DeltaHawk DHK180 Receives FAA Certification


DeltaHawk announced on Thursday that it has received FAA type certification for its 180-HP DHK180 piston engine. The four-cylinder, clean-sheet design features an inverted-V engine block, turbocharging and supercharging, mechanical fuel injection, liquid cooling, direct drive and, according to the company, “40 percent fewer moving parts than other engines in its category.” It is capable of burning Jet-A and sustainable aviation jet fuels.

“We began by completely reimagining what a general aviation engine should be,” said DeltaHawk CEO Christopher Ruud. “And the result is that we now have a certified engine that is a game-changer. It’s been a long time coming but, in engineering, simple is hard. However, this engine’s performance, simplicity, and reliability have made it worth the time and the investment, as it is truly ‘Power Reimagined.’”

The DHK180 measures 33 inches by 24 inches by 22 inches and has a dry weight of 357 pounds. DeltaHawk reported that performance and technical upgrades are currently underway as well as additional endurance testing and flight evaluations on several aircraft. Deliveries are expected to begin in 2024. Pricing for the engine has not yet been announced. DeltaHawk noted that the DHK180 is intended to be the first of a family of engines.

Kate O'Connor
Kate O’Connor works as AVweb's Editor-in-Chief. She is a private pilot, certificated aircraft dispatcher, and graduate of Embry-Riddle Aeronautical University.

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    • That is true…
      However, the Deltahawk unfortunately is not a modern engine design. It is build with failure prone mechanical controls instead of redundant, safe and more efficient electronic FADEC.

      • I believe, as one of the founders of DH in 1996, that is the best “barnyard” variety of excrement that continues to be said by those who would rather still marvel at the Model-T. Keep saying what others want to say but, now,… can’t. By the way…. men have landed on the moon. Just FYI.

  1. No mention of TBO, that can’t be a good sign. :7(

    Really hope we get more modern alternatives like this into the marketplace. Congrats DeltaHawk team!

    • While I agree TBO could be a vague indicator of the longevity of the engine when viewed by the manufacturer, I’m not sure what value it has, especially at this point. What would a notional TBO tell you at this point? It’s just a number, subject to being wrong to one degree or another, potentially to the good or the bad. I mean, look at the history of basically every other engine before it; some were miserable failures that didn’t get close to TBO, while others soldier on for hundreds (or thousands) of hours beyond TBO. There are even plenty of very popular/common engines that owners routinely seem to accept will need a top overhaul about halfway to TBO as a matter of course.

      As for me, I’m tickled to see a genuinely new, seemingly well-thought-out design that could be a meaningful improvement over legacy engines while also presenting plausible retrofit options for existing aircraft. I figure that reliability will be at least comparable (since it survived certification) and subject to improvement over time. Frankly, the only number that worries me at this point is the price. If these things are too expensive, they will die on the vine, just like several other promising engines before them.

      • But it’s not a plausible to retrofit option for us 160-180hp trainer type airplane owners with gas engines. Hand one of these turbo JetA water cooled engines to your mechanic and ask him “how much” to install it on your Cherokee.

        • Oh, I have no delusions that it will be cheap. We’re talking Aviation here, and certified at that. That means any technology will be 10 to 100x more expensive than it would be in basically any other context. But, this engine will apparently work on an SR20, which is a by at least some measure a “trainer airplane with (a) gas engine”.

          But, that aside, my main point here is that I think we are running out of runway for conventional aircraft engines. It is pretty clear that half the government and plenty of anti-GA special interests have it out for us now. Eventually, I think they will get what they want and they will either outlaw the legacy engines outright, or they will kill them by not letting them be replaced or repaired. Either way, I’m not liking my chances of being able to afford a brand new airplane that meets with their approval. This way may be a long shot, for sure, but I think I see better odds of this being viable than of, say, converting that Cherokee you mentioned to electric.

          • No, eventually people will figure out what chemists have always known (that global warming is the cause of the rise in co2) and that very complex engines are less reliable than simple ones. Hopefully people will embrace the good news that there is no need to buy “advanced” systems and can save boatloads of money by using what we already have.

