Diesel powered helicopters

[widgeon]

On the RAR news group there was some conjecture that Robinson were soon too announce a Diesel powered ( French of German ) engine R44 . The french one claims 3,000 hr TBO and 30 % les fuel cost. Do you think it would catch on ?. I've been told engine is around 80K usd.

[Helinut]

I have no idea whether Robinson are developing a diesel Robbo, but here in Europe where Avgas is both very expensive and soon likely to be scarce it seems like a great idea. Avgas is around 90 p per litre with Jet A1 around 30-35 p. Aside from reduced fuel costs, you don't get carb icing, and I would much rather carry a tank full of Jet A1 than Avgas around with me.

All of these things matter much less across the pond, let alone in California. I hope the rumour is correct or stimulates the factory or some other outfit to look at it.

[Nick Lappos]

Generally, diesel engines weigh considerably more for the same power, because of the heavier structure in the engine to withstand the very high compression required to ignite the fuel. Diesels burn less fuel in the job, though so they offset some of the engine weight. Diesel aircraft are rare because of the weight issue.

[Lu Zuckerman]

There are two types of Diesel engines. The one mentioned by Nick fires by the heat of compression and in many cases has a blower of some type acting to pre-compress the charge although some compression Diesels do not employ a blower. As Nick indicated this type of engine is quite heavy for its’ physical size. This type of engine is normally of the two-stroke type and runs at a lower RPM than the engine type described below

However there is another type of Diesel engine (referred to as Hesselman Cycle) and this type of engine uses glow plugs to ignite the fuel and as such does not require the robust structure employed on a compression Diesel engine. As a result they are much lighter in weight. There are several German companies developing radial Diesel engines for use on aircraft.

[Duncan Ogilvie]

As stated by widgeon, a similar topic was discussed in rec.aviation.rotocraft. The original post had nothing to do with diesel engines in Robbies, however the discussion turned in that direction. There was speculation about an R55 / R66 – turbine, turbo, diesel etc … all speculation !

One of the things that was uncovered was that there are a few companies developing diesel aviation engines. The first consensus was diesel’s will never hack it, they are too heavy ….. well if we examine the Zoche vs the Lycoming we get :

ZO 02A 530. .Height 25.5 24.5. .Width 25.5 33.3. .Length 32.9 37.2. .Weight 271 369. .HP 250 300

Zoche also claim sea level performance up to 9000 ft. Believable if you consider the major advancement in diesel technology in the past 2 years or so. Ever driven the latest BMW 530D. Before I get shot down, I know the BM doesn’t have a Zoche under the hood, however technology has advanced and performance / reliability has had a serious shot in the arm.

I’m a recreational pilot and only fly for the pleasure of it and all my flying is done above 6000ft, in fact I have only ever logged 1.5 hr at sea level. If there were two 44’s next to each other, one standard and the other diesel, it wouldn’t be a difficult choice for me to make to fly the diesel version. We always joke here, the 44 is a great 2 seater ! Considering we all trained in the 22 and still fly them all the time, maybe there should also be a diesel option for the 22 !

[gasax]

The weight issue is no longer such a big deal - I would hesitate to use Zoche as an example - he has spent more money on attending Oskhosh than on developing his engines! However if you look at the Thielert it has a similar firewall forward weight to an O-320. The Thielert is 135 hp and obviously the Lycoming 160. Once you are over 3000' then the Thielert is more powerful. Now given that the Thielert is a Mercedes conversion the arguments about diesels being a lot heavier seem to fall to bits.. .Dedicated designs, I suppose the Wilksh is closest at the moment should be a lot lighter - the 120hp wilksch has a target weight of 100kg, versus the 137 kg of the Thielert.. .Even the Renault engines are said not to be much heavier - and the fuel burn is so much lower that the extra weight is not a handicap.. .Given European fuel costs there is a real need for these fuels - lets hope the rumour is true!

[IanSeager]

I know that it is an aeroplane and not a helicopter but I've flown a PA28 fitted with a 1.7 litre diesel in Germany and there is a DA40 flying in Austria with the same engine. Diamond hope to bring the diesel version to market sometime later this year. In addition they hope to fly a diesel twin (aeroplane) at ILA Berlin later in the year. SMA are also producing aero diesel engines.. .<a href="http://www.thielert.com/en/index.html" target="_blank">Thielert</a>

[Vfrpilotpb]

Whilst Diesels now seem to be the fashionable thing for GA FW's to think about, I do feel that a thumper in the back of any R22 or R44 would be very counter productive, in my humble opinion the only way forward for the light helicopters is to go turbine, Now the R44 with a turbine and a three or four blade head, and individual cyclic's would be somthing that would be worthy of sitting in everyone's front garden, it might even allow the rear end of the R44 to be finished off properly, rather than look like it has has some collision with a low brick wall! After all we are told that the Jetranger is being stopped, so uncle Frank could step in and take the lead in small privatly owned Helis for the future. :)

[widgeon]

If someone could come up with a small turbine that had reasonable purchase cost and more importantly overhaul costs then it would be possible.R44 is currently 310K USd extra purchase cost with current certified turbines would be closer to 500 K usd ( Engine exchange cost is 21K allison 250 is closer to $200 k ). Operating cost is 124 USd/hr , turbine overhaul reserve would add minimum of $50 an hr. The Enstrom turbine has not been exactly flying of the shelves .

[IHL]

There is a discussion about diesels on the TECH forum.

I think they would be a great idea as in remote areas it is a lot easier to find jet-a1 than avgas.

Another benefit if there are many aircraft working at a remote site i.e. forest fire fighting . .the contracting agency would only need to stock . .1 type of fuel .

[lmlanphere]

I wonder if anyone has thought about fuel cell applications for light aircraft - seems to be the wave of the future for cars - if you listen to the media.

[chips_with_everything]

I think the diesel heli idea has a lot going for it.

As well as fuel commonality mentioned earlier a decent range might be possible.

Being more efficient there's less waste heat to lose, and presumably less useless time needed for warm up and cool down.

Possibly more tolerant of abuse, and surely a longer TBO just like road engines.

For me the greatest bonus is losing the magnetos and carby ice.

