Monday, May 30, 2011

Speed Bumps

I've posted a couple of videos and stories about flying these new mini-wings on windier days, and it's obvious that my overall impression is that they're super fun. But maybe it's not so obvious that they're also super sketchy! Many of our pilots are worried that the early adopters might not realize that the increased fun factor comes with increased risk factors. There is no question that it's a higher risk activity. I'm still not sure it's something I'm going to be doing in the future, but I'm definitely happy to have tried it, and to have survived my first few flights. Let's discuss some of the issues that might temper our excitement about flying on windier days.


These small wings cannot pass tests for recovery after inflight malfunctions. They are all uncertified by the DHV or the EN board for any weight range at all. They do not recover from collapses, spins or stalls in any predictable way. The wing loading is higher, so it takes more energy to collapse, but when it goes, it goes hard and fast. (I took a frontal collapse as I was making a toplanding approach near upper launch at Kahana the other day, and it was terrifying.) Very few of us would be willing to fly uncertified comp wings or acro wings. Let's keep that in mind when we think about getting into this brave new world.


Many pilots are flying these smaller wings without any back protection or reserve parachutes. Most pilots are flying with special harnesses that keep you more upright, with split legs and no seat plate. Some experts don't recommend using a standard reclined PG harness with a seat plate, nor do they recommend flying with a reserve in strong winds, because the dangers of a horizontal impact or a high wind dragging outweigh the potential benefits. If a pilot insists on flying with a reserve, they recommend having a quick release system.


When flying these small wings, EVERYTHING happens a lot faster. Because of that, they require above average reflexes and situational awareness. The increased speed is obvious when flying near the terrain, and also when making a downwind turn. The downwind speeds are astonishing. Also, when you apply what you think might be a normal amount of brake pressure for a turn, the wing banks up instantly and corkscrews straight down within a single rotation. When you come out of that kind of corkscrew, the wing has a lot of energy that needs to be managed.

A session on a small wing is way more intense and exhilarating than the typical relaxing and mellow flight we are used to having under normal sized wings. The flights on these smaller wings tend to be shorter, because you just can't maintain that kind of intense focus for long.


Flying one of these small wings on a strong wind day can be compared to whitewater kayaking. When a familiar river is running at a normal level, you know where the rapids will form, and what the tricky parts are. When the river is running at an extra high level, suddenly the rapids are all in different places, and they're enormous.

The same is true for the wind. The kinetic energy of stronger wind creates more turbulence, and the mechanical rotor effects are bigger and stronger. We know that the energy of the wind increases with the SQUARE of the velocity. So a 15 mph wind is not half again more turbulent than a 10 mph wind, but instead more than TWICE as turbulent. An 18 mph wind has FOUR times the energy of wind blowing at 9 mph. So the rotor will reach four times farther behind obstacles, and will hammer our wings with four times the turbulence.


Landings are very interesting in these small wings. If you try to make a normal landing, the high speed and decreased glide ratio of the wing makes for a fairly hard and ungraceful landing. Like with skydive chutes or speed wings, it's best to build up some speed and energy as you approach, with a dive or turn near the ground at the last minute, and then burn off the energy in a long low swoop, to make a nice no-step landing.

But landings like that are going to require a lot more room! We can't make landings like that on a crowded day at the beach. We'll need to either resign ourselves to a landing where we just plop down a bit harder, or we need to make sure we aim for a long and deserted stretch of the beach to perform a swoop.


Looks good, you go first! These are still the early days of speed soaring here. Let's learn from our local pioneers of small wing flying. We have several good role models: Fireman Dave, Carson, Frank, Scot, and Maui Doug. As paraglider pilots, we understand what it means to use a progressive approach to learning new skills. We understand the value of passive safety and certification. We understand the value of practicing our skills on the ground before taking them to the hill.

Scot has taken an extremely measured and progressive approach. He hung up his harness at home to get used to it. Then he kited his small wing a lot before hiking with it. Then he flew it on lighter wind days, happy to get sled rides as he got used to the dynamic handling, before finally climbing out and soaring higher on the stronger days.

Maui Doug has also taken a conservative approach, which includes tons of kiting in the park. Doug prefers using north launch for high wind soaring at Kahana, no matter what the wind direction, because east launch seems to have lots more turbulence swirling around it. He also prefers to land at Punaluu because the risk of turbulence there is lower than at the Kahana LZ.


Thom said...

Thanks Alex,

I thought I was going to have to be the water on the fire of this speed drug that some are getting hooked on.

I admit after not flying for almost 2 weeks and no PG flyable wind in sight I was getting anxious. Watching Scot & Maui Doug fly every darn day was killing me.

I realized after listening to these pioneers talk about it, it sounded to me to be alot more risk and very vigilant flying. I took a step back and started looking at the ramifications. Its usually a low in the bowl flight. After watching Doug come to Punaluu Beach, I realized its not a scenic xc tour, you got to stay on it constantly.

I kinda got on Alex about how fun and easy he was making this flying sound in his stories. "Pilots not as good as you read this", "Some of which need to fly every day and have looked at this as a fix for high wind." (me). I know my skill level is not at the level that this type of flying is going to require.

I for one will be a spectator for this type of flying for quite sometime, not saying I never will but for now I want to perfect my abilities in a slightly safer vehicle.

Those of you that are thinking of getting into these smaller wings should reflect on your abilities, your ground handling and time in the air.

Good Luck, Fly Safe.

JK said...

What a good balance between exhillaration and caution (aka thrust & vector). Every day, I'm impressed by this flying community.

Anonymous said...

Great write up Alex. Only 2 comments after all that chatter ? Ike