I
felt at home very fast with this wing.
No problem with the brake length or handling.
The wing felt very solid to me, light and very
easy to inflate and control - not over passing at all. To that point that I went
flying thermals hands up to see what was going to happen.
It is very solid and pitch stable. Kind of wing
that I would go fly to take pictures. At the end, it will close but it is much
more collapse resistant than my Airwave/Mustang (DHV2).
The brakes pressure increases a lot when lowering
hands. Impossible to stall it by mistake. Kind of tiring to keep it at min speed
for a while when top landing.
When flying at full bar (pulley against pulley)
across active thermals, got 3 asymmetric collapses and one frontal.
It is very stable with a half-bar.
The wing is fast in active air/face wind, at
least this was my impression.
Was flying for the whole afternoon almost alone
so no way to compare it with anything else.
At the end of the day I was able to compare it
against another wing (Sigma5) in very weak thermal conditions.
There was not much difference noticeable climbing
slowly up to the top.
Although, I don't know the other pilot's weight
and wing size.
.
APRIL 29, 2010 | BY FREDRIK
AHL | WINGS
This
review was sent in by reader Vincenzo Di Francesco. This is his thoughts on this
new glider from Windtech
This is an
independent review of the recent wing of Windtech available on the market from
March 2010. The author has about 2000 hour of flight on different wings mainly
in the intermediate class, his test flight of this wing size M loaded at 100 Kg
has been done in Socorro SP Brazil, a site with mountains ranging from 700 to
1500 meters with abundance of vegetation and of rain. Conditions where generally
weak normal with the exception of some day with prefrontal meteo conditions and
with meteo wind of about 20 km/h in the central hours of the day, maximum vario
range was 5 m/s and minimum -6 m/s.
Wing description may be found on the windtech
site, to make few comments here the wing has a pronounced
wingtip curvature and a flat top, as I like to say a strong ellipticity since
the front profile looks like an ellipse, more than like a arch on the span
direction the profile of the wing is of latest generation with a pronounced v
shape of the leading edge that is like in the new aerofoil wings for same
example GIN Boomerang GTO SOL synergy 4 etc. This wing has also a record line
reduction with only 9 main lines for risers and a reduce pilot-wing distance.
It was intended for pilots in EN C category but thanks to his high stability got
a EN B certification.
Lets see its behavior in flight, all the
comments here are based on my personal experience have not been verified
with test pilot of Windtech so they are as it is comments.
Take
off
The take off is easy both in high wind or in light one, in weak wind you have to
brake a lot it when overhead to avoid that it passes you since the wing has an
higher trim speed respect to other wings in the category, once airborne you can
release the brakes progressively, check if the Liros top cascade lines get a
knot near the start of the main line sewing, also consider that in case you have
a small cravatte on the wing tip it do not solves itself at least groundhandling
so better to remove it manually with the wing on ground. I do not registered any
strange behavior during take off after about 50 of them.
Handling & feelings
In flight the wing show its aggressive design, feedback on the risers are
consistent, not to say bumpy, pitch is relevant when entering turbulences and
needs attention and control by the pilot, roll angle are instead completely
dampened, this means that under instable condition the wing tend to eliminate
extra energy pitching more than rolling.
The great difference in the handling of this
wing is due to the brakes, they have an impressive utilazable range
offering to the pilot great opportunity to tune the turns and the thermal
action, this is a big advantage when finally the pilot adapt at it but at first
impression this wing seems an alien.
Lets talk a little more about the brakes in
turns, there are two optimal modus operandi, the first at trim speed
using large amount of weightshift plus the internal brake, this gave very flat
turns but a little insensible to detect the core of the thermal given the roll
stability of the wing. The second option is to brake heavily it up to the
minimum sink speed around 30-33 Km/h this is achieved with hands below the
carabiners so I suggest to take 1 wrap of brake line in the hand to maintain
the normal pilot posture with hands over the shoulders.
This second style of thermaling is more
sensible for the purpose of centering the core, as well permit to change the
wing course promptly and effectively giving an high value of handling for this
wing, it is really possible to turn tightly, with flat turns with inclined turns
and to center the core releasing both brakes or pushing them low when dolphining
inside the thermal. Unfortunately this high tunability of the wing has a cost,
the brakes are quite hard at this point, remember that if they tend to go slack
this means that you are approaching the stall point so my suggestion is to
operate the wing in the harder part of the brake resistance and to
monitor accurately the feedback of the force necessary to pull down them. Except
the tradeoff of a high physical exercise on the brakes this method permit very
fast climb in thermals dampening the turbulences and keeping the wing in full
control, essentially you are putting more than 10 kg on each brake so you are
hanging now on 4 points the two risers and the two brakes handles being in full
touch with the wing movements. This is my suggested method to ride strong
punctual thermal cores, just a recommendation, avoid to do it when very low.