Brilliant, hope they do it :)

[mihael]

1. Avgas is the only leaded fuel around here. Since the airplane fuel usage vs. automotive usage is just a drop vs. ocean. Not only ecology but also oil rafineries will drive out avgas - (not all engines can accept Mogas).. .2. Current piston engine designs are unbeliveably obsolete,(thirsty, ecollogicaly unacceptable, heavy) Nor Lyc nor TCM considers any radically new gasoline powered design - they even work on their own diesels (maybe to little, too late). .3. Small turbine which is affordable, is not achievable (yet). .Considering these facts, SMA (Renault), Thillert...diesels are the way we will go in piston engine powered aircrafts.. .First Tillert conversion is hopefully coming to an aeroclub nearby - I`m barely waiting to check it out!. . Mihael

[baranfin]

I remember seeing on the discovery channel a bus that was powered by a small turbine, I was not sure of the model or manufacturer but it was used solely to generate electricity for the bus. It was also very fuel efficient. Perhaps the technology does exist?

[Head Turner]

Now that the fixed wing fraternity have a Jet A powered craft when will the rotary wing manufactures follow suit.

Why should helicopters designed in recent years be powered by engines of the 1930's?

Will Robinson, with it's huge output of rotorcraft lead the field?

Anybody know anything on this?

[Helinut]

HT,

Its an interesting thought - there has been at least one extensive thread in the past with, as I recall, all sorts of interesting perspectives. Have a look when the search function is operational.

It would not half bring down the cost of operating an R44, for example.

[Aesir]

Just two weekes ago I sent a e-mail to Schweizer asking if they were considering installing a diesel in the 300C. Maybe something like the SMA 230 hp engine.

I received response immediately and they said they were indeed considering diesels but at the time they were not an option due to cost but they were following all advances in the diesel tecnology.
They also said that the SMA diesel, although in the same horsepower category as the HIO360 D1A Lycoming at 225 hp was to heavy to be feasible.

[Dave_Jackson]

This web site may be of interest; DeltaHawk Diesel Engines (http://www.deltahawkengines.com)

Ditto for the second half of this page; The Front Royal Unicom (http://skylinesoaring.org/FRR-NEWS/200404.pdf)

Dave J.

[rotorrookie]

I think this one should also be here "Randcam Rotary Diesel" at least it has power to weight ratio around 0,34kg/hp when most piston engine are between 2-3kg/hp. lycoming maybe 1,5kg/hp
so from fact that you could have 230hp engine that where 80kg
sounds to good to be true
http://www.regtech.com/ (http://)

[B Sousa]

Ah, the advances in technology. How about maybe a Coal/Wood Fired Steam Engine. That way the Robbie could justify a flight engineer also to shovel fuel.......
Better yet...Nuclear Power.....The new age of Crash and Glow.......

[CS-Hover]

Hi

diesel in aviation, is still making is first baby steps (in the fixed wing world) so to "jump" to the rotory world, will take a little more time (i think ... :O )

plus, if you think, for example, in the "Uncle Robby" models, where we like it or not they are the best/more selled models, until there is a "new kid on the block" they don't need to improve/go step futher using diesel engine... (don't know if make my point... :hmm: )

only to know, another brand that advertises aero diesel engines for years, but still don't know how it goes this days is

ZOCHE aero-diesel (http://www.zoche.de/)

happynewyear
regards

[CRAN]

Diesel engines will never be the best choice of engine for helicopters, unless the objective is to have a helicopter whose sole purpose is long range flight.

If any of the manufacturers were to design a new helicopter today they would not choose a diesel engine over a Ly-Con, Bombardier or turbine. For the simple reason that the weight of a diesel engine in a helicopter would marginalise the performance of the machine to such an extent that it would not be worth bothering! Yes, Avgas is expensive and yes, helicopters burn rather a lot of it, but even in 'rip-off-Britain' the fuel cost is typically only ~25% of the true operating cost of the machine. Further, if we all switch to Jet fuel then how long do you think it will be before the government bump up the tax on jet fuel for GA customers!

Helicopters designed and built today will be in service for at least 2-3 decades and so critical design decisions like the one relating to the powerplant must be made to create the best helicopter possible and not pander to current tax laws for an apparent 'easy-saving' on DOC. Imagine what would happen if the government increased the tax on Jet fuel for GA users and a manufacturer had just built a new machine with an over-worked aero-diesel engine (to get a sensible power-to-weight). The machine would be more expensive than a Gasoline/Avgas equivalent, would have less payload, perform worse, require more maintenance and would likely be less reliable (for a number of reasons)...then the tax goes up and all of a sudden its no cheaper to operate either! Just food for thought…

Also if a manufacturer was going to design a new engine for a GA helicopter it would not be a diesel engine - as they will always be much heavier than any of the serious alternatives. It is possible to design modern gasoline engines that are very efficient (in comparison to existing aero 2-stoke diesels and in particular Ly-Con engines) and there are many other propulsion technologies that provide interesting opportunities.

Diesel cycle engines are not the way forward for helicopters, as we will all see in due time.

Hope this helps

Christmas CRAN
:ok:

[Hughes500]

Cran

Please explain how some Swedish guys have a 300C up and flying with a diesel. Pilot mag about 6 months ago. A modern diesel engine is close to 75% thermaly efficient, is pretty light and produces a serious amount of torque.
Compared to a 1930's engine - eg HIO360D1A in a 300C which is very expensive to run and maintain.

Lets face it we have put up with rubbish engines for way to long. I have recently been training the owner of one of the big GB rally teams. You should see his face when one explains the finer points of a Lycoming and Magnetos !

A question for all you piston rotorheads - if you spent £ 15000 on a car would you expect it to use 1 litre of engine oil every 4 hours / 300 miles ? i would be taking it back to the manufacturer, The Dept of Trade and Industry would be sueing over " not fit for purpose " But us aviators will spend £15000 on overhauling the lump of Cra_. !!!!!!!!!!!!!!!

[NickLappos]

Hughes500,

Cool your jets. If you have an engine that is 75% thermodynamically efficient, run, don't walk, to the patent office, you are an instant millonaire!

The hype in the above posts is like those internet legends about an engine that runs on water, but is suppressed by the "oil companies" or some such truck.

The figures given by rotorrookie are truly from a rotor rookie, the typical helicopter gas engine weighs about 0.66 Kg per HP, not the inflated numbers he found somewhere. While there might be some advantage to diesels in aircraft, I think the data must speak for itself, and it should be good data, not that drawn from sites that are selling.

