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1. Summary |
by Jérôme Daoust. Revised 2003/8/14. |
Summary (Top of Page)
Thanks to Alan Bradley (Nova USA, E-mail) for supplying this test wing. This section is a summary of my experience, some of which described in the Daily Notes. An Artax M was tested on an alternate day.
· Model flown, Medium (24), has a 90 to 110 kg weight range. My total flying weight was 99 kg (45% into the weight range).
· See Daily Notes for flying conditions and more detailed notes.
· The harness used is a Sup’Air EvoTop, with 20 cm Bump’Air protection, and a chest strap set at minimum length (maximum relaxation, sufficient feedback and weight shift to my taste). Riser separation (between bottom centers) was measured it in flight, to be 41 cm.
· No aerodynamic-enhancing device (tight sleeves or pants, formed harness shape) was used.
· Deliverables.
o Wing, line and riser assembly.
o Yellow helmet bag.
o Speed bar with a first step wire loop. Speed bar accelerator line and Brummel hooks (the latest kind with X-locking of line).
o Small windsock.
o Wing strap and bag.
o Carrying bag, which in my opinion is the best in the industry. Wing, harness with 20 cm Bump'Air, helmet and extra clothing easily fit.
· Risers.
o Simple system of 3 risers (picture). Risers feel thin and long. When this picture is displayed at 100% its size on a 19" monitor, the dimensions are close to reality (my hand matches the one on the screen). No split A's (I don't care for that).
o Brake snaps are non-magnetic (picture). I prefer that.
o Brake pulley is large (picture), I suspect a ball-bearing mechanism. Pulley is stamped with the words : Holt-Allen, England. "Made in England" is good, right ? The pulley is not attached to the last riser (C in this case), but to an extension of the B riser, which is sent through a ring, attached to the C riser. Here is the explanation from Nova/USA :
"It is integrated with the speed system because as the speed system is applied the brakes need additional slack or they will become taught and actually deflect the trailing edge. ... It eliminates the long brake travel that would be needed otherwise."
o All riser quick-links were properly torqued (tightness of the spinning bolt head), enough and not too much.
o The accelerator line attached to the riser, ends with a Brummel hook, being braided back on itself (picture), instead of the usual stitching. This allows the line to feed back completely into the pulley, and have the hook next to the pulley. This provides more travel potential for accelerator travel, before the Brummel hook meets with the harness pulley.
· Lines.
o The number of lines leaving the risers, seems to be minimized. At the wing, some of them also divide along the chord direction.
o From the B riser, there is a very fine red line (picture) going to the tip of the wing.
o The last length of lines connecting to the wing is unsheathed (picture).
o The lines connect to external tabs on the underside of the wing (picture), providing easy line replacement. But there is a good way (picture) and a bad way (picture) for the line loops to bull on these tabs (Thanks to US-Champ-Len for letting me know). About 85% were correctly set.
· Wing.
o Rapid inspection did not reveal external seems on the top surface, except at the cell openings in the leading edge.
o Top surface has that waxy feeling to the touch of Gelvenor fabric.
o The cell openings seem big (picture), which probably explains the easy inflation.
o The leading edge seems reassuringly fat.
o Color alert : Think transparence. I just realized that a Blue top and White underside produces a light Blue in transparence (picture, thanks Mike). So guys, think twice before getting Red on top.
o This wing is light (6.5 kg). I have noticed during re-packs that the total package (wing + harness) fits easier than my previous wing (Gin Gliders/Oasis M at 7.3 kg) in the same transport bag. In comparison, the Apco/Keara M is 7.4 kg.
o Leading edge dimples : Details.
· Light wind (3 km/h). Rapid inflation, slow rise. Not a beginner's wing, but not a difficult wing either. Kiting in a light breeze.
· Moderate wind (12 km/h). Easy inflation and kiting.
· No hard-point noticed during inflation and rise of the wing to an overhead position.
· Nothing to declare. Mushing (increased sink at very low speed) seems usable. Picture of top landing at Marshall (thanks to Mike Masterson).
