Ampaire flew its hybrid electric Caravan for the first time Nov. 18, completing a 33-minute hop from Camarillo, California. According to Green Car Congress, the short flight was conducted to do initial checks on the propulsion system, which consists of a compression ignition engine coupled to a generator that charges a battery bank in a belly pod which, in turn, powers the electric motor that turns the propeller. No issues were reported.

Seguin took the Caravan to 3,500 feet at full power and then spent 20 minutes at various power settings checking temperatures and other parameters. The hybrid actually has a greater range (more than 1,000 miles) than a standard Caravan and has the same payload. Because the batteries are in the pod, cabin space and passenger capacity are also the same. Ampaire says the overall reduction in operating costs is 25 to 40 percent and if the generator is run on sustainable aviation fuel its net carbon contribution is almost zero. The company hopes to have the mods STC’d by 2024.

37 COMMENTS

  1. Why would you want it “carbon neutral?” The latest reports, far from “99% of climate scientists believe global warming is real,” suggest that around 40% have now changed their minds. On the contrary, CO2, a trace gas (4 parts in 10,000 of the atmosphere) is extracted by plants to make 100% of the oxygen that keeps animals like, say, humans, alive, as well as providing all the nutrients that feed tasty those herbivores, like beef. Combine that with the fact that only 3% of atmospheric CO2 comes from humans; 97% comes from natural sources over which humans have no control, and what’s the point?

    I live on a small acreage, and I always keep a brush pile handy for burning. Should be able to burn one today if the weather cooperates. Just doing my part to support the planet.

        • Quick to wrap yourselves in a white coat there, aren’t you?. There’s just a tiny chance that you missed a very important point. CO2 is plant food. The feedstock for photosynthesis which is the engine of life on earth. Treating it like a noxious chemical is somewhat suicidal. It’s a sad truth but “scientists” need funding and, like preachers, they are tempted to throw in an end-of-the-world theme in order to gain a following.

          • 100% agree. As I learned many years ago from my statistical analysis professor, “statistics can be manipulated to tell any truth that you want to present, with the same numbers”. IMHO climate change alarmists are full of it. Read the studies done by Nir Shaviv, highly respected astrophysicist. (Chairman of Hebrew University’s physics department, first university to be established in Israel)Since he disagrees with the tree hugging, Mother Earth worshipers his studies and opinions are buried. One comment he made in an article published in Forbes magazine is “that his research and that of his colleagues, suggests that rising CO2 levels play on lay a minor role compared the influence of the sun and cosmic radiation on the earth’s climate.”

    • https://iopscience.iop.org/article/10.1088/1748-9326/ac2774/meta

      LETTER • THE FOLLOWING ARTICLE ISOPEN ACCESS
      Consensus revisited: quantifying scientific agreement on climate change and climate expertise among Earth scientists 10 years later
      Krista F Myers1, Peter T Doran4,1, John Cook2,3, John E Kotcher3 and Teresa A Myers3

      Published 20 October 2021 • © 2021 The Author(s). Published by IOP Publishing Ltd
      Environmental Research Letters, Volume 16, Number 10
      Citation Krista F Myers et al 2021 Environ. Res. Lett. 16 104030
      DownloadArticle PDF DownloadArticle ePub
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      Abstract
      The scientific consensus on human-caused global warming has been a topic of intense interest in recent decades. This is in part due to the important role of public perception of expert consensus, which has downstream impacts on public opinion and support for mitigation policies. Numerous studies, using diverse methodologies and measures of climate expertise, have quantified the scientific consensus, finding between 90% and 100% agreement on human-caused global warming with multiple studies converging on 97% agreement. This study revisits the consensus among geoscientists ten years after an initial survey of experts, while exploring different ways to define expertise and the level of agreement among these groups. We sent 10 929 invitations to participate in our survey to a verified email list of geosciences faculty at reporting academic and research institutions and received 2780 responses. In addition to analyzing the raw survey results, we independently quantify how many publications self-identified climate experts published in the field of climate change research and compare that to their survey response on questions about climate change. As well as a binary approach classifying someone as ‘expert’ or ‘non-expert’, we also look at expertise as a scale. We find that agreement on anthropogenic global warming is high (91% to 100%) and generally increases with expertise. Out of a group of 153 independently confirmed climate experts, 98.7% of those scientists indicated that the Earth is getting warmer mostly because of human activity such as burning fossil fuels. Among those with the highest level of expertise (independently confirmed climate experts who each published 20+ peer reviewed papers on climate change between 2015 and 2019) there was 100% agreement that the Earth is warming mostly because of human activity.”

    • from the NASA website:
      Yes, the vast majority of actively publishing climate scientists – 97 percent – agree that humans are causing global warming and climate change. Most of the leading science organizations around the world have issued public statements expressing this, including international and U.S. science academies, the United Nations Intergovernmental Panel on Climate Change, and a whole host of reputable scientific bodies around the world. A list of these organizations is provided here.

