Pipistrel introduces electric trainer

[riggerrob 558]

Pipistrel just introduced an electric-powered trainer. The new WATTsUP has two seats an a 90 minute endurance on batteries. Most flying lessons only last 50 or 60 before the student pilot is exhausted. Batteries can be recharged in an hour or replaced much quicker. They are marketing the trainer to schools with noise restrictions (e.g. surrounded by housing).

How long before we get electric-powered jump-planes?
My guess is - within 5 years - some manufacturer (e. g. Gippsland Airvan) will offer an electric-powered airplane for sight-seeing tours that will be perfect for skydiving.
Within the next 5 years, I also expect electric conversion kits for kit planes, followed a few years later for Cessna, Diamond, Piper, etc trainers.
Bets?

[dthames 0]

Since jump planes haul weight to altitude, "work" is a huge part of the endeavor.

Jet Fuel, 43 MegaJoules per Kilogram
Battery, less then 1

http://en.wikipedia.org/wiki/Energy_density


Lots of luck jumping on battery power. Hydrojet powered fuel cell,......maybe someday.

Instructor quote, “What's weird is that you're older than my dad!”

[riggerrob 558]

Your critique is valid for long-range airplanes, but becomes less relevant for short-range airplanes. You are ignoring the rise in petroleum costs versus the decline in battery costs. For a short-range (less than 1 hour) fuel weigh is less and less important. Remember that most petroleum-powered jump-planes refuel every hour or so. If they can re-charge several sets of batteries during (less expensive) off-peak hours, electricity might be less expensive. In the long run they might find it more cost effective to cover their hangar roof with solar panels, then sell excess electricity to the town Monday through Friday.
The greatest challenge is conversion cost. Remember that most DZOs only install more powerful engines after they have worn out the stock engine.
Now we are speculating about how soon some other niche market (e.g. sight-seeing or crop-dusting) will develop an electric conversion that is cost-effective for jump-planes.
There are a dozen different ways to swing the cost differential as petroleum increases in cost while electric costs remain comparatively flat.

[theplummeter 14]

While long range aircraft will likely need the high energy density fuel for some time, electricity could more quickly become a viable option for smaller aircraft on shorter flights. I would also think that an electric motor is not likely to lose torque in thinner air like a combustion engine is so maybe it could be an ideal setup for jumping. Changeable battery banks at a charging station would the transition seamless, and the electric motors could come to a full stop after the climb, or the windmilling propeller(s) could be used as a source for partial recharging during descents. I think it's all a matter of battery technology versus weight.

[riggerrob 558]

, or the windmilling propeller(s) could be used as a source for partial recharging during descents. I think it's all a matter of battery technology versus weight.

...........................................................................

The windmilling propeller could also be used as a dive brake. If the prop governor was adjusted correctly, it would make it impossible for a new pilot to exceed the maximum dive speed (Vne).

[dthames 0]

The high power for lifting is developed from a turboprop regardless of how much or how little fuel you carry. The power output does not greatly change the dead weight (within some normal range of power)

But when you need more power for electric motors and you do that with batteries, then you are now carrying more weight just to get more power, which means you need yet more power for the extra weight, or less cargo.......degrading spiral.

If you wanted to climb at 200 feet per minute, it might be a lot different story than say 800 feet per minute.

Instructor quote, “What's weird is that you're older than my dad!”

[riggerrob 558]

Sorry, but I am not following your logic.

Let's start with with your turboprop analogy. Turboprop power is limited to the "maximum continuous power" ("climb power" in skydiver parlance) stamped on the engine data plate by the engine manufacturer. As long as you have sufficient fuel flow (measured in "pounds or gallons per hour") your turboprop engine will develop maximum continuous horsepower.
At risk of over-simplification: a Twin Otter gets roughly 4 hours flying time out of the 4 fuel tanks in it's belly. If you only fill one belly tank, your Twin Otter will generate "maximum continuous power" for only 1 hour.

