Deutscher Hängegleiterverband e.V.
DHV
  • Deutsch

Equipment Portal

Gradient Nevada 28
Sicherheitsklasse 4
Gradient Nevada 28

Instability rating
Safety class 1 Safety class 2 Safety class 3 Safety class 4 Safety class 5
asymmetric collapse
course change
forward pitching
height loss
sink velocity
G-Force
Frontal collapse
course change
Speed (Recovery)
height loss
sink velocity
Spiral dives
G-Force
Sink velocity after 720°
Maximum sink velocity
Behaviour on brake release
course change after spiral dive exit
Height loss during recovery
Safety class 4
Pilot skill requirements:
Pilots should be able to recognise the onset of instability and be able to prevent or minimise glider reactions through immediate and precise pilot inputs.
Advanced piloting skills and regular flight practice necessary.

Glider characteristics
Launch preparations: average
launch characteristics: delayed, delayed climb,needs pronounced guidance, minimal feedback during inflation, overshoots, pronounced braking required, accelerates before zenith, tends to stall during control check
asymmetric collapse: canopy collapses at low angle to leading edge, moderate dynamics, total course change 90-180°, (1), delayed course change, marked forward pitching 60-75°, (4), high height loss 40-49 m, (3), moderate sink velocity 15-19 m/s, (2), G-Force < 2,5 G, (1)
Frontal collapse: canopy collapses with low total collapse area, marked pitch backwards 45-60°, moderate pitch forwards 30-45°, moderate dynamics, course change <90°, (2), variable recovery behaviour, at times immediate, at times delayed, automatic recovery, (3), asymmetric recovery, delayed return to normal airspeed, delayed reinflation of wingtips, moderate height loss 30-39 m, (2), low sink velocity 10-14 m/s, (1)
Spiral dives: rapid sink velocity increase, Very low G-Force < 3 G, (1), Sink velocity after 720° <18 m/s, (3), High maximum sink velocity < 22 m/s, (3), sink velocity increase < 6 m/s on brake release, (2), Course change 360-540° after spiral exit, (3), moderate height loss during recovery 30-60 m, (2)
B-Stall: normal force required, marked pitch backwards 30-45°, marked pitch forwards 30-45°, stable sink phase, low deformation tendency, immediate return to normal airspeed, 8-10 m/s, height loss on recovery 20-40 m
big ears: simple initiation, stable flight phase, wingtips flatter markedly, delayed automatic recovery, Vsink unaccelerated 2,5-3 m/s, Vsink accelerated 4-4,5 m/s, Vunaccelerated 0-3 km/h less than trimspeed, Vaccelerated >8 km/h faster than trimspeed

Notes
Launch characteristic:
Both Gradients Nevada and Mac Paras Eden 5 were more difficult to launch. At the beginning of inflation both gliders tend to hang back a little requiring careful pressure from the pilot on the risers. At the end of the climb, both gliders tend to accelerate and surprise the pilot with needing a good jab on the brakes to stop them at the zenith and stabilise there. Too much brake brings the canopy down quickly, but once our testers had gotten used to this behaviour, safe launching was no real problem

Asymmetric Collapse:
Mac Paras Eden 5 and Gradients Nevada react similarly to assymetric collapses. Compared with other
gliders in this class both gliders slow on collapsing and course change is delayed. The rate of
course change and pitch forward angle begin to increase markedly after about 90°, moreso with the Eden 5 than the Nevada.This type of behaviour gives a pilot more time to react and prevent further difficulties
but may also lead to a spin or stall if the pilot brakes too early to recover.

Front collapses:
Gradients Nevada displayed moderate reactions even to front collapses which deformed almost
the entire canopy. The canopy recovers quickly with only slight assymetric or chaotic tendencies.

Spiral Dive:
The spiral test produced no great surprises.No glider demonstrated tendencies to
remain in a stable dive after the brakes had been released to initiate recovery. High end B class gliders do tend to collapse on the outer wingtip when spiralling due to their higher aspect ratios. These small collapses produce sufficient resistance to prevent the gliders accelerating further in
the spiral. Here all spirals were flown according to LTF test regulations without
using weight shifting. Spirals flown in practice by pilots using weight shifting and stabilising the outer wingtip sufficiently to prevent it collapsing may well lead to further acceleration in the dive and produce a stable spiral dive once the brakes are released to initiate recovery.

B-Stall:
the wingtips of Gradients Nevada begin to bend to the back, but this tendency is clearly indicated.

Big Ears:
The two gliders with only two main A Lines (Gradient Nevada and Skywalk Chili 3)
had the most effective sink rates.

Rating

Safety class 4

This class of paraglider reacts demandingly to one or more of the following manoeuvres: frontal collapse, asymmetric collapse or spiral dive.
Demandingly means that the above manoeuvres result in marked dynamic reactions from the glider and/or large height losses.

Advanced piloting skills which need to be regularly practised, together with good personal reaction times are required to safely fly this class of gliders. Basic recovery techniques for ending a manoeuvre are not sufficient to maintain control, reduce height loss to a minimum and prevent subsequent critical reactions. Pilots should be able to recognise the onset of the above manoeuvres and be able to prevent or minimise their effects through immediate and precise pilot inputs.

Additional experience such as regular ground handling and SIV training is required to safely fly gliders of this class. Special training or pilot skills which exceed standard training may be required for the safe performance of emergency descent techniques. Gliders of this Safety Class are not suitable for beginners, irregular flyers or low-airtime pilots.