Aviawinch has not one but two radio transmitters and on differentiated frequency ranges which greatly reduces the risks (complete redundancy of security actions). In any case, if one or both radio links are jammed or cut out, tension stops automatically. The line slackens off and you just have to glide down to land. Other securities have been added, we explain them in the answers to the following questions.
This is the heart of the problem of remote controlled towing! This very small risk must not be neglected. Electronics and software can fail, a servomotor can also have an internal failure that would make its motion uncontrollable.This technological command chain is like the winchman's hand. A winchman is rarely heavy-handed and when it happens he realizes it quickly... So we had to limit these risks and the consequences as much as possible.
To go through all the securities available with Aviawinch, let's imagine a very bad scenario possible when several failures add further to a lack of appropriate reactions from the pilot...
You are on the ground, tied to the line, ready to take off, the engine is running, the pre-tension is over. You have just enabled the level two of "TCS" (patented Tension Control System) to start the taking off stage. Suddenly the servomotor of acceleration fails and tension starts pulling you...
Several securities then come into play...
1 - The problem obviously comes from the servomotor itself due to an electrical or mechanical malfunction, therefore the software part of ACS (patented Acceleration Control System) that limits the displacement speed of the servomotor does not work.
2 - The mechanical part of ACS in the form of independent hydraulic cylinder fortunately reacts and mechanically limits the brutal acceleration which becomes progressive but, for all that, does not stop...
3 - The software part of the TCS could have stopped the tension when finding, through a position sensor, that the servomotor is not on zero as it should be because you did not press the acceleration trigger.
Bad luck, surprised by the unexpected starting of the tension you have clutched the acceleration trigger tensely... Finally you release the acceleration trigger.. but surprinsingly the tension doesn't stop... To crown it all, this software part of the TCS has just broken down... bad scenario, you had been warned!
The TCS has also a mechanical part, not affected by electronics failure, that remains active and controls the tension effect by limiting it to its maximum tension of the taking off stage, that is to say around 40 kg (parametrizable for tandem flight).
4 - During this first second of inadvertent tension, you could have thought of releasing with one finger but you forgot...
5 - you could also have thought of using a finger of the other hand to switch off the engine by pressing a very easily reachable button on one of the handles. The command would have been transmitted by the two transmitters but you didn't think of that either...
6 - Really it is not your day... another second has gone by and with this 40 kg tension you stumble, the wing in a jumble behind you... Now your brain tells you to release and switch off the engine, you even remember that you have a red handle easily reachable on the shoulder to cut the line, switch off the engine and even release (all that in one single move!) but ...you remain passive...
7 - On the third second following the beginning of the incident, sensing that the integrity button placed on one of the handles has not been pressed and after setting off its new alarm, the HCS (patented Human reaction Control System) activates the stopping of the engine... You are a bit groggy but you're ok...
6bis - Let'go back at the end of step 5. With this 40 kg tension, your well-positioned wing has got filled out and you have now left the ground. You are progressively getting higher... You think that after all you fly, you were ready for that...
7bis - Two seconds have now elapsed since the beginning of the incident... You think it would be better to regain control... you finally press the stop button... Nothing happens... Really it is not your day: a malfunction of some element in the chain of commands has occurred...
On the third second following the beginning of the incident, you finally think to simply release with just one finger... At the same time, with no integrity information from you, the HCS activates the stopping of the engine... You are 10 metres high, you get down and land right in front of you... All is fine...
8 - You take a deep breath thinking it could have been worse without all those redundant securities that activate themselves. You also realize that you have not been the best "captain" possible... You contact us annoyed about these malfunctions but at the same time grateful for this big work on security. You legitimately ask us to activate the warranty. That will not stop you, considering the incredible liberty that Aviawinch gives you!
No, it is even rather easy because you are guided by a charming female voice telling you what can be a problem or reminding you of the actions taking place. Most securities activate themselves alone. Handles are ergonomical and you can put them away by rolling them into an adjusted pocket of the cockpit after releasing and rewinding of the line.