I highly discourage the shortening of the
brakes line, I saw a performance degradation both at trim and ad full speed if
the brake lines have not a wide curvature under the relative wind pressure,
brakes have to be left free at pulley to leave the trailing edge of the wing
undeformed this means you have to go with your hands quite high.
This wing is very sensible to brakes
settings, the central top brake line top cascade is shorter and tend to deform
the trailing edge of the wing, optimal performances at trim get deteriorated if
the trailing edge is not perfectly flat, also the brake system of the
zenith apply the first bunch of deformation on the side of the wing near the
wing tips, only pushing forward the central part of the trailing edge get
deformed and with it the final part of the wing tips. So to mantain a small
amount of brake pressure is inefficient for this wing, it has to fly free.
Climb in thermal
The wing is very talkative, at the first flight you will be disoriented by the
multiple input it will transfer to you, when approaching a thermal from the
front it will be sucked in an the vario will start to scream, it has a great
efficiency in front entrance and I had never experienced reluctance of the wing
to enter, you can brake the wing at the moment of wing entrance without to risk
to see it drop in your back. Things get a little different if the thermal is at
one of your side, in that case the wing it is reluctant to be sucked in the
thermal, you can understand there is one close because of turbulence the wing is
transmitting to you but the wing will not turn to bit the thermal like if the
thermal is in your front. I guess this behaviour is connected with the roll
stability of the wing, you have to be conscious of this and adapt your thermal
search strategy, in my case I went back to the area of maximum turbulence on a
near by straight line, remember that the wing is very sensible in case the
thermal is sitting straight in front of you. Some pilots deducted that the wing
do not like to be in the core, the real fact is that the zenith go exactly where
you drive it to go so the capacity to center the core or not to center it is all
on your senses and capacity, the wing will provide you with all the necessary
input but is your skill and dedication that will make the wing climb well or not
in the thermal.
The wing suffer a little if at the border of the thermal in the turbulent area,
in my opinion more than other wings, and climb better than other wing when in
the core, but to be in the core is your responsibility.
As I said once I get in the lift area I switch to minimum sink speed to center
the core in a fast and autorithative way. I noted that my comparative climb
performances where low when I was not concentrated in the action.
Transition
This wing is a master in straight flight, if you will be able to select the lift
area in your transitions from one thermal to the other you will experience a
glide that few years back was available only to competition wing, we are talking
of glide values very close to the 10 mark. In case you enter descending stream
of air the friendly usage of the speed system will reduce the altitude lost you
can tune the actual relative speed respect to air just listening to the wind
noise on the lines, a real pleasure, especially when you go at full speed and
leave other class brother wings in the back.
In case you enter the new lifting area you will recognize it easily, better to
step to half speed if you want the help of the audio of your vario.
Speed System
Speed system, his quite soft having a two pulley system, I did not have any
problems to keep it under turbulence both at half speed bar or at full sped bar
the wing feel rock solid, but the amount of turbulence here is classifiable in
the range by weak-medium, i.e. in my site I can forget to stay with bar on and
go straight in the local turbulences when high over ground, several time I
pushed the speed also low when finding a spot to land in strong thermal activity
and I did not experienced any surprise. the wing polar is quite flat but not
comparable to wing of higher class especially passed the half speed bar mark,
but the reliability of the wing on speed allow a continuous usage of it since
the stability of the wing at speed is reassuring. You will see the central part
of the top leading edge canopy far from the mylars reinforcement to flect a
little under turbulence but this is normal and do not represent the signal of an
impelling frontal since the profile of the wing at mylar remain solid.
The speed of this wing is one of its peculiarity and one of the reason to select
it between competitors, it is a great adds on for a EN B wing.
Descending methods
My preferred methods is the big hears plus speed, the descending rate is not
very high but the relevant forward speed lets you counteract contrasting wind
and go easily out of the overdeveloping area, I used big hears and full speed a
couple of time and all was in control, I also used limited G spiral to loose
some altitude but honestly I did not enter nose down spirals so I cannot report
about this extreme maneuver, I have just seen easy access to the limited G
spiral that I entered.
Overall performances
First of all you have to consider that at 1500 meters asl I recorded an averaged
trim speed of 43 Km/h, a top speed of 58 Km/h and as I said a minimum sink speed
of 32 km/h, so this wing is tuned for high wind sites to counteract it, I had
not any problem to escape congestus clouds suck or to go back to take off upwind
thanks to this higher speed range respect the average of wings in the same
class, so the speed is the main characterization of this wing coupled with an
high resistance to turbulences. Thanks to this characteristics the wing suffer
in weak condition compared to other wings and the overall performances is poor
in weak rotted conditions.
I had the impression that the wing has very good glide in calm air in the range
of 9.8 and higher, and this help in transitions and in convergences where you
can cover good distances at trim speed.
