Asymmetric Collapse
The asymmetric collapse, an inevitability of learning to fly in thermic air. We learn to first mitigate and then prevent them by flying in increasingly active air, preferably under instruction.
Mitigation can come by way of active weight shift and braking technique. The ultimate goal is collision avoidance, be it with the ground, terrain, or other pilots.
Another means of mitigation is wing selection (passive safety). A lower EN/LTF rated wing can help reduce the aftermath of the collapse. An instructor is the best place to start with deciding which wing is best suited to the pilot. That said, the first steps we take as a pilot-in-command is making and accepting responsibility for own decisions. The more information the new pilot has, the better the decision they can make.
The basic certification system (EN/LTF) is not perfect, as per Divide 'EN', Conquer. But the certification system is continually evolving. Part of this evolution is the trial testing of wings by the DHV using a data logger and documenting the post collapse behaviour beyond a simple change of direction/pitch.
DHV Safety Class
The core of the DHV Safety Class is a trio of safety ratings per wing: symmetric collapse, asymmetric collapse, and spiral dive. In addition, notes are provided on altitude loss, G forces experienced, cravat and cascade tendencies. It is these notes that are of interest.
Below are the DHV Safety Class Notes on unaccelerated asymmetric collapses for common paragliders used in the Fraser Valley (Vancouver) for student and novice pilots:
The source for these values and notes can be found under the DHV Safety Test webpage.
In addition, the suitability for training and manufacturer notes regarding the target pilot are included to give a more complete picture. This data was pulled from the manufacturer webpage and user manuals.
* There is no clear indication regarding suitability (or lack there of) for training. Consult your instructor.
Side note: notice any differences between the DHV and Manufacturer Notes?
The HPAC Novice/P-2
The current Hang Gliding/Paragliding Association of Canada (HPAC) requirement to be awarded a Novice/P-2 rating includes the following prerequisites:
B. Prerequisites
Anyone flying in the Fraser Valley will receive their Novice/P-2 with the Thermal Endorsement (due the lack of a consistent Coastal/Ridge Soaring Site).
The asymmetric collapse, an inevitability of learning to fly in thermic air. We learn to first mitigate and then prevent them by flying in increasingly active air, preferably under instruction.
Mitigation can come by way of active weight shift and braking technique. The ultimate goal is collision avoidance, be it with the ground, terrain, or other pilots.
Another means of mitigation is wing selection (passive safety). A lower EN/LTF rated wing can help reduce the aftermath of the collapse. An instructor is the best place to start with deciding which wing is best suited to the pilot. That said, the first steps we take as a pilot-in-command is making and accepting responsibility for own decisions. The more information the new pilot has, the better the decision they can make.
The basic certification system (EN/LTF) is not perfect, as per Divide 'EN', Conquer. But the certification system is continually evolving. Part of this evolution is the trial testing of wings by the DHV using a data logger and documenting the post collapse behaviour beyond a simple change of direction/pitch.
DHV Safety Class
The core of the DHV Safety Class is a trio of safety ratings per wing: symmetric collapse, asymmetric collapse, and spiral dive. In addition, notes are provided on altitude loss, G forces experienced, cravat and cascade tendencies. It is these notes that are of interest.
Below are the DHV Safety Class Notes on unaccelerated asymmetric collapses for common paragliders used in the Fraser Valley (Vancouver) for student and novice pilots:
The source for these values and notes can be found under the DHV Safety Test webpage.
In addition, the suitability for training and manufacturer notes regarding the target pilot are included to give a more complete picture. This data was pulled from the manufacturer webpage and user manuals.
