DHV Safety tests of LTF A- and B-Paragliders, Part 3

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1 DHV Safety tests of LTF A- and B-Paragliders, Part 3 This article is a continuation of the safety test series first published in DHV-Info 174 (also available on the internet under on the Safety and Technical page). Details on test criteria, practical relevance of the test aeuvres with regard to accident statistics and current LTF airworthiness requireents can be found there. The testing tea fro the DHV's Safety and Technical departent chose current LTF-A and low end LTF-B paragliders available on the arket designated as suitable for schooling by their anufacturers for part 3 of the safety test series. In the next issue of the DHV-Info and in the near future on our website there will follow a report on current high-end LTF-B gliders fro the following anufacturers: Gradient Nevada, U-Turn Blacklight, Icaro Wildcat, Air Design Rise, Mac Para Eden 5, Skywalk Chili 3, Nova Mentor 3, Advance Epsilon 7. Safety testing was conducted at the top 25% of the weight range for the following gliders: LTF A Icaro Cyber TE M Ozone Mojo 4 L Independence Pioneer M Nova SuSi M Niviuk Koyot 2.28 LTF B Low Level Swing Arcus 7.26 Air Design Vita M Sky Paragliders Anakis 2 L Certification nuber DHV GS AIRT GS_ EAPR-GS-7502/12 EAPR-GS-7618/12 AIRT GS_ DHV GS EAPR-GS-7386/11 AIRT GS_ Launch preparations In particular we look at the risers and line systes, how easy they are to sort, if looping or kts in the lines are easy to see or t and the functionality and ergoics of the risers. Novas SuSi M set the standards in this test series. No other glider tested here was set up and sorted as quickly and easily as the SuSi. On Independences Pioneer sorting the lines is also very easy due to its effective line geoetry. More attention to detail was required on the LTF-A gliders Icaro Cyber TE, Ozone Mojo 4 and Niviuk Koyot 2 due to any thin unsheathed lines un the upper gallery, particularly at the wingtips. The 3 low end B gliders could also be easily set up and sorted without using any particular tricks. Air Designs Vita has risers which require an extra check and feel soewhat unusual. Also the stabiliser lines require careful checking as on Swings Arcus 7, due to the larger nuber of attachent points. The soft riser webbing used

on Skys Anakis 2 is kept nice and siple, but does tend to twist in on itself

Pictures (left to right): above: Koyot 2, SuSi, Cyber TE, below: Mojo 4,

The Pioneer webbing is soewhat hard and bulky, its brake handles reind of

Pictures: The Sky Anakis 2 riser (left) is light and uncoplicated but very

Unusual: The Bruel hooks for the syste is attached to the inside of the

On the Vita fro Air Design (iddle) risers are ade of thick but soft webbing

Swings Arcus 7 has standard risers with thing unsual about the (left).

2 on Skys Anakis 2 is kept nice and siple, but does tend to twist in on itself in practice. The thin ain lines used also require careful sorting. Pictures (left to right): above: Koyot 2, SuSi, Cyber TE, below: Mojo 4, Pioneer. Solid and uncoplicated LTF-A risers. The Pioneer webbing is soewhat hard and bulky, its brake handles reind of trariser fittings. Pictures: The Sky Anakis 2 riser (left) is light and uncoplicated but very soft. This akes handling ore difficult. Unusual: The Bruel hooks for the syste is attached to the inside of the A-riser. On the Vita fro Air Design (iddle) risers are ade of thick but soft webbing with a total of 4 etal syste rings, and need a little getting used to. Swings Arcus 7 has standard risers with thing unsual about the (left). In accordance with the LTF airworthiness requireents, lines to stabilisers ust be of a differing colour to all other lines on the glider. All gliders with the exception of Independences Pioneer had this iportant feature (used for recognising to correct line to pull when trying to recover fro a cravat). See picture below.

Plastic rods for stiffening the are w also coonplace in alost all LTF-A and B gliders (Ozone Mojo 4 detail). Only the Anakis 2 fro Sky used conventional aterials.