When we transfer that logic to an electric-powered airplane, the "maximum continuous power" is limited by the size of the electric motor. Any single battery should be able to drive that electric motor at "maximum continuous power."
Now let's pretend that our hypothetical electric airplane was originally designed to fly 4 hour sight-seeing tours with 4 batteries. If you leave 3 batteries on the ground, you can still develop "maximum continuous power" but only for one hour.
Then the greedy DZO can replace the weight of the 3 missing batteries with more paying skydivers.
So an electric-powered jump-plane should be able to generate the same "maximum continuous power" as a turboprop jump-plane. The only variable is how many hours it can fly. Endurance is determined by how many fuel tanks you fill or how many batteries you install.

[billvon 2,383]

Let's see:

Let's say you want an aircraft that can bring six people (say 600 kilograms of people + 400 kilograms of airplane) to 3500 meters. You need about 10 kilowatt-hours of energy to do that for just the potential energy requirement. Let's double that to account for drag and inefficiency; now you're at 20 kilowatt-hours.

A Leaf battery is 24 kilowatt-hours, weighs 200 kilograms and costs about $5500. Thus it weighs about what a C206 engine weighs, and costs about 1/4 of what a rebuilt IO-470 costs.

So it's roughly doable, at least for small low traffic DZ's. The simplicity of the drive (fixed propeller, one moving part in the motor, off the shelf inverter) would improve reliability and save weight. However you'd only get one ride to altitude per charge, so you'd have to either fast charge (about half an hour) or swap packs. You'd get roughly 500 full altitude loads per battery pack, after which you'd have to "retire" it to hop and pops.

[DrDom 0]

The biggest problem will be the same as most electric cars (I have a tesla so am used to this): RECHARGE TIME. Unless you can hot swap batteries you really will need more time between jumps or more planes. The regenerative braking is a tiny amount of endurance in my car and would imagine the same in a plane.

If you could "supercharger" rig a plane it would be useful.

Filling a plane still lakes less time than a charge.

with that in mind, if there were a viable small electric plane I'd buy one and let you guys jump it! I'm working on a light enough electric paramotor...

You are not the contents of your wallet.

[GalFisk 0]

Three years later, and the Tesla model 3 battery pack would give us roughly 36 kWh at 200 kg weight, an improvement of 50% over the Nissan Leaf pack from 2013.
The wholesale price is $150 per kWh, or $5400 for our 200 kg pack. They are rated at 3000 charge cycles to 80% of nominal capacity, and at 80% we can still haul a full load to altitude. Not charging them to 100% will both speed up charging and prolong battery life. Swappable batteries are the only realistic solution for now, maybe forever.

I would love for our small weekend DZ to cover the hangar roof with solar panels and charge 3-4 sets of plane batteries during the week. The excess (if any, a very rough calculation shows there will be plenty most of the year) could be sold or stuffed into cheap storage batteries.

I used to drive a Nissan Leaf 24 kWh, and it could be charged to 80% in about 20 minutes (the last 20% also took 20 minutes). The charging characteristics are better for newer batteries. It would require several beefy (expensive) chargers, and unless we can make and store our own power, quite a beefy and expensive power line too.

I hope the first electric DZ is less than five years out. Electric cars are at the tipping point right now when it comes to TCO. Electric airplanes are behind, but not that far. I hope that some time in the future, flying electric will be so inexpensive that jup ticket price actually goes down.

[dthames 0]

GalFisk

Three years later, and the Tesla model 3 battery pack would give us roughly 36 kWh at 200 kg weight, an improvement of 50% over the Nissan Leaf pack from 2013.
The wholesale price is $150 per kWh, or $5400 for our 200 kg pack. They are rated at 3000 charge cycles to 80% of nominal capacity, and at 80% we can still haul a full load to altitude. Not charging them to 100% will both speed up charging and prolong battery life. Swappable batteries are the only realistic solution for now, maybe forever.

I would love for our small weekend DZ to cover the hangar roof with solar panels and charge 3-4 sets of plane batteries during the week. The excess (if any, a very rough calculation shows there will be plenty most of the year) could be sold or stuffed into cheap storage batteries.

I used to drive a Nissan Leaf 24 kWh, and it could be charged to 80% in about 20 minutes (the last 20% also took 20 minutes). The charging characteristics are better for newer batteries. It would require several beefy (expensive) chargers, and unless we can make and store our own power, quite a beefy and expensive power line too.