I'd suggest that you have a bit of trust in the guys who build what you fly. Do you feel like the people who design and build the machines know what you do? Do you think the design engineers at the manufacturers wait for the latest "Pilot" magazine to help them drum up new ideas?

The engines we use are proven and work well. The margins in the helo industry don't allow much error in picking the engine. I am also intrigued by the web site that shows a diesel that is 10% lighter than a gas engine (nice trick, when the 17:1 compression ration dictates much higher stresses and more engine structure to withstand the ass-kicking thoise pistone give the engine). I am not saying that I disbelieve the diesel sites, but I surely would like to see their Type Certificate Data Sheets, issued by a strong governmental test org, before I took those figures to the bank (or trusted my family to the reliability of the engine they are selling.)

Frankly, the Deltahawk site impresses me, the figures look about right, and the engine is not overplayed. It will be quite something if they make a good FAA certificate, but they haven't even started down that path. Note the worry about endurance at high power. This is where you cut the nut in engine design/test. I wish them best of luck, but FAA test is when the fun begins, I think!

[Flight Safety]

Nick, here's the FAA Type Certificate for the SR305-230 diesel engine.

FAA TC - Societe de Motorisation Aeronautiques (SMA) SR305-230 diesel engine (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/7F891374B255D22986256EE4006F8AF7/$FILE/E00067EN.pdf)

SMA SR305-230 engine, general info (http://www.smaengines.com/enginesr.htm)

[delta3]

Cran

I am surprised with your firmness on the diesel 'unfitness'.
Does any one have specifique power figures and tendencies ? (Nick gives .66 Kg/Hp for avgas, of 1.5 lbs/HP, I would put diesels at 2.0 lbs/HP)
It seams to me that at least the diesels are catching up. At least in cars they really do.
In aero (wing) Thielert and their new V8 (certified now in the HP-plane) looks impressive.
It still is perhaps 100 lbs too heavy, but I think at full range it can, save almost 100 lbs on fuel, so in my opinion it is getting close. Tax can be a non- issue but lead is not just a tax issue it makes avgass expensive (somebody told me it only takes a few days to make the world production and it is quite expensive to clean the system after a production batch)

delta3

[CS-Hover]

Hi

again:

diesel engines are STILL making is first steps in "flight environment", because of many reasons... certification, reliability, etc...

but they will come to stay (i believe... :O ;) ), right now, with present models, it's not worthy to try to use them in rotor world because the bad thing's that they (still) have don't outcome the plus things they have, when compared it "normal" av-gas pistions
(weight/power, reliabilty, new tech/high cost, etc.. )

(in the fixed wing world, they already are making some ground ....)

maybe i'm nobody, and for sure that i don't know mutch... but if you believe in history, and you are in europe (sorry rest of the world), you can see how in the automobile industry, every one is going crazy with diesel, when, at what 10 15 years ago, diesel car engines were slow noisy undepowered smokysh and so one...
now every one whats a diesel.... :)

there was a great improvement in technology, high investment, etc... and a great pie of all auto engines became diesel..

if you think/extrapolate to de flight cene, and remember that the piston engines technology, has allready a "few" years old, plus a huge investment in this "new" diesel tech... will see that in few years there will better diesel engines and will overcome in some aplications the "old" av-gas pistion...

regards

happynewyear

edit: to put a few more lines

the fuel consuption is another issue (you can see with auto industry if you like), vif you can have the same power, it more or less the same engine weight, but with a lower consuption, it's not dificult to guess to where "everybody" falls ;)

even more truth, in rotor world (i will not give numbers, because i don't have any, but if anyone have... lets see..)

pick an piston engine heli, see how much fuel it carry and how much uses in a given time (so far , all possible), pick an "example" engine (say it's the same size / power and weight... maybe not truth right now, but will be... or will weight the same, and "drink" less, or will have more power..), and make the math to our heli, with this new engine... ans see how much payload you can carry or how far you can go more

regards

[Flight Safety]

delta3, the above mentioned SR305-230 comes in at .83kg/hp or 1.84lbs/hp (based on installed weight of 423lbs(192kg), and 230 hp).

[3top]

Hello everyone,

the quest for diesel-power is not so much for "true diesel power" as in "compression ignited fuelmix", but for an engine that is substantially cheaper than a turbine and can "eat" Jet-A or Diesel.

Gasoline costs are getting out of hand in a lot of parts of the world.
In Europe, a diesel conversion that costs twice as much as a new gasoline engine is amortized in less than 300 hrs flying!!
Jet-A is cheap and available everywhere.
So it is not necessary to have a REAL Diesel engine, but rather one that can burn Jet-A/Diesel in some way...

I guess Mistral-engines of Switzerland will be the first to certify a Jet-A powered engine at about the same cost as the Lycosaurus engines.
As far as I understand the engines are rotary-design (like the Mazda rotary car engines). Naturally aspirated or turbocharged 2 and 3 rotor engines from 190hp to 360hp, gasoline or Diesel/Jet-A burning.

The Jet-A versions will have a computer controlled fuel injection AND IGNITION! So it does not need the diesels inherent need for ultrastrong structure.
A relative low overhaul-cost after a 3000 hr TBO should help to float the product too. Certification for the gas-powered 2-rotor engines is expected for 2005.

Mistral also flys a Turbo Arrow III with Embry Riddle in FL, no problems so far (this is a gas-powered one....)

The Jet-A burner is running on the dyno already.....

Check it out!! http://www.mistral-engines.com/


3top:cool:

PS: The Mistral engines match or beat the power-equivalent Lyc/Cont engines with installed weight incl. systems - cooling, etc.

[2beers]

The way I remember it from my fw-flying, wasn't NASA involved with a couple of companies to develop new engines, including cheap turbines? Now that is definately much more interesting.
A small sturdy FADEC-turbine with a simple design, yummy!