| Wing Made/Model | Height Loss | Pitch Angle | G Force | Training Suitable | DHV Notes | Manufacturer Notes |
|---|---|---|---|---|---|---|
| Skywalk Mescal 4 | 20 - 29 m | -60 degrees | 2.4G | Yes | Massive collapses and maximum deformations usually recover with little diving and course change. | Suitable for beginners on the training hill, the MESCAL4 also offers lasting satisfaction for ambitious hobby pilots for their first XC flying experiences. |
| Icaro Cyber TE | 30 - 39 m | -65 degrees | 2.3G | Yes | Relative moderate reactions, moderate dynamics | Beginners who are looking for a fun, but performant and fast glider, that—nevertheless—still is gentle and easy to fly, will find a good companion in the new Cyber TE. |
| Ozone Mojo 4 | 40 - 49 m | -65 degrees | 2.3G | Yes | Greater height loss and course change angles than other [...] gliders. | The Mojo 5 is designed for new pilots. First and foremost it is a safe, fun, and easy high-performance wing suitable for students in training but ideal for the newly qualified. |
| Wing Made/Model | Height Loss | Pitch Angle | G Force | Training Suitable | DHV Notes | Manufacturer Notes |
|---|---|---|---|---|---|---|
| Ozone Buzz Z4 | 30 - 39 m | -60 degrees | 2.3G | N/A* | Moderate dynamics, height loss < 40m. Maximum collapses result in large pitch forward dives and occasional opposing collapses, but without course changes. | The Buzz Z4 is an ideal choice for pilots who fly approximately 30-50 hours per year [...] . |
| Skywalk Tequila 4 | 40 - 49 m | -75 degrees | 2.9G | Yes | Difficult to collapse to measurement field limits. Marked rotation with dive angles of up to 75° for large collapses. Opposing collapses observed with occasional cravats and course changes. | The T4 is quite forgiving, making it the right choice for talented beginners. |
| Icaro Instinct TE | 40 - 49 m | -75 degrees | 2.9G | Yes | Without using special collapse techniques the wing collapses very steeply and has high rotation and pitching dynamics, resulting in opposing collapses and cravats on both wingtips. | Since it performs at a very high level, but is also very pleasant and well-behaving at the same time, the Instinct TE is the perfect glider for all pilots who want to feel comfortable in the air. |
| Icaro Wildcat TE | 40 - 49 m | > -75 degrees | 2.6G | No | Height loss is average for its
class, but reactions are very
dynamic, dive forward angles
are severe and course changes
are rapid. The canopy folds steeply, creating a lot of resistance and turns abruptly and dives forward steeply. Total height loss was average for the class. Generally the canopy shows a tendency to dive forward steeply which often leads to cascades and cravats. |
Recommended flight experience: 20 - 30 flying hours per year. |
| Gin Atlas | 50 - 59 m | -60 degrees | 2.3G | N/A* | Relatively low dynamics (pitching, G-forces, sink velocity) for its class, but delayed recovery resulting in higher height and course changes. In some cases, recovery had to be aided with a little pilot input. |
The Atlas is suitable for beginning to intermediate pilots. |
* There is no clear indication regarding suitability (or lack there of) for training. Consult your instructor.
Side note: notice any differences between the DHV and Manufacturer Notes?
The HPAC Novice/P-2
The current Hang Gliding/Paragliding Association of Canada (HPAC) requirement to be awarded a Novice/P-2 rating includes the following prerequisites:
B. Prerequisites
- Paragliding P1 Beginner Rating
- Thermal Endorsement or the Coastal/Ridge Endorsement
The Thermal Endorsement includes the following:
- Demonstrates proper directional control and correction of full (i.e. 50% of the wing span) asymmetric collapses.
Anyone flying in the Fraser Valley will receive their Novice/P-2 with the Thermal Endorsement (due the lack of a consistent Coastal/Ridge Soaring Site).
Under the current HPAC requirements, the Novice/P-2 candidate who satisfies the Thermal Endorsement will have demonstrated the proper response to a 50% asymmetric collapse.
Re-read the above descriptions of asymmetric collapse behaviour and ask which wing would you want to be on with less than 25 flights and asked to demonstrate the 'proper directional control and correction of full (i.e. 50% of wing span) asymmetric collapses'. Demonstrating a response means experiencing the collapse to then demonstrate the proper response.
I suspect if this requirement was fully enforced by HPAC, we would see very few students on EN B wings.
It is better to have a wing you can grow out of than one you need to grow into.
It is better to have a wing you can grow out of than one you need to grow into.