· Stability.
o Collapses. So far, so good. Only a small step up from a high performance DHV 1-2 ? I was able to prevent a couple of frontals. I got a 25% collapse while flying through turbulence on purpose with ½ speedbar activation : Benign recovery. Does not seem to collapse more often than other pilots I fly with.
o Pitch. Wing does not pitch back much when entering strong lift : Tendency to stay overhead. Reminiscent of a Swing / Astral 2.
· Collapse recovery.
o Induced. Induced accelerated frontal collapses (2) revealed adequate recovery. Induced accelerated 50% collapses (2) revealed mild reactions (good).
o Turbulence. One 25% asymmetric during thermalling. Avoided a couple frontals with rapid brake pull.
· Big Ears. Under accelerated flight, wing oscillations due to tip flapping, result in an uncomfortable feeling.
· Accelerator. Very smooth action. Good feeling of added speed on trajectory, without excessive dive.
· Thermalling.
o Agility. Defined as the ability to ease to stay in sharp-edged lift that wants to push you out its side. Low agility may force a pilot to explore the limit of brake pull prior to inducing a spin. My scale of 0 to 10 :
o 0 for an Apco/Presta M at the bottom of its weight range.
o 5 for a Nova/Carbon.
o 10 for an Advance/Omega 4, Gin Gliders/Oasis or Independence/Dragon.
I rate this wing as a 6. I would qualify the agility as sufficient/adequate, almost pleasant. Even with sharp brake pulls to stay in lift, not spin initiation was observed.
o Brake input. Brake pull is smooth with a gradual increase in tension. Overall brake tension is average. Very easy to thermal with inside brake alone (I like that). The outer tip seemed to remain solid even without brake input. The wing does not dive into a spiral dive, if we maintain the brake pull that initiated a decent turn (I like that).
o Feedback (41 cm riser separation). Ample feedback was available through asymmetric pull of the risers. But comfort-wise, only slightly more feedback than on my previous wings DHV 1-2 wings (Nova/Carbon, Gin/Oasis), and probably comparable to my previous DHV 3 wings (Omega 4 and 3).
o Spin. Prior to a spin, the brake tension rises sharply, as if it doesn't want to go further. It has to be deliberate.
o Weak conditions. I seemed to do as well as anyone. No handicap here.
· Energy retention. I performed wing-overs. The wing behaved nicely, maintaining good energy retention between turns. This was also confirmed when I tried to destroy altitude prior to a top landing, by doing figure-8 turns.
· Stall point. During one of the top-landings I swooped/skimmed the ground in an attempt to get a stall by continuously adding brake. I could not find it. Next time I will be more aggressive.
· Performance. Same L/D at max speed as a Windtech/Syncro M with unsheathed (competition) lines (Details). Better accelerated performance than Sky Paragliders/Brontes (Details).
· I believe I can relax "enough" under this wing for the year to come, but time will tell (summer is not here yet). I'm ready to commit for a year and reflect on the experience afterwards.
· Pleasure of flight through performance feels good, probably more than sufficient for my recreational flying.
· I often get asked : In your quest for high-end DHV 2 wings, why not an Apco Keara ? I could be making a mistake, but here are my considerations by order of importance :
o Just for me (but that's what matters in my selection)... At 100 kg TFW (Keara is 1 kg heavier), I am ill adapted to the weight range of the Keara, placing me either at the very top of the Small (99 kg upper limit) or 1/4 into the Medium (starting at 95 kg). I don't want to carry ballast.
o I expect the Keara to outperform the Aeron (see rumors of performance).
o I appreciate that Nova will soon release a DHV 2-3 wing (Radon) hinting to a decent safety margin on the Aeron in real-life situations.
o The lower aspect ratio of the Aeron (5.66 vs 6.10), provides some (unjustified ?) reassurance with respect to frequency of asymmetric collapses I get during summertime.
Daily Notes (Top of Page)
2002/12/23
· I received it today, along with another test wing (Artax M). I went to a nearby park for an hour of light wind kiting. Wind was 10 km/h in the gusts at the beginning, switching 90 degrees at times, down to almost nothing at the end. Good for testing light wind launching ability.
· Holding the A risers, I had to hold at some distance (about 4 cm) below the quick link as my arm length would not allow for the riser to be in tension to the harness when pulling. And I though I had long arms. Holding the risers centered on the red wrapper seemed correct. I just had the habit of feeling the quick-links before. Not important.
