Frequently asked questions to the PMA decision towards FAI-Classes

Why do we need FAI-Classes - What is the FAI-Definition of a paraglider - What is a rigid primary structure? - and more...

Q1: Why do we need FAI-Classes?

A1: The FAI-Classes have been introduced by the Fédération Aéronautique International to separate flying machines with different properties and different performance to allow fair and level competition. The FAI-Classes are also used for record attempts. You can read more in the FAI Sporting Code.

Q2: What is the FAI-Definition of a paraglider?

A2: The FAI definition of a paraglider, FAI-Class-3 has been introduced about 22 years ago to separate hang gliders from paragliders. It has been written by Walter Newmark from Great Britain, one of the founders of ACPUL. ACPUL was the first organisation to test paragliders.
The FAI-Class-3 definition is: "Hang gliders having no rigid primary structure (paragliders), and which are able to safely take-off and land in nil wind conditions." You can read all FAI-definitions of the different types of "hang gliders" (A glider of being capable of being carried, foot launched and landed solely by the use of the pilots legs) in the
Sporting Code section 7B for paragliders.

Q3: Why does PMA think this 22 years old FAI-defintion is still valid?

A3: The main difference between a hang glider and a paraglider consists in the fact, that one does have "bones" and the other one doesn't. This has not changed in the past 22 years.

Q4: What is a "rigid primary structure"?

A4: The PMA had to decide about this part of the definition. So what had to be answered first is: what is primary and what is secondary? As a primary structure the PMA considered everything which, if removed, results in the fact, that the paraglider does not fly at all anymore or flies completely different to the way it has been designed to fly.

Q5: So what is rigid then?

A5: This has been the key question to be answered. Rigid is basically the opposite of flexible. Since there are no absolute values for rigid and flexible the amount of rigidity and flexibility had to be defined. This was where the existing FAI-definition for Class 3 was not precise enough and needed precision. The best way to define flexibility is to try to bend some component of a glider and see if it gets damaged (permanent deformation). If you can bend it around a very small radius, then it can be called flexible. If the radius is rather big, then it should be called rigid.

Q5a: Isn't it too fine a filter to allow rigifoil material (weed wacker line) as used in many paragliders in FAI-Class-3, but not 1.5mm carbon rods?

A5a: The filter which is proposed as a limit for flexibility/rigidity of components for FAI-Class-3 paragliders hasn't been chosen arbitrary. FAI-Class-3 as the class for flexible paragliders should exclude components which support compression loads. Components which support compression loads allow different design principles (e.g. gliders with only 2 rows of lines) and therefore should be in a different FAI-class in competition.

Q6: Is it the combination of rigid and primary which actually matters?

A6: Yes exactly. The point where rigidity starts and flexibility ends can be discussed forever. It's a matter of the point of view. The engineer who designs a 300t bridge will have a different perception of flexibility compared to the designer of a paraglider. But since the combination of both properties matters, the question if a glider with about 70-80cm long 1.5mm diameter carbon rods, which are pre-tensioned like a bow and sewn to most of the profiles has rigid primary structure, could be answered clearly: Yes it's at least primary!

Q7: Why does the PMA ban the carbon?

A7: The PMA does not ban the carbon at all. What the PMA does is to make the existing definition of a paraglider more clear and understandable for every pilot and designer, competition organizer and jury in competition, and last but not least also for the testing laboratories. The FAI-definition of paraglider also is the definition of a paraglider in the EN-926. A new FAI-Class for paragliders with rigid structure can be created.

Q7a: What is this revised, more precise definition for FAI-Class-3 paragliders, which the PMA proposes?

A7a: Hang gliders having a flexible structure (paragliders), and which are able to demonstrate consistent ability to safely take-off and land in nil-wind conditions.
Flexibility is defined by the ability of a component to be bent around a radius of 1cm by 180° without being damaged. This test of flexibility will be executed in at least two perpendicular planes and will be performed when the component is integrated into the glider.
Note: all rigifoil materials and all Mylar reinforcements as used up until today in certified gliders will fit inside this definition.

Q8: What is the FAI-Class-6?

A8: The FAI-Class-6 will be the new class for paragliders with rigid structure. Every time when the evolution of hang gliders and paragliders requires the creation of a new FAI-Class it's added to the existing classes. The last time when this was the case was the creation of FAI-Class-5, the Atos class, about 10 years ago.

Q9: What will be the definition of FAI-Class-6?

A9: This has not yet been decided, but it will allow more room for rigid structures compared to the first competition glider with rigid structure which successfully competed in the 2009 PWC. There are different proposals, based on volume and weight and the fact to be able to pack it into a rucksack. E.g. 120L and 10kg or 80L and 15kg and also to leave this new FAI-Class completely open to allow "the Atos on a string."

Q10: When will we see paragliders with rigid structure as serial gliders?

A10: The testing laboratories agree, that at the moment it is not possible to test them, because the existing EN-926 is not designed for this type of glider. Careful research will have to be made before modified flight test maneuvres can be introduced. Maneuvres like front collapse and asymmetric collapse look completely different on a glider with rigid structure, which enables to build it with 2 rows of lines only compared to gliders with 3 or 4 rows of lines.
Also these rigid parts (and this is the reason why they are used) can support compression loads. So far we had to load test paragliders only trying to find out if something rips, now it can break as well.

Q11: Are gliders with rigid structure dangerous?

A11: We don't know this answer yet. In the history of paragliding there have been several attempts to rigidify paragliders. All have ended in a dead end street. Some have killed lives, others have killed companies. If today’s development will be successful and safe we don't know yet.

Q12: What is possibly dangerous on a paraglider with rigid parts?

A12: In case of a collapse it must be possible, that the paraglider deflates very fast. An inflated or partially inflated paraglider causes a lot more drag and therefore the violence of a rotation is much bigger. One of the old designs of Ailes de K, the Trilair where the outer part of the wings could not deflate because of build-in valves was a typical example for this fact.

Q13: I am a normal pilot and don't fly competitions. Does it matter to me if I fly a FAI-Class-3 or a FAI-Class-6 glider?

A13: No, it does not matter at all. All which probably matters to you is the question: Is it safe, what EN-classification does it have and off course how much performance does it have and is it fun to fly. The FAI-Classes are only important for the competition pilot to allow a level playing field in competition.

Q14: If the existing EN-926 needs to be modified to test paragliders with rigid structure, who will decide about these modifications?

A14: It's the EN-working groups for EN-926-1 (load test) and EN-926-2 (flight test). Both working groups consist of members of the 4 testing laboratories, Academy (EAPR), DHV, FFVL and Paratest (Air Turquoise) and members of the PMA.

Q15: Which persons from the PMA are members of these EN-working groups?

A15: David Dagault (Ozone), Manfred Kistler (Skywalk), Hannes Papesh (Nova), Thomas Ripplinger (Advance). All four are paraglider designers, Manfred Kistler and Thomas Ripplinger are aronautical engineers as well.

Q16: Isn't the reason for trying to separate paragliders into different classes now only a commercial reason by those manufacturers, who don't have the technology of rigid reinforcements at the moment?A16: It is not possible to give a correct answer to this question without being able to look inside the brains of the 76% of the voters within the PMA who voted for limiting the FAI-Class-3 to flexible elements with 1cm bending radius. In the end, after the technology of rigid paraglider reinforcements has proven it's usability for everyday use and normal pilots and certified paragliders with rigid elements will exist, it will commercially not make any difference for a manufacturer if he sells a FAI-Class-3 or a FAI-Class-6 paraglider.