        • Once again, can’t figure out why so many people are so pro horse and buggy. Thankfully some of these luddites aren’t in positions of power or lending. Instead we have risk-tanking entrepreneurs and engineers who see an opportunity to improve an industry with decades old engine designs and see if they can invent something better. Having followed Delta Hawk for a while now, excited to see this big step. Hopefully they continue to improve and refine, and step over the people who are still trying to protect the horse whip industry.

          On a separate note, Mr. Foyt, can you point me in the direction to the research where “chemists have always known” that global warming is the cause of rise in CO2? I’m merely an atmospheric geochemist (the pure chemists sort of look down on us), but we’re all in pretty strong agreement that after decades of work, thousands of research projects and yottabytes of data, that your statement is contradictory to virtually all of the evidence (there’s still some work to be done on ocean and atmospheric sinks of CO2 and the relation to a lag in temperature linkage, especially in events such as the Younger Dryas). If you can illuminate me to your sources, I’ll make a big splash in the research community by upending more than a century of research. Every scientist likes to make big new discoveries, so please, from one pilot to another, help me out.

          • Thanks for the measured and scientific response. Great to see someone who actually knows something about Co2 post here.

          • My current 120kt “horse and buggy” will not be any faster with engine (though I will be $100K lighter in my pockets with this conversion).

            Any P-Chem student with a CRC manual can look up the Ksp of CO2 in water. Baring that, anyone who opens a can of coke knows the difference when opening a hot can Vs cold. Hot releases co2 and colder absorbs it. We live on a planet 3/4 covered with water those who did not take earth science.

          • Mr. Foyt, thank you for finally showing that the emperor has no clothes. I was really hoping for some research showing that global warming is the cause of rising CO2. Instead you seem to be confused by the difference between CO2’s properties as a gas, liquid and solid, while interacting with a gas (atmosphere), liquid (ocean/lakes) and solid (I’ll leave other planetary bodies out of this discussion). The Ksp of CO2 in water plays no real role in the atmospheric interaction of CO2 and the photons from the earth and sun, I’ll explain below.

            But first, I do like that you included the can of coke though, it’s always a great way of explaining some fundamental physics and chemistry. Unfortunately according to both Henry’s Law which you allude to, and the ideal gas law which plays a greater role when a can is opened, don’t bolster your argument regarding atmospheric CO2.

            First off, both a cold can of coke and a warm can of coke release CO2 when opened. I’m assuming by cold we mean refrigerated (not super cooled to near 0K). And by hot I’m assuming warmed in the sun or left by a heater (not superheated to a plasma or something). When you open either can, and release the pressure, via the ideal gas law and Henry’s Law we know that some of the CO2 that dissolved in the liquid immediately boils out due to the reduced pressure (same way blood boils in space despite the very low temperatures). So I’m not sure where you have done experiments showing a cold can of coke will absorb CO2 in normal conditions. In fact to get the liquid coke to absorb CO2, the canning facility has to inject it under rather high pressure which causes the temperature to rise significantly. Anyhow, enough of the coke can, it really has nothing to do with your statement about global warming causing an increase in CO2 (even if we include the oceans, the analogy is so misconstrued as to be dysfunctional).

            So, in the atmosphere, CO2 is in it’s gaseous form and with photons, not liquids where Ksp plays a role. So we have to abandon that red herring and instead focus on radiative transfer. Here we just look at CO2 as a molecule, and the earth and sun as sources of radiation (not the bad kind at the really short end of the spectrum to the right, but the longer ones more towards the middle part of the spectrum we call infrared).

            It turns out that by looking at the blackbody curves of the sun (roughly 5780K) and the earth (roughly 255K), and using Wien’s Displacement Law, Stefan Boltzman Law along with Planck Function (I include these for the geeks and the curious who want to look them up), we can figure out how those CO2 molecules are effectively transparent at 5780K, but act like a barrier at 255K. So that radiation (aka heat) from the sun makes it through to the surface, but the radiation from earth, is absorbed by the CO2 molecules in the atmosphere (and yes, even more so by other molecules including H2O, the most effective). Because of the physics behind electrons getting excited, the CO2 molecule increases it’s vibration/energy. As explained in other comments, increasing the energy of a molecule is the definition of increased temperature. This radiative transfer process where CO2 is transparent to incoming radiation, but absorbs outgoing radiation is the same process that allows a small glass building in the back yard to be transparent to the incoming radiation from the sun, but opaque to the outgoing radiation from the ground, and we call it a greenhouse.

