Naime, dulje vrijeme se pokušava dobiti što lakša oprema (sjedalo), a da ujedno štiti pilota u što većoj mjeri. Popularni back protektori dolazili su u raznim debljinama, a što deblji time i teži. Konačno, certificiranje je postalo obvezno i kod sjedala, pa su ti protektori morali zadovoljiti nekakve minimume zaštite. Potreba za što lakšom opremom dovela je i do razvoja airbag sustava na sjedalima koja postoje već neko vrijeme, ali uz odsutnost dobrog aerodinamičnog dizajna te ograničenoj uporabi (malo jače slijetanje poderalo je sjedalo). Problem se pojavio u fazi polijetanja gdje je jako visok postotak ozljeda, a pri čemu airbag još nije bio u potpunoj funkciji. Danas postoje različiti sustavi koji sjedalo pripreme i pune zerakom i prije polijetanja, pa je pilot zaštićen od početka, ali i sustavi koji omogućuju da airbag ostaje aktivan i kada pilot pada pod rezervom te nema zračne struje koja bi ga trebala puniti kao kod normalnog leta. Sve to zajedno potrebno je i uskladiti sa sustavima za izvlačenje rezervi te odgovarajućim položajem karabinera kako bi pilot imao maksimalnu zaštitu i imao sjedalo koje je udobno, lagano i dobro upravljivo.
Iskustvo nas uči da razvoju nema kraja i da svakodnevno dolaze noviteti, no u posljednje vrijeme inzistira se i na tome da sve izmišljeno mora zadovoljiti i neke standarde.
S tim u vezi donosim prepisku jednog teksta iz DHV magazina gdje se spominje i Skywalkov Cult C, no, dobro je pročitati što se danas očekuje od novih sjedala sa airbagom.
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New Airbag Technology
“You cannot negotiate with gravity”
Sonny Crockett in “Miami Vice”
...and due to this, paraglider pilots need effective back protection. Unfortunately, this area of
equipment development in paragliding has not been basking in glory. Over the last few years,
back protectors have been continuously reduced. Before the times of competing Test Centers,
no manufacturer would have dared presenting one of todays “mini-protectors” to the DHV for
testing. Now we see certified products on the market where the protector is only present at the
point of impact of the test-dummy, the rest of a pilots back is left unprotected. Of course this
satisfies the paperwork and is legal to fly with, as the LTF airworthiness requirements only
state that a protector should be present from the middle of the pilots thighs to the shoulders,
but do not specify any particular energy absorbtion values for it.
Airbags which take an age to fill after launching are a particular step back in pilot protection
and safety. The DHV test of reversible harnesses in 2011 indicated some serious deficits in
this area. In a lot of cases, these airbag harnesses offered practically no protection during
launching. Swing was the only manufacturer to improve their product after these tests. The
harness Swing Connect Reverse was modified with a flexible plastic plate to help pre-inflate
the airbag. With this pre-inflation this airbag has then sufficient volume to pass the LTF
protector test (this was the first harness to ever manage this) with no additional ventilation
required.
Skywalk have also used the idea of pre-inflating their Cult C harness. Before launching, the
pilot needs to assemble two small fibreglass rods with velcro attachments in the rear of the
harness above the main airbag compartment (time required, approximately 20 seconds). With
a few good shakes this pre-inflates the airbag completely and extends its protection right to
the top of the pilots shoulders. The stowage space in the harness is connected to the airbag via
a valve, and is also ventilated through the main airbag air intake during flight. The system
works so well, that the harness passed all the LTF protector tests with very good energy
absorbtion values without additional ventilation. In accordance with LTF airworthiness
requirements for certification, airbags should be fully inflated prior to testing. This was not
required for this harness. This means that the airbag offers good protection during launching
or for a vertical descent (on a reserve parachute) where front ventilation is reduced.
Particularly noteworthy for this harness is the protected area, which extends right up to the
pilots shoulders.
Simone Caldana, designer of Woody Valley harnesses had similar thoughts. He too wanted to
develop an airbag harness which functions without the need for additional external
ventilation. In his airbag he did away with ventilation slots and built in a large weak spring to
push out the bottom of the airbag and effectively pre-inflate the airbag once it is taken out of
the bag. No further pilot action is required to activate airbag protection. Tests on the LTF
protector test machine were passed with very good energy absorbtion values. Woody Valley
have designed their protector to address some of the main crash sceniaros evaluated by the
DHV. Impacts with the pilot inclined to the back are the second most common typ of
accidents after vertical impacts. To help offer protection for this type of crash, the Haska's
protector has its widest point positioned somewhat to the rear. However, compared with the
Skywalk Cult C, the total protected area is smaller, extending from mid-thigh to the lower
lumbar area. The upper lumbar and thoracic spine areas are left unprotected. The Haska can
be fitted with additional side protectors.
Advance have modified their Axess 2 Air harness with its self inflating protector and now
market it as the Axess 3 Air. The main criticism point of insufficient back support has been
addressed with a new back construction which is more stable and immediately noticable
during flight. According to Advance, the protector has also been improved with additional
internal ribs, which aid stability and the protector can now also be replaced if needed. The
Axess 3 Air protector lies between the classical foam or mousse constructions and airbags:
sidewalls and ribs are made of foam components, the space between is filled with air. The
entire protector packs up very compactly, and self-inflates once out of the bag to provide
immediate full protection. The protective area is only designed for vertical impacts, no
protection is present for impacts to the upper back.

Picture 1: An indication of spinal components for a seated pilot. LWS = lumbar, BWS = thoracic,
Steißbein = coccyx. Most protectors offer maximum protection for vertical impacts directly to the
coccyx.

Picture 2: Skywalk Cult C. The protective area is optimised from mid-thigh to the lumbar spinal area.
The airbag reduces in thickness towards the shoulders but is still present at the thoracic spine area.
The harness offers protection for both vertical and supine impacts.

Picture 3: The protector position on Woody Valley's Haska offers protection for both vertical and
slight supine impacts. Its protective area extends to the lumbar spine. For impacts to the thoracic
spine no direct protection is present.