I hope the first electric DZ is less than five years out. Electric cars are at the tipping point right now when it comes to TCO. Electric airplanes are behind, but not that far. I hope that some time in the future, flying electric will be so inexpensive that jup ticket price actually goes down.

The 36 KWH battery could deliver (in theory) 150 HP for about 19-1/2 minutes. That is not accounting for the heat (I^R) loses in the battery. Double the battery size and you can double the HP to 300 HP. Now you are carrying/lifting 200 kg more, the weight of 2 jumpers.

Jump planes do a lot more "work" (physics term) than a plane that climbs and flies at a cruise attitude.

Most 150 HP jump planes are pretty slow to climb.

Instructor quote, “What's weird is that you're older than my dad!”

[RMURRAY 1]

from wikipedia (260kW is 348hp)....but yes the battery/fuel cell issue...
330LE
The Extra 330LE is a one-seat aircraft powered by an electric engine made by Siemens, delivering 260 kW, for 50 kg. On Thursday, March 23, 2017, the Extra 330LE set two new speed records, said Siemens : "At the Dinslaken Schwarze Heide airfield in Germany, the electric aircraft reached a top speed of around 340 kilometers per hour (km/h) over a distance of three kilometers. On Friday, March 24, 2017, the Extra 330LE gave another premiere performance by becoming the world's first electric aircraft to tow a glider into the sky". [5]

[dthames 0]

RMURRAY

from wikipedia (260kW is 348hp)....but yes the battery/fuel cell issue...
330LE
The Extra 330LE is a one-seat aircraft powered by an electric engine made by Siemens, delivering 260 kW, for 50 kg. On Thursday, March 23, 2017, the Extra 330LE set two new speed records, said Siemens : "At the Dinslaken Schwarze Heide airfield in Germany, the electric aircraft reached a top speed of around 340 kilometers per hour (km/h) over a distance of three kilometers. On Friday, March 24, 2017, the Extra 330LE gave another premiere performance by becoming the world's first electric aircraft to tow a glider into the sky". [5]

Do you know how long they can sustain that 260kw output?

Instructor quote, “What's weird is that you're older than my dad!”

[RMURRAY 1]

I do not but it can climb also...

https://www.siemens.com/press/en/feature/2015/corporate/2015-03-electromotor.php?content[]=Corp

translates to 2264 ft per min

edit...fascinating stuff!

https://www.youtube.com/watch?v=Xe1g1JrRRkY

[tkhayes 124]

true. There is not much more efficient way to get work done today than burning fossil fuels inside large cubic-inch-displacement engines, at least in the mere HP versus size....

I learned that a long time ago building cars, trying to make small engines do things they were never designed to do and wondering why they constantly burn up and wear out. Nothing like simple cubic displacement to increase power....

yes we will come up with new technologies. I doubt batteries will be flying airplanes en masse anytime soon,

[riggerrob 558]

Battery/electric planes will start with short-haul operations: aerobatics, glider-towing, self-launching gliders, flying schools, short-hop commuters, parachute schools, flying schools, etc.

[billvon 2,383]

I think the progression will be, as it has been in the past:

1) Schools buy electric aircraft as primary trainers. Their simplicity and low maintenance/operating costs will appeal to them - and range/turnaround time isn't as important.

2) Pilots trained on electric aircraft will buy them for themselves because they are used to them.

3) Used EA's come onto the market. Once they get cheap enough, a few single-cessna DZ's buy them as a second aircraft to put up static lines on weekends.

4) Larger DZ's start buying them and upgrading them for better performance.

All this will take decades.

[cpoxon 0]

Hybrid Electric Aircraft Propulsion Case Study for Skydiving Mission

Quote

Abstract

This paper describes a case study for applying innovative architectures related to electrified propulsion for aircraft. Electric and hybrid electric propulsion for aircraft has gained widespread and significant attention over the past decade. The driver for industry interest has principally been the need to reduce emissions of combustion engine exhaust products and noise, but increasingly studies revealed potential for overall improvement in energy efficiency and mission flexibility of new aircraft types. In this work, a conceptual new type for a skydiver lift mission aircraft is examined. The opportunities which electric hybridisation offers for this role is analysed in comparison with conventional legacy type propulsion systems. For a conventional commercial skydiving mission, an all-electric propulsion system is shown as viable, and a hybrid-electric system is shown to reduce aircraft fuel costs and CO2 emissions whilst maintaining conventional aero-engine operational benefits. The new paradigm for aircraft development which hybrid electric propulsion enables has highlighted significant issues with aircraft certification practices as they exist today. The advancement of aircraft design and production to harness the value of new propulsion systems may require adaption and development of certification standards to cater for these new technologies

Skydiving Fatalities - Cease not to learn 'til thou cease to live

[riggerrob 558]

Dear copoxon,
Thanks for sharing that fascinating study.