            So as you can see, it is not the Ksp of CO2 in water, or the can of coke, but how the CO2 in the atmosphere and black body radiative transfer physics that demonstrates irrefutably that an increase in CO2 raises the temperature of an gas. Now we can debate if that raised temperature is good or bad, but you cannot debate the physics, and nobody does, at least on this planet with our current knowledge of Newtonian physics.

            Now in reality this is a good thing, it is this physics that makes life as we know it possible on the surface of the earth. This radiative transfer has made the planet warm enough to live on. And thankfully because CO2 is a trace gas and doesn’t absorb too much of that earthly radiation, we’re not in a Venus situation where CO2 is the primary gas in the atmosphere and spacecraft melt/die in minutes because it’s really hot, like damn hot.

            So, in the end, blackbody physics and CO2 is not the same as aqueous physics and CO2. So Ksp not so relevant, Mie and Rayleigh Scattering very relevant.

  2. No engine mount, no STC, no prop, no support in the field, it’s 60 pounds heavier than air cooled Lyc, it also needs the weight/drag of a radiator. Unless it’s free then a conversions would be double the cost of a standard engine replacement. And then try finding Jet-A or sustainable fuels at small airfields….

    • If I remember right(Ill need to look at picture of it hanging on the scale, with log books)
      my customer’s custom lightweight Lycoming O-360 was 262 lbs so most of 100 lbs heavier…. hanging out front…. how much useless lead will you need to put in tail to offset that!

    • “Weight/drag of a radiator”; your aircooled relic has a large amount of cooling drag; a properly engineered radiator can have less drag than air cooling.
      Your “lightweight Lycoming was likely weighed without all the accessories that are included in the published weight of the Deltakawk.
      Yes, it is heavier, so is the fuel, but the reduced fuel consumption will offset that to a good degree.
      The simplicity of the design, and the reduction in operating cost will make the engine attractive to such as flight schools, never mind getting away from Avgas, a boutique product that is increasingly scarce in much of the real world.

    • “No engine mount…” I recommend you look at what Deltahawk had on their Cirrus SR20 test bed ten years ago ( The engine definitely is mounted and cowled. Since then, I’m sure they’ve improved on the design. Also, the frontal area of the radiator intake is probably not much more than what is needed for an air-cooled engine. I believe at the time, Deltahawk was working on an STC for the SR20. Now that the engine is certificated, I expect we’ll see an STC for the SR20 soon. I also expect to see STCs (or an equivalent thereof) for aircraft in international markets. After all, Jet-A is MUCH more plentiful around the world – and cheaper – than avgas. I bet it may make more economic sense for some international operators to consider aftermarket conversions, especially if the price is right.

      As Brian Hope points out, it is heavier but the fuel savings due to greater efficiency may mean you can leave more fuel in the truck and still accomplish your mission. I also think operating costs will make more sense with this engine. Jet-A can be cheaper than avgas so some cost can be saved there. Also, there’s no magnetos to replace every 500-1000 hours and no lead fouling on spark plugs.

      Another benefit is simplicity of operations. No mixture control means simplified operations. If you’re trying to teach the next generation of pilots how to fly, especially those going to the airlines, having a single power lever removed the need to teach mixture control techniques. I didn’t need to learn how to use prop controls to fly the T-6A Texan II with its single power control lever and I wasn’t a worse pilot when it came to flying heavy transport jet aircraft later on.

      “No prop…” Finding a prop may be more difficult due to the diesel’s power pulses compared to those of an avgas Lycoming or Continental. However, Austro, Continental, and Lycoming seem to have found props for their diesels. Deltahawk managed to fly their diesel-powered SR20 to Oshkosh ten years ago so I’m sure they found a suitable prop.

      “No field support…” This is a valid point and will be something Deltahawk will have to work on and develop. This is true for any new aviation business.