/2Beers

[rotorrookie]

The figures given by rotorrookie are truly from a rotor rookie
Well Nick I got these figures from that website without taking a second look but when I run over them again I see that 2-3kg/hp isn’t even close to modern piston engine (more like flathead hurricane engine from 1940´s jeep)
If we use figures from the comparison sheet on the Delta hawk website for Lycoming360 that says it weights 148kg we have power/weight ratio around 0.74kg/hp

So if the numbers for the Randcam being 0.34kg/hp is true, they got great advantage over piston engine, but they probably not even half way down the path and I doubt this will be the same number they end up with when reach the far end, if they ever will.

p.s. Nick I promise to be more precise next time, don’t want to be rotorrookie forever :{

[NickLappos]

rotorrookie,

This is a great thread, fear not, and thanks for your contribution to it! That was too good a snipe to pass up!

The data on the Deltahawk engines show them at the same weight as the equivilent HP gas engine, which is closer to what we could expect. The estimates about overhaul costs also seem very low, since these engines are turbocharged, which brings a pretty fine set of components into the game, despite the simplicity of the deisel itself.

The Mistral engines are much lighter, but they are rotary engines, and no rotory can achieve the fuel efficiency of a piston engine, so I would expect their fuel burn to be like a gas engine or perhaps a bit higher. I note that they don't publish any fuel figures (or did I miss them?) Also, rotary tip seals have not yet been perfected, I think (but have no recent data on).

If these engines can pass the cert tests, and show good reliability in the field, they can certainly liven up the field for our piston members!

[Flight Safety]

Interesting differences between the Deltahawk and the SMA diesel engines.

First, the Deltahawk is a 2-stroke, while the SMA is a 4-stroke. This yields best BSFC figures of .39/lb/hp/hr for the Deltahawk, and .35lb/hp/hr for the SMA. The Deltahawk has a very strong torque curve, but you would expect that from a 2-stroke engine. That could be useful in a helo application.

The Deltahawk is a V4 while the SMA is a flat 4. This makes the Deltahawk more compact and lighter (it's also lower powered so it's lighter for that reason as well). However the Deltahawk is liquid cooled and requires a radiator, while the SMA is air cooled. I'm not sure how well a radiator on a piston helo would work out though.

[bobknowledgy]

Hi Everyone,

Currently in the automotive industry, diesel engines are now performing with better output than petrol engines.

The major manufacturers are building engines with 50Kw/Litre which is equivalent to most petrol engines (not racing engines). The difference is that the torque output is equivalent to a petrol engine almost double. This is achieved through the use of electronic injection and "common rail" technology.

An example of this is Peugeot's diesel in it's 407 line, it's 2 litre 4 cylinder engine produces 100Kw and 320Nm Torque @ 2000 rpm (236lbs/ft). That's equivalent torque to most 6 cylinder 4 litre engines!

Torque in both fixed and rotary wing is very important, that's why we have been using large capacity petrol engines for so long.

Fuel burn at maximum power/torque is around 25% below petrol engines, and would be significantly more compared to larger older designed air cooled flat 4's and 6's.

Although these engines (diesel) are very suited to aviation, especially their torque, reliability and the safety of a lower flash point (less likely to catch fire), it will be sometime before we see them in our rotorcraft, mainly due to the high cost of r&d and the low unit sales figures of helicopters (very low return on investment).

However I am sure it will happen. The same as hydrogen powered cars are our future, but we will not see them on the roads in the near future due to the large revenue return governments around the world derive from the oil industry.

[rotorrookie]

In the Deltahawk performance sheet for the 200hp it says 7gal/hr at 65%(130hp) power and 11.2gal/hr at 100%(200hp).
The 300C with Lycoming 360 IO doing 12gal/hr at 85%(190hp).
I thought diesel engine main advantage should be good fuel efficiency, but you never get good fuel efficieny from a 2stroke specially at high engine output.

So to stay in tha fuel consumpsion range the Deltahawk would have to be 300hp at 100% to give us 195hp at65%.
How much will 300hp Deltahawk weight? maybe little more
And would it burn more fuel? likely
Maybe Deltahawk works well for small fixed wing but after all probably not as well for helicopters.
:confused:

[rhmaddever]

Hi,

The whole weight issue is a bit of a blind statement - The performance of Diesels continues to improve - and weight will only be reduced in the comming years.

The Diesel Engine would be ideal for a Helicopter - because of what a diesel is good at - That is running at low revs all day!

Even the best Diesles will top out at 5000rpm -



Isn't the question therefore wheather or not we can design a suitable gearbox? Can we really have a diesel flat out at 4 - 5000rpm geared up enough without losing power for even an R22?

Just a thought

Rich

[NickLappos]

The actual issue is not comparing modern, newly developed turbo diesel with ancient, 30 year old technology gas engines, is it? If diesels just coming out of research can rival today's gas engines in weight, it is probably time for the gas engine manufacturers to redesign their engines to get more weight out and beat the diesels. Inherently, gas engines will be lighter, since the stresses of 9:1 compression are much lower than 17:1 of diesels.

I would expect that the same tools that made diesels approach gas engines (CAD design, close attention to thermodynamic processes, water cooling, rotory technologies) should let gas engines reduce considerable weight and widen the gap.

Competition is good, let the games begin!

[HeliEng]

How about this for a diesel????



Diesel Engine Link (http://www.bath.ac.uk/~ccsshb/12cyl/)


Don't think it'd fit in your average R22





"Mad as a mooing fish!"

[Giovanni Cento Nove]

A big hurdle that has yet to be discussed here and can be hugely expensive to address is "torsional vibration".

An example - look at the difference in TBO and finite life of the TR gears in a 300C versus 500C. Exactly the same gearbox but massively lower lives when fitted to the piston machine.

Avgas burns slower than Jet or Diesel in a piston engine and the power spikes are lower and longer. With a diesel this while be a real problem to damp without introducing mass of some sort.

I always find it amusing when people think they can just put a car engine in an aeroplane and away you go. Has never really happened yet has it? Wonder why? The operating regimes are miles apart.

[leemind]

I always find it amusing when people think they can just put a car engine in an aeroplane and away you go. Has never really happened yet has it? Wonder why? The operating regimes are miles apart.

