Paragliding: the Rule of Thirds: Draft

"I guess a little more info on the 1/3rd rule is needed here for me. I do like the concept though."

We cover iParaglide's "Rule of Thirds" over a series of lectures including hand drawn drawings/ diagrams, so a little tough to cover on this forum/format without drawings etc.  Needs at least 10 hours and a more detailed paragliding article: was planning on one in the spring. Here is a draft summary:

Like most rules of thumb, the key concepts, the "why", rather than precise math, is what is important. Please note: I am first and foremost an engineer, not a mathematician! It doesn't cover every situation in paragliding, but is a good general guide.

In general, asking the question "does the paragliding rule of thumb apply here?" often leads to greater truths, especially when dealing with the exceptions.

"If you are capable of flying in strong laminar air of 25 km, does that mean you should only go out in 8km?"

Not literally, 100% of the time. But darn hard to find perfectly laminar air, especially when it hits 25 km/hr, isn't it?  Turbulence varies as the velocity squared.  Maybe at Point of the Mountain?

The rule of thirds applies to the 80-90th percentile of the bulk of your paragliding hours.  And knowing which percent of your flying capabilities you are currently flying at. That is, you need to know when you are stepping out of the safety zone to learn something new, but then step back to a lower performance requirement for the bulk of your paragliding, in between learning events.

Can't draw a curve here to represent the discussion, but imagine a curve like a cardio gram with learning occurring during the brief spike (performance requirement is at or near 100%, while safety reserves are reduced) and the flatter lines in-between representing the bulk of your flying, relaxed, allowing you to flow, and have a significant safety margin.

For example, when we first teach students paragliding SIV: they are clearly out of the comfort zone, outside the rule of thirds, and flying at 100% of their abilities. We control the safety margin, by coaching them through the maneuvers, and only doing them over the water, with freshly packed reserves and reserve training, with a rescue boat on standby. But one of the very last things we do at the end of the SIV seminar, is to remind the pilots that the intent of the seminar was to encourage them not to fly stalls, spins, wing overs or spirals over hard ground! Conversely, we teach paragliding advanced maneuvers to increase the performance/knowledge headroom and help prevent, intercept and recover from adverse situations.

 

Without getting into writing the full article, here are just some flying situations where the rule of thirds works reasonably well, again, for the bulk 80-90th percentile of your RECREATIONAL paragliding, assuming you want to have a safe, fun, relaxed and long flying career to your old age:

• set up to be able to safely achieve takeoff within the first 1/3 or your launch. Gives you 2/3 of runway to abort.
• set up your paragliding landings to land in the first 1/3 (furthest downwind) part of the LZ. Allows for getting popped by unexpected thermal or other lift. Allows for wind gradient and ground effect. Keeps you out of the rotor zone generally in the last third of most LZs surrounded by trees.
• fly the bulk of your turns keeping your speed up on your paraglider, using weight shift and up to 1/3 brake (and occasionally 1/2 brake), saving the remaining brake travel for interception moves to counteract turbulence, loss of pressure in your wing and/or associated big pitch/yaw/roll oscillations. Flying sustained in brake ranges beyond  1/2 is recipe for inadvertent deep stall, spin, or stall, when you use up control headroom...
• if you have flown maneuvers at SIV over water and incurred roll and pitch angles up to 90 degrees off level flight: do not exceed 33 degrees over ground.
• if you have flown an SIV spiral to -20 m/s, keep your over the ground spiral to -7 m/s to learn higher control, precision, and prevent black-out due to g-force.
• if your paragliders top speed is 50 km/hr, keep your launch velocity base wind below 17 km/hr.  Will also prevent you from being inadvertently plucked.
• if you have flown in thermals beyond +14m/s sustained (I have, not fun) keep the bulk of your flying in the 4-5 m/s range: a lot more relaxing and stress free.
• if you have flown all out un-certified competition paragliders (been there done that), try flying the latest ENC class wings. Almost the same performance, at a fraction of the stress, with lots of safety margin, better and more intuitive handling: adding up to a lot more fun. 

If the above seems overly conservative, remember, most paraglider pilots are recreational pilots flying some weekends only.  Recreational pilots fly first and foremost for fun. The above was about optimizing SAFETY and enjoyment.  If you want to compete or fly acro, you will likey need to revise the rule of thirds, which is a perfectly fine choice, but recognize by optimizing performance, you are sacrificing safety margins.  But even here, the concept from the rule of thirds will still help you.  And more important than the "what", the numbers you assign, having a rule and understanding and being able to justify to yourself the "why",  is key. 

 

What paragliding flying rule are you using? Rule of: 1/3s? 1/2s? 2/3s? 3/4s? 4/4s?

Why?