2012 June 20 Please see "Safety
Ring Retrofit" for information on the safety ring that can be
purchased.
Here is more on SafeStart
2009 Aug 6 Jeff Baumgartener has designed a strong
safety ring for the Skybolt v2 that could easily be retrofitted to a
wide variety of paramotors and demonstrated its ability to withstand 170
pounds on a highly vulnerable spot of the netting.
Here is an article
showing what he built. Of course nothing is foolproof so its
still always up to the pilot to exercise good judgment at all times.
Safer gear just improves your odds of surviving an unexpected thrusting motor
trying to chop body parts.
2009-Oct-25 Safestart almost made it. Apparently there's just not
enough money and too much liability. See
this article, with video on work done by Christian Bultmann and
Wayne Mitchler.
Animation showing several ideas to improve prop
safety
The best designers will help reduce our sport's most prevalent serious
injury and much of that will come through cage improvements. The section
highlights efforts to do just that. I applaud those who make gains in this
area. Nothing is perfect, everything can be improved. If you know of a
paramotor maker that has made improvements to cage design that will reduce
the possibility for hand or leg injuries, please send it to us at
contact.
The safest cages will pass the hand test: That is, prevent an open human
hand from contacting the prop if holding back the paramotor at full rated
thrust from anywhere on the cage or netting. They should also prevent
reach-around injuries where the pilot is grabbing for brakes or falls
and manages to whack a hand by going around the cage hoop.
The cage ideas in the diagram at right have been added to address
actual injury accidents. It's been enhanced over the years as different
causes have appeared. For example, it has become apparent that the prop
should be forward of the hoop and well away from the pilots reach. Several
injuries struck pilots when, during launch, they were able to get their
hand around the cage. The pilot couldn't do it while just standing
there but, with the motor bobbing around, he was able to and with tragic
results.
Another area that must be addressed is the frame bottom. I know of two
serious injuries where the pilots calf muscle was cut when running for
launch and two other accidents where the pilot was launching. One was on a
forward launch where the pilot put his hands back and down, the other
was during an abort where the pilot got whacked after pulling full
brakes. Make sure your frame protects from this.
Cage Hand Test
A critical test for paramotor prop safety is whether it can withstand
the hand test. You should be able to put your hand anywhere on the cage
and, at the motor's full rated thrust, NOT be able to touch the
prop. It's a simple test: push on the weakest part of the cage netting
nearest the prop (usually its tips) and see if you can touch the blade.
If you can, you're at higher risk of a prop strike. There should also
not be any large holes that would easily allow a stray hand to go
through.
Here's another test that is easier to do. See if a 3 x4" block of
wood can be pulled into the prop by pulling AGAINST the prop, through
the netting, with half the rated thrust. If it can, you're at fairly
high risk.
It may seem extreme to require passing the hand test at full thrust
since it will never likely be pushing only on that one point. But all it
takes is a quick bounce of your hand or shoulder into the prop arc and
you're doomed. Plus, the hand test doesn't take into account that the
prop tips are arcing slightly (up to an inch) towards the cage or that
the motor may flex on its mounts when you stop the cage with your hand.
So the full rated thrust hand test is a minimum that motors
should pass to have reasonable prop safety.
Even a machine that passes the hand test is not bullet proof. Cage
pieces or lines can fail so it should never be relied on. All starting
should be done with the anticipation of full power and a plan to handle
it that does not include going for the cage.
There are a number of machines that can pass the basic hand test as
some manufacturers have taken the initiative to pay it attention. The
list of machines is growing, it seems, and hopefully more manufacturers
will take this risk more seriously.
Safety Ring
Jeff
Baumgartner, Skybolt designer, puts ideas into action.
He has come up with several implementations meant to address cage
safety including the one pictured here, a prototype. Jeff explained that,
on the next version he would decrease the open space between the hoop and
motor. That would help as a pilot could get through. The intent is to show
that the netting will easly pass the hand test. Reach-around clearance is
provided by having an oversized cage and enclosing the prop fully. Jeff
explains that clearance depends also on prop size. This cage with a 48"
prop will not have the same protection it will with a 46" prop.
Another video showing the Safety Cage (aka Safety Ring).
These are examples of the
inner safety ring put on at the prop's radius. Ideally, the ring should
go all the way around to the bottom. Several pilots have fallen down on
launch and instinctively put their hands down to catch themselves. The
hand went through to the spinning prop. Here is the detail page for the
Safety Ring Retrofit.
