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Τελευταίες 5 Αναρτήσεις Paragliding And Aviation

Πέμπτη 24 Ιουνίου 2010

DHV - Paragliding Lifejacket test

 *Άρθρο της /www.dhv.de

Lifejacket test
After a fatal accident during an SIV course, safety requirements for training over water are being carefully examined. The accident occurred in the autumn of 2008. After a pilot landed in the water, the automatic lifejacket failed to function and the pilot drowned before the rescue boat reached the scene. (Accident report link here).

SIV trainings are conducted over water, to reduce injuries from hard impacts, should something go wrong. The water itself, can however become a significant danger factor, if key components such as lifejackets and rescue boats fail. The training system is layed out redundantly, so that if the lifejacket should fail, then the rescue boat should be immediately at the scene, or should the resue boat fail, then the lifejacket should keep the pilot afloat. The question is, how safe are the different lifejackets?

After a water landing, the harness protector (either foam or airbag) which is very buoyant, tips the pilot forward. The lifejacket should then provide sufficient floatation to prevent the pilots head from being forced under water. As long as the pilot is able to swim, it is usually possible even without a lifejacket, to keep your head over water for several minutes. Should the pilot be unconscious due to a blackout from high g-forces, or from the impact with the water, then a functioning lifejacket is mandatory.

Whether lifejackets typically used in SIV trainings over water are sufficient or not, was the central theme of an investigation made by the DHV safety department together with the Achensee flying school at the Achensee in July 2009.

Three pilots who volunteeered to test lifejackets were to simulate unconsciousness on impact with the water. This they managed so convincingly, that observers in the rescue boat had their doubts at times, if everything really was ok(!) The rescue boat of the Achensee flying school with its sinkable transen for the easy recovery of objects in the water, was always present at the water landing site.



Picture 1 - always close to hand - the rescue boat.

The life jackets:
Five different lifejackets were tested:
1) Nautomatik 3002S automatic lifejacket with 150 N (15.3 kg) buoyancy according to the EN 396 standard. This EN standard defines that the lifejacket should inflate automatically within 5 seconds of water contact, and have sufficient buoyancy to keep the head of an unconsciuos person wearing oilskins out of the water. This is the most commonly used lifejacket in SIV trainings over water.
2) Plastimo 275 N automatic lifejacket with 275 N (28kg) buoynacy according to the EN 399 standard. This lifejacket has the largest buoyancy tested, and should keep an unconscious persons head out of the water when wearing full bad-weather clothing.
3) Secumar Alpha 275 3D automatic lifejacket with 275 N (28 kg) buoyancy for use with extremely buoyant clothing. This lifejacket has a special shape to assist turning a unconsciuos person wearing buoyant clothing on to his / her back.
4) Secumar foam lifevest according to the EN 393 standard. This norm declares that this lifejacket is not sufficient to keep an unconscious persons head out of the water. This type of lifejacket is still used in several SIV training courses.
5) Secumar automatic floatation device, made especially for paraglider pilots - (sales under www.freiflieger.eu)
This device was announced in an article in "Thermik magazine".



150 N Lifejacket in harness

150 N Lifejacket inflated

275 N Lifejacket in harness

275 N Lifejacket inflated

275N 3D Lifejacket in harness

275N 3D Lifejacket inflated

Secumar foam lifevest in harness

Secumar foam lifevest

Secumar automatic floatation device in harness

Secumar automatic floatation device inflated
HarnessesAll paraglider harnesses were LTF certified, three had foam protectors and one used an airbag protector.
Water landing with the 150 N automatic lifejacket.
After landing, the pilot stayed face down in the water. The lifejacket inflated within 5 seconds, but the buoyancy of the lifejacket was insufficient to clear the pilots nose and mouth from the water.
The pilot could only keep his head over water by actively stretching his neck.

Video 1: Wasserung Weste 150 N (water landing 150 N lifejacket from boat)
Video 2: Wasserung Weste 150 N (water landing 150 N lifejacket from shore)


Water landing with the 275 N automatic lifejacket.This lifejacket had the best results in the test. After landing in the water, the pilot initially stayed face down. The lifejacket inflated within 5 seconds, turning the pilot on to his side, with his face clear of the water. Part of the velcro closure on the lifejacket did not open completely (see picture 5 and video) and had to be opened manually before the lifejacket inflated completely.
Video 1: Wasserung Weste 275 N (water landing 275 N lifejacket from boat)
Video 2: Wasserung Weste 275 N (water landing 275 N lifejacket from shore)

Water landing with the 275N 3D automatic lifejacket.
This lifejacket is commonly used in commercial operation e.g. oil rigs, and should be sufficient to turn people wearing heavy waterproof cloathing on to their backs even if they are unconscious . In these tests however, it was demonstrated that the large buoyancy container is positioned too low, and the pilots head can remain half underwater.
Video 1: Wasserung mit Weste 275 3D (water landing 275 N 3D lifejacket from boat)
Video 2: Wasserung mit Weste 275 3D (water landing 275 N 3D lifejacket from boat)



Water landing with the 50 N foam lifevest.
Foam lifevests are not declared as lifejackets capable of supporting unconscious people, merely as floatation devices to assist swimming. This was verified in the tests - the pilot was only able to keep his head out of the water by actively swimming.
Video 1: Wasserung mit Feststoffweste 50 N (water landing 50 N lifevest from boat)
Video 2: Wasserung mit Feststoffweste 50 N (water landing 50 N lifevest from shore)



Water landing with the automatic floatation device from "Freiflieger.eu"This device is a large rectangular airsack which inflates automatically from a CO2 cartridge on water contact.
During the tests, the velcro closure did not open completely, preventing complete inflation. The device does not ensure that the pilots head is kept clear of the water. A conscious pilot can use the device to stay afloat and compensate for the buoyancy of the harness protector.
Video 1. Wasserung mit Auftriebskörper "Freiflieger.eu" (water landing with Freiflieger.eu flotation device.)



Other observations
In two cases, stuck velcro closures prevented full inflation of the lifejackets. A regular opening and closing of the velcro, could help prevent this from happening.

Large volume lifejackets can conflict with pilot helmets - this is especially the case with full-face helmets as illustrated in the picture below. The helmet may become forced up by the lifejacket, tightening the chinstrap.  Participants of SIV trainings over water wearing full-face helmets should be instructed to release the helmet chinstrap immediately on water contact. Tests indicated this to be no great problem.




The lifejacket forces the helmet up, and tightens the chinstrap.
Conclusions

Only one of the tested lifejackets fullfilled the test requirements: the Plastimo 275 N was the only lifejacket tested , able to keep an unconsciouss pilots head over water.
The Secumar Alpha 275 3D could not guarantee to keep an unconscoius pilot face up in every case, and the other three tested systems offerred no help at all to an unconscious pilot.

This test was conducted with a small sample of the available lifejackets found on the market today. Lifejackets in the 275 N class from other manufacturers may, or may not be suitable for SIV trainings over water.

The DHV requests flying schools offering SIV courses over water to test their lifejackets in a similar manner, and to only use systems which guarantee that an unconscious pilot remains face-up after a water landing.

Our special thanks go to the pilots Flo Peter (assistant instructor), Ronny Schmidt and Simon Winkler, Ecki Mauter and Cordula Cröniger from the Achensee flying school, Chiemsee flying school for the harnesses and reserves, and Nova paragliders for the test paragliders.


Karl Slezak
DHV-Training/Safetya

Fotos: Ecki Maute
Video: Wolfram Kastl, Karl Slezak 
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