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EN-926 / LTF
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November 28, 2008
Further explanation by EN working group coordinator Hannes Papesh
The EN Standards 926-1 and 926-2 itself will remain unchanged. There were only some comments added to clear up some issues and some points adapted to the practical requests. As well there were some translation errors into German corrected. These comments are agreed by all the test centres (Air Turquoise, Aerotest, Academy and DHV). It's a working instruction how to deal with the existing En 926-2, not a change of the norm. A change would have taken too long, as well as all agreed, that it's too early to rebuild The EN-standard, as we have not enough practical experience with it yet.
Our working groups keep on working and a reconstruction of the EN-Standards is projected for the next 2 years (so valid maybe by the the end of 2011).
It will be a big change (not only in Germany), off course.
We all have to think in A, B, C, D now! (1, 1-2, 2, 2-3 are gone).
It was time to do this step! We're a small scene, we need to work together and don't need more than one test standard. The old expert's system of the LTF (the test pilot is the expert and can decide on his own responsibility) is not applicable for the situation of having more than one test centre. A documentary system is needed like the EN (clear, accurate descriptions, as good as possible documentation), to ensure, that you will get similar results wherever a wing is tested.
A big advantage as well is, that the manufacturer is enabled to do a better prediction of the results of the certification.
The expert in the LTF system was very free to decide. So you never knew in advance. Now the rules are clear for everybody.
I would like to thank everybody involved in that process!
The names and members of the working groups are:
INFERNO (926-1):
Academy (Guido Reusch, Markus Haubt, Peter Bruggmüller)
Aerotest (Marion Varner, Vincent Teulier)
Air Turquoise (Alain Zoller)
DHV (Hannes Weininger, Reiner Brunn)
The manufacturers (PMA):
Thomas Ripplinger (Advance)
Manfred Kistler (Skywalk)
Hannes Papesh (Nova): coordinator
NEW WAVE (926-2):
Academy (Toni Bender)
Aerotest (Marion Varner, Vincent Teulier)
Air Turquoise (Alain Zoller)
DHV (Hannes Weininger, Reiner Brunn, Karl Slezak)
The manufacturers (PMA):
Thomas Ripplinger (Advance)
David Dagault (Ozone)
Hannes Papesh (Nova): coordinator
November 18, 2008
4th Round Table Meeting in Germany
On Tuesday 18th of November the 4th Meeting of „The Round Table“ took place at lake Starnberger See in Germany. The participants agreed about the future standards for paraglider test flights and paraglider load tests.
The „Round Table“ is an institution put in charge by the German Civil Aviation Authority, Luftfahrt Bundesamt, to negotiate about the airworthiness standards which should be applied in Germany (LTF). The Round Table members unanimously decided to ask the Luftfahrtbundesamt to change the LTF as follows: The European standards for paraglider flight tests EN-926/2 and paraglider load tests EN-926/1 will be the basis for testing also for the German LTF (airworthiness standards).
All members of the Round Table, DHV (German Hang Gliding and Paragliding Association), DMSV (German paramotor association), EAPR (European Academy of Parachute Rigging) and PMA (Paraglider Manufacturers Association) agreed on the above statement.
The EN standards will be commented to prevent misunderstanding and to specify certain points in the EN better, which have not yet been 100% clear defined.
The 1 to 3 classification system which has been used in the LTF up until now, will be replaced by the EN structure A to D in the near future.
A big thank you to all parties and persons who made it possible to bring forward a worldwide standard in paraglider certification.
It is planned to put all these changes into force by January 1st 2009.
October 28, 2008
Meeting of the EN-926 working groups for paraglider tests
There was a meeting of the EN-926 working groups for paraglider flight tests and paraglider load tests in Villeneuve Switzerland, at October 28 2008. The participants were members of the testing laboratories Aerotest (F), Air Turquoise (CH), DHV (D), EAPR (D), of the Paraglider Manufacturers Association PMA and as well the chairman of the EN working group WG 6.
The atmosphere during this meeting was very constructive. Several agreements have been met, which not only consisted in further technical developments, but most of all will lead to greater transparency of the tests.
Through these measures the demand to define a one and only testing standard for paragliders was met. The goal is the implementation of the EN Standards 926/1 and 926/2 into the LTF (German airworthiness standards).
Here are the most important points:
Test manoeuvre spiral dive:
Agreement: The technical requirements for variometers used by test pilots will be specified as follows: Time of reaction 0.2 sec, clearly recognizable sink tone when -14m/sec are reached and also clearly recognizable modulation of the sink tone when even higher sink rates are reached. The acoustic signals of the variometer must be recorded in the documentation video as well. These measures will allow the test pilot to evaluate the manoeuvre spiral dive more objectively and to give a more differentiate judgment of the behavior of the glider in spiral dives. So far this was very difficult for the test pilot because of the high acceleration forces and the physical stress involved.
Agreement: The G-force, which is building up in spiral dives is the most important figure to be measured to enable us to evaluate the amount of stress on the pilot. Our goal is to experiment a lot more with G-force measuring instruments to finally be able to use G-force measuring as an additional parameter to evaluate spiral dives. G-force measuring shall be used in other test manoeuvres as well.
Agreement: Exceptional behavior in spiral dives, as -for example- very fast acceleration of the paraglider, must be commented by the test pilot in the test report.
Test manoeuvre asymmetric collapse:
The German LTF only defines the maximum size of the asymmetric deflation (leading edge 75%, folding angle 45°), other definitions of the the size and shape of the test collapse are not given. The EN 926/2 in this respect is a bit more precise: Size of the asymmetric collapse (70-75% of the leading edge), folding angle (45°), as well as the maximum size of the collapsed trailing edge (50%) are defined.
One result of the practical work of the working group in their flight tests in summer 2008 was, that it was impossible for all of the test pilots to collapse a wing exactly along a specified folding line and angle.
The definition of a tolerance area which has been found now and as well a better video documentation shall guarantee, that each collapse which is used for evaluation of the glider complies with the definition (and moreover has the correct size of collapsed trailing edge as well).
Agreement: The lower surface of the paraglider has to be marked in a very well visible manner with the tolerance area for collapses according to LTF, respectively EN (70-75%).
The tolerance area has the following dimensions: On either side of a line which goes from the centre of the trailing edge to the leading edge of the wing in an angle of 45°, there is a tolerance area of 5% of the wings span. Have a look at the drawings of wings with different aspect ratio and also look at the video for better understanding.
Agreement: To get a good documentation of the size of the collapse within the tolerance area, the test collapses have to be filmed from the ground looking at the glider flying towards the camera, as well as looking at the glider flying away from the camera. In the view from behind it must be visible, that the collapse is going all the way to the trailing edge.
Harnesses used for paraglider test flights:
Agreement: A standardized definition of the dimensions of the harness used for paraglider test flights shall be found as soon as possible.
A new way has been found to capture the influence of different harness geometries in flight by one single parameter.
Publication of the video documentation of paraglider test flights:
The paraglider manufacturers association PMA and the LBA approved (German Federal Office of Civil Aviation) testing laboratories DHV and EAPR came to the agreement to publish all videos of the tested paragliders in the internet together with the test flight protocols.
November 03 2008
For the DHV: Karl Slezak
For the EAPR: Guido Reusch
For the PMA: Hannes Papesh
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