Well, it has actually. Take a look at Diamond Aircrafts DA40 and DA42 Twin. Powered by Thielert Centurion 1.7 Turbo Diesels which are modified Mercedes A-Class engines. http://www.centurion-engines.com/index.htm

The DA42 Twin crossed the atlantic on 72 gals of fuel! If that isn't efficiency I don't know what is. Maybe that particular engine isn't powerful enough for even the smallest heli, but Jet A1 burning pistons must be the way forward for aircraft like the 22 or 300

It might make them vaguely affordable (nahh, who am I trying to kid)

fly safe

[Vfrpilotpb]

Heli,

I love that big engine, please would you post a piccie of the Rotor, ...I bet thats a big rascal!


Nothing Beats HORSEPOWER.


Vfr

[ShyTorque]

The problem with "Gas / petrol" fuelled engines for European use is that the fuel (AVGAS) itself is so expensive, also fewer outlets are now supplying it. AVGAS is environmentally unfriendly due to the high lead content (much higher than motor fuel ever contained, despite the "LL" suffix).

The modern aviation diesel engines are being specially designed to use Jet A-1 fuel which is much cheaper and available at many more airports.

A diesel engine cannot suffer from carb icing (there is no carb) and has no ignition components to fail in flight. There is also no mixture control to worry about.

I am certain diesels are the best way forward (pun not intended!) for light aircraft. :ok:

[Robbo Jock]

Is that the new diesel conversion for the Mil 26 ? :}

[Giovanni Cento Nove]

Torsional vibrations (http://www.lovejoy-inc.com/Articles/article-newtwiststodieselvibration.htm)

So you have a little more insight to the issues.

leemind

I am aware of these engines. Yet the engine does have a reduction gearbox and a torsional vibration damper fitted as well which more than likely only matched to the MT propeller. This part of the adaptation probably accounts for 30% of the weight. Add in the torsional vibes from a rotor system and you have some major issues.

Ideally of course the drive system will need better integration to achieve the desired result - read clean sheet.

[ShyTorque]

Of course there are normally some problems with any new direction of technology. I'm certain the problem of vibration can be dealt with by design.

For example, one could even drive the gearbox with a couple of rubber bands. On second thoughts, no-one would fly in a helicopter driven like that, would they? :E

[Flingwing207]

The Rand Cam and Dyna-Cam engines certainly are a lot smoother in their torque delivery than a conventional piston/crankshaft recip. One or the other could easily find its way into that 250 - 400 SHP market as an economical alternative to a small turbine.

BTW, a 2-stroke diesel does not suffer from the same efficiency problems as its premix/petrol brethren. Their power/weight ratio goes up a lot, while their fuel-for-hp rate gets only a little worse. If you need the power, 2-stroke diesel is the way to go!

[glyn thrash]

what do you guys think of putting a diesel engine in heli's?? i am thinking of putting one in mine. www.copter.com.ua ,

here are the engine's:

http://www.smaengines.com/index.html
http://www.zoche.de/
http://www.dynacam.com/Index.htm
http://www.deltahawkengines.com/
http://www.centurion-engines.com/c17/c17_start.htm

some of these are close to certification with the FAA and some are not.. what are your opinions??

although the Dynacam engine is very radical, it is just simply a cool looking engine!!

[Thomas coupling]

thats ok then - as long as it looks good!

[claytona]

This helicopter you want to put the diesel in looks like a 269 or 300.
How can you have solid landing gear with a 3 blade rotor? Is it rigid like a BO105?
What is the current engine?
Thanks
Clayton A.

[slowrotor]

Diesels are typically quite heavy because of the 17 to 1 or so commpression ratio.Helicopters have favored low weight engines even if thirsty for fuel.
If a long range helo is desired, then a diesel may make some sense, because the fuel weight savings could offset the heavy engine.
My diesel tractor seems to leak almost as much fuel as it burns (just kidding) 5 gallons will run it all day.
Diesels have good low rpm torque and that would help reqain low rotor rpm in flight.
Consider the shaft dynamics and stresses that would be very different for a diesel.

[glyn thrash]

the current engine is a sub-EJ 25

[Flingwing207]

I favor the DynaCam, as it has the best pwr/weight ratio and will also provide the smoothest rotational power. I think it also provides the easiest packaging options. However, it is a gas engine (albiet one that will run on mogas or avgas).

On the diesel side, I like the Zoche and the DeltaHawk, both 2-strokes with four-cylinder 90-degree opposition which will also provide acceptably smooth rotational power. However, the Zoche line seems to be missing an engine right where you would want one, in the 180 - 220 HP range. Also, you would have to devise a cooling-fan arrangement for the Zoche.

I think the flat-four 4-stroke diesels will be too heavy and their power pulses too strong for your use.

[sparks and stuff]

On the subject of compression ingnition engines for helicopters then how about the realy excelent engine from Wilksch?. This is a very clever modular designed engine that has fantastic power/consumption/torque figures. This engine would be a fantastic replacement for the aging lycoming fitted to light helicopters such as the R22. Advantages would be the fuel consumption (and lower price of Jet A-1!) and total lack of any dependancy on electrics to fuction. With direct injection there is no danger of any form of carb icing. There would also be long term savings in maintenance costs with no plugs,leads or mags to worry about.
The engine is a bespoke design rather than an adapted car or truck engine and considering it is by a Cosworth trained designer, comes with the very best of pedigree. It can only be a matter of when rather than if that we will convert to this type of engine. If ,in America, you had to pay UK fuel prices then it would be here now! www.wilksch.com

[IHL]

I think diesel is the way to go.

Automotive diesel is relatively cheap and readily avialable. Jet fuel is also readily available, I think there may come a time when avgas becomes difficult to find.

[Finnmoderator]

Glyn or Pepper or what ever you want to call yourself today, repeat after me: Diesel engine, I need a diesel engine.....:}

[Dave_Jackson]

How about putting an air engine from an air car into an aircraft?

The Air Car (http://www.theaircar.com) :O

[Graviman]

Industrial diesel engines are big, because they are expected to have a service life of 15'000 hours and must meet emission standards (ie low RPM). I have uncovered some interesting facts:

Rudolf Diesel intended to achieve 240 Bar in his engine, with fuel injected to achieve isothermic expansion. This would get around most emission problems, allowing much higher RPM. Modern diesels are up to 170 Bar and so, with improved injection technology, can spin at higher RPMs. Some way to go though...

The limiting factor on pressure is the small end bush. This must package into the piston, and is splash lubricated. Ceramic coatings are allowing higher bearing stresses, with less cooling requirements. Larger pistons, however, allow more heat to be rejected at TDC, resulting in less benefit from higher pressures.