      “Try finding Jet-A or sustainable fuels at small airfields.” I think not finding Jet-A or SAF at smaller fields may not be as big a factor as long as Jet-A is available at a nearby field and/or your mission allows you to tanker in fuel to destination small field. I’ve done that before when going to fields with no fuel available. You just have to plan for it.

  3. I love it but AJF brings up valid points and concerns but this may be the beginning of a new line and has promise to keep GA alive just a little longer.

  4. Wow, must be unseasonably chilly in hell today.

    I wish them very well, it’s been a LONG time coming.
    Also, we shouldn’t count the chickens yet, they’re not actually hatching until next year. At the earliest.

    • Since 1996 and much pain. People love to see failure such as Elon Musk rockets blow up. The TBO must be ascertained over time and performance. It isn’t just “granted” as 2000 or 3000 hours. The proof in in the pudding if the quality and longevity is there. The Ruud family has spent missions to get to this point and the FAA was kindly there to help us. They saw the failures AND THE SUCCESSES!. You just don’t go out and ask the FAA, “Uh, can I get his certified?” Much pain and many failures were experienced but we believed in the design and the capability. Mr. Ruud has invested vast amounts of money and did not lose sight of the goal. Give the man a chance to speak and see what happens. He deserves the admiration of putting money where his mouth is. so,.. as Teddy Roosevelt wrote: “To The Man In The Arena” Many of you will never know what it’s like to risk that amount of sweat, blood and money to just get to this milestone. Yes, Your Welcome.

      • You are welcome…. I thought I would post the incorrect “Your” to see who responds with “hey, you can’t even use correct grammar. Now lets see a show of hands who thought that.

  5. On a very basic level…inverted cylinders bring their own issues…oil/fuel hydro lock. A customer base expecting/accustomed to “turn the key” starts might not align with the potential consequences of failing to clear cylinders before operation.

    It will be interesting to see how their design (or perhaps something inherent in compression ign architecture in general) and procedures prevent and address the hydro-lock issue. Pulling thru a compression ignition engine might be a bit “strenuous” and there’s no spark plugs to pull if you do have a filled cylinder.

    • An inverted ‘v’ in a compression ignition engine is not as problematic as you might think if they are equipped with a compression release as are many diesels. Pull the compression release and roll through 6 blades. Slowly release compression release while cranking to start. Problem solved. That technique also works for a low battery.

    • If it’s a 2-stroke, and it sure looks like it is from the location of the intake and exhaust on the cylinders, unboosted compression is probably very low even compared to spark-ignition engines it’s intended to compete with. It probably achieves compression ignition through boosted pressure from the turbocharger AND the supercharger.

      The “40% fewer moving parts than…” sales pitch seems to point to a 2-stroke as well.

      • It is a two stroke; piston ported.
        The compression is higher than gasoline engines, or it wouldn’t be a compression ignition engine.
        The boost from turbo and supercharging is to ensure altitude performance; a pure compression ignition engine unboosted will stop running as it climbs; not enough ambient air pressure.
        The supercharger ensures retarts at higher altitudes; a problem with turbo only boosting.

        • A 2 stroke’s effective compression ratio is determined from the point the piston blocks all ports, not from the complete piston travel. Compression does not begin until that point. Boosted intake pressures make everything work as if the mechanical compression ratio is higher overall than the simple measurement of sweep and volume would indicate. I still think this is the purpose of DeltaHawk’s two stage boost scheme. Gasoline engines “detonate” or pre-ignite as if they were compression ignition when their boost is higher than appropriate.

  6. As a retired A&P I always wondered why there was nothing , for the most part, beyond the typical opposed piston engine design we’ve known forever. Yes, FAA certification raises the cost but, as an example, is the Marvel-Schebler carburetor from the 1920s-’30’s the best we can do?

  7. Good to see a new engine come to the market. Advanced technology and designs are needed to power tomorrows aircraft.

  8. There’s a lot of chicken and egg issues with new engines. I see this as great news.

  9. Finally certified!
    This engine has gone through a lot of changes since the first version.
    The amount of development that has been done will hopefully lead to a long lived viable alternative to the relics powering our aircraft.
    No valves or valve guides to burn or stick.
    Widely available fuel, not exotic expensive gasoline!
    The only possible fly in this particular ointment is the 2700 rpm prop speed; noise limits will be problematic in some parts of the world.
    It will be a good option where that is not an issue, and will also be a good option as a generator for hybrid powertrains.

