This post is aimed at either "wuffos" (people who are not hang glider pilots) or other new pilots who haven't flown double surface wings. I figure pilots more experienced than I would, obviously, already have their own opinion on the topic.
In the world of hang gliding, there are 4 basic classes of wings:
- Beginner
- Intermediate/Advanced (kingposted)
- Topless
- Rigid
The wing I've been flying for the last year and two thirds and 112 mountain solos has been a beginner wing, the Wills Wing Falcon 3 195 (3 is the version, 195 refers to the square footage of the sail). The other term for this class of wing is "single surface." These wings have, for the most part, one surface to their airfoil.
Intermediate/Advanced wings have two surfaces. They have a top surface similar to the single surface wing, but their bottom is also covered to significant amounts by another surface. This allows for cleaner, faster airflow. Less drag means the wing can go faster and will go further in static conditions than a single surface wing.
Intermediate/Advanced wings also have a "VG" (variable geometry) system that allows the wing's shape to change in flight. A "full on VG" means the wing will glide better, faster and more efficiently, in a straight line, but will be more difficult to turn. It also lends to a more pronounced stall at a slightly higher speed.
The Wills Wing Sport 2 175 (20 square feet larger than the one I flew Friday)Friday, for my second flight, I rented a Wills Wing Sport 2, an intermediate level wing. It is well known for having a very good combination of improved performance with still fairly easy handling.
Boy, did I notice the speed. That thing really zips around compared to the Falcon.
When I am in the Falcon, I am either putting along fairly slowly at around 24 mph. It pretty much feels like I have one speed. If I pull in to gain speed, I feel more like I am going down than anything. Things get pretty loud and the ground starts rushing up to me.
The upside of that lower speed is that the Falcon handles very well and crisply at its lower speeds. If I fly into a thermal at "trim" (that optimal speed), it is easy to turn the wing and stay in the thermal, for two reasons. The first reason is that the wing turns more easily than double surface wings at the same speeds. The second reason is that I'm not going very fast, so it takes a while to get through the thermal.
In the Sport 2, I felt the wind more, but heard it less. The wing really felt smooth and fast. It turned easily, but I felt like I would have to put more effort into putting it on a wing and coring a thermal. The difference between it and the Falcon felt like the difference between changing direction while running vs. changing direction while on a bicycle. With the Falcon, if I felt a thermal, I feel like I can just "crank it" into a turn. I didn't really try, but it doesn't quite feel like it would be more difficult to do that in a Sport 2, in accordance with what I've heard.
The only hard part of the flight was my approach, where I thought like a Falcon pilot and just buried the control bar to get speed up. Well, the Sport 2 speeds up in a hurry and so I turned to downwind a bit late and low. I also lost a lot of altitude in the turn, due to the bar being buried. I think I was even oscillating due to speed and poor control (this is called PIO for Pilot Induced Oscillations). I eased back on the control bar, turned a bit too low straight to the LZ, cutting the corner but heading right into the wind (somewhat by plan), got the wings level, thought I should flare, hesitated and mushed it in on my knees. Grass stains on my pants were the only dinger to pilot or wing... I'll take it.
I wanted to rent the Sport 2 for a number of reasons:
1. To see what it was like to fly a double surface wing
2. To see if I had the chops to fly an intermediate wing
3. To help my planning for buying the next wing, in both timeframe and type.
Here are my intial reactions:
1. It's a lot of fun. It's fast, smooth, clean. I felt like I was almost on a completely different kind of wing. It was really nice not to lose so much altitude going places. I got to just crank on the VG and zoom across to a spot that I wouldn't have reached in a Falcon.
2. I give myself a passing grade on the flight as a whole. Good launch (near as I could tell), good control in air, poor approach, adequate save on landing.
3. I need to lose weight and try again (I was a bit heavy on this one) on the Sport 2 155. I am better fit, weight-wise, for the next one up the ladder, the U2 160. I think I am going to have to rent the Sport 2 enough times to get familiar with it, if Rob has one available, then try to get a U2 rental or demo to see what the difference is. The U2 has slightly better performance but is more significantly difficult to fly, according to Wills Wing.
I need more time to answer all those questions adequately.
In sum, it was fun to fly, I am going to set aside the whole question for now, try to lose some weight, hopefully fitting into my sleeker harness, get used to that, and try again. Hopefully, that won't be too far off.
Whatever the case, I will always want a Falcon in the quiver. It's tough to beat how easy it is to fly.
Here's a chart of the various wing type "polars." Basically, the shallower the curve, the better the wing performance. That'd be the Falcon there on the bottom. The wings between it and the Sport 2 are older wings. According to this, at 30 miles per hour in static air, the Sport 2 would only be descending about 215 feet per minute. At that speed, a Falcon would be dropping like a rock, 400 feet per minute.
