By Eric Laforge on 25 August 2022
I started flying in 1984 with a hang glider and then in 1985 I switched to paragliding. I have been checking flight equipment since 1987, when I imported the Japanese FALHAWK paragliders into the JDC Electronic SA company, and since 1992 in my company, ASAGIRI SA.
I learned that the French Federation has the objective to create a label for the revision of paragliders and to facilitate the creation of workshops within paragliding schools. The intention is commendable, but it is not taking the problem by the right side.
I am passionate about the subject and it concerns the main activity of my company, so I submit to you my remarks a little bit in bulk about the maintenance of paragliding equipment.
Old pilots and old generation paragliders
Too few pilots have their paragliding equipment checked. It is mainly the old pilots (also the old pros) who are not used to maintaining their equipment.
Their behaviour is based on older generations of paragliders that required less care… They were FIATs, now we have FERRARIs!
Freedom and individual responsibility: OK, but not for the tandem!
Pilots do as they please, that’s OK, because I’m all for freedom and individual responsibility, but where it worries me is when I know that tandem paragliders are not properly maintained or even never maintained !
Passengers on tandem flights know nothing about our activity and they have the right to expect proper maintenance of the equipment, just like when they take a taxi, a cable car or a plane!
Think of this when you entrust a loved one to a tandem pilot or when you fly yourself with a passenger.
Catastrophic anecdote
I have been told that tandem pilots no longer dared to make turns with their tandem paraglider “washed out” by hundreds of flights and never maintained.
They don’t want to waste money a few months before reselling their paraglider (without control!) in Africa or elsewhere…
Trimming out of approval already after a few dozen hours of flight !
Who says it??? Some manufacturers dare to write it: NERVURES, NOVA, OZONE + a few others… Most brands (all in fact) know it, but they are afraid of criticism if they disseminate this information, which is nevertheless essential:
“The settings of new paragliders are often out of certification after a few dozen hours of flight ! »
To effectively analyze the trimming of a paraglider, it is necessary to measure all the lines. To correct it, it is necessary to intervene in the maillons, in the connections of lines between them and in the attachments of the lines to the canopy (strap of the attachment points). It’s a lot of work, but if you don’t do it, the wing does not conform to the certified model.
Security and performance?
If the trimming is out of tolerance, it is not necessarily dangerous, but it is not the paraglider that the pilot has chosen by going through and comparing for weeks the technical data of various manufacturers and the results of flight tests during certification! A very common difference of 10 to 20 mm (between the A lines and the rear lines) over the entire wingspan of the paraglider can change the speed by several km/h.
It’s much more than going from one size to another !!!
I laugh softly…
…when I see pilots carrying 3 kg of ballast to be right in the middle of the weight range of their wing (light!), while the trimming has not been measured and corrected!
The remaining life slider
In our ASAGIRI workshop in Switzerland, when a paraglider passes the inspection, it means that it is fit to fly in accordance with the model approval.
For us, it’s ON/OFF, there is no in-between. The lines are strong enough or not. Porosity is OK or not.
On the other hand, the trimming can always and must be corrected so that the paraglider is able to fly according to the certification.
Pending a “standard” on estimating the lifespan of a paraglider, we do not publish a cursor, but we still give an indication of the aging of the fabric: “With a porosity of order of 50 units (JDC porosimeter), the paraglider could have reached half of its life.” At this time, we decline to be more specific, as we are not diviners. We have no idea what will happen after our check:
- if the paraglider is going to be used intensively or sporadically
- how it will be exposed to moisture (the real fabric aging factor !)
Porosity
Go from a cull value of 10 to 5 units ?
It seems that this idea is in the air… What is the use of this possible change for a greater tolerance? Will this save lives? Does a technical and efficient paraglider of today tolerate high porosity better than a rudimentary model of 30 years ago? I doubt it and besides no paraglider is made with porous fabric.
The coating does not only affect the airflow over the profile. It also gives the fabric stiffness on the bias. The gradual disappearance of the coating (this is what increases the porosity) also indicates probable deformations of the fabric, in particular of the ribs.
One idea would be to subject porous paragliders to certification tests, but at what cost and what real use? During our checks, if the porosity drops below 20 units over more than 3 measurements (out of a total of 9), we inform the customer that his paraglider will probably not pass the next check (a priori one year later…).
When there is little coating left on the fabric, the porosity can increase rapidly. So going from 10 to 5 as cull value will “save” maybe some paragliders from scrap.
What would be the security gain for our activity? Nothing, especially since I would have no desire to fly with such paragliders!
Should lines be broken? Intensity of use
It is not necessary to test the resistance of the lines on a paraglider less than 2 or 3 years old, used “normally” and without any particular incident.
In all other cases, you have to break the lines (at least one lower one) to find out their resistance! Especially for tandems and all paragliders used intensively. Should a blood test be taken during a medical check-up? If there are only 0.5% of serious cases detected, can we consider it not useful??? (I like this example, while I hate blood tests).