  10. One of these days I will work on a statistical study on all the “game changing” engines that ever came to be. Here we go, another one >> “The four-cylinder, clean-sheet design” illusion. It is just crazy how many people think that in order to create an engine from scratch all you need is solidworks and “new” ideas. Wonder why we don’t have many options to count on. It is really hard to come up with a “great idea” out of the box and have the project run without any problems right off the bat. “this engine’s performance, simplicity, and reliability have made it worth the time and the investment, as it is truly ‘Power Reimagined.’” Great! The problem is the word “reliability” here is used in vain. No project can be considered reliable before its run time for hundreds of thousands of hours at least. I do hope this engine gets through. I do. Unfortunately, with all the assumptions posted by the company it’s hard to believe it will win the market. There’s way more to new engine projects that meet the eye.

    • You know, there’s a LOT of evidence that the main problem is that all the “experts” have some crazy attachment to antique designs. Seriously, it should be enough that someone has to overcome all the friction with the FAA and the entrenched competition, and the fact that new, certified airframes are not easy to sell so they don’t want to risk using a new engine.

      But, hey. Keep it up. Rotax will be the only player left because the lycosaurs are eventually going extinct.

    • They have been working on this engine for nearly 30 years. I’m sure they are well acquainted with the difficulties that new engine projects bring.

  11. I remember 2 stroke motorcycles until emissions killed them off in the 80’s.
    I had a VW Diesel that was part of the dieselgate buy-back because high diesel particulates were bad.

    Correct me if I’m wrong, but this is a 2 stroke, diesel?
    For all those the manufacturers that have ditched 2 stroke engines and diesels, how is this “the future” of power?

    • Power stroke x2 Piston porting with laminar flow of the charge. 34 % more efficient and no valve train. The 50 hour check- is the serpentine belt tension still correct. Compression checks- over. It starts- the compression is good. I cd go on but credit belongs to the Ruuds. Let us enjoy this accomplishment for the pain. You can bury me later.

  12. I wonder what ever happened to Duke Engines? I thought that engine might have been a game changer for small aircraft, but they seemed to have disappeared. Their website is still up but no updates for a decade or so.

    • I always thought the swashplate crankshaft linkage would be their downfall. I don’t know if it actually was.

  13. The 2-stroke diesel is not a new design. Detroit Diesel made 6 and v-16 diesels in 1938…

    But DeltaHawk is probably using higher strength materials to get the weight down to something usable in a aircraft.

    Aircraft require reliability over any ‘technically advanced’ electronics.
    mechanical injection allows the engine to continue operating with an electrical failure.
    ‘TA’ electronics require a back up battery of an hour or 2 capability.

    The ‘dry’ weight of the GO-300 in my C175 is 320 lb, and it’s CG range is ok.
    Putting a heavier 4 cylinder vs the 6 cylinder with a gear box at the prop, can allow mounting the engine closer to the firewall to minimize the CG change.

  14. Given the uncertainty over the future of Avgas, and the limitations of electric power, it will be interesting to see if we are going to see a more definitive trend to diesel power plants for GA aircraft

  15. Kate
    Thank you for the update and congratulations to Delta Hawk.
    You reported that ‘The four-cylinder, clean-sheet design features an inverted-V engine block . . . . according to the company, “40 percent fewer moving parts than other engines in its category.” ‘
    Why not mention that what distinguishes it from conventional gasoline burning aircraft engines is that this is a 2-cycle diesel engine with a monobloc crankcase and cylinder block which means that it has not self-disassembling cylinders, no camshaft, valves, guides or valve-train, no magneto, spark plugs or other ignition system.
    It has more in common with Detroit 2-cycle diesel engines which will happily run for 20,000 hours.
    Delta Hawk will have to work hard to produce these at Lycoming prices because $100,000 that Delay Hawk previously mentioned is not going to create lots of lines of people lining up with their check books.