Right from Scratch DIY

I agree, but I am curious why you think an electric paramotor is notably more risk than a gas solution? Are you expecting a higher rate of failure, or are you thinking about battery life, or just scary things the wing can do in unknown/variable wind conditions, or…?

the motors could be isolated which would make this safer than any single prop plane in terms of a motor out. Some of the islands have ripping Venturi effect between them. I skydove in the windiest place in all the islands and the winds were rarely under 30mph past 8am. This would need to be done just before sunrise, and with flares and a little inflatable raft. I’d just get stuff that I could bail out with and use a round into the water if something went wrong. The gear is gone in the event of a water landing. A heli won’t cherry pick the rig I don’t think. But with proper safety equipment a rescue is possible. Boats have radios designed for this sort of thing. I think it would be best to call the coast guard and give them a heads up. But I don’t see why not. With everything designed specifically for this I’d say it’s way safer than any single prop engine. That is IF an engine out could still get you there with isolated motors/batteries.

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@fredrick 00
With a gas engine you can fly 2,5 to 3 hours with elektric 45 to 60 minutes.

If your energy is used you will have to land .

There will be no upwinds and not much thermal action over water.

There are trade winds in your aerea as well and high waves…

There are some things to avoid when flying…

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Makes sense to me, and on a well designed and tested system which has a water sealed electrical system (to prevent salt water corrosion), my limited knowledge on the topics involved agrees… If you could wrangle a support team up, you could have contacts on your departing and arriving islands set to contact rescue services if you lose contact for a specified amount of time. (Which wouldn’t be very long)… I think you’d want an EPIRB with you as a raft between the islands is a pretty small target, but at that range, an EPIRB would probably be pretty effective. I’d also let the coast guard know as you mentioned.
With our current technology, you could even have people e-monitor you where you have cellular reception. I know between Big Island and Maui, there’s only a very short span where cellular cuts out at higher altitudes, but seems to remain functional at about 50’. (Per watching a guy fly his 4G drone over)
If you put together all the equipment for it, you should swing by one of the outrigger canoe clubs, and see if they’re interested in doing an inter-island voyage to coincide with your flight… then they could act as a safety boat for you, you could spot for them, and you could both get a lot of publicity by filming from air and water. Would want to wait until they were 1/3 of the way between islands or so to take off I would expect… depending on currents, winds at cruising altitude and all of course… but could be a fun PR stunt.
If you really have a sizeable budget, the SS/Li hybrid batteries might be something worthwhile to you. They advertise over twice the energy density of standard LiPo batteries, and are primarily manufactured using existing lithium battery production facilities making the price very possibly reasonable.
Not nearly as cool as Hydrogen… Lithium is toxic with a horrible mining process, and human rights violations associated with it’s mining… but the only H2 solution which seems remotely economical at this time would be a combustion engine… maybe a series of jets like the ones the jetpack guys use. The fuel could be renewable sourced which would be great, and with a bunch of carbon fiber canisters, and H2 weighing virtually nothing, you could carry almost unlimited fuel… without proper planning you would burn lines in a heartbeat, but the reduced intake/exhaust surface area might make it overall safer than a standard rotor setup.
(EDIT: my mistake; you can supplement the gas easily… a full conversion is trickier.) You can also convert a gas engine to run directly off H2 with very little modification. If you pump H2 in the air intake, it should run without gas supplied in most, if not all, instances. I’d want a pretty solid mechanic to listen to and play with the engine for a bit before I’d trust it… but gasoline is low in oil, so my main concern would be that the mix be correct so you don’t blow your engine up. H2 combustion engines are notably safer than gas engines too… no residual fuel to keep a fire going after any initial problem, and H2 will generally blow out it’s own fire.
You wouldn’t get the “silent” glide… but you could put an electric start on it, and still be much lighter than a standard petrol setup. Even without electric start, I would expect H2 to start far easier due to the dispersion/surface area of the explosive element making every combustion a complete combustion. Being an H2 buff, you probably already read about gas having an energy density of only 45MJ/Kg whereas H2 is 120-140MJ/Kg, making the cylinder you store it in the only real weight to consider. Gasoline engines have a thermal efficiency of less than 40% (generally less than 30%), so that’s about 14MJ/Kg for gas… H2 would probably be a bit more efficient, but still similar for about 40MJ/Kg.
(Assuming I made no errors)
Electric’s a bit different, but if my calculations are correct, I’m seeing LiPo as having an energy density of about 0.7. (192W/kg based off the weight and capacity of the Bonka)
I’ve been thinking about rigging a paraglider to a recumbent bicycle so I can para/bike/camp my way up through indonesia for a journey hopefully ending in Tibet, to continue to Jerusalem if I felt up for it still (Following a historical martial arts path)… that would be a while down the road for me yet, as once I have a rig that could be capable, I’ll have to devise how to make it practical. My current plan is to hire boats or airlines to get across the major water stretches… but I have been thinking about if I could make the recumbent water proof, and extremely buoyant, landing in the water in and of itself might not be a deal breaker for me. Wing’d be done at that point though… though I could rig it as a sail and it’d dry out if I could figure out counter-ballast… if I were an anime character, I’d just go into submarine mode at that point though.