· Light wind (3 km/h). I had to keep pulling on the A risers for a long time, but the wing does eventually come up all the way. The wing inflates rapidly to form a rising wall. In the case of an asymmetrical rise, the wing responded well to displacing the body to the lower side of the wing. Exaggerated brake pull when the wing is overhead, results in the half wing hinging back from its center. Not a beginner's wing, but not a difficult wing either.
2002/12/24
· Site : Marshall. 2 hours 15 min airtime. 12 km/h wind, best climb rates of 5 m/s. Multiple climbs to 320m above launch. 2 top landings, condition started average-strong and ended weak.
· Stability. Worst turbulence felt was 4/10 on my personal scale. No collapse which were not self-induced.
· Induced collapses. I was left with a comfortable feeling (slow overall movement of the wing overhead, no rapid whipping around) :
o 1st accelerated frontal. Wing hangs back and forms a horseshoe. Once wing returned overhead with horseshoe, brake applied symmetrically and normal flight resumes.
o 1st accelerated 50% collapse. Little input, wing turns by about ½ turn. Slow re-opening of last portion of wing.
o 2nd accelerated frontal. Wing hangs back and partially makes a horseshoe. Wing recovers on its own with an asymmetric exit.
o 2nd accelerated 50% collapse. Typical input, wing turns ¼ turn.
· Big Ears. From trim speed : Stable configuration. After full acceleration : Moderate wing oscillations due to flapping of the tips, which provide an uncomfortable feeling. Verified by repeating the configuration.
· Accelerator. Very smooth action. Good feeling of added speed on trajectory, without excessive dive. No obvious "knee" in the polar curve.
· Thermalling.
o Agility. Defined as the ability to ease to stay in sharp-edged lift that wants to push you out its side. Low agility may force a pilot to explore the limit of brake pull prior to inducing a spin. My scale of 0 to 10 :
o 0 for an Apco/Presta M at the bottom of its weight range.
o 5 for a Nova/Carbon.
o 10 for an Advance/Omega 4, Gin Gliders/Oasis or Independence/Dragon.
I rate this wing as a 7. I would qualify the agility as sufficient/adequate, almost pleasant. When doing full turns close to the ridge, I had to allow a bit more room than usual (no big deal). But this may be due to increased speed in turns compared to my previous DHV 1-2 wing. Even with sharp brake pulls to stay in lift, not spin initiation was observed.
o Brake input. Brake pull is smooth with a gradual increase in tension. Overall brake tension is average. Very easy to thermal with inside brake alone (I like that). The outer tip seemed to remain solid even without brake input. The wing does not dive into a spiral dive, if we maintain the brake pull that initiated a decent turn (I like that).
· Top landing. I was able to slow down the wing until mushing was felt, without experiencing a stall.
· Inflation and kiting. Easy inflation and launch in the 12 km/h wind on launch. After top-landing, wing was easy enough to kite overhead.
2002/12/26
· Site : Marshall : Crestline and Marshall launches. 2 hours 30 min total airtime. 12 km/h wind, best climb rates of 4 m/s. Got to 1850 m ASL after launching Crestline. Multiple climbs to 350m above Marshall. 2 top landings, conditions were average-strong.
· Riser separation. I fly with a fully shortened chest strap. In flight, I measured the distance between the bottom-center of each riser, to be 41 cm (Back of elbow to 2nd joint from tip of little finger).
· Stability. Worst turbulence felt was 6/10 on my personal scale. I was able to prevent the beginning of a frontal. I got a 25% collapse while flying through turbulence on purpose with ½ speedbar activation : Wing stayed on course and recovery was benign.
· Brake pulley. During activation of speedbar, I verified the effect on the brake pulley location, which rises to follow the trailing edge as the speedbar is used. Smart design.
· Energy retention. Now with sufficient altitude, I performed proper wing-overs. The wing behaved nicely, maintaining good energy retention between turns. This was also confirmed when I tried to destroy altitude prior to top landing, by doing figure-8 turns.
· Thermalling.
o Feedback. At the edge of sharp lift, ample feedback was available through asymmetric pull of the risers, even with my chest strap fully shortened (41 cm riser separation). A bit more feedback than on my previous wings DHV 1-2 wings (Nova/Carbon, Gin/Oasis), and probably comparable to my previous DHV 3 wings (Omega 4 and 3).