Cylinder liners can be coated in ceramic material, to reduce heat rejection. Higher pressures become more practical. This also allows lower friction losses, improving efficiency. Liners also result in a block that weighs no more than a gasoline engine.


The practical upshot is that diesel engines are the fastest evolving engine technology out there. A 2-stroke turbo diesel could be thought of as a 2-stage gas turbine, with very high pressure ratios. I expect that not only will all (small) helicopters go diesel, but some may even go diesel/electric hybrid! This allows optimum rotor design for many different mission profiles, without the complexity (say) of multiple engines...

Mart

[3top]

Hi Nick,

a little late for a reply, but better late than never!
Congrats to your new post!
Are we goin' to see some Gulfstream-helicopters soon?:)

To the Rotary engine:

Seals are not a problem any more - actually since decades.
Also Mistral will probably offer Ceramic seals as an option in the turbo engines, which should outlast the TBO of the engines.

Also the Mistral gasoline engines are on par or slightly better than the Lycosauros on BSFC. If you are interested I can forward you some test data from Mistral or put you in direct contact with them.

The missing data is from Lycoming, as they do not publish any consumption data over 70% power!! But what is available shows at least even or better efficiency on the Mistral. However you probably cannot compare these numbers with anything on the road - on the other hand anything from the road would never last in the air at the required power levels.


To all:

The real problem with the diesel is that after you pass a power level of around 135- 160 hp, the engines become rather heavy.
Thielert promoted his V8-turbo diesel at 300 hp. Now it is out at max-cruise 260hp - around 600 lbs !! And no TBO, but TBR (time before replacement)
You can't compare car engines with aviation engines. The duty cycle in a car engine is roughly 35-40%. In an aircraft engine you have it running between 70-100% all the time.
Toyota certified its V8 gas engine at 300hp max cruise - TBO 300 hrs!!
The one exception is the rotary engine as it is very compact and robust - if configured it will outlast any other piston.

For now the best you can hope for is something like Mistral - Jet-A burning with ignition - potential power level that can be reached easily is around 450 hp max continious, after that the price/weight/power relation probably favors the turbines again.

Just a side note: Hartzell never made a heavier prop than the one for the SMA diesel ( for the power transmitted) the lighter props would shatter after a short time due to the power pulses from the engine!!

Cheers,

3top

[Head Turner]

There is plenty of technical data here and from an overview it would seem that helicopters like cars are heading for diesel power as the better way of powering small light helicopters.

I have to admit that I prefer the diesel car to it's gasoline brother for the better fuel consumption, longer life and better torque. Emissions also are environmentally more friendly.

My question is 'Who will be the first manufacturer to provide a diesel (Jet A1) powered helicopter'. Will it be Frank?

[airborne_artist]

It should be borne in mind that diesels have a much narrower power band than petrol engines - hence the need for a 16 ratio box on a large truck, and why car drivers comment that they are more frequently changing gear in a manual box diesel.

Would this characteristic have a bearing on rotary suitability?

[Graviman]

Powerband is only limited by emissions, and installation, but not engine design . Usually it is most noticeable in turbo diesels. The combustion speed, hence RPM, is limited so that you need more torque for power similar to gasoline model. Trouble is it's likely to be a derivative of the same gearbox, so that limits torque. The net result is that the max torque ends up closer to the max power, so smaller power band.

Since helis are constant RPM machines, i see no problem with a diesel installation. If anything a turbo diesel is ideal, since all can be matched for single RPM operation.

Mart

[3top]

If you want to make Diesels for helicopters you will need a minimum of 180 hp at no more than a Lycosaurus's weight - at that weight it will not last 2000 hrs - not even 500.
Not counting for the heavier clutch/damper/trans you need to deal with the sharp torque spikes with every power stroke...
For anything bigger than a R22 you will need more likely 300hp at some time in the performance charts.
Again the only Diesel close to these numbers is the German Thielert V8 with a max cont. power of 250 or 260 hp at 600lbs!!

However if Diesel or better Jet-A burning is good enough for you, watch for the Swiss Mistral-Engines.
If they pull off their 1st certification this year or next, I bet you will see a 360 hp Jet-A burning 3 rotor-turbo engine within 4 years! 3000 hr TBO at no more than $10000.- of todays value (for the overhaul!! Compare that to a Lycoming...), at a weight of no more than a Lyc 540!

3top


:D

[CRAN]

A german company MK Helicopters displayed the first prototype of their MK3 helicopter at the Aero2005 Airshow at Friedrichshafen last month. This new machine on first glance appears to be the answer to many Rotorheads dreams, a diesel light helicopter!

The machine has an empty weight of 700kg, a MTOW of 1182kg and is powered by the SMA 4-stroke flat-four diesel unit, producing a maximum rated power of 230hp. The machine has a two-blade main and tail rotor with composite blades and is very, very nice to look at!

http://www.mk-helicopter.de/wEnglisch/img/mk3_eigenschaften_1.jpg

http://www.mk-helicopter.de/wEnglisch/img/mk3_einsatzgebiete_2.jpg

http://www.mk-helicopter.de/wEnglisch/img/mk3_einsatzgebiete_1.jpg

http://www.mk-helicopter.de/wEnglisch/img/mk3_motor_en.jpg

http://www.mk-helicopter.de/wEnglisch/bildergalerie/galerien/MK3_Prototyp/1166.JPG

http://www.mk-helicopter.de/wEnglisch/bildergalerie/galerien/MK3_Prototyp/1176.JPG

I think this machine has a great deal of potential, but appears to have a VERY low power-to-weight ratio, which I fear may criple the machines performance. My guess is that during flight test they will find they either have to accept lower than claimed performance or a significantly lower than advertised gross weight. I hope not though; if they can offer what they claim at a price somewhere between R22 and R44 then they have a winner on their hands!

Good luck to the MK Team!

CRAN

NOTE: Edited to ad web address; www.mk-helicopter.de

[Aesir]

Veryvery nice helicopter.

Looks like it can be flown RH seat with 2 pax!

Also looks like they are planning to have the Garmin 430/530 pack on the center console. The G-1000 would be even better!

Crashworthy seats, probably required for EASA 27 certification.