3 Plastic rods for stiffening the are w also coonplace in alost all LTF-A and B gliders (Ozone Mojo 4 detail). Only the Anakis 2 fro Sky used conventional aterials. Launch preparations Glider Easy Average Difficult Nova SuSi M Independence Pioneer M Icaro Cyber TE M Ozone Mojo 4 L Swing Arcus 7.26 Niviuk Koyot 2.28 Air Design Vita M Sky Paragliders Anakis 2 L Launch characteristics Inflation, clib rate, requireents to stabilise and necessary brake inputs. A tea of 4 instructors judged the launch characteristics of the gliders. Special tricks were t required to launch any of the gliders. Four of the five LTF-A gliders deonstrated good school suitability in ters of launching the glider. For this segent it is particularly iportant that gliders do t tend to overshoot, as this quickly over-challenges new pilots. Niviuk Koyot 2, Icaro Cyber TE, Nova Susi and Ozone Mojo 4 are all excellent here. Their capies clib

steadily with cofortable pressure on the A-risers and slow autoatically as the reach the zenith. Only oderate brake appliance is necessary to stabilise the.

4 steadily with cofortable pressure on the A-risers and slow autoatically as the reach the zenith. Only oderate brake appliance is necessary to stabilise the. Independences Pioneer is a little ore dynaic, this capy clibs faster and requires ore brake appliance to stabilise. Low end B gliders fro Swing and Air Design behave very siilarly. During inflation these gliders need to be guided a little, but do t hang behind or overshoot at all. Skys Anakis 2 cant be classed as an overshooter, but it did have the greatest dynaics in the test set. With a relatively gentle ipulse on the A-risers the capy clibs quickly to the zenith where it needs a good jab on the brakes to stabilise it. Launch characteristics Gerät Delayed Balanced Dynaic Icaro Cyber TE M Nova SuSi M Ozone Mojo 4 L Niviuk Koyot 2.28 Swing Arcus 7.26 Air Design Vita M Independence Pioneer M Sky Paragliders Anakis 2 L Particularly for inexperienced pilots, the easy launching characteristics of the SuSi fro Nova (LTF-A).

5 Test aeuvres / recovery fro instability All test aeuvres were filed with onboard GoPro caeras, ground caeras and docuented with the DHVs data loggers. Test aeuvres were perfored by the DHV test pilots Reiner Brunn and Harry Buntz. Info Data loggers The pilot data logger is firly attached to a ain suspension strap on the pilots harness. A second saller glider logger is attached to a cell wall inside the glider using two strong agnetic plates. The best position for data collection has been deterined to be where the C-gallery lines are attached to the capy at the 70% arker points. Logger data is collected continually fro the beginning to the end of the test flight and the two instruents are synchronized with each other via a low-range radio signal. Data sets are transferred fro standard icro-sd eory cards to a PC after landing. The loggers collect the following inforation: Pitch, roll and yaw angle, Pitch roll and yaw acceleration, Vertical velocity calculated over a 0.5 second window fro the baroetric altitude sensor, Velocity: the pilot data logger contains a 5 Hz GPS, fro which the velocity over ground is calculated, G-Force: fro the acceleroeters contained in the pilot data logger the G- force acting on the pilot is calculated, Altitude: both the baroetric height (recorded at 100Hz) and the GPS height (5Hz) are recorded. Data processing: the processing software is written to autoatically recognize the beginning and end of a test aeuver. Pilot and glider oveents are siulated fro the recorded data, and this siulation is synchronized with the video aterial of the test flight. Test pilots check the synchronized results for plausibility. Data loggers are instruents to assist test pilots and provide additional objective inforation on paraeters which are difficult to judge in the air such as roll and pitch angles, height loss, course changes and durations. Flight stability Through induced pitch testing a easureent of a gliders pitch stability can be ade. The angle to which a capy dives forward during pitch testing is a good indicator of the potential dynaics which ay develop during such circustances. Pitch angels were easured after the third pitch cycle during testing. Nickwinkel Gerät < > 60 Icaro Cyber TE M Nova SuSi M Independence Pioneer M Ozone Mojo 4 L

Swing Arcus 7.26 Air Design Vita M Niviuk Koyot 2.

the tapes stuck to the lower sail), i.e. the axiu for certified gliders.

generally results in less dynaic behaviour.

ease of handling in ind with large air intakes and a low aspect ratio and reacts very benignly to

Typical for the LTF-A class are the results fro Independence (Pioneer M) and Icaro (Cyber TE M).

