First Electric Aircraft in Oz
Thread Starter
Join Date: May 2012
Location: Blue Yonder
Posts: 47
Likes: 0
Received 0 Likes
on
0 Posts
First Electric Aircraft in Oz
I'm surprised this hasn't popped up here so far.. perhaps I missed it.
Australia's first electric passenger plane takes to the skies of Perth, with Rottnest in its sights - ABC News (Australian Broadcasting Corporation)
Electro.Aero completes first flight of Pipistrel-made electric light sport aircraft in Australia | Australian Aviation
Australia's first electric passenger plane takes to the skies of Perth, with Rottnest in its sights - ABC News (Australian Broadcasting Corporation)
Electro.Aero completes first flight of Pipistrel-made electric light sport aircraft in Australia | Australian Aviation
It's great to see this sort of development taking place and I know it's only baby steps. However I wish they'd be more restrained with some of their claims.
I'm struggling the comprehend how an electric motor will reduce the time it takes to learn to fly. Yes, the risk of engine failure may be reduced but there will still be a need to be train for a power off emergency landing.
Given that fuel and engine related costs are about half of the total operating cost of an internal combustion engine aircraft (including engine overhaul), there will be some costs associated with an electric engine. It's pretty hard to see the operating costs with the electrfic engine being 70% less.
One article quotes a life of 1000 hours for the batteries. What is the cost of replacing the batteries. How will the cost of battery replacement compare with engine overhaul costs? What inspections will be required on the engine and batteries? I assume there will be bearings that need checking and perhaps replacement. What about the brushes or are they using brushless motors? The batteries will need monitoring of some sort to keep an eye on endurance.
I'm curious as to how they monitor battery endurance. As a battery ages it endurance reduces, so it will no longer be 60 minutes flight time with 30 minutes reserve. Doing this in flight when the battwry is under load isn't that difficult. I'm wonder how accurate the figures would be when measured before flight, i.e. during the preflight when you want to know "what's in the tanks". No load or small load battery tests don't usually give accurate results. Perhaps they have some tricky circuitry to do this.
"You are dealing with 50 years (of) engine technology in aircraft, so that complexity adds to the risk of flying and the time it takes to learn to fly," he said.
Technologies developed specially for this aircraft cut the cost of ab-initio pilot training by as much as 70 per cent, making flying more affordable than ever before,
One article quotes a life of 1000 hours for the batteries. What is the cost of replacing the batteries. How will the cost of battery replacement compare with engine overhaul costs? What inspections will be required on the engine and batteries? I assume there will be bearings that need checking and perhaps replacement. What about the brushes or are they using brushless motors? The batteries will need monitoring of some sort to keep an eye on endurance.
I'm curious as to how they monitor battery endurance. As a battery ages it endurance reduces, so it will no longer be 60 minutes flight time with 30 minutes reserve. Doing this in flight when the battwry is under load isn't that difficult. I'm wonder how accurate the figures would be when measured before flight, i.e. during the preflight when you want to know "what's in the tanks". No load or small load battery tests don't usually give accurate results. Perhaps they have some tricky circuitry to do this.
Last edited by 27/09; 6th Jan 2018 at 20:37.
Join Date: Jun 2011
Location: Bradd
Age: 61
Posts: 159
Likes: 0
Received 0 Likes
on
0 Posts
Electric aeroplanes.
One of the biggest issues as this technology is scaled up is the fact that landing weight will almost always equal takeoff weight. Alright at 2000kg, no so good at 300,000 kg. The implications for landing gear and aircraft pavements are not inconsiderable.
Join Date: Jul 2010
Location: YMMB
Age: 58
Posts: 703
Likes: 0
Received 0 Likes
on
0 Posts
I think this electric plane is an early step and we'll see a lot more development in this area.
There are a number of off-the-shelf aviation electric motors available now so I think there will be a lot more electric planes in the future.
Endurance and battery weight are the main limitations now, but as this area continues to improve I think these problems will be overcome.
What's the price of this plane?
There are a number of off-the-shelf aviation electric motors available now so I think there will be a lot more electric planes in the future.
Endurance and battery weight are the main limitations now, but as this area continues to improve I think these problems will be overcome.
What's the price of this plane?
Lots of questions, allow me to give you lots of answers.....
An electric powered aircraft should not really reduce training times noticeably, you still have to learn to fly! You need to learn all of the navigation rules. air rules etc. but, it should be cheaper in the long run because you are not doing any engine run ups, magneto checks or anything like that. From the moment you start the motor you can simply go 100% power so this should make it cheaper for those learning to fly because they will get the same amount of flight time but with very little ground time.
Every landing is the equivalent of an engine off emergency landing because from mid downwind to touch down the "throttle" is in the off-position and the aircraft is basically a glider for the rest of the circuit. The propeller wind milling during this stage of flight recharges the battery. There is a theoretical recharge amount of 14% in each circuit.
The cost of complete overhaul of the electric motor at 2000 hours is currently €500 in parts +12 hours of labour significantly cheaper than a gasoline equivalent.
