The big problem with the small planes is not the engine and fuel (still can't beat AVGAS in term of efficiency), but price; any part that exists in the automotive industry gets a 3 time price increase if it is used in aviation, 5 times if it is certified. A 1.4 liter 4 cylinder engine with 100 HP, that would be maybe 15-2000$ in a car, is ... 17.000$ for a small plane. A mobile radio for aviation starts from $300, a fixed one from $1500. That makes me believe the simple to maintain electric engine will have a 10 times price increase when used in an aircraft, just because they can and also because of all the crazy litigation system in US where 50% of the price of a new plane is put aside to pay for future litigations. In Europe we have huge taxes, so the price is even higher.
The FAA's Part 23 rewrite should help this. Just this month Dynon managed to get their D10A EFIS STC'd even though it isn't TSOd. Basically we will be allowed to put avionics designed for the experimental/homebuilt market into certified aircraft, resulting in a huge cost saving.
Does anyone have more specifics about the actual capabilities of the prototype? I'm skeptical they're able to get 3 hours of flight time out of a battery pack without sacrificing just about all the weight capacity for things like... a pilot. It's great to see that companies are actively working on electric-powered flight, though, especially in the small aircraft space where it has high potential.
Also a small beef with the article - it makes it seem like there just aren't enough pilots to fly commercial planes, which simply isn't true. There are plenty of pilots, they just don't want to work for the terrible pay and life-destroying hours most carriers are offering, while at the same time often having to cover their own massive training costs. Some more info on the situation: http://time.com/4257940/pilot-shortage/
Agreed, very little real information here. Nothing about range, top speed, weight, etc.
A big part of training is doing "touch and goes" to practice approaches, landing, and taking off (the most dangerous phases of flight) which I would think would tax the battery a lot more than just cruising around for three hours.
It's not stated very directly, but it appears the article is referring to hybrid propulsion systems much like in hybrid cars. That certainly makes sense for reducing fuel costs, as well as reducing the volume of fuel you'd need, thus reducing weight as well.
As someone who really would love to get into general aviation but finds the fuel costs off-putting, I'd love for this to be successful. Isn't the big problem with electric planes supposed to be the energy density per kg? Wikipedia is showing 46MJ/kg for jet fuel, vs only ~1MJ/kg for lithium batteries [1]. Is this a lesser concern than I've been led to believe, is there recent development that improves lithium batteries by at least an order of magnitude in this property, or are they using some different battery technology entirely? I'm disappointed that there's no mention of the battery tech.
Another issue is that fuel tanks get lighter as the conventional airplane flies. This increases cruise speed, shortens landing roll, decreases energy that needs to be dissipated in the event of a forced landing, allows trading off cabin payload vs fuel payload, and taking off at partial weight for better runway and initial climb performance. I can burn off over 1000# or 1/6 of the ramp weight and still be legal to land, and the airplane picks up 3-5 knots in cruise speed from max takeoff weight to landing with reserves weight.
Batteries are just as heavy at landing as they were at takeoff.
A reasonable rule of thumb is that fuel costs between 20 and 33% of the total cost of owning and operating the airplane. Battery tech won't materially change the total costs in my estimation/experience. It would be nice to get rid of TEL-doped fuel, but electric trainers are not going to make flying cheaper, especially when compared to a 60s/70s 150/152/172.
>As someone who really would love to get into general aviation but finds the fuel costs off-putting
I'm not sure why you think the fuel costs are off-putting. I fly a Cessna 150 which burn 5.5 gallons per hour. If you fill it with unleaded (which can be done with a $150 piece of paper), the fuel cost is less than $15/hr.
Cessna takes about 8 gallons per hour to fly; if you want to fly at 3 gallons per hour then go for any Rotax 912ULS plane, most are LSA but you can upgrade the license to PPL adn the flight time on LSA (cheap) is considered for PPL. In the end a Comko Ikarus C42 has similar performance with a Cessna 152 and a Pipistrel Virus SW is lighter and much faster (+30%) than the 152 for less than half the fuel consumption.
You can't buy a modern Pipistrel for th price of a 1975 Cessna. A huge % of the light 2 and 4 seat aircraft out there in the c172 and smaller sizes are 25+ years old.
You are right, but that does not make it right to compare a new electric plane's cost, flying performance and energy efficiency/consumption with a 1975 Cessna except if you have a time machine to send the electric plane back in 1975.
Except that 1975 Cessna is much, much more likely to be what a small flight school/rental operator/FBO company can afford to buy. $35,000 and ongoing maintenance vs $175,000+.
My concern about training on an aircraft of this fashion is that you get no exposure to controls such as carb heat, fuel mixture, etc.
I wonder if a distinction will be made (in the not so far future) between getting rated on a combustion plane vs. electric? Much like you get rated for high-performance or twin engines today.
> no exposure to controls such as carb heat, fuel mixture, etc.
Right. None of which are relevant to turbine aircraft anyways, which is the majority of all planes in the sky.