Gotcha. Makes sense… Yeah, the fuel issue will definitely need to be resolved… For something like that, I’d want to end my flight with at least 1/3 of my fuel remaining, and during the crossing (particularly into a headwind), constantly be evaluating if the fuel last as expected, and where my point of no return is. If you do those things, however, the fuel supply issue is really just a matter of carrying enough fuel… which may not be reasonable with LiPo, but that’s another topic :wink:
Trade winds are consistent winds from a given direction… would that not be an advantage? If he goes from Oahu to Big Island, it would be a bit of a headwind from the left side which may not be ideal, but with enough fuel it’s easy to adjust right? Trade winds are usually about 15MPH, rarely higher, though what they do as they whip around the islands is another matter.
High waves I would only see as a concern if you had to make a water landing, and then, their primary issue is if there are also high winds, or just because they make it harder for the coast guard to find you when you’re in the trough. In high winds, they’d be breakers and would make life on the raft waiting for the coast guard pretty lively… but I don’t think you’d want to make the crossings during high winds anyway, and the weather systems in Hawaii are fairly predictable. (We either see it coming across the ocean, or it’s a localized system)
The other things are always a very real concern… I don’t think anyone could do this crossing without a thorough emergency backup plan and be remotely safe… as it is, Hawaiian residents tend to be a bit more willing to risk their lives than mainlanders… so long as a person is fully aware of and understands the risk and prepares as best they can, however, it tends to work out for the best.
I know a number of people who have kayaked from Big Island to Maui in plastic kayaks with plastic pins holding part of it together… I think the risk factor is fairly comparable, particularly if he has redundant propulsion, and coordinates and prepares as he mentioned.
I think it’d definitely be a feat… I’d watch at least an hour of it on youtube for sure :wink:

@fredrick 00
1.) Great idea to travel with the paramotor
Becouse especial the open ppg is very light and transportable.
The downside here ist that there is no cance to transport bonka litium batteries in any plane. You can search here the comments many users have made.

  1. Please read :

My opinion: when you land in water more than 1 meter deep you will die.

Even if exact where you hit the ocean are some divers to cut your lines and give you air to breath i would not bet that you survive.

Becouse all your gear is pulling you down in the same second like you have stones mounted on you, all the lines can easily be in the way, all the canopywhich is airtight and prevent you from seeing something and breathing.

I think when you are not able to jump from your equipment to be free bevore you hit the ocean there is no chance at all to survive longer than you can hold your breath.

And if your batterie gets a little defect at your crash you have all the selfignitionproblems of this batteries they could burn underwater while sinking and selfignighting one after another…

So all your safetyequipment will sink or burn or be in the way to free yourself from the sinking stuff and lines.

Cant imagine how anyone would safely survive under any circumstances the first 6 minutes after watercontact.

All the best

Flotation devices for both yourself and motor might buy you enough time to cut your gear free and survive until you die of exposure or are rescued. SIV courses happen over water and people pull reserve and hit the water when the inevitable happens. There are boats standing by so it’s just a learning moment not the end.

@grejen 711
Siv trainings are mostly or always without ppg motors as they would be damaged when they get under water, not sure if any trainer would like to be responsible and allow you to use a litium powered ppg in his course where it is expected to land in the water if something does not work.
Often people test there rescuecanopy in such a course to simulate what it will feel to have 2 canopies open at 1 time.
A flotationdevice for the motor and batterysystem is hard to install in a way that the on the back mounted motor and the heavy batteries does not float over you and does turn you face down all the time.If you lie on the water you will float - think about the weight of 2, 4 or normaly 6 bonkas, they will not float at all.
When you mount 1 device to the motor and a seperat one to you expect that you will sink about 1 sec. Like a stone bevore they fire and than you will go up quick direct into all lines and 50 m2 of glider and parachute with no rescue teams waiting for you on the ocean.Not to forget having maybe an already underwaterburning battery mounted on your back at that moment.Even if you invent a way that you and your motor are floating face up in all circumstances you will float direct under 1 or 2 canopies which also will not help to survive longer than you can hold your breath even in a bestcasesecenario with no wind no waves and rescueboats and divers being prepared.I think if you plan to jump with your car from a driving ferry into the ocean and plan how to survive that stunt becouse you call the coastguard before you start your car is more save than those scenarios.

