Paraglider Review: 2009
Ozone Viper Custom 20
Reviews, 08-13-2009 | Ratings: 1 is bad, 10 is good |
| About the Testing
the newer Viper 2 Review
The Ozone Viper is among a new breed in high performance reflex
technology. Like the Dudek Plasma and Paramania Fusion, it mates an
efficient, high aspect ratio wing with a reflexed profile for speed. The
Viper is not quite as reflexed as others but achieves nearly the same
result. Given the inherently draggy nature of paragliders, fast models
must be clean so Ozone spent some engineering effort doing just that. Of
course, when fully accelerated, you'll still need lots of thrust.
I've never been a big fan of reflex wing handling, harder inflation and
increased fuel consumption. With the advent of the Plasma/Viper/Fusion,
that has changed. In fact, I
really enjoyed these wings and relish the ability to go fast on Top
80 power with great handling.
Flights were done both morning and evening on light days. The sink rate
tests were done at a temperature of 65�F on a Miniplane Top 80 (55 lbs
with fuel) at an inflight weight of 225 lbs. Altitude ranged from 1200
feet to 1500 feet MSL.
This review includes some comparison with the Viper 2-24 since the 20
meter prototype I flew didn't have many of its features. Those features
turned out to be real important. The 20 was more of a Viper 1 without
tip steering and with the old-style brake design. The Viper 2 is leaps
ahead in handling. It's semi-reflex has maybe 50-80% the reflex amount
as Dudek or Paramania models.
Handling (7): When trimmed slow
the Viper Custom is decent but has a noticeable adverse roll. If you
weight shift first then brake, you don't notice it. But if you
just pull left brake, your left butt cheek goes up and the glider seems
to bank slightly right before turning left. Again, that's only the Viper
Custom, the Viper 2 handles better. You can pull a brake and dive if you
want which is what I want in a good-handling glider.
When trimmed fast, these wings are typically flown with tip steering
lines since brake pressures are so high and brakes defeat the airfoil's
reflex. The Viper 1 had no tip steering but the Viper 2 did have it and
it was very nicely implemented. Not surprisingly, brake pressures while
fully accelerated were high.
Brake pressures and tip steering pressures on the Viper 2 are quite
light. In precision-type competition flying, you'd probably have the
trim set at about two inches out so you could still use full speedbar on
straight segments. The manual suggests you can use speedbar while
trimmed slow but do so in mellow conditions. To me that means sticking
with half-fast trim to safely use the speedbar. After all, in
competition type maneuvering it's almost a given that you'll be flying
through your wake. I did so on my test flight and it handled it just
I didn't do brake pressure tests because the 20 meter Viper 1 model I
motored with would have given unfairly higher readings, much moreso than
a Viper 2.
Inflation (-): Reflex gliders as a breed require more effort to
inflate. But then small wings are easier since the wing doesn't oppose
your effort so much. I did several no-wind forwards, a light wind forward
and a light wind reverse without any problems. You're running faster but
not as much as you'd think. Most of the time I had the trimmers out a
couple inches but had no problem inflating with the trims full slow. By
the time I was testing the Viper I had put some time on the Plasma and had
it pretty much figured out�once you've got the technique, they're quite
easy to launch.
In strong wind you'll love it. Overshooting is less of an issue than
regular wings although may be a bit more prone to it than the Plasma. Of
course any wing can be made to rocket past an unwary pilot. All reflexed
gliders have less tendency to experience a frontal collapse.
Kiting (4): Kiting is so much easier with small wings.
Different, for sure, but just easier. Being high aspect ratio presents
some extra challenges, though. For example, when it gets off to one
side, you can only pull so much brake before the tip stalls and falls
back. Kiting is easier with the trimmers neutral since brakes still work
well. Its small size means it doesn't pull quite as hard.
The reflex effect is best seen while kiting. Let the trimmers out and
inflate vigorously so that it overflies you some. Instead of front
tucking, the trailing edge goes up and the wing descends fully open. Of
course you can cause a frontal with enough provocation and if it
goes off sideways it will really go quickly. I didn't get to try both
the Plasma and Ozone back to back in strong conditions because the
weather was too nice while I had them both. Oh the burdens. But it seems
like the Plasma may be a bit more resistant to front tuck at fast trim.
I'd welcome other input but will say that the difference seemed very
small if any.
