Hang gliding 2016 part 3
This page continues from Hang gliding 2016 part 2
Hang glider: Wills Wing 145 U-2
Harness: Aeros Myth 2
In-flight camera: GoPro Hero 3+ Silver Edition
Dukes of hazard
Ringstead, on the Dorset coast of England, is a public space whose hazards include people sunbathing and walking on the launch slope, inexperienced paraglider pilots inflating their wings in front of hang gliders ready to launch, and the west end of the ridge is often occupied by radio control gliders. In addition, in the air you are likely to fly in the company of dual paragliders taking passengers for rides. Basically, flying here should be regarded as similar to flying at an air show, where public safety is paramount.
I launched at 16:00 BST, just after the dozen or so paragliders and hang gliders that had been soaring the cliff landed. I saw only one hang glider remaining above the cliff. Fortunately, although the wind was well off to the west and fairly strong, the lift was reasonable. I gained 580 ft above take off.
Long time UK importer of Moyes hang gliders (Australia) Simon M always reminds me of the guy on the left in the iconic photo on the dust jacket of the Pink Floyd LP Wish You Were Here. (It is just the hair style really.)
And when I first met another hang glider pilot whose facial profile resembles that of the fellow on the right in the Pink Floyd photo (coincidentally also named Simon) I resolved to get those two in one place to reenact it somehow. (Just one of my as yet unrealized ambitions.)
Incidentally, when the photo was created in 1972 or 73, there were no digital effects, so they just set fire to the actor on the right! They at least gave him a flame-proof suit and mask. Nevertheless, according to what I read, that protection was not wholly adequate. And you thought hang gliding was dangerous!
In the photo with Simon on my front wires (an extra safety measure while maneuvering on this popular hillside) I am wearing shorts (I guess that’s, cut-offs in US English) and — after my accident in the summer of 2013 — knee pads. As it turned out, despite a turbulent landing approach, I made a ‘zero step’ stand up landing in the field behind take off (to which new restrictions apply).
My camera caught this view of Jon H’s new Avian Evo 3, the glossy finish of which imparts an impression of it having been just beamed down from Mars. The Evo 3 is a high performance ‘topless’ flex-wing. In other words, instead of a king post and top rigging, it uses an extra strong cross-tube made mostly of carbon fiber to take any negative loads. ‘Topless’ wings are normally heavier than wings with king posts and top rigging. However, having picked it up, it feels no heavier than my Wills Wing 145 U-2 — an ‘advanced intermediate’ flex-wing.
He was below me because he lost height deliberately to set up for this photo. The paraglider at top right of the photo landed as a precaution against the strengthening wind shortly after this shot was taken.
I made the cover of the USHPA’s Hang Gliding & Paragliding magazine, September-October 2016.
Furthermore, this photo of mine at Bell Hill in July is on the cover of the 2017 hang gliding calendar!
At Ringstead again in early August we encountered a westerly wind that became gusty in the heat of mid afternoon. I launched into sinking air and struggled to gain height at the lower ‘step’ cliff, as this photo illustrates. I left my harness zipper undone ready for landing in the emergency field a short distance up-wind from here. Eventually, I gained enough height to make the transition to the main cliff.
This photo of British champion Grant C, who borrowed my wing, illustrates the orographic cloud that formed above the cliff.
Comparing this photo with the previous one (and all photos of me flying the U-2) shows the difference in the sail curve between the variable billow (VB) off state and VB on. I fly with little or no VB applied because I prefer the glider’s handling in that state. Here, in contrast, Grant has a large amount of VB applied, as indicated by the amount of light-coloured cord trailing from the right corner of the control frame. Pulling the VB cord acts, via a gang of pulleys, to widen the airframe nose angle a degree or two. As a consequence, the sail is less ‘billowed.’ The angle of attack at which the wing meets the air is more constant across the span than when the VB is off and the sail is ‘loose.’