I think the proposed TBO time for the SMA 230 is 3000 hrs. If that holds it a very big plus.

I can´t see any baggage hold? Hope they include some kind of baggage/cargo space!

Unfortunately great ideas for new helicopter pop up quite regularly and disappear just as fast! I hope this one makes it to production.

To have it powered by a diesel should make it a winner.

[delta3]

Whow CRAN

Do we witness a shift in opinion between dec 28 and june 11....


Delta3

[CRAN]

D3,

Certainly not! I'm always pleased to see new ideas and designs in the market place and so try to be as positive as possible, even when I don't agree with the approach adopted. You'll note that I immediately commented that the power-to-weight ratio is (IMHO) very low and that they are having to work the un-proven engine extremely hard just to achieve this low power-to-weight ratio.

Simply stated the machine will be underpowered and I personally would expect reliability problems with the over worked engine. In practise I think that the machine will have pretty poor performance; worse than that claimed and also when compared to the R44, simply because its too heavy.

I hope this clarifies things.:ok:

CRAN
:E

[Aesir]

Yes CRAN I absolutely agree with you that those performance figures seem to be overly optimistic to me as a layman.

However we do not know yet if the SMA 230 is overworked when producing 230 hp constant!

Usually aircraft engines are not designed like car engines, where the car/automobile engine is only designed to produce its rated horsepower for less than 25% of the time and aircraft gasoline engines for less than 75% continious power.

Lets hope the SMA and other diesel engines were designed to produce rated power 100% of their operating time, does any one know?

[CRAN]

Aesir,

A few years ago, when the SMA305 series first appeared (along with the other aero-diesels) I looked into them in rather a lot of detail with regards to using them to power light helicopters. I found that I couldn't satisfy myself sufficiently that you could expect to produce a diesel engine light enough while maintaining the level of reliability and cost-effectiveness that people seem to be claiming for the demanding helicopter duty cycle. Sure you can do it, with some expensive materials and clever engineering, but then you end up with an engine costing as much as an equivalent turbine and I know which I would rather have powering my machine!

For those that are interested an early report on the subject is given in NASA CP-3260, by Alex Brouwers, in April 1980, whom studied a configuration not dissimilar from that subsequently developed (but not brought to market yet) by Zoche. The report clearly highlights both the well published benefits and many of the technical challenges in the field that to my knowledge have simply not been addressed. Furthermore, the literature is littered with accounts of companies both automotive and aeronautical attempting to 'get the weight out' of diesel engines and failing miserably; running into enormous technical problems! Has anybody wondered why SMA, Wilksch, Zoche, DieselAir and Deltahawk Diesel have all been ‘developing’ engines for over ten years, even with their doubtless capability and credentials? Or why both Lycomming (with Detriot Diesel) and Continental (NASA GAP Project) have abandoned their efforts? There are some very good reasons I assure you…

I know I keep hammering on with the same point, but you simply cannot escape the fact that helicopters have one of the most demanding duty cycles of any application for engines, not least of which is the requirement for engines with and extremely high power-to-weight ratio (i.e. turbines optimised for the application). Diesel engines occupy the opposite end of the P/W spectrum, having one of the lowest power-to-weight ratios, so where is the sense in trying that! This is a simple fact that if ignored will lead to an expensive, underpowered, underperforming, bulkly white elephant. (No pun intended.)

I will follow the MK Project with great interest and dearly hope, for their sake, to be found to be incorrect.

Best Wishes
CRAN
:ok:

PS: Would you really want an engine in your helicopter that had absolutely nothing in reserve? No spare couple of inches of MAP! No five min or 30sec rating?

[3top]

CRAN,

if you are in contact with MK, tell them to talk to the Mistral-people in Geneva! ...maybe they already did.

Just to repeat it, the Mistral-JetA is not a real Diesel (their CEO hates the word Diesel by now!), but a spark ignited, direct-injection, JetA burning, turbocharged Rotary.
Their W/P ratio is at or better what you find in any Lycosaurus.

MK will get no where with the SMA - too heavy, and as you said " no spare MP" ", I also hope (for them...) they have some luggage-space - at least what Robinson has, or forget it!

Beautiful machine though!

3top
:cool:

[RotorDompteur]

Worlds first diesel engined helicopter...?

http://www.airliners.net/search/photo.search?regsearch=OH-HIN&distinct_entry=true

There has been a lot of talk but this is the first time I have heard of actual testing.

RD

[nigel f]

I wonder what it flys like with the TDI engine, they make lots of Torque but only about 170 BHP.

Does it run on normal Diesel or can it run on A1 JET ?


Nigel

[Graviman]

VW TDI is a good choice for a heli powerplant, since it is reasonably high revving so relatively light. I wonder if they have retuned it for fixed RPM operation. If lag is no problem turbo could have been pushed up, and cam may be altered, so max torque is on max RPM. Also emissions will not be such a consideration so they may run it closer to stoichiometric before the fuel limiter cuts in. All go to bettering that 170BHP figure, without seriously affecting engine life (since combustion pressure balances piston inertia - high torque at low RPM is worse case).


Mart

[Spunk]

I was just looking at the MK-Helicopter project. To me it looks as if they are using Jet A on their "diesel" engine. Why would you want to do this, use Jet A instead of the much cheaper "diesel".

When I first looked at it I was telling myself: great idea, good looking helicopter, finally something new, something more sophisticated then a Robbie or a Hughes.

But then again I figured out that it is just a project, following MK I and MK II (also good looking machines). And when looking at the main rotor mast...

http://www.mk-helicopter.de/wDeutsch/bildergalerie/galerien/MK3_Prototyp/1169.JPG

... well so far only that tiny little mast of a Robinson scared me.:}

[Graviman]

Well, i think 3-top has hit the nail on the head. The SMA engine is not a true diesel, in the sense that it is "spark ignition" and not "compression ignition". The main reason for high compression ratio in a true diesel is to get the ignition, which is where the weight comes in. I imagine that Jet A ignites far more easily than diesel, since this is how turbines are started.

In truth you can actually get good efficiency out of a petrol by pushing up the turbo boost pressure (eg VAG 1.8 turbo can offer 275 BHP, while still achieving 30mpg). You need to intercool the mixture to avoid detonation, and never quite get around the NOx emission problem (ie need a catalyst for auto use). The trouble is that by the time you've pushed up the "pressure ratio" enough to offer diesel type efficiency the need to improve crank and cylinder liners means the thing weighs as much as a diesel.