    • CO2 is NOT the only thing affecting the Climate Emergency…from NASA:
      The gases that contribute to the greenhouse effect include water vapor, carbon dioxide (CO2), methane, nitrous oxides, and chlorofluorocarbons (CFCs).
      The thawing of the permafrost, in The North, is releasing MASSIVE amounts of Methane, which is a large contributor to the Climate Emergency.
      The amount of O2 in the atmosphere today, is only about 50% of what it was for most of human history. We are not designed to operate optimally with this low level of O2 to breathe.

    • James, why not take up smoking? I hear that it is good for you or at least the tobacco companies could find “experts” that would claim that. The last number that I heard was that at least 97% of the scientific community believe that the global warming is human caused by CO2 and other greenhouse gases. The other 3% are quasi experts that work for the fossil fuel industry, have research projects funded by the fossil fuel companies, or have been bought off by the fossil fuel companies in some other way.

    • The most current reported level of carbon dioxide in the atmosphere is about 420 parts per million (ppm). Since 10,000 ppm equals 1%, the current concentration is 0.042%. Since ppm equals milligrams per kilogram it would be 420 milligrams of C02 per kilogram of atmospheric air, so it is a weight percent number not a volume percent number. There is substantial evidence that globally, increased atmospheric carbon dioxide content is increasing plant biomass and improving plant growth rates. Atmospheric oxygen content appears stable at about 20%.

      • Dale writes:
        > …Since ppm equals milligrams per kilogram… so it is a weight percent number not a volume percent number.…

        Actually, no. “…the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction…”[1] So, it is neither a weight percent number nor a volume percent number. It is a quantity percent number. “ppm” equals molecules of CO2 in per million assorted molecules of air.

        > …it would be 420 milligrams of C02 per kilogram of atmospheric air, …

        Air has an average molecular weight of 28.95 g/mol [2], CO2 has a molecular weight of 44.01g/mol [3], so 420 ppm is 420*10^-6*(44.01 g/mol) / (28.95 g/mol) = 0.000638, or 638 mg CO2 per kilogram of atmospheric air.

        It does not change the thrust of your argument. I would just like us to use terms like “ppm” correctly, and get us practised at checking and citing our sources.

        [1]
        [2]
        [3]

        Wikipedia is not by itself a reliable source, but it is often correct, particularly in this case, and it is easy to cite.

        • OK, AVweb, I know you don’t welcome links in replies, even if they are good faith citations of sources. Let me see if I can evade your robots this way.

          [1] (en.wikipedia.org …wiki/Parts-per_notation)
          [2] (en.wikipedia.org …wiki/Atmosphere_of_Earth#Composition)
          [3] (en.wikipedia.org …wiki/Carbon_dioxide)

  2. As the driver of a plug in Prius , and a pilot, I think a hybrid aircraft makes much more sense then a pure electric one. I’d like to have a small battery pack in my exp., for extra power on takeoff, then have it slowly recharge while in level flight, and of course while descending. I don’t drive the Prius because i think I’m saving the planet, but because it’s a dandy piece of engineering and the mid to high 60 mpg per tankful doesn’t hurt either.

    • The last time I flew the Maule to the Central Coast of California we rented a Corolla Hybrid. Basically a Prius drivetrain as I understand it.

      Excellent car. I didn’t want to buy one but I appreciated and respected its capabilities.

    • As the driver of a Chevy Bolt, I think that a pure electric aircraft makes more sense (and will make more dollars) than a hybrid electric for at least some applications such as shorter range feeder flights. Note that Eviation Alice is flying and has a projected range (plus reserve) of 250 nm using current technology lithium ion batteries. It should have a range of 2 to 3 times this with lithium sulfur (see https://lyten.com/products/batteries/ ) Anyway, the real driver will be economics and not “greenness” as the cost per seat mile or ton mile will be about 1/4 that of a comparable turbo prop.

    • As the driver of a Chevy Bolt, I think that a pure electric aircraft makes more sense (and will make more dollars) than a hybrid electric for at least some applications such as shorter range feeder flights. Note that Eviation Alice is flying and has a projected range (not including reserve) of 250 nm using current technology lithium ion batteries. It should have a range of 2 to 3 times this with lithium sulfur. Anyway, the real driver will be economics and not “greenness” as the cost per seat mile or ton mile will be about 1/4 that of a comparable turbo prop.

      Note: I tried submitting this with a lithium sulfur reference but it is awaiting moderation. But, OK, I understand that someone could but in a nefarious link.

  3. Hi Russ

    It would be great to have some details about the powerplant that is lifting this Caravan into the air.

    It appears, from a press release issued at Oshkosh 2022, that Ampaire have installed the RED V12 diesel engine.

    This engine produces 550 HP and is running in parallel with an electric motor, of 250 HP or more, to produce 800 HP.

    It looks like the majority of the efficiency improvement is from a diesel piston engine, replacing the turbine, which saves the weight of fuel carried.