Unfortunately this good glide get a little penalized in case the air is more
active with alternation of ascending descending air streams, if the pilot do not
counteract actively they may go at very low value and the glide may be reduced
at a mere 8.0 value.
In case the pilot counteract actively giving a contribution for the pitch
stability of the wing or at the contrary to smooth the reflex response of the
wing when getting out of the ascending air stream, i.e accelerating the wing in
time to avoid a sort of reluctance of the wing to leave the thermal with a pitch
back action of the wing, the performances became really impressive for a wing of
this class. I guess this is the consequence of the reflex angle of the lower
part of the canopy that give auto-stability but at the cost of loosing energy,
when flying actively you can hold more of the glide in calm air. So my overall
comments about the real performances of this wing is very positive definitively
over the average of the EN B wings and in the top of the EN C ones but at the
cost of pilot concentration, it is not a wing that fly with the autopilot
function, it require pilot sensibility and attention in active weak air, mainly
using weightshift to put the weight on the right half of the wing, brakes have
to be kept quite to do not distort the wing profile, in case the air activity is
big the inherent stability of the wing compensate for not optimal pilot
inputs.It must be remembered that brake action must be limited at the essential,
with his high trim speed this wing dissipate a lot of energy if brakes are not
kept calm.
Given the high values of the glide and the speed range this wing is a good
solution for who is interested in demanding conditions crosses, and generally
for who want to interact with air to learn new tricks that could be reused once
on higher kind of vessels .A very good training machine.
Unwanted wing configuration
When I approached this wing I got several asymmetric closures about 1 over 3-4
hours in air, now after about 30 hours this number is reduced to one over 6-8
hours and going lower, the wing reopened without pilot input as in the
certification of the wing, but in same case I had to dampen the swirl under the
wing that can be huge, the wing do not change direction but tend to introduce
roll swing during the reopening, this must be considered if very low over the
ground, in any case I did not loose more than 5 meters of altitudes in the
closures that I experienced. The wing also accept abuse of the brakes action by
the pilot during the reopening.
Spins, I spin the wing 4 times 3 times intentionally and one time by mistake, I
have to say that was just the entering of the spin, well recovered by releasing
the internal brake, two spins has been induced by me top landing to avoid
several obstacle when still being 1-2 meters over ground, the first time I
released the brake and acquired forward motion the second I went to the ground,
the acceleration was progressive and consistent, but I was very close to the
ground. The other two spin was in air, one times I intentionally spin the wing
to avoid a collision with another pilot that cut my way abruptly, I released the
spin after about 120 degree when my way was clear, the second spin was
unintentional during a low save in turbulent condition, the wing lost
consistence and I had to release the two brakes, this time the reaction of the
wing was a little violent considering the presence of the rotorized air. So,
obviously this is a wing that must be treated with respect and where brakes may
be abused but in some condition must be released very quickly without any
indecision.
Final comment
this wing has peculiar characteristic that differentiate it from the rest of the
wing available on the market, it is a wing with top score characteristics in
terms of speed and glide, handling is also impressive but in some sense complex,
require a good training under it.
The 3 4 Km/h of gap in top speed respect to concurrent wings may be used to came
out from difficult situation, the same top quality glide if not deteriorated by
air condition offer opportunity for improved crosses. The price you have to pay
for this extra bonus is an accurate piloting both in thermal or when selecting
the path for transitions,
if you are a relaxed pilot not interested in challenging yourself this wing is
not the right one for you, if at the contrary you fly in conditions that require
some extra wing performances to came out of troubles this wing may offer
performances of a LTF 2-3 wings not being so demanding in case of closure and
unwanted wing configuration.
You have to fly this wing with a responsive harness and with a wide chest strap
setting to transmit weightshift to the wing in turns and in turbulence, plus you
have to use a consistent brake force and be tuned on wing behavior in
turbulence, this is a wing for ambitious pilots that want to test some advanced
wing characteristics keeping the passive safety of an EN B wing. Some of this
behavior comes by the short pilot wing distance that make the wing change the
angle respect to the vertical faster than for other wings, so pilot response
have to be fast as well.
You will be never tired to fly this wing, it will gave you good satisfaction on
your habitual flying site when conditions are marginal and difficult, and will
leave you a little disappointed when the conditions are weak. I have no doubt
that this wing offer good training opportunity for who want to step faster on
more advanced wings, and generally speaking
for who want dedicate energy to understand it and refine the style of piloting
to achieve maximum performances from it, unfortunately the same extra
performances will be negated to who fly the wing passively, without weightshift
and using the brakes in not in phase moments, the zenith in that case became one
of the wing of the flock.
The windtech zenith is a real outstanding product no way to have total overall
performances with other EN B wing quite hard with EN C wings and in some air
condition equal to EN D wings of latest generation.