Why couldn’t you just bail out with a round parachute and all safety equipment strapped to your chest/lap in the event of a unavoidable water landing? It’s like any other flight, plan for the worst case. If anyone died because of a water landing it’s not because they flew over water. It’s because they weren’t prepared for the worst case scenario.

Finally found a solution:

With canopy it looks way different:



Becouse there is no cutawaysystem

And freefallingsequence with motor and equipment seems to be no good idea.

I’m talking about bailing out, not cutting away. Again observing the first rule of flying: Always plan for the worst case. If I were to fly over water I’d rather not use a paraglider. A trike with a good rigid wing is best for reliability sake.

  1. A simple bucket seat with a single point seatbelt release could be used to make it easier to bail out. I’d use a static line for this. Bailing out would take seconds and deployment would be almost instantaneous.

  2. Rigid wings are far less susceptible to collapsing in turbulent conditions.

  3. The payload can be increased with a trike allowing for there to be way more batteries.

It would not be easy to prepare to fly over water but done properly I think it’s much safer than flying a small single engine aircraft over the same 20 mile stretch. Wired properly the unit could potentially fly on just 3 of the 4 motors in the event one went out.

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@ bodewah

Understand your ideas,

Just thought in any violent much g rotating situation it could be challanging to bail out without cutaway handle…

I had the opinion that to throw a reserve in a way that it does not collide with the other stuff allone would be inough stress, but if you would manage to bail out in a save hight and get away far as possible from all other equipment would be a good joice.

And not be trained in skydiving people dont like to bail out or cutaway from any m2 of canopy, even with static line.

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love the audio selection on Gift wrapped tumbling. first song “do you really want to live for ever, forever young” acro to slo mo fall… second song after reserve deploys… “im bullet proof nothing to loose… I am titanium”

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@fredrick 00

Solution refuel in flight

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Haha, so epic… I was gonna post this in here today! :wink:
I was thinking you could totally do that with a battery pack… but it’s a lot heavier, so I might want to actually hook it with a beaner on a short rope so my foot’s only guiding it. You’d probably need to gain altitude, then hook up the second battery, then flip the switch from one battery bank to the other, then you could come back and drop off the depleted battery pack (or fly with it, and you could flip the battery switch back to drain the last of it’s juice as needed)
Maybe that’s the future of LiPo paragliding… launch w/ 5 minutes of battery life, pick up another 2 hours/100lbs of batteries once you’re already in the air :wink:

I’m a sailor and a dive instructor, and getting sucked under water by wrapped lines attached to your PPG or EPPG would be pretty terrifying, and quite dangerous. I’ve had anchor lines go taught as the boat reaches the end of the line, and gotten dragged off by a high tension kink, and other similar situations… anyone without training or extensive water experience/comfort would definitely wrap themselves up in the lines and drown if they start wrapped in lines, and aren’t free if they don’t have flotation… anyone with training would have a chance of a narrow escape. (Main reason training matters is staying calm and dealing with issues in an order that helps… like free your straps before trying to swim away… I’ve had divers get a straight taught fishing line snagged on their tank, then proceed to roll it around themselves until they were trussed up and helpless) A high G entry where you couldn’t untangle yourself before hitting the water would be particularly devastating. (whip-lash, air knocked out of lungs, dazed, head possibly shoved back to hit something hard…) If it’s just a power out landing, however, you could unstrap before hitting the water, and then the trick will be to keep your canopy from overshooting you when you land so that it doesn’t end up infront/across you dragging you down. If you get gift-wrapped in the water attached to a sinking motor, that’d be it… but if you’re over water, you should really have flotation.
The concern about electric shock and fire is overrated, I believe. If the batteries burn up, they’re still back there in the water, so the fire wouldn’t spread, and the flotation is in the front. (So the pilots not underwater) The batteries (in salt water) would short instantly which could create a very high volt/amp discharge, but would be fairly short followed by a minimal leaching discharge. In the ocean, that current will travel every direction, and your body would be no more grounded than anything else, so it wouldn’t be a focused jolt like if you touched a negative and positive wire.
Different people also have different resistances to electricity. (The more resistance you have, the more dangerous it is for you :wink: I, for example, have touched 110 numerous times, and 220, all while barefoot, the 220 while on a ladder, and I only ever experience a tingling effect. (Tinging on to numbing if I maintain contact) I’m pretty quick about breaking the connection, and don’t tempt fate… but so far, in over half a dozen encounters with 110, it’s only mildly alarming for me. (Apply it closer to my heart or spine for a party though :wink:
I would be really interested to see some tests where they toss a high A/V LiPo pack into salt water, and measure the current…
If you water sealed your battery and the contacts (which it already is right?), and then wired that to a fuse before it feeds anything else, then a short would only occur momentarily, and would be virtually no risk to anyone. The builds which are used probably have that or an identical mechanism built in already I would imagine.