6 Swing Arcus 7.26 Air Design Vita M Niviuk Koyot 2.28 Sky Paragliders Anakis 2 L Asyetric Collapses Asyetric s are conducted at tri and at full with pilot action. Capies are d to the top liit of the field defined in the LTF airworthiness requireents (visible fro the tapes stuck to the lower sail), i.e. the axiu for certified gliders. During LTF testing it is also to certify a glider d at the iniu liit of the LTF field, but this generally results in less dynaic behaviour. For this reason we often see differing results here in safety testing, when copared with those of the certification tests. Novas SuSi M was the least challenging glider tested here: the glider is designed with siplicity and ease of handling in ind with large air intakes and a low aspect ratio and reacts very benignly to asyetric s. Typical for the LTF-A class are the results fro Independence (Pioneer M) and Icaro (Cyber TE M). Mojo 4 and Koyot 2 change course to a greater degree and suffer ore height loss than the other test gliders. Behaviour of the low end LTF-B Arcus 7 glider fro Swing was generally very siilar to average LFT-A class gliders. Air Designs Vita reacts unspectacularly to s perfored at the iniu liit of the LFT field, however towards the axiu liit, reactions becoe increasingly dynaic with larger course change angles and associated height loss. Sky Paragliders Anakis 2 behaves very siilarly. None of the tested gliders indicated tendencies to cravat or cascade (e.g. on the opposite side on recovery). Collapse Anakis Collapse Arcus Collapse Cyber TE Collapse Koyot 2 Collapse Mojo Collapse Pioneer Collapse SuSi Collapse Vita

7 Asyetric Collapses Glider Height - loss in Pitchangle in LTF A Nova SuSi M Icaro Cyber TE M Indepen dence Pioneer M Ozone Mojo 4 L Niviuk Koyot LTF B Low Level Swing Arcus 7.26 Air Design Vita M Sky Anakis 2 L Pitch change rate in /sec G- Force in G Coursechange angle in V/sink axiu in ,0 G ,3 G ,3 G ,3 G ,2 G ,0 G ,2 G ,4 G Notes Very oderate reactions, low dynaics, relatively low height loss Relatively oderate reactions, oderate dynaics, height loss < 40 Greater height loss and course change angles than other oderate LTF- A gliders Greater height loss and course change angles than other oderate LTF- A gliders Relatively oderate reactions, oderate dynaics, height loss < 40 Very oderate reactions to s at the iniu of the LTF field. Slow course change < 90 For s over the entire LTF field this glider reacts with greater height loss, greater course change angles and generally ore dynaically than other LTF-A gliders. Collapses need active pilot recovery actions. Greater height loss and course change angles than other oderate LTF- A gliders

Front s Front s are perfored at tri and at full in two different configurations: firstly by collapsing only 40% of the, and then by collapsing as uch as of the gliders.

Pilot action to recover is only perfored when the glider does t self-recover. Novas SuSi rarely needs ore than 25 to recover fro even the hardest destroyer front.

8 Front s Front s are perfored at tri and at full in two different configurations: firstly by collapsing only 40% of the, and then by collapsing as uch as of the gliders. Many gliders are certified at the iniu 40% liit. We often see large deviations to certification behaviour when gliders are tested at the upper liit. Pilot action to recover is only perfored when the glider does t self-recover. Novas SuSi rarely needs ore than 25 to recover fro even the hardest destroyer front. The capy opens very quickly and regains ral without delay but with a tendency to dive soewhat. Icaros Cyber TE opens with a slight to oderate delay, soeties asyetrically which then results in a course change. This behaviour is oreso with the Independence Pioneer, course change and height loss are greater. Ozones Mojo 4 opens first in the iddle, but the ears stay closed with sink velocities of about 5 for a period before recovering copletely. Sink rates are relatively low for the Mojo 4 even for large s. Swings Arcus 7 stands out fro the others that its height loss on large s does t differ significantly fro saller ones. The reason for this: on saller s the capy ears tend to stay closed which delays recovery to ral flight. On larger s recovery is usually iediate. Niviuks Koyot 2 reacts as expected for an LTF-A glider for front s up to 40%. For a axiu the capy tends to reain in a stable closed position for several seconds. Air intakes are t filled, and the capy then horseshoes to the rear with long recovery delays. Air Designs Vita M is unspectacular and returns quickly to ral flight on sall front s. Things look different on large s here behaviour is chaotic and opening ay be fast, syetric and with a large dive or reain in a stable closed state. When this happens the capy then enters a horseshoe and begins to rotate. Recovery does eventually happen without pilot reaction, but with large delays and severe height loss. Novas SuSi LTF-A (right) and the low-end LTF-B Swing Arcus 7 (left) recovered fro assive front s with the lowest height loss.

9 Ozone Mojo 4 (right) recovers delayed after a front, Sky Paragliders Anakis 2 (left) recovers very quickly. These gliders tend to fold in the iddle on a hard front and ay recover asyetrically: Independence Pioneer (right). Reduced tendency on the Icaro Cyber TE (left). Sall s are unspectacular on Niviuks Koyot 2 whereas larger ones display a tendency to severely delayed recovery.