· XC. I left the nest and went for a short XC (10 km). Glide felt good, and I was comfortable using ½ speedbar to get out of strong sink (3+ m/s down) or when facing a headwind. I look forward to a better day, this one being marginal for this type of flight. I am left with a satisfied feeling with respect to the wing's performance.
· Stall point. During one of the top-landings I swooped/skimmed the ground in an attempt to get a stall by continuously adding brake. I could not find it. Next time I will be even more aggressive.
2002/12/27
· Site : Marshall . I flew an Artax M (70% into weight range) for 2.25 hours in strong conditions : 6 m/s climbs to 750m above launch, and hit 8/10 on my turbulence scale.
· Thermalling.
o Feedback. Almost as much as the Aeron. Which makes me think that the Aeron may feel almost as comfortable when the air is rough (prior to a collapse at least).
· Wing. I have been noticing during the re-packs that the total package (Aeron + harness) fits easier than before in the same transport bag I have been using in the past (2 year old Nova/Carbon bag). I dismissed this as probably a tighter roll-up of the wing, but after looking at the weight of the wing (6.5 kg) on Nova's web site, this makes sense compared to my previous Gin/Oasis M (7.3 kg). In comparison, the Apco/Keara M is 7.4 kg. This wing is light. Aside from the obvious weight saving, light wings can help (although not the only factor) in reducing surge (forward pitch motion) amplitudes.
2002/12/30
· Site : Marshall. 2 hours 5 min total airtime. 5 km/h wind, best climb rates of 2 m/s. Best altitude of 150 m above launch. 1 top landing. Weak conditions, but experienced 5/10 on my turbulence scale because I flew close to the terrain most of the time. Jason Biggins took pictures I will receive around January 6.
· Collapse. I got a 25% asymmetric, but chose to ignore it and kept thermalling. It popped itself out after 3-4 seconds. I prevented at least one frontal collapse.
· Thermalling.
o Agility. I revise my rating for this wing to be a 6. Having scratched and thermalled in weak lift all day emphasized this behavior. There are a couple of times where I had to invert my direction of turning to relieve muscle fatigue in the centering arm. But muscle fatigue is normal when flying to optimize sink rate for this extent of time, so this not unusual.
o Spin. In an attempt to determine the amount of inner brake pull, which would initiate a spin, I exaggerated the pull when re-centering the thermal a few times. Prior to a spin, the brake tension rises sharply, as if it doesn't want to go further, and pulling beyond this point induced a quick rotation of the wing. Upon immediate release, thermalling resumed as normal. For a spin to happen, one has to do it on purpose.
· Pitch stability. I paid attention to the wing's pitching motions during thermal entry and exit. Amplitudes felt normal.
2002/12/31
· Site : Marshall. 1 hour total airtime. 15 km/h wind in beginning and 3 km/h at the end, best climb rates of 1 m/s. Best altitude of 50 m above launch. 2 top landing. Rapidly weakening conditions under a solid cloud cover.
· Landing. Able to use mushing (increased sink at very low speed) to do a spot landing, by adjusting airspeed to adjust glide.
· Performance. Pleasant surprise. Matthew Carter offered for our last flight (no chance to soar) to compare glide by flying alongside. He was 80% into the weight range of his Windtech/Syncro M with unsheathed (competition) lines. We concluded that the L/D was identical at the maximum speed of the Aeron (45% into weight range), with 2 cm pulley separation remaining on the Syncro.
--- Only the
unusual is reported beyond this point ---
(not all flying days reported)
2003/1/8
· Pictures from Jason Biggins (thank you), taken on 2002/12/30 :
o Kiting in a light breeze. Conditions are not yet strong enough to soar.
o Leading edge dimples. We can see a dimple on the bottom of the leading edge near the wing tip (where red arrows point to). On my wing (the blue one), this seems to occur symmetrically (both wing tips), and a picture from Nova’s web site reveals a similar dimple. So it seems to be the way the wing was designed, not just a line tangle/knot on my wing. Anyway, it seems to fly fine this way (See Details of performance comparison done the following day).