Efficiency (7): The idea is that, when trimmed slowly, it's
essentially a regular paraglider as far as efficiency is concerned. And
that is largely true since you're going faster than most wings so the
power required vs speed is the same as any other high-aspect ratio wing.
You'll burn more fuel per hour but probably less fuel per mile. The same
ratio is true on small vs large wings.
It uses cascades, internal bracing and unsheathed top lines to
improve efficiency and it shows at the higher speeds. Although my Top 80
barely produced enough power to stay level trimmed fast with full
speedbar, I was rocketing fast. And on landing I had an enormous amount
It's not as efficient as a similar non-reflexed glider, even trimmed
slow, but since it starts with an efficient design to begin with, it's
Sink rate power-off 30 second altitude losses from 2009-08-14 test.
Trim full slow = 1300-1140 = 160 (320 fpm), 2nd run = 1300-1120 = 180
(360 fpm) for an avg of 340 fpm sink rate.
Trim full fast = 1300-1080 = 220 (440 fpm or 5.00 mph).
Trim full fast + Speedbar = 1500-1080 = 420 (840 fpm).
Note: I would welcome others to do these
same tests for verification. Be sure to include your all-up weight
(motor, fuel, accessories, you). These numbers seem high and,
although I did two tests to help establish consistency, they seem
high. To do the test, go to an altitude let off the power and hack a
stop watch. At 30 seconds, note the altitude. Subtract the two
altitudes and double to get feet per minute.
Speed (9.5): This wing is fast with a really effective
speedbar. Not surprisingly it took full power on my Top 80 to barely
stay level. The most likely use for fast trim and full speedbar will be
coming out of turns unless you've got lots of power. The Vipers would be
well suited for Cloverleaf type tasks for those who get on the speedbar
during rollout. It handled flying through my own wake without problem
although I never got a big bump.
Here are the GPS speed readings from 2009-08-13 test. The initial
upwind/downwind test to establishes wind speed so as to convert the
remaining gps readings to airspeed. MSL altitude was 1200 feet (smooth)
through the test.
Trim full slow = 25 mph.
Trim full fast = 29.5 mph.
Trim full fast and full speedbar = 37.5 mph.
Raw data: Test shows wind was 17mph which was used for determining
1. Exactly upwind, hdg 200� slow trim: 16 mph, downwind hdg 020�, 34
Wind speed=9mph, airspeed=25 mph.
2. Trim slow=16 mph, Trim fast=20.5
3. Trim slow=16 mph, Trim fast with full speedbar = 28.5 mph.
4. Into wind run three. Trim fast(11)=14 mph, full speedbar=24 mph.
Here's where the afterburners lit up. Trim at 0, speed 9 mph;
speedbar fully deployed, speed 17. That's a huge range! Remember, this
configuration is not recommended for doing in any turbulence. Instead,
go to trims full fast then push speedbar. With Trims fast (11 setting)
speed was 14 then, with full speedbar, it was flying 24 mph. Given the
average 8 mph headwind, that means an airspeed of 32
Construction (8): It's built well with strength in all the right
places. Chad Bastian, the wing's owner, had the brake lines adjusted just
right so I didn't have to change anything.
Trimmers were standard, with no markings.
Brake keepers were old-fashioned snaps. They work well and don't get
clogged with iron sand for those california flyers.
& Safety (6): It's not certified nor would it make much difference in
this class since they're basically competition wings. Skilled sport pilots
may like it if they don't mind the fast launch and landings. We're flying
so heavily that it's probably not possible to certify but, if you did, it
would probably come out as AFNOR Competition, DHV 3, or EN D.
When trimmed fast and hands off, there is decent passive safety in
terms of collapse resistance although probably not quite as much as the
Plasma. Since I'm a fan of active flying, when big bumps come along, I
prefer to trim slow and keep my hands on the brakes. Plus, lets face it,
if you do
take a collapse while flying at the speed of heat it won't be
pretty. Risk probability low, severity high. I would only recommend this
wing to PPG 3 level pilots.
Avoid being trimmed slow and using speedbar, a potentially nasty
combination. The practice is common on regular paragliders but not
recommended for reflex gliders. This wing does allow speedbar while
trimmed slow suggests only doing so in calm air.
Warrantee: No information here.
Overall: If you wanna go fast with great handling, the Viper 2
is a great glider. I'm torn between the Viper 2 and Plasma, both great
selections in this class of high-aspect, responsive reflex gliders. I
still have yet to motor the Viper 2 but can actually see owning one of
Be careful and enjoy.