Opening sequence in the LTF (german type approval) load test at Kochertal bridge (Annular 36 with 250kg test load). Length: from the opening of the container to the load bearing capacity of the reserve canopy : 1.3 sec (picture 4-15)

 

1. Weight hangs underneath the 185m high bridge with the reserve
parachute.

 

2. Weight and reserve parachute are let off and fall 85m, when it is forced to open (150km/h)

 

3. After 2/3rds of the way the rope to force the reserve parachute open is visible

 

4. Opening: test load and reserve parachute reach 150km/h. The container is delayed by the now taut release line and separates from the test load.

 

5. The container has separated itself from the reserve parachute. The reserve has to stretch now.

 

6. Through the resistance of the still packed canopy the lines are stretched. You can see how the pack’s rubber rings hold the lines together. The container leaves the photo (4-5m distance to the reserve parachute’s canopy).

 

7. Lines are stretched, the reserves canopy is still completely closed and is now stretched.

 

8. Reserve canopy is stretched, now air can stream into the canopy.

 

9. Because of the very tight base the first litres of air stream into the reserve. Air is gathered in the upper part of the canopy.

 

10. The base is still fairly closed and now has a diameter of 1 m. You can see a pear shape forming.

 

11. The canopy is now filled, so the inside pressure of the canopy pulls the base apart. The opening is very even - now you’ll see whether or not the reserve was packed properly. The base is still fairly closed - but the highest pressure is on the lines of the canopy.

 

12. The upper part of the canopy has reached its’ final shape through the filling. The base is still closed. You can see the side winds’ influence clearly now, it won’t let the canopy open up evenly. During this test day there were winds up to 30km/h at the Kochertalbridge. Such winds have very bad influence on the test, as uneven openings pressurise single lines more and there is a risk of the canopy being burned.

 

13. Now the base opens up.

 

14. The base is now almost completely opened.

 

15. Reserve is open. The opening blow reaches the canopy. Now the material is fully strained. The shockwave from the opening blow can be seen nicely to the left and right of the parting (picture12 - 15 is the shortest described time section).

 

16. The opening blow enables the canopy to breathe (similar to the swimming actions of a jellyfish).

 

17. The canopy’s movement calmes down.

 

18. The reserve is stable and sinks to the ground.

 

19. The weight has ground contact. The influence of the wind immediately pushes the parachute’s canopy to the right. In this picture you can see the Annular’s shape nicely. This shape is especially good because of its’ resistance i.e. good descending speed.