You can see how the trailing edge of the sail takes on a flatter curve. In addition, you might notice that the undulations in some of the stitching lines in the under-surface are flattened out. In the photos of me flying the U-2, you can see some upper surface; including even a sliver of the black top panel. Not so in the photo of Grant. Less billow equates to less aerodynamic drag, which results in a flatter glide and a slower sink rate, which – in smooth coastal lift – causes you to rise to a higher altitude.
A peculiarity of this rather basic means of tightening (and loosening) the sail is that, when you pull it tighter, it pulls the leading edges down a bit because the side flying wires are of fixed length. The result is more anhedral (or less dihedral; same thing) which you can see from the photo. (The right wing tip is lower in the field of view than in my other photos.) That causes the glider to ‘wind in’ to a turn. Because of that spiral instability, you have to ‘high side’ it in turns just to maintain a given angle of bank. That feels precarious to me, especially when trying to fly straight and level in turbulence, which is why I normally fly with little or no variable billow applied.
Another lesson from this photo, completely unrelated to aerodynamics, is the theory of thirds in photo composition as explained in a recent article by USHPA photographer of the year Ryan Voight. In the photo of Grant, the glider (and pilot) are in the upper right third of the photo. Holworth House occupies the lower left third and is visually in the middle distance. The farm house on the right, dimmed by the cloud, is arguably a feature of the far distance.
In conventional photography, you can aim the camera with such aesthetics in mind. With this kind of hang glider photography, you cannot really do that. (Not easily, anyway.) Instead, I set my GoPro Hero 3+ Silver Edition to take one photo every five seconds. If I am lucky, in any given flight I get one photo worth keeping. With even more luck, it conforms, to a greater or lesser degree, to the thirds rule and stands some chance of appearing in either the USHPA magazine Hang Gliding & Paragliding or the BHPA magazine SkyWings. (At the time of this writing, I have been on the cover of SkyWings twice.)
This photo made the cover of the November/December 2017 Hang Gliding & Paragliding.
At Bell Hill near Blandford in north Dorset, England, the mid afternoon thermals of early August carried some paragliders flown by skilled pilots all the way to the coast about 30 miles away. Steve W in his rigid hang glider flew for several hours, sometimes a speck near cloud-base, other times zooming by below the hill top.
I launched into a mix of punchy thermals with sink in between. I never rose above the height of the hill top and I landed after nine minutes in the air. A wild ride.
These buildings are signposted The Cross and the shadow of my wing is about to cross the street below the road junction at lower left. The buildings on the right constitute Belchalwell Street.
The French and Germans outnumbered the Brits on a Sunday in mid-August at Ringstead. When I arrived, about ten paragliders were flying in hazy sunshine speckled with cloud shadows, but by the time I was rigged, an overcast had developed. The two other hang gliders there nevertheless soared the cliff while the paragliders all landed because of a strengthening westerly wind. After an hour, the hang gliders also landed just when the day began to brighten again, but at the same time a mass of orographic cloud formed on the cliff.
Eventually, the orographic cloud dissipated and wings took to the air again. The wind was very light and off to the west when I launched, but I was lucky and was lifted by a smooth thermal right away, which allowed me to reach the lower cliff with height to spare.
In this photo, a line of cumulus some miles inland marks the convergence of the light northerly wind and the south-west sea breeze.
A paraglider flying close to the cliff edge, with the wing just above the cliff top and the pilot just below it, appeared to be ‘sucked’ into the air over the grassy cliff top. The pilot struck the slope, then the wing collapsed onto the path along the top. It looked slow and easy, but where he came to rest was precarious. The pilot was uninjured and ‘walked away’ (as we Brits say).
A Sunday in early October brought a cold north wind…
When Steve performs a high-speed pass through turbulence close to the hill in his rigid-wing hang glider, I notice how the whole wing flexes — in a way quite unlike that of a flexwing — and it reminds me of these words on aeroelastic flutter by aerodynamicist Theodore von Karman:
Some fear flutter because they do not understand it. And some fear it because they do.
However, modern hang gliders are so strong structurally that they are virtually unbreakable in flight.