If the lines are broken, they must of course be replaced. This requires having lines in stock (for recent paragliders and even for those over twenty years old…), having a sewing machine, know-how and common sense. All or part of this is missing for those who believe that it is not useful to test the resistance of the lines! It seems to me that it is only the complication of this important part of control that puts them off.
Revealing information. Frost and Kevlar.
Did you know that a paraglider used intensively (professional tandem) in a ski resort can have its lines down to the limit of acceptance after only one year?
With freezing, the Kevlar fibers stick together and only a few take the load and break. If this is repeated during the winter, the resistance limit can be reached quickly.
Who has the resistance of the lines of his tandem used intensively in a ski resort checked???
Details on line replacement. Replacement of main A and B every year?
It rarely happens that we have to replace all the lines (complet set of lines). Only the main brake lines are subject to wear by friction and, given their essential role, their replacement is frequent. Other lines should be tested for strength.
Obviously the lower lines are the most important, especially the A and B lines which take almost all the load. I think it is reasonable to replace them on a tandem paraglider after one or two seasons of intensive flying. Who says it and who does it?
On the other hand, replacing the brake lines, the upper lines C, D, E is most often completely useless!
Of course, damaged lines should always be replaced. If they are numerous, the replacement of all the lines can in this case be envisaged.
Intensity of use of paragliders
There is a strong disparity in the intensity of use of paragliders and it is unfortunately not taken into account to establish the frequency of controls.
It’s revolting, especially for tandem paragliders (see above) !
And the harnesses ?
Although the approvals also include a review period for the harnesses, very few pilots are aware of the need for these checks.
The most serious: some Airbags are totally ineffective for the following 2 reasons:
- High porosity. In the event of an impact, the air escapes through all the “pores” of the fabric. It’s treacherous, because the airbag seems perfectly inflated. This problem is not visible.
- Twisted rod (or plate). The volume of the airbag is reduced, the air inlet is no longer in the correct position and the non-return valve may no longer work. This problem is visible.
The damping during an impact is not only reduced in these cases, but absolutely zero, as if you only had a “string” harness without an Airbag!
What do the federations do? Swiss specialty?
In Switzerland, for a student examination, the SHV / FSVL (Swiss Federation) requires that the model of the paraglider used be homologated (even if the certification is 30 years old) and there is no requirement or even recommendation on the maintenance of the paraglider used during the examination:
- it can be completely porous
- with lines that break at 20 kg…
Seems to me that needs to change! A maintenance requirement during an exam is likely to encourage pilots to carry out maintenance on their equipment on a regular basis.
Should everyone be able to do checks ?
Setting up a control workshop is not easy. Wanting to do a check from time to time is a bad idea !
To do paragliding checks, you need a lot of things…
of a room
- 10m x 5m minimum and 5m high!
an equipment
- a bar of at least 9 m to hang the paraglider and open at least half a wing + a system to be able to raise and lower the bar
- strong lighting to examine the canopy
- a special zig-zag sewing machine for lines
- a device for measuring the trimming etc.
a stock of materials
- lines
- adhesive fabric
- maillons
- blocking links
- etc
technical information
- given the huge amount of brands and models for more than 30 years, the search for information takes time…
tranquility
- you have to be focused
- when you control a canopy, you can’t answer the phone, welcome customers…
to get used to
- to minimize errors and maximize efficiency, you have to do the same things often.
Do you want to be operated by a general practitioner who does this once a year or by a surgeon who does this several times a week?
Example
I don’t pack my parachute myself, because once a year isn’t often enough for me to have the confidence to take care of a safety element. So I give my parachute to pack to one of my collaborators who has the habit and the experience to do it.
a sufficient volume of checks to be profitable
If you do not have enough checks to do, missing technical information, partial equipment, not enough stock, little practice and if you are often interrupted, the effectiveness of the controls suffers. If we are not profitable enough, we may tend to rush the work, not do it completely… You risk making more mistakes.
Considering the investment for the premises, the installation and the stock, it is very difficult to be profitable by making checks from time to time…
In conclusion
Information to pilots
If we really want to improve the safety of our activity, we must encourage pilots to maintain their equipment by informing them of the usefulness of controls.
Tandem scandal
If you combine “old pilots” and “heavy use”, you get the lowest maintenance rate! Especially for tandem paragliders and it is scandalous !
Evidence of recent maintenance
Proof of recent maintenance (dating back less than a year) may be required for patent examinations, training courses or competitions and especially for performing tandem flights in a commercial setting or within a club.
Line resistance
You have to test it !
Porosity
Why would you want to reduce the requirements by moving to a reform value of 5 units instead of 10, when you want to increase security ?
Control workshops
Wanting to promote the creation of paraglider control workshops as a very incidental activity is a bad idea.
If workshops are missing, it must be a real activity with sufficient volume !
Happy flights and take good care of yourself and your equipment !
Eric Laforge
I have developed many paragliding models and participated in the development of certification standards… My colleagues and I have been checking and repairing all paragliding equipment for over 30 years with the same passion!