It's relevant sure but the big things you learn in flight training are how to figure out where in the sky you are and should be, lift/drag stick and rudder stuff, and endless amounts of regulations.
The means of propulsion is important sure but it's a small minority of the info you absorb.
All the bizjets, King Airs, PC12s, TBMs, and Caravans are turbine (and most are GA). Plenty of turbines in GA and they fly a lot of hours. (It's not the majority of airplanes, but it probably is the majority of hours flown.)
I would gladly pay for 5 hours of training for a combustion endorsement, if I could avoid fuel costs for 40+ hours of training to get my private certificate.
Fuel for a typical 4-cyl trainer will be around 8 gph at < $5/gal. 40 * 8 * 5 is $1600. 5 extra hours of dual in a rented piston plane is going to run you more than half of that possible savings. The net savings will be several hundred dollars, pretty much a drop in the bucket for flying expenses.
Why would it have to be "extra"? ISTM they could just train as they do now, except that they would concentrate all the ICE issues in the five hours in which they're flying with ICE.
Every new airplane type takes some type-specific instruction. True, it could count towards the FAA-minimum 40 hours, but almost no one takes a checkride with 40.0 hours in their logbook. I was a pretty dedicated student and at least a fair stick, and I was still in the 55-57 hour range when I took the checkride. Most people training at towered fields are in the 60-75 hour range at the ride.
Fuel isn't the dominant cost in flight training. (Source: I bought my first airplane during flight training and have been flying for almost 2 decades now. Fuel is more than a rounding error, but tends to run around 1/4 of my all-in costs.)
If this proves to be all it's to be, then soon this will make no difference. Just like in the US, getting a driver's license is not required to be done on a stick shift, cause 97% of the cars on the road are automatic. So will getting certified in an electric airplane make no difference compared to its old and 'outdated' internal combustion friends.
As far as career progression for a professional pilot, most pilots don't deal with mixture/carb heat etc as jet engine themselves are mostly fully automatic with a start button and a fuel cutoff switch and a thrust lever. And even some of those are coming out too and will become obsolete within just a few years time.
Serious question from someone who knows very little about planes. Do they seriously still have new carbuereuted planes? I can understand if it's a Cessna from the 50's, 60's, 70's, but I'm surprised they haven't been converted to EFI just from an efficiency and reliability stand point. Does that have to do with all the certification required for aircraft? (ie, if you change the engine, the aircraft has to go through another inspection by the FAA or whomever?)
The problem in general aviation is the cost. As the article mentions, even a simple Cessna purchased new costs as much as a house. The result is that there are a LOT of planes flying that date back to the 1940s, 50s and 60s.
Most of the injection systems on piston aircraft are mechanical injection, not EFI, for reliability reasons. EFI with closed-loop lambda control for street cars makes sense because of the widely varied load that a street car has to do and the need to keep the mixture in a close range to keep the catalytic convertor working well under these varied conditions.
An airplane engine has a far more steady-state load condition. As a result, fixed ignition timing and mechanical fuel injection with manual mixture control is "good enough" and very simple/reliable. Likewise for carbs and carb heat on the O- engines. It works and works very well.
There is a process for modifying certified aircraft. STC (Supplemental Type Certificate) is the primary means for changing engine configuration. It's some amount of work, but isn't prohibitive. (I have STC'd modifications on every airplane I've ever owned. It's not that big of a deal, if your modification has sound engineering basis.)
Converting from a carb to fuel injection is possible, but many of those conversions involve installing a fuel header tank that the airframe didn't originally have. Sometimes this changes the fuel system for the worse (eliminating the "both" tank setting) and/or puts a header tank in a place to spray pressurized fuel into the cabin in the event of a forced landing. I looked into converting my 182 to an IO-550 (from an O-470) and that was unappealing to me. Instead, I upgraded to an O-520 (still carb'd, but larger displacement).
> Do they seriously still have new carbuereuted planes?
Yes, and for example you can choose your new-from-the-factory Robinson R44 helicopter with either carb ( Raven I ) or injection ( II ). The former has slightly lower fuel consumption and longer engine life, the latter better performance.
Should be no issue. Most people get transition training when starting to fly a new type. Carb vs fuel injection, normally aspirated vs turbo-normalized vs turbo-charged, use of flaps for max performance takeoffs, etc are all minor (but important) differences.
Minor nit: high performance is an endorsement, not a rating. (It's a CFI sign-off, not a checkride.)
In 2016 having a fuel mixture in a plane makes me wonder why is that needed; not only that some popular engines (like Rotax 912 family) do not need it, but processor controlled injection engines definitely do not need it. Fuel mixture is so 1960 and carb heat so 1990... (I'm a pilot in my free time flying propeller driven 2 seaters).
Very interesting. But sadly the article mentions the same old line: not enough airline pilots. The truth is that the airlines are not willing to pay for airline pilots. That's how capitalism works. You want workers? You pay workers. Simple as that.
Not an expert - don't know if they can be compared and the article lacks any actual specs to compare by, but the pipistrel's electric plane seems to be much cheaper.
"Pipistrel expects to bring the final product to the market in 2015 with a target price below 100,000 EUR."