The electric motor has three rebuild cycles so it is good up to 6000 hours where the manufacturer declares it should be replaced. The cost of placing the electric motor at 6000 hours with a new motor is €10,000
The batteries can be replaced complete or the cells can be replaced in the battery housings which use a much cheaper option. The cost of a complete replacement battery set is €19,500. The cost of replacing the battery cells only is €12,000. To eliminate the claims of being able to fly for two dollars an hour it is easy to see that the battery replacement cost is $12 per hour. The cost of replacing the motor at TBO is $0.75 per hour. Add maintenance to this every hundred hours which is only lubricating moving parts on the airframe because you don't touch the motor or the electrics until TBO you can see that the true operating cost of this aircraft is below $20-$25 per hour.
The batteries have a display on them showing the temperature of the battery, the state of charge and the health of the battery. New batteries obviously have 100% health but they deteriorate over time. At 1000 recharge cycles the batteries will be showing approximately 75% health. It is completely possible to still fly the aircraft's this configuration but more endurance will obviously be reduced. The manufacturer states that 75% the batteries are at the bottom of the useful life and should be replaced but at 75% you still have a battery system with 30 kW capacity. I am sure there will be a huge market secondhand for depleted aviation battery systems including motor vehicles, homes etc.
The instrumentation on the panel of the aircraft displays the remaining power. We only display it as a percentage of power remaining. We do not display as flight time remaining for obvious legal reasons. If someone looks down and it shows 30 minutes remaining and they increase the throttle 10% then the flight time will be less so we just display the percentage of battery remaining. For a normal flight the useful range of the battery is from 100% (fully charged) down to 20%. We consider 20% to be empty on the batteries. You can still fly the aircraft until the batteries are completely exhausted but you must know that the battery life will be reduced each and every time this is done. The batteries must be managed correctly.
To answer an obvious question, mind you I had to ask this the first time as well. There is no difference in the weight of the aircraft when the batteries are depleted or full (that is measurable)
Everyone must remember that this aircraft has been solely designed for training, the circuit operations only. It has not been sold or marketed as a cross-country aircraft of any description. It has 60 minutes endurance in the circuit area with a mandatory 30 minute reserve.
This aircraft is just the first steppingstone to many big improvements in the future. The next generation of batteries we are currently testing will give more endurance. We have 4 seat electric aircraft already with hydrogen fuel cells that recharge the battery system which can travel more than 1800 km without landing. The beauty of the Pipistrel ALPHA Trainer is that when new battery technology and systems are introduced it is simply a matter of pulling out a 50 kg battery pack and replacing it with new technology.
An electric powered aircraft should not really reduce training times noticeably, you still have to learn to fly! You need to learn all of the navigation rules. air rules etc. but, it should be cheaper in the long run because you are not doing any engine run ups, magneto checks or anything like that. From the moment you start the motor you can simply go 100% power so this should make it cheaper for those learning to fly because they will get the same amount of flight time but with very little ground time.
Every landing is the equivalent of an engine off emergency landing because from mid downwind to touch down the "throttle" is in the off-position and the aircraft is basically a glider for the rest of the circuit. The propeller wind milling during this stage of flight recharges the battery. There is a theoretical recharge amount of 14% in each circuit.
The cost of complete overhaul of the electric motor at 2000 hours is currently €500 in parts +12 hours of labour significantly cheaper than a gasoline equivalent.
The electric motor has three rebuild cycles so it is good up to 6000 hours where the manufacturer declares it should be replaced. The cost of placing the electric motor at 6000 hours with a new motor is €10,000
The batteries can be replaced complete or the cells can be replaced in the battery housings which use a much cheaper option. The cost of a complete replacement battery set is €19,500. The cost of replacing the battery cells only is €12,000. To eliminate the claims of being able to fly for two dollars an hour it is easy to see that the battery replacement cost is $12 per hour. The cost of replacing the motor at TBO is $0.75 per hour. Add maintenance to this every hundred hours which is only lubricating moving parts on the airframe because you don't touch the motor or the electrics until TBO you can see that the true operating cost of this aircraft is below $20-$25 per hour.
The batteries have a display on them showing the temperature of the battery, the state of charge and the health of the battery. New batteries obviously have 100% health but they deteriorate over time. At 1000 recharge cycles the batteries will be showing approximately 75% health. It is completely possible to still fly the aircraft's this configuration but more endurance will obviously be reduced. The manufacturer states that 75% the batteries are at the bottom of the useful life and should be replaced but at 75% you still have a battery system with 30 kW capacity. I am sure there will be a huge market secondhand for depleted aviation battery systems including motor vehicles, homes etc.
The instrumentation on the panel of the aircraft displays the remaining power. We only display it as a percentage of power remaining. We do not display as flight time remaining for obvious legal reasons. If someone looks down and it shows 30 minutes remaining and they increase the throttle 10% then the flight time will be less so we just display the percentage of battery remaining. For a normal flight the useful range of the battery is from 100% (fully charged) down to 20%. We consider 20% to be empty on the batteries. You can still fly the aircraft until the batteries are completely exhausted but you must know that the battery life will be reduced each and every time this is done. The batteries must be managed correctly.