@frederick 00
Did you see the 3 videos from the link waterlanding what would happen?

I think you are right electric shock is not the problem but burning with a lot of toxic smoke when you are trying to breath to live is not ideal, also the filmed reactions of the damaged lithiumnatteries under water are very violent, if a very small battery can selfignight to a glassmelting fire in the wather i think big ones like the bonkas used here are not less dangerous if damaged and under water.

Yeah… pretty fun stuff! :wink: Hopefully if you have to do a water landing it’s because of something manageable like a motor out… if you have to do a water landing gift wrapped, then the dangers are pretty notable w/ or without motor… hopefully you land conscious and don’t die on impact!
The smoke would suck, but you’d either be above water breathing (which is good at that point), or the smoke’s the least of your worries. Coughing right before you get sucked under again would be regrettable… but if you’re not getting sucked under, hopefully you can untangle yourself and get free of the smoke. From the videos I found on lithium hazards, fire, and salt water discharge, the smoke/steam did not seem to even be a minor irritant on the small scale batteries they used… makes me think it’s not a bad enough toxin that it would be much worse than any rubber fire or the like. (Short term anyway.) Good news is, the wind will probably take your canopy down-wind of you turning your paramotor so the smoke is also down-wind… once you get free enough that your not right over it. I’m curious as to which lithium fire video you watched / are referring to? Were they able to create a fire without severely sabotaging the battery packaging first?
WRT fire, I’m looking at the openPPG, and the batteries are mounted a bit closer to your back than I had envisioned… but, they are on the other side of a good deal of fabric and frame… the frame should slow down the time it takes any fabric to catch, particularly in the water, and the water would help disperse the heat. I probably wouldn’t volunteer to be gift wrapped to that, but if you’re not strapped in, it wouldn’t be hard to create some space… and, the fire will only happen if the actual battery components are exposed to the water, or if a short manages to not burn the wire up first… a fuse would eliminate the second risk, and well sealed batteries would notably reduce the first.
I’d love to do some salt water crash tests to see how it all pans out, but probably out of the budget to do more than 1 accidentally :wink: $500 to throw a battery pack in salt water is probably more than I’m willing to spend unless I’m actually planning a water crossing with them. (By the time I plan to do a water crossing, I expect dual carbon batteries will be the new norm which will eliminate many of the safety hazards mentioned)… but they do use LiPo in boats and subs with minimal protections in place, and I’m not familiar with horror stories from that.

@ fredrick 00 [quote=“fredrick00, post:50, topic:207”]
Were they able to create a fire without severely sabotaging the battery packaging first?


Here you see how batteries are build

Only if they get too hot at charge or discarge or if they have an internal short (which is also a fast discharge) they can catch fire.

As you see in the video of the factory or the waterexperiment the lithium layer is on a thin sheet.

As the batteries need cooling you can only protect them with a ventilated housing.

If you check the celltemperatur and watch out to not let them overheat nothing should ever happen as long as there is no shortage in the system or a mechanical damage at the pack.

If you would land at a resevecanoppy on a hard surface you could eventual damage a battery.

The soft packs are not used for rc buggies becouse there are always shocks and vibrations.

Solution could be a cutaway for the batteries which also have to disconnect the cables from the system and let go all batteries away.
maybe 2 stage release of the pack - first drop to 7 meter webbing hanging under you for safe landing as the military troopers use for landing theyr heavy gear under a canopy and 2. Stage if necessery releae coplete via handle or just cut the webbing and drop it comlete.

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