50% of the cost of a plane sold in USA is put aside as reserves for litigations; that doubles the actual cost of the plane, so the Pipistrel that is sold in Europe for 100,000 EUR may be $220,000 in USA.
The Cessna 172 is 300k; a modern Pipistrel with better flying capabilities is 100K (there are a couple of 2015 Pipistrel planes on my base airport). Cessna does not sell lots of 172's, but neither Pipistrel does not sell in USA at 100k.
The aviation in USA is mostly based on cheap old 1950-1970 planes, the cost for new is astronomical.
Are you sure about this? I'm not in the market, and don't know the details, but it looks like Pipistrel USA is advertising "Ready to Fly" prices (denominated in Euros) that are much less than you say.
To be more serious, a Cessna 152 has an 82 kW engine and a wing area of 14.9 m^2. On a sunny day (1 kW/m^2) with 20% efficient panels and a 90% efficient motor, the solar panels would supply 3.2% of that power. So it's not possible to build a solar plane this way, but it's not 0.01% either.
I can't say anything to the power efficiency of solar cells, but I can see how they could be useful for when you're not flying. "Free" energy for when you're ready to fly if you don't fly the plan daily, but instead just fly on the weekends or such. In the middle of nowhere without fuel or electric hookup? Wait a few days and at leas the plane will have energy to fly out of there. I'm not saying that will be the case, but an interesting aspect of solar panels on wings.
You'd be much better off to simply have a few panels on a rack that you put out next to the plane. Being forced to haul around the extra weight of the panels on the top of the wings would be counterproductive, and if you really wanted the panels with you one day, you could pack them up and take them with you.
I wonder how long the batteries will last for? Not the flying time, I mean instead their useful lifetime. It might become extremely expensive if you have to replace the batteries every year or so...
I know every one is talking about the energy density of gas, but wouldn't there reduction in moving parts in the engine offset? How does a Tesla compare to an average cat?
A Tesla's motor saves 200 lbs over a 4 cylinder engine but the battery pack adds 1000lbs over a 12 gallon fuel tank which would allow you to drive that 4 cylinder car twice as far.
Early PT6-114s (the turboprop engine on the early 208s) have a takeoff torque limit of 1658ft-lbs. Later PT6-114As (the current engine on the 208s) has a takeoff torque limit of 1865ft-lbs.
The Tesla P85D has less than half of that.
The Caravan has much less initial acceleration than a Tesla, but far more torque.
Probably not in the foreseeable future; the market just isn't there, and in large part- the technology isn't either.
For one thing, the technology for truly automatic or nearly-automatic landing (takeoff might be simpler) requires a lot of equipment at the airport, which the vast majority of airports a hobby pilot would fly from will never install. Since takeoff and landing are by far the most difficult and dangerous parts of the flight, this pretty much automatically precludes the possibility of an untrained pilot.
Add to that, the stance in aviation is that the pilot must be capable of taking control of the aircraft if there is any problem with the automation. I don't know the statistics, but presumably the sensors and automation by itself are not reliable enough to function completely autonomously and without supervision 100% of the time. And if you're gonna have a hobby pilot that is perfectly capable of flying the plane manually, full automation is just a massive waste of money.
An electric powerplant with effectively one moving part should also have dramatically lower mantenence cost than a traditional, gasoline-powered engine of more than 1,000 components
I see this sort of statement made about electric cars also, and I think it's really not true. Modern internal combustion engines are very reliable, and need very little maintenance. Yes they need oil changes every so often, and I guess that's "dramatically" more in a divide-by-zero kind of way, but realistically it's not going to make a huge difference in the operational expense of a GA aircraft. Also not addressed in this piece, how long do the batteries last and what does it cost to replace them?
Conventional wisdom around owning a gas powered vehicle is to maintain it until either the engine or the transmission goes. The reason for this is not because engines and transmissions are unreliable its because they are insanely expensive to manufacture and repair which often exceeds the value of the vehicle in the first place. As far as I'm aware with an electric vehicle there is no transmission and the electric motor is basically a spinning coil without any significant point of friction so its orders of magnitude cheaper to manufacture and replacement would be something your average consumer could potentially do themselves.
Batteries are definitely the bottleneck but its basically the only area further innovation is needed for the foreseeable future.
Basically what this means is that with electric vehicles you can continually drive and repair them until the chassis is no longer serviceable OR more likely your EULA runs out and you are forced to upgrade for licensing (software) reasons because there will be significant services revolving around these vehicles (autonomous driving, parking, recharging, repairs).
Absent a propeller strike, a teardown inspection is almost never indicated between overhauls. Yes, the airframe and engine get inspected annually, but the engine is not "torn down" during those inspections.
The teardown and inspection of an electric motor is trivial compared to that of an internal combustion engine. Generally speaking, you'd undo a few fasteners, pop off a cover, and check/clean the rotor/windings. 15 minutes tops - heck, you could do it before every flight and it'd still be cheaper than paying for the 100-hour maintenance on a GA plane.
