Reserves (in English)
What a pilot should know about reserves?
There are now on the market reserve systems that will provide a very high probability of a quick and safe opening, together with a slow descent rate. Most companies (reserve and harnesses) however don’t do much research and keep using the same model with a new look. As well, this, most paragliders pilots don’t care to have any reserve system.
At Flying Paradise, our centre in Greece, we find out that when checking the equipment of paragliding pilots, on average out of 10:
- 2 reserves wouldn’t have opened at all (sometime because of the impossibilities to get it out of the harness)
- 3 would have probably deployd, but very slowly (over 5 second)
- 4 were safe, but could have been improved.
- 1 was perfect
If considering only the vertical speed, 6 out of 10 would have had a high impact on the ground (Equivalent falling from 3 metres high).
- 3 to 4 of them where ok, with an impact equivalent to that of a fall of 1.5 metre or less.
Here is a list of real life situations that we found when checking the gear of pilots or that we seen happening on simulation.
You will see:
-The problem, sometimes the cause of it, the probable consequences.
- Apex outside; reserve inside out.
- Reserve very unstable, high impact
- Bad packing. Long opening or none
- Tissue stuck together; damp, packed for a long time.
Long opening or none
- Elastic loop of inner bag too tight or line loop too long.
Probably No opening
- Bad inner bag; reserve becomes stuck in inner bag.
Slow or no opening
- Handle going around reserve line; bridle too long. No opening
- Accidental opening: bad handle design, wrong positioned handle.
- Inner bag thrown into paragliders or risers: shoulder mounted or bad throw. Very bad / uncertain
- Impossible or difficult to reach or find handle: bad design of container / handle system. Slow or no opening
- Impossible or difficult to pull inner bag out: container problem, handle too long.Slow opening or none
- Difficult to throw the reserve when out: long bridle, rear mounting
Long, slow opening
- Reserve line gets caught on pilot: system problem. Unstable
- Pilot remains holding handle after attempting to throw release handle. No opening
- Reserve breaks during opening: speed of deployment too high (not designed for freefall), material quality. Rare
- Reserve to small or of an old design; high mirror effect increasing speed and instabilities. High speed impact, very commun.
- Bad position during descent: bad harness design, Velcro sticks,
High risk during impact due to incorrect body positioning
- Arms caught by bridle : throw reserve wrong side or bad set up of system. Broken arm during throw.
What you should look at with a reserve system
- Proper size reserve for your weight and physical shape.
- Right length of line relative to glider, recent design from a good company
- Recent and good professional packing
- Wall massive at top of packing
- No visual sign of apex line
- Lines nicely folded
- Inner bag not attach to reserve (you risk your life for 15 euros?)
- Preferably 2 stage opening (type Apco/ Parateck/Metamorfosi)
- Inner bag size and tension of elastic of inner bag
- Attachment point of reserve bridle, no nylon on nylon, right sized carabineer working in right way, bridle properly routed and of right length.
- First metre of line out of inner bag and sheathed
(Cannot catch on anything and will open away from you)
- SHORTEST DISTANCE POSSIBLE BETWEEN HANDLE AND INNER BAG (AROUND 10 CM OR LESS)
(Cannot go around line, more efficient throw)
- Solid handle holding its shape, with as little Velcro as possible
(Velcro power varies, they can catch on lines)
- HANDLE MUST BE VISABLE AT ALL TIMES.
- HANDLE MUST BE OF EASY ACCESS EVEN UNDER G FORCE. (Nothing in the way) and must offer the right resistance for YOU!!!
- IT SHOULD BE POSSIBLE TO THROW YOUR RESERVE ON YOUR SIDE AND BEHIND YOU IN ONE MOVE!!! (ideally from both sides).
- Make sure that you buy your equipment from a good professional.
- Ask for certificate and manual for the model
- Ask to simulate a deployment on a sheet whilst hanging in the harness
- Ask to be taught how to replace the reserve into the harness
DO THIS BEFORE ANY PAYMENT!!!
IF YOU UNDERSTAND THE BASICS OF A RESERVE SYSTEM, it will make very easy to check it. Make some simulated throws by yourself.
A RESERVE IS USELESS IF DOESN’T WORK!!!!!
Between the moment where you will decide to throw your reserve and the moment where you will be hanging under it open, will take a minimum of 3 seconds.
- Approximately one second for your brain to transmit the order to your body.
- Approximately one second to pull the reserve out.
- Approximately one second for the reserve to deploy.
Every one has heard or said that a bigger reserve needs more time to deploy. This is actually right because there is a bigger volume and longer lines. However, the difference between each size of reserve is approximately 10 to 15% of the opening time, so 0.1s to 0.3s at the most.
At 15m/second these differences in time mean a difference of opening distance of 1 to 4 metres in the worst case…
- During a real life deployment the pilot is falling between 5 and 10 m/s, rarely over 12 m/s because of drag. This does not include the speed of their rotation.
- Some people say that a big reserve will inflate slowly but will slow you down even before been completely inflated.
It’s totally wrong! A reserve only works when the lines are under tension, which happens only when the reserve is fully inflated.
All certification companies are different and disagree with one another. None of the testers would jump over ground with some reserves that pass the test, due to high sink rate deemed acceptable by the certification companies.
- For instance, 6.8 m/s (max DHV) is equivalent of a jump from 2.4 metres, TRY IT!!!
Some more numbers (rounded)
- 4.5 m/s descent rate is equivalent to fall from 1 metre high.
- 6 m/s will give you an impact of double of that, so 2 metre fall
- Easy to jump one metre on clear grass, what about obstacle,and wind?
- Also a 20 km/h wind will multiply the impact by 2 !
- But the most important is how the descent rate affects the mirror effect (also called down plane).
The effect of down plane on your reserve is directly proportional to the vertical speed you have. At 4 m/s, your glider may fly around a bit, but will not have any serious effect on speed of descent.
With 6m/s sink rate it is essential to pull your glider in, this however can be very difficult.
Unfortunately professionals can do and write just about anything what they want.
We have a lot of manuals from different companies: They all give completely different numbers. One says that there 25 m2 (famous in the UK) can take up to 106 kg while another says that they recommend 80 to 100 kg with there 40 m2 one!!!
I have jumped with both of them (both on my video). Guess which one is the better!
The surface unfortunately is not all. The design will of course have a big difference.
Opening shock is speed2 (we don’t have to worry too much about that), however : If X is the opening shock, then:
60 km/h speed = X
120 km/h speed = X x 4!
180 km/h speed = X x 9! (terminal speed in free fall after 8 seconds, on your belly)
- Don’t count too much on your back protector, your legs are your best absorber, use them.
- A quick release system of your glider is good but complicate due to the speed system. However some people use it especially with Rogallo reserve
- Best way to be and feel safe is to test your reserve over water before to buy it!
- Don’t forget Murphy’s Law; “what shouldn’t happen will happen eventually.”
- You shouldn’t have to pull the glider in, if you got the right reserve. However, to pull the C but not completely is a good bet, also the sooner the better.
- The throw of the reserve must be BELOW HORIZONTAL, other wise it will go up and will have to go down afterwards.
- You must let go of the HANDLE, there are still some people who believe they have to hold it.
Pass the word around
Flying Paradise director
-Over 30 personal deployment, 3 with tandem.
-Around 200 organised at our centre.
-300 Sky dive –30 base jump