To answer an obvious question, mind you I had to ask this the first time as well. There is no difference in the weight of the aircraft when the batteries are depleted or full (that is measurable)
Everyone must remember that this aircraft has been solely designed for training, the circuit operations only. It has not been sold or marketed as a cross-country aircraft of any description. It has 60 minutes endurance in the circuit area with a mandatory 30 minute reserve.
This aircraft is just the first steppingstone to many big improvements in the future. The next generation of batteries we are currently testing will give more endurance. We have 4 seat electric aircraft already with hydrogen fuel cells that recharge the battery system which can travel more than 1800 km without landing. The beauty of the Pipistrel ALPHA Trainer is that when new battery technology and systems are introduced it is simply a matter of pulling out a 50 kg battery pack and replacing it with new technology.
Join Date: Jul 2010
Location: YMMB
Age: 58
Posts: 703
Likes: 0
Received 0 Likes
on
0 Posts
Doesn't look to far off the mark.
Batteries weight ~100k more than a tank of Avgas, but the electric engine only weighs 11kg.
https://en.wikipedia.org/wiki/Pipistrel_Alpha_Trainer
Batteries weight ~100k more than a tank of Avgas, but the electric engine only weighs 11kg.
https://en.wikipedia.org/wiki/Pipistrel_Alpha_Trainer
One of the FAQ's answer was not very clear.
It was about removing one of the batteries to carry more baggage - maybe baggage could be changed to more useful load?
As there is no place for baggage it was not a good question to be asked - But as many countries have average male weights close to and over 80kg, I see the need for a greater payload in many cases.
What could the useful payload be increased to with 1 battery and some ballast to keep in the C of G envelope?
It is understood that the endurance is reduced - but it is a quick simple change to replace the flat battery over with the full one removed and continue training. Being compliant with the paperwork would take longer.
It was about removing one of the batteries to carry more baggage - maybe baggage could be changed to more useful load?
As there is no place for baggage it was not a good question to be asked - But as many countries have average male weights close to and over 80kg, I see the need for a greater payload in many cases.
What could the useful payload be increased to with 1 battery and some ballast to keep in the C of G envelope?
It is understood that the endurance is reduced - but it is a quick simple change to replace the flat battery over with the full one removed and continue training. Being compliant with the paperwork would take longer.
Interesting stuff.
I couldn’ quite work out from the document at the link whether there is a temperature limitation or not and, if there is, whether it’s 39 c or 40 c.
I couldn’ quite work out from the document at the link whether there is a temperature limitation or not and, if there is, whether it’s 39 c or 40 c.
Its 40 degrees celcius at the moment. That's the maximum we have been able to test at in Europe and the USA so far. I expect the temperature limit to be lifted to 45 after further testing and evaluation.
mccoates, I saw an article about this aircraft a couple of days ago and happen to be in Jandakot, fairly sure I saw it on the Tarmac or Taxiing out as well and am extremely impressed, this is definitely the future of Aviation and it's absolutely incredible to see Australians at the forefront of this and leading the way!!
I noticed in the blurb that it mentions the motor switching off when gliding, presumably not only when landing?
The motor stays "alive" all the time when you are flying but when at a holding point on the runway or on descent the 'throttle is off and the motor stops, completely stops, the propeller stays still. On downwind or base when you do this then the propeller stops and then the motor starts windmilling and producing power and recharging the battery.
I have 'flown' one for more than 3 hours by going up and down a ridge-line windmilling and recharging the batteries back from about 40% to 60% again.
I have 'flown' one for more than 3 hours by going up and down a ridge-line windmilling and recharging the batteries back from about 40% to 60% again.
That is largely the answer I was hoping for. Thank you.
Fieldmouse.
I think you are getting ahead of yourself talking about a 300,000 kg landing weight electric aircraft. This is greater than the MLW for the B747-400.
I think you are getting ahead of yourself talking about a 300,000 kg landing weight electric aircraft. This is greater than the MLW for the B747-400.
Join Date: Oct 2017
Location: Ireland
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
I'm really glad that there's progress in the field of electric GA aircrafts, but it's usage is so limited, pretty much just a visual pattern work. Can you have IR panel and fly long ILS / NDB approaches? That's would be really a game changer, imo.
Current battery technologies is what holding this back. Energy density must greatly increase to make it more useful.
Current battery technologies is what holding this back. Energy density must greatly increase to make it more useful.
Join Date: Jul 2006
Location: Australia
Posts: 325
Likes: 0
Received 0 Likes
on
0 Posts
One of the biggest issues as this technology is scaled up is the fact that landing weight will almost always equal takeoff weight. Alright at 2000kg, no so good at 300,000 kg. The implications for landing gear and aircraft pavements are not inconsiderable.
That’s an advantage not a disadvantage. In a heavy the take off weight is much higher than landing weight to allow for fuel consumption not to Carry extra useful load. If the take off weight = landing weight then the undercarriage need only be designed for the landing weight which is generally considerably lower.