I like the way the cabin is wider than most current jump planes.

I especially like the way the cabin is deeper than current jump planes WITH under-belly cargo-panniers. Taller cabins make standing exits more "natural." Bigger cabins make loading quicker, making thier proposed airplane more attractive to courier companies. Taller cabins could hold LD3 containers to reduce manual labour and speed loading.

Hint: courier companies bought half of the new Cessna Caravans that eventually trickled-down to become jump-planes.

[johnhking1 70]

billvon

I think the progression will be, as it has been in the past:

1) Schools buy electric aircraft as primary trainers. Their simplicity and low maintenance/operating costs will appeal to them - and range/turnaround time isn't as important.

2) Pilots trained on electric aircraft will buy them for themselves because they are used to them.

3) Used EA's come onto the market. Once they get cheap enough, a few single-cessna DZ's buy them as a second aircraft to put up static lines on weekends.

4) Larger DZ's start buying them and upgrading them for better performance.

All this will take decades.

If you consider the average of jump plane (some Cessna 182's 60 years old) and DZ's are likely the last stop on the way to the salvage yard, If they had electric planes flying tomorrow, it could be 40, 50, 60? years before they show up at a DZ

[riggerrob 558]

Impending shortages of 100 octane, low lead aviation gasoline will accelerate retirement of older, piston-pounding jump-planes. In many parts of Africa and the Arctic, av gas is either frightfully expensive or impossible to buy.
As for the rest of general aviation ..... it is only a question of "when?" My guess is over the next 20 years. 40 years from now, not even warbirds will be able to afford av gas, because refineries will have stopped "finishing" av gas.
The first to go will be high-compression, turbo-charged, 6-cylinder engines that require higher octane fuel.
A couple of companies are developing 300 horsepower diesels to replace the Continental O-470 and TIO-520 engines currently powering Cessna 206 jump planes. Development is slow, but there are thousands of privately-owned Cessna's, Mooneys, Pipers, Beechcraft, etc. that will need to convert engines over the next 20 years.

[DBCOOPER 1]

182's and such are very low compression and were designed for 80 octane. They run fine on regular auto gas without the addition of alcohol. These work horses are like cars in Cuba,they will be around after we're gone. Stop by Oshkosh some time and see how many "vintage" aircraft are still flying. The problem with developing lead free avgas is the high compression engines in more modern planes.The lead boost the anti knock properties and really isn't necessary for the lower compression engines, but they are looking for a one fuel replacement for the entire fleet.The third world needs the single fuel system because they don't have the infrastructure to support duel fuels, its mostly done with 55 gallon drums.

Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

[Phil1111 908]

I agree with Rob and you. I can see the day when 182s and turbine ac are 99% of whats flying on DZs.

[GalFisk 0]

billvon

I think the progression will be, as it has been in the past:

1) Schools buy electric aircraft as primary trainers. Their simplicity and low maintenance/operating costs will appeal to them - and range/turnaround time isn't as important.

2) Pilots trained on electric aircraft will buy them for themselves because they are used to them.

3) Used EA's come onto the market. Once they get cheap enough, a few single-cessna DZ's buy them as a second aircraft to put up static lines on weekends.

4) Larger DZ's start buying them and upgrading them for better performance.

All this will take decades.

I'm hoping that improved simplicity, operating cost and cycle times will mean that electric or hybrid jump ships will start to make business sense for DZs in a much shorter time than this. The paper posted by cpoxon, and running cost estimates posted by current manufacturers, give me hope. Though since no jumpship class hybrid or electric aircraft has been built yet, it remains to be seen.