Siilar behaviour for the Air Design Vita: the closed prevents quick recovery, recovery does occur without pilot input but with severe height loss.

10 Siilar behaviour for the Air Design Vita: the closed prevents quick recovery, recovery does occur without pilot input but with severe height loss. Front Collapse Glider Heightloss in LTF A Nova SuSi M 40% Maxiu Icaro Cyber TE M 40% Maxiu Pitchangle in Pitch change rate in /sec Rotation, G-Force in G Coursechange angle in < Yes, < Independence Pioneer M 40% Maxiu Yes, Ozone Mojo 4 L 40% Maxiu Niviuk Koyot % Maxiu 50- > Yes V/sink axiu in Low pitch back, oderate pitch forward, iediate recovery, course change, low sink rates Moderate pitch back, arked pitch forward, fast recovery, course change, low sink rates Low pitch back, low pitch forward, slight delayed recovery, course change, low sink rates Moderate pitch back, arked pitch forward, slight delayed recovery, slight course change <90 Low pitch back, low pitch forward, slight delayed recovery, course change, low sink rates Moderate pitch back, oderate pitch forward, delayed recovery, asyetric opening course change Low pitch back, low pitch forward, slight delayed recovery, course change, low sink rates Low pitch back, arked pitch forward, delayed recovery (ears reain closed), course change, low sink rates Low pitch back, oderate pitch forward, slight delayed recovery, course change, low sink rates Low pitch back, oderate pitch forward. Leading edge ay reain closed, if so the capy enters a horseshoe. Severely delayed recovery, strong course change tendency.

11 LTF B Low Level Swing Arcus % *30-39 **40-49 Maxiu Air Design Vita M 40% Maxiu *30-39 **70-79 *30-45 **-30 *55-65 **-30 Sky Paragliders Anakis 2 L 40% Maxiu * **Yes > Low pitch back, oderate pitch forward, *iediate recovery or **delayed recovery with closed ears, low sink rates Marked pitch back, oderate pitch forward, iediate recovery to ral flight, course change Moderate pitch back, oderate pitch forward, fast recovery, course change, low sink rates Glider has two different reactions: *fast recovery with high pitch forward angles, **front horseshoe with rotation >360, large height loss, severely delayed recovery with low pitch forward. Moderate pitch back, oderate pitch forward, iediate recovery, course change, low sink rates Marked pitch back, arked pitch forward, iediate recovery to ral flight, course change. Spiral dive Spirals are flown such that after at least 5 seconds and before the 540 point the capy is fully locked in the rotation. The testpilot then keeps the glider in the spiral using the brakes for a further 2 turns (720 ) before releasing the inside brake to start recovery. The spiral test provided great surprises. All gliders behaved in accordance with their LTF classifications. Swings Arcus 7 tends to reain longer in the spiral when recovering fro fast spirals before going se up and self-exiting. Due to this the height loss was the greatest under the tested gliders. Siilar, when t quite as severe, was the behaviour fro Novas SuSi. Spiral dives LTF A Nova SuSi M Vsink after 360, 720, ax G- Force after 360, 720, ax. 1,9 G 2,7 G 2,9 G Height loss after 360, 720, ax Height loss fro brake release to regaining ral flight 70 Tie to Total 0-10 s s Action after brake release Acceleration fro 13 to 17 in the next 90 constant sink for 270, then autoatic exit Notes Recovery relatively challenging as the glider continues to spiral and autoatic exiting is delayed. Relatively low G-forces.