Response from Hannes Papesh (Nova designer), 2003/1/8 : During construction of a wing, you have to calculate all forces and tensions. Diagonal ribs only work, when there is tension in wingtip direction. Every force (tension) in the wing has to be earned and costs performance. So I try to keep it all just balanced. The arrow is pointing to the 3 suspensions in the wingtip (the inner one of 2 suspension triples hanging together on the A3). A photo is just showing a short moment. Could be, when the stabilizer is not producing enough tension because of air turbulence or a roll-movement of the wing (rolling to the left gives the left stabilizer less angle of attack), the diagonals between this suspension triple and the next inner suspension pair let the wing in this part go up a little. When you have a look on the pictures of the [Nova] gallery there is certainly no dimple and a clean curve (this is the same wing as on Jerome’s first picture): see attachments. On the kiting picture there seem to be no dimples also. This is an explanation (as far as all the lines have the right length, which I suppose). BTW. Of course, you have different trim angles over the wingspan, and different airfoils, tensions, sweep angles, radiuses ... :-) Hannes
Update : Picture from the following day (2002/12/31) that the dimple picture was taken. No obvious dimple.
· Wing has been purchased, and will be kept for a year or 125 hours airtime, whichever comes first.
2003/1/19
· Site : Marshall. 3 hour 30 min total airtime. 10-25 km/h wind, best climb rates of 6 m/s. Best altitude of 1050 m above launch. 5 top landing.
· Stability. In Nova's web page, they write : “In strong thermals you will enjoy the new airfoils stability: the glider doesn't drop behind the pilot on entering a thermal and does not lose performance in turbulence. The AERON is not nervous: this wing is full of energy, but still relaxing.” So, I paid attention to this. It became obvious that the wing does not drop back much when entering sharp lift. It reminded me of the Swing / Astral 2 in this respect. Relaxing indeed.
· Performance. I went on glide with a friend on a Brontes in front of the mountain (almost calm air), side by side. The Brontes was loaded at 75% into the weight range, while I was at 45%. We both had regular type harnesses. While I used 1/2 speedbar on the Aeron, the Brontes was at full bar to match the horizontal speed, and the Brontes had a slightly worse sink rate (my guess : 0.15 m/s difference). When putting the Aeron at full speed bar, it had a definite horizontal speed advantage, without having a significantly greater sink rate than the Brontes.
2003/2/6
· When asked about the line and riser strength, Hannes Papesh (Nova designer) gave this information :
We made lots of test
with almost all lines available on the market.
Peter Mack (factory director) built a special machine for long term load
measuring. We made our decision for the
lines of the Aeron on the basis of very careful comparisons.
We're using the new
LIROS PPSL line for bottom and middle cascades because they have some
advantages over common Technora lines :
o
They loose nearly nothing during aging : a normal Technora line looses up to 50% by
getting older. Therefore the DHV tests
all lines by bending them 1000 times around a sharp edge "DHV Knick
Test". The experience shows, that
in practice, some Technora lines are loosing even more. So even when a new Technora lined glider is
holding 12g during load test it may only hold 6g when older (or less).
o
PPSL lines are carrying more load in the combination
test. No line in a paraglider is loaded
between 2 quick links. So it makes
sense to test them looped together as in real life. Technora lines don't like being bended over a small radius : the loops are cut. Practice showed (see DHV safety warnings) that specially the
middle cascades are a weak point in several recent paragliders.
o
PPSL lines are thinner : Because of the aging and bending problem, Technora lines have to
be oversized to fulfill the demands : a
280kg Technora line (1.9mm) is carrying around 120kg after the DHV bending
test, a 200kg PPSL line (1.4mm) still over 180kg.
o
In contrast to old type Dyneema lines, the PPSL
lines are very low stretching even under long time load. So there is no disadvantage against Technora
lines in that point.
Disadvantages :
o
PPSL lines are more difficult to sew (a longer and
more accurate sewing is necessary).
o
PPSL lines are more expensive.
o
They are still uncommon and need some introduction
(see this).
We decided to use the
thin uncovered Dyneema lines near the canopy to point up the performance claim
of the Aeron. They are very short to
lie on the canopy, not the ground. They
are many and are carrying 70kg each.
Dyneema is loosing much less in UV than uncovered Technora.
