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It seems that wings are getting smaller so I thought it might time to
explore their behaviors, risks and benefits. I, too, have come to love
flying smaller sizes but there are, as always, tradeoffs.
What we're really talking about is flying heavily loaded. After all,
what's small to a 250 pounder is huge for a 140 pounder. Most pilots fly
at wing loadings (pounds / projected area) below about 12 pounds per m².
I consider a wing small at loadings around 14 per m², extremely small
over about 17 lbs/m² and crazy small over about 20 lbs/m² . I've done
that once and will never do it again.
Risk
Heavily loaded generally means more resistance to collapse but a more
spirited response. It clearly means faster takeoff and landing speeds,
and much more dynamic handling.
So far, our limited accident data doesn't suggest that small wings
increase fatal accident risk. It appears that most risk comes from
falling due to the higher takeoff and landing speeds and to mishandling
on launch. I've seen examples of this.
High loadings increase risk after engine failures on takeoff or at
low altitude cruise, between about 5 and 20 feet. It takes a lot power
to keep small wings happily aloft and when that power dies, they dive.
Not handling it right could be quite thwackful. At heavier loadings you
need enough height so that, if the motor quits, you can establish a
glide and regain enough speed for a full flare. 10 feet might not
be enough. On really small wings, 30 feet might not be enough. There are
ways to best handle this, of course, but they require practiced reaction
to engine failure and still won't necessarily leave you standing.
Inflight left/right oscillation is another minor problem. Many
wing/motor combinations will oscillate left/right even without any brake
input. The slightest bump gets them started and, in a few cases, without
any pilot input, they can get progressively worse until becoming big
wingovers. Of course YOU won't ever let that happen.
Knowing You're Ready
How can you know if you're ready? Well one way to handle this
question is to progressively fly smaller gliders. Do some maneuvering
each time, though, so you get a feel for the wing. If you're already
flying in some level of turbulence, or come from thermal-based free
flight, you're probably in good shape from a maneuvering perspective.
One thing to be proficient on is the slider landing, where you slow
down with moderate brake pull then, at 20 to 30 feet, let off the brake
to dive and use that extra energy to flare, sliding slide along the
ground briefly before stopping. If you've got that down, you'll be
better prepared for the necessary technique of small wings, or at least
the most reliable technique for landing at their higher speeds without
falling.
Benefits
The biggest benefit of small wings is incredibly crisp handling. Load
'em up a bit you can they bank extremely aggressively. Plus they have
quite a bit of speed range. You want to be real carfule because you're
already loaded heavily and then, if you get into a bit of a spiral, the
reaction becomes eye popping. The heavier the loading the more
responsive it will be. And by responsive I mean that it might only take
an inch of brake travel to effect and immediate 60 degree roll. Do that
close to the ground and you'll become unwittingly one with earth.
Another benefit is super easy inflation. Not only does the wing have
little area to resist your run with, but it doesn't have far to come up.
Get some speed, as with any wing, to be sure it doesn't fall back.
If you're into soaring or handling high winds, small wings rock.
They'll let you at least kite in 20 mph winds and, if you're at a
soaring hill, it's possible to soar them in strong conditions. You can
use a LOT of brake to slow down and reduce descent then, when you want
to sink, let off the brakes to plummet. Very cool.
Anyone who likes to go fast will enjoy being loaded. You can have the
speed of a reflex glider but pay a price on the low end since a larger
reflex glider will go just as fast but be able to go slower.
Lastly, they pack up into a duffle bag and weigh next to nothing.
Folding is fast.
Drawbacks
Nothing is free and the benefits derived from flying heavy come with
various drawbacks.
- Risk is obviously the biggest drawback so you'll want to be
highly experienced, risk tolerant and pay lots of attention while
flying.
- You'll need more room for launch and landing.
- You'll need more power and will burn more fuel.
- You'll need to run like a gazelle and have really good technique
in zero wind.
Conclusion
For the experience pilot who knows the risks and that wants to sow
some oats these are great fun. Be careful, make sure you're ready and
enjoy!
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