Warning – Unsafe Flying Conditions Ahead

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This article appeared in the August 1999 issue of Paragliding magazine as a sidebar to the Arcus Review.

We at Wills Wing are very excited about the latest paragliding technology, and we are very gratified at the extremely enthusiastic pilot response to the extraordinary combination of performance and stability represented in the new Arcus model.

At the same time, we would like to sound a note of caution. A paraglider – any paraglider – is an aircraft of extremely limited capability with regard to wind and turbulence. As a lightly loaded, relatively high aspect ratio ram air inflated wing, a paraglider is highly subject to spontaneous distortion or partial collapse induced by turbulence, which will result in some degree of both increased descent rate and loss of control. Should this occur close to the ground, an impact at a speed high enough to cause injury or death is not unlikely.

Throughout the history of hang gliding – and we include paragliding in the term “hang gliding,” there has been a tendency for pilots to push the limits of the capability of their aircraft. This has always been a significant cause of accidents, injury and death, and that situation continues today. Manufacturers, have, throughout the years, strived to improve both the performance and the airworthiness of their aircraft – and in many ways have achieved notable success. It has been frustrating, however, to watch as pilots have taken the expanded strength, stability and performance capabilities of their new aircraft and, rather than use them to improve their safety margins, have instead used them to push the envelope still further in terms of the weather conditions and sites they will fly, and the tasks they will attempt.

When hang gliding exploded in popularity in the early 1970’s, many soaring pilots looked at the basic nature of our craft and attempted to sound a note of caution about their unsuitability for strong weather conditions. Dr. Paul MacCready, Jr. wrote a very thorough, and somewhat technical article which was published in Ground Skimmer Magazine in January of 1975, and re-published in Hang Gliding Magazine in January of 1978, in which he analyzed and warned of the dangers of flying hang gliders in strong weather conditions. I will not re-visit the technical aspects of his article here, but it is instructive to look at a few of his main conclusions:

“Strong winds, with strong solar heating, over rough terrain, is simply not an acceptable hang glider flight situation. … By unsafe we do not maintain that you cannot do the flight, but that the flight will be uncomfortable, and that if you give nature many opportunities to cause you severe trouble, she will eventually oblige you. … Twenty knot winds, which are often utilized to permit slope soaring, turn out to be beyond the safe limit for all but the most conservative flying at ideal sites. … A hang glider cannot be flown really safely unless the turbulence is considerably smaller than its lowest flight speeds. This would limit flight to winds of ten knots, and sometimes even less.”

When warnings like this were sounded by the soaring aviation “establishment,” one segment of the hang gliding pilot population seemed to take it as, effectively, a challenge to their manhood, and their response was to do everything they could to “prove the old farts wrong.” So we’ve had a twenty five year history of hang glider pilots flying in extreme weather conditions, racing to goal in contests ahead of thunderstorm gust fronts, being sucked up into cumulo-nimbus clouds and frozen to death, being tumbled out of the sky, crashing on landing due to turbulence induced loss of control, et cetera.

When paragliding exploded in popularity in the early 90’s, many hang glider pilots warned of the dangers of flying paragliders in strong winds and mid day thermals. A segment of the paragliding community responded by taking this as, effectively, a challenge to their manhood, and their response has been to do everything they can to “prove the old farts wrong.” So now we have a new medical condition called “the paraglider limp,” and we’ve had to say goodbye to some very close friends who managed to survive hang gliding at the highest levels for 25 years but were killed by untimely collapses in paragliders.

In our opinion, history has proven Dr. MacCready far more correct than wrong. In our opinion modern day paragliders are at best no more capable of handling wind or turbulence than were the hang gliders of 1975, and probably not as good. (In our opinion, modern day hang gliders are not capable of safely exceeding MacCready’s suggested weather limitations by any significant degree either.)

Please note that we’re not trying to tell anybody what to do, or what not to do. We believe in freedom of choice. We are not particularly bothered by pilots who make an informed and conscious decision to accept a significant risk in exchange for what they perceive to be a significant reward. (We might disagree with their decision, and we might prefer they do it on somebody else’s glider, but that’s another issue.) What does bother us is that pilots in general tend to look at what is being done by others – in the area of pilot decision making – as representing the standard of what is proper or advisable. In the interest of losing as few friends as possible in the future – and we would like to consider every pilot to be a friend – we would simply like to point out that in our opinion too many paraglider pilots and too many hang glider pilots are, at present, way too far over the line of safety in terms of the wind and weather conditions they choose to fly in (and, in many cases, the maneuvers they choose to perform).

Thanks for listening.