The riser material was
specially woven for us and finally is carrying more as we were expecting
(1500kg with press button in it).
So there is no reason to feel unsafe under an Aeron because of it's fragility. But off course, you can order also one with normal 25mm risers (2000kg) or normal covered 70kg Dyneema lines for the top cascades. Or you better take one with the tandem rigging : 380kg Technora in bottom (190kg after aging test), 220 kg in the middle (115kg aged) and the PPSL 120 in the tops cascades (remain 120kg). :-)
2003/7/29
· During a road trip with the people who import Aerodyne in the USA, and had good opportunities to fly next to 2 other pilots on Shaman(s) (AFNOR Performance), so I can give my impression with respect to our relative flight paths. In the smooth ridge soaring at Point of the Mountain (Utah) we compared glide at trim. Nicolas on the Shaman was at about 75% into the weight range while I was about 55% on the Aeron. At our trim speeds, the Shaman was creeping at about 0.25 km/h higher speed, with an equal glide. While at full speed bar on the Aeron, the Shaman was matching glide and speed with about 3/4 bar. When using full bar on the Shaman, the tips tucked in, despite the smooth air. While thermalling, it seems the Shaman has an ever-so-slight advantage in climb efficiency. Maybe because I was taking pictures at the time ? ;-) On glide between thermals (some gusts), efficiency of both wings seemed comparable.
2003/8/9
· Site : Marshall. In a strong thermal, I purposely pulled the inner brake beyond reason and observed a Spin : The inner half wing bends back (instead of wing rotating as a whole) and normal flight resumed without noticeable yaw rotation.
Testing Expectations (Top of Page)
Why I am testing this wing :
Having flown competition-level wings for 7 years, I realized I could not relax
while flying in Southern California’s strong mountain conditions. Afterwards, I flew DHV 1-2 wings for 2
years, and had fun, but realized that I rarely got collapses and that they were
benign when they happened. On a few occasions,
I was left lusting for more performance.
Now I’m thinking that DHV 2 could be the best compromise for me. But to get a proper appreciation, I choose a
wing that should be at the high end of this rating. After a year, I will re-adjust my wing level selection for the
next one.
What can be done (by order of importance):
o Does the wing keep increasing its bank angle, past what the initial turn response lead me to expect ? I don’t like a wing that seems to screw into a spiral dive after a moderate turn initiation. No (2002/12/24).
o Can internal braking alone, easily regulate the bank angle ? I don’t like to use external braking for this purpose. Yes (2002/12/24).
o Sufficient agility to feel safe from inducing a spin. Yes (2002/12/26).
o Am I getting many more collapses that the others I fly with ? Not so far (2002/12/26).
o Did I get a collapse that I feel is unjustified ? Not so far (2002/12/24).
o Decent recovery from accelerated collapses : frontal and asymmetric ? These 2 events are likely to happen during ownership, so if I don’t feel comfortable enough inducing them under controlled conditions, I should not be flying this wing. I don’t need to re-certify the wing (perform all test or repeat them many times), just gain some trust from the recovery behavior under accelerated flight. Yes (2002/12/24).
o Verify stability. OK (2002/12/24).
o In combination with Big Ears, verify stability. This technique is useful for escaping cloud suck. Uncomfortable oscillations (2002/12/24). No oscillation noticed under Big Ears at trim speed.
o Can I bring the wing overhead in null wind ? Yes (2002/12/23).
o Does the wing have a “hard point” during inflation ? No (2002/12/23).
o Is it easy enough to kite the wing ? Not a beginner's wing, but Yes (2002/12/23).
What will not be attempted :
Rumors (Top of Page)
The following is unverified...
Performance.
According to the manufacturer, the best L/D (Lift/Drag) should be equal to a
Nova/Argon with unsheathed (competition) lines. Looking at past reviews of the Argon, and accounting for a 0.3
improvement, I expect 8.75 for its best L/D. This figure, along with claims of improved performance (over the
Argon) in accelerated flight, would place the Aeron amongst the top performers
in the DHV 2 category. The only wing I
expect to have an advantage is the Apco/Keara, since its predecessor (Simba)
already had 8.88 for its best L/D (according to Vol Libre). But the Keara also has a higher aspect
ratio.