    Best wishes

    Philip

  4. All aircraft are the culmination of a long series of tradeoff decisions. It’s all a matter of what you are willing to give up in getting something else.

    Here we’re replacing a PT6 with a weighty package consisting of a diesel (driving an alternator?), a battery pack, a electric motor, and a bunch of assorted electrical/electronic hardware. Tradeoffs abound.

    What we’re seeking, primarily, is to be able to tout “greenness”, so we do get that right away. At some point, though, we also will need to sell, in practical, financial and socio-political terms, the reality as well as the perception that enough is being gained to balance that which is traded away. Socio-politically is easiest, because in the socio-political world reality is amorphous. You can fudge values on both sides of the tradeoff to achieve the desired outcome. On the practical & financial sides though, reality is much harder to manipulate because we’re dealing with stuff that is numerically quantifiable.

    • “You can fudge values on both sides of the tradeoff to achieve the desired outcome. On the practical & financial sides though, reality is much harder to manipulate because we’re dealing with stuff that is numerically quantifiable.”

      Unless government interferes, and changes the options available (either through regulation or taxation) to their desired outcome–in which case, “practicality” goes out the window–much like the old “Great Leap Forward” of Communist “Seven-Year Plans” mandated by the government.

      Why not let the marketplace prevail, instead. Offer the “Green Option” as well as the “current offering” (UNLIKE California, which seeks to ban the sales of petrol-fueled cars).

  5. Somewhere around 1970 or so Popular Mechanics or Popular Science mag had an article, complete with plans, about a hybrid/electric car (homebuilt of course) based on a VW Beetle chassis. The VW motor was removed and replaced with a starter/generator from a jet engine. A bank of numerous (I don’t remember the number) auto batteries were the electricity storage. The power to charge the batteries was provided by a Briggs & Stratton lawn tractor motor (18 HP if I remember correctly) driving an automotive generator. The design kept the VW drivetrain except for the horizontal engine: the transmission/differential combination remained, along with the steering gear up front. I seem to remember that the body was plywood and fiberglass and likely not street-legal today, and it was a 2-seater. I don’t remember how efficient the design was or how much range it had, or whether the batteries ran out of power before the Briggs & Stratton motor ran out of gas. Interesting concept that has been around for a long time, now an interesting concept in an airplane.

  6. Couple of things don’t add up. #1, the Caravan pictured in the video has wing fences outboard of the landing light lens. That is a STCed gross weight increase kit that adds about 300 lb to the allowable gross weight for takeoff. #2 unless there are some new extremely lightweight batteries out there, the cargo pod would have to be reinforced due to the light floor loading of the factory cargo pod, to accommodate the weight of the batteries. That gross weight increase kit would help counter any loss of payload this hybrid requires, but landing weight stays the same. #3 although a Diesel engine would burn less fuel per hour, current diesel fuel prices are going through the roof right now costing more than jet fuel. #4 what about overhaul times and cost? And what about systems integration? The pt6 supplies plenty of hot bleed air for cabin heat, where does the cabin get its heat source with this new setup? BTW, I have about 4000hrs in Caravans. Everything in aviation is a tradeoff, you don’t get something for nothing, as far as I know the laws of aerodynamics haven’t changed. I have already said my opinion on climate change so I will leave that argument for someone else.

    • “…although a Diesel engine would burn less fuel per hour, current diesel fuel prices are going through the roof right now costing more than jet fuel.”

      The RED V-12 is a compression ignition engine – but it burns Jet-A.

  7. The project is a repeat of the 1970’s projects during the so-called energy crisis.
    It once again underscores the limitations of batteries for sustianed powered flight.
    Fun to have lived long enought to see repeats of some of the bad ideas from times past.

  8. I find the controversy about the “climate” hilarious when the story is about the Hybrid Caravan. Guess the “climate” trolls are out in force here. We will be utilizing petroleum based fuels and engines for a long time, yet.

    • Since the exercise is one of “carbon contribution” then the plane is being sold and marketed as a “climate” solution. I’m sorry, but that makes it fair game to question whether it will have any tangible benefit in that area.

  9. As Samuel Clemens said” there are 3 falsehoods in the world. “Lies, Damn Lies and Statistics”.

    Stats are what you want them to be, and you can’t argue with them….there “stats”.

    P.S. The weeds and brush are always thickest near the roadways…..CO2 baby.

  10. Sigh…..

    All the major advances in aviation since the Wright brothers have been driven by advances in propulsion technology.

    These guys want to try something different ? I say good on you and ignore all the trolls that want to score political points off you.

  11. How can you burn aviation fuel in “compression ignition engine” what ever that is and leave no carbon footprint?
    Com’on you butch of Tree Lickers even in grade four we were taught that you cannot create or destroy energy, you can only change it from one form to another.
    When you create energy you produce wasted heat energy and when you charge that battery you create wasted heat.
    It gets better you also when you again convert to thrust you create wasted heat!
    How did you get the payload numbers??? Did you go for anm increase in gross weight?