12 Icaro Cyber TE M Independence Pioneer M Ozone Mojo 4 L Niviuk Koyot ,8 G 2,9 G 3,3 G 2,0 G 2,9 G 2,9 G 2,0 G 2,8 G 3,8 G 2,1 G 3,2 G 3,3 G s s s 9-13s s 7-11s s 7-11s and recovery in the next 90 Acceleration fro 17 to 22 in the next 180, then autoatic exit and recovery in the next 180 Vsink reains at 15 for 180, then autoatic exit and recovery in the next 270 Acceleration fro 17 to 20 in the next 90, then autoatic exit and recovery in the next 180 Vsink reains at 17 for 180, then autoatic exit and recovery in the next 180 Entry siple. Exiting ore challenging than class average due to acceleration for 180 Dynaic transition fro entry to spiral. Glider s on outer ear at 15 which resists further acceleration. Relatively low G-forces. Relatively dynaic transition fro entry to spiral, with rapid increase in sink rate and G-force. Exit relatively siple. Relatively dynaic transition fro entry to spiral, with rapid increase in sink rate and G-force. Exit relatively siple. Glider s on outer ear at 17 which resists further acceleration. LTF B Low Level Swing Arcus Air Design Vita M Sky Anakis 2 L ,0 G 3,1 G 3,9 G 1,9 G 3,1 G 3,5 G 1,9 G 2,9 G 3,3 G s 9-13 s s 9-13s Acceleration fro 17 to 23 in the next 90, Vsink > 20 for 360, then autoatic exit and recovery in the next 180 Acceleration fro 14 to 20 in the next 90, then autoatic exit and recovery in the next 180 Acceleration fro 13 to 19 in the next 90, then autoatic exit and recovery in the next 180 Siple entry. Challenging exit behaviour with aintained high sink rates for 360. Relatively high height loss on exiting. Ipulse required for correct entry, relatively dynaic transition fro entry to spiral. Siple exit. Siple entry and exit.

13 B-Stall Pitch back behaviour on entry, pitch forward behaviour on exiting and sink velocities. In particular we look at the capy stability and tendencies to defor on longer B- Stalls (>10s) and any recovery probles. The LTF-A gliders Nova SuSi, Icaro Cyber TE, Ozone Mojo 4, Niviuk Koyot and the low end LTF-B Swing Arcus 7 and Air Design Vita displayed good behaviour in B- stalls. No deforation tendencies, stable sink phase with good sink rates and recovery or deep stall probles on exiting. Independences Pioneer displayed a slight tendency to defor on longer B-stalls. Skys Anakis 2 enters a short deep stall on exiting fro a B-stall but self recovers fro this within the next 3 seconds with a arked pitch forward. B-Stall Glider LTF-A Nova SuSi M Icaro Cyber TE M Independence Pioneer M Ozone Mojo 4 L Niviuk Koyot 2.28 LTF-B Low Level Swing Arcus 7.26 Sky Anakis 2 L Air Design Vita M Sink rate in stable B- stall. Deforation tendencies Rotation slight 8 slight <90 7 slight Pitch back on entry / pitch forward on exit > 45 Height loss on exit Notes -20 Large entry force, very stable sink phase -20 Very stable sink phase, low pitch forward on exit - 20 Slight deforation tendency in Capy iddle - 20 Very stable sink phase, low pitch forward on exit - 20 Very stable sink phase, slight rotation tendency -20 Very stable sink phase -40 Very stable sink phase, short deep stall on exiting. -20 Very stable sink phase

14 Big Ears Big ears at tri and at full. Glider sink and is easured. Any entry difficulties or deep stall tendencies on exiting fro tri big ears are ted. Perforing big ears on all of the tested gliders was unprobleatic. Icaros Cyber TE tends to flap its ears and snake a little in straight flight at full. This behaviour is te ted at tri. Big Ears Glider Entry Exit Vsink (tri) Vsink (full) LTF A Nova SuSi M siple autoatic 2, 5 3,5 Icaro Cyber TE M Independence Pioneer M siple autoatic 3 4 siple autoatic, arked delay 3 4 Ozone Mojo 4 L siple autoatic 2,5 4 Niviuk Koyot 2.28 LTF B Low Level Swing Arcus 7.26 siple autoatic 2, 5 3,5 siple autoatic delayed Sky Anakis 2 L siple autoatic, arked delay Air Design Vita M siple autoatic delayed , 5 3,5 Speed difference tri - full approx.3-5 k/h less than tri approx. 3-5 k/h ore than tri approx. 5-8 k/h less than tri approx. tri approx. 5 k/h less than tri approx. 5 k/h ore than tri approx. 5 k/h less than tri approx. 5 k/h ore than tri approx.3-5 k/h less than tri approx. 3-5 k/h ore than tri approx. 5 k/h less than tri approx. 5-8 k/h ore than tri approx. 5 k/h less than tri approx. 7 k/h ore than tri approx. 5-8 k/h less than tri approx. 5-8 k/h ore than tri Notes Ears flap at full Delayed recovery Delayed recovery

Deutscher Hängegleiterverband accident report

Deutscher Hängegleiterverband accident report 4.02.2011 Date 18.7.2010 Time 21:20 Land Denmark Site Lökken/Lygnby, Denish West coast, soaring Pilot M, 42 years old, experienced Pilot, PG- Licence since