The Aviawinch releaser has been specially designed to release with a finger under heavy load without any important effort. It is based on the 3-ring system that divides by 100 the necessary force to release regarding the force of the tension exerted by the line. This kind of system has been used for decades in parachuting to release the main wing. However you can still release by hand in the usual way by pulling a cord/handle or, in case of emergency, by pulling the emergency red handle placed on your shoulder. We even supply you with a safety knife (skydiving type) so that it will always be possible to manage to extricate yourself from the line by cutting it or cutting the straps of the releaser (unheard of and really extreme case!)
That is not very nice from him/her. That being said, if you wish to share a winch and go cross-country running, you can then acquire a second (or as many as you like) complete transmission and control system including cockpit, handles, releasing device and of course the two built-in transmitters.
It is like trying to have your cake and eat it... but we are all a little bit like that... Towing is normally practiced in country areas where thefts are less frequent. However remoteness can represent a risk that we have tried to limit:
Aviawinch is delivered with an antitheft device for the hitching
It works when the hood is locked. Only the mast with the antennas and the line are visible.
Option 1: antitheft wheel-clamp for trailer (additional deterrent)
Option 2: installing of an antitheft self-fed and hidden beacon (GSM/GPS)
The motorbike is just an all-terrain vehicle that allows you to have flights following another easily and quickly. We also enjoy motorbike rides... so all we like is on the trailer... but all the other means are also possible... on foot, mountain bike, etc. It is also very common to undo the hitching of the winch, to install the wheel wedges and the retractable jaws to be able to use your vehicle to unwind the line.
With the usual towing practise, there are other types of risks: the winchman must be trusted... He is 1 km away and does not always understand well what the taking off assistant tells him on the radio (if there is one and if he expresses himself clearly). The winchman won't feel the gust of wind that blows at the exact moment of taking off, he will winch too hard or not enough... The starter might not see the knot that you have in the suspending lines or the twist in the brake that you see too late and that makes you feel nervous... etc.
When being alone you will be able to decide by the second on the right time for taking off and on a possible stop if detecting a problem. Thanks to the trigger, you will be able to feel and adjust the exact tension effect you need for taking off, which even enables very good pilots to enjoy flying nearly touching the ground for as in the film "Just you & Aviawinch" (for experts only and to practise with moderation)
When you take off with a paramotor with 30 kg and a propeller rotating on your back, you concentrate and avoid accelerating brutally... With Aviawinch it is the same thing but much easier... because you don't have 30 kg on your back, there is no reverse torque, you are tugged and not pushed, you have a mechanical and software limiter of brutal acceleration and an automatic torque limiter during the taking off stage... In fact you won't have a hard time taking off... What will be really difficult is to stop flying and get home or to the office on time... ;-)
For all those years when we have been working on Aviawinch, we went through all the potential risks and have developed original and efficient solutions. However as with any product depending on technology and piloting actions from the user, there will always remain a few risks to which you will have to react quickly.
A good piloting level, a minimum half day training in towing, a mental and simulated repetition of the security actions before each flight, regular practice and a good maintenance of the winch will be essential to greatly limit those risks.
The price of the winch can be justified by several factors:
Very advanced technical quality: high costs in equipment and human ressources (mechanics, electronics, computer development, assembling)
High insurance costs and regulation constraints (EC norms, etc)
Amortization for years of Research & Developments
Specific and limited market so few economies of scale
The price must really be relativized. It is less or equivalent as most multi-axis ultralight aircraft, gyrocopter or even pendular. For a private individual it's a big present but for a firm, a free flight school, a club or even a group of friends it is in fact a reasonable price regarding the advanced technology and incredible possibilities and liberty it offers.
Yes, you could be insured by taking out a classical insurance contract for free flying pilot with our partner SAAM Insurance (Verspieren group). The new way of towing with the Aviawinch has been included in their contracts without additional cost.