even lower.
Sting Notes: For the Sting: what is the time lapse between activation and opening of the parachute?
Vit: 5.8 seconds to full opening.
Sting Notes: For the Sting: what is the vertical velocity when the airplane touches the ground?
Vit: 6.9 meters/second, which is equivalent to an 8 foot drop.
Sting Notes: How is the GRS system superior to other ballistic recovery systems?
Vit: To summarize. Due to the new, patented technology of the canopy and the system of quickly propelling the container above the aircraft before opening the canopy, it is superior to all other systems. Our way is different, not like the other systems. Unlike the competition, all our tests and video footage can be seen on the web. You can measure the opening time. Last year at the meeting of FAA in Prague, we proposed that the time of opening at low speeds must be published, not only at high speeds. We state it everywhere unlike the competitive producers. You can find all of our info on the web at www.galaxysky.cz
Sting Notes: You have recently extended the inspection cycle on new GRS whole plane parachute systems to 9 years. How is GRS able to go to such an extended inspection cycle?
Vit: At the end of last year we decided to find a way to prolong the repack cycle. For this we developed a new design of the launching peg and the launching mechanism and switched the production of the new enhanced rocket parts to a very high quality manufacturer, AXL ltd. They produce the catapult rocket seats for theL39 fighter invented by Mr. Matějíček, who also invented the rocket engine for our system. We also use a low-pressure packing system so that the fabric of the canopy is not so tightly compressed and does not tend to fuse over time, as is the case with some of the competition.
This new 9-year inspection cycle applies to all GRS systems produced or repacked after June 1, 2008.
Sting Notes: Why would you rather have a GRS than a BRS system?
Vit: As stated above. Every producer is able to build a system that opens quickly at high speed and maximum weight, but it is much more difficult is to show that it opens quickly at stall speed.
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