I suspect that as turbos become multistage, for fast response and high pressure ratios (along with lighter ceramic construction) petrol efficiency will improve - as long as the engine is designed for boost from the outset. Equally as combustion development continues (mostly through ECU injection control), diesel power to weight will improve. My own preference is diesel, since i see advantages in alternate fuelling and fuel metering for combustion temperature (engine at part load is also inherently efficient)...

Mart

[Head Turner]

Where in Finland can I see this diesel engined 300C?

I think it is a hypothetical item as certification issues would hamper any progress of this kind of technology. Or is the Finnish CAA more forward thinking than the majority of correspondents on this post.

IMHO I believe that there is never a reason for 'quoting' ''It will never happen on a helicopter as it will be too heavy''.

I once wrote that soon helicopters would be crewed by law enforcement agencies who would have gun/rockets fitted as a response to criminal activity, and I was shot down in flames by many who said it was impossible.
Well, what has now happened? There are seroius proposals to fit guns/misiles. So why is it not possible to have a light weight powerful diesel engined helicopter?

Of course there will be such machines, and sooner than the sceptics would believe.

The diesel helicopter is coming and yes the big danger is governmental taxation of GA diesel fuel.

If there is a popular item then the tax man will want to tax it, that's for sure. I would hope they didn't but my hoping will not save the world.

[CRAN]

Would you not be better putting all that R&D money, time and effort into something than is fundementally more suitable...

One example, 17kg (with gearbox removed), 200hp, better fuel efficiency than Lycoming:

http://savoiapower.8k.com/Images/Labala.jpg

Or following Inodyns efforts:

http://www.innodyn.com/images/img_prototype.jpg

Just food for thought...

Helicopters need an incredible power-to-weight ratio, so why not start with the type of engine that gives the best power-to-weight ratio?

Hope this helps
CRAN

[Graviman]

Site looks good:

http://www.innodyn.com/aviation/products.html

Couldn't see any quotes for fuel consumption. Don't forget an automotive diesel can achieve 200 g/kW-Hour which would be hard matched by a turbine.

Mart

[CRAN]

Is that really a benefit?

Most missions carried out by commerical helicopters require a flight time of less than 3hrs (@ cruise power). If we go to jet fuel then the cost of fuel becomes a relatively unimportant part of the operating cost, so we are back to considering the weight issue as the design driver.

Considering the total weight of the engine system as the weight of engine+fuel then for an example helicopter requiring 200hp.

SMA SR305-230 Diesel
-------------------------
Engine=225kg
3hrs Fuel = (200hp*0.36lb/hp-hr*3hrs)/2.2lb/kg = 98kg

Total = 323kg


SavioPower Turbine
---------------------
Engine=17kg
3hrs Fuel = (200hp*0.5lb/hp-hr*3hrs)/2.2lb/kg = 136kg

Total = 153kg

Therefore the turbine unit, despite using more fuel offers a 170kg payload advantage for a realistic mission which is the difference between 2-seats or 4-seats plus bags in your helicopter for the same power and MTOW. (Or 2-seats with high performance and a crash worthy fuselage depending on how you wish to spend your additional weight budget)

This is why I keep hammering on about diesel engines and helicopters. I love diesel engines, my car has a diesel engine - but I wouldn't dream of putting one in a helicopter because they are not the right engine for the job. Gravy, you correctly point out that automotive diesels are producing BSFC's of 200g/kW-hr. Sadly they wouldn't be able to produce this at peak output and thats how you would have to use them to get a helicopter off the ground.

Hope this helps
CRAN

[ShyTorque]

Not that I don't like turbines - I've been flying them since 1978...

But........

Don't forget to compare the other, possibly more important "power to pounds ratio", i.e. initial engine purchase cost and the subsequent overhaul costs. What might be acceptable for commercial ops may be totally unrealistic for a private aircraft owner.

Turbines can make your cheeks squeak and your eyes water.

:p

[Graviman]

Cran,

Thanks for your very informed posts on this thread.

"I love diesel engines, my car has a diesel engine - but I wouldn't dream of putting one in a helicopter because they are not the right engine for the job."

Good point very well made - my car too. I can definately see the weight advantage of a turbine. My real point regarding diesel is that if you were to design an engine specifically for heli usage, you would run at least 2 stage (or even 3 stage) turbocharging to get the best power to weight (ideal is also 2-stroke). The actual engine would be very "solid", but would be very small for the air mass flow rate. This gives a happy compromise between cost, power, efficiency, and weight. Think of it as a piston high pressure stage gas turbine, which strikes me as the future of IC engine design anyway.


"Sadly they (auto diesels) wouldn't be able to produce this at peak output and thats how you would have to use them to get a helicopter off the ground."

If the diesel was optimised for constant RPM apps, then i don't fully agree. Cam would put max torque on max rpm, which would make for an undriveable car. Turbo is optimised for this RPM, at max power, which (for single stage) introduces lag similar to turbine. Boost then becomes BMEP controlled, maintaining efficiency. Again the result is a compromise specific to heli duty cycle.

Mart

[Graviman]

Just found this site on VW diesel development:

http://www.greencarcongress.com/2005/10/vw_introduces_t.html

It does seem to point the way towards smaller diesel engines which are more dependant on multiple turbo charging stages. The problem is how to ignite the charge which, when intercooled, does not achieve the same temperature prior to combustion. The VW solution is to use spark ignition (at lower power settings).

At some point turbo-diesel development will begin to challenge pure turbines for aero applications...

Mart

[Gaseous]

One of the issues here is the taxman. A stroke of the chancellors pen could pretty much eliminate the cost differential as it did with automotive fuel a few years ago.

Make no mistake. The UK Government are aware of the tax advantage of diesel and are actively looking for a way to close this 'tax loophole' according to my local MP.

If JetA1 goes to £1 a litre will tubines look so attractive?

[TechHead]

Question:

How will the low temperature properties of diesel fuel effect the introduction and/or use of diesel engines on helicopters? Depending on the specifications of the diesel fuel used, wax crystals will begin to form round about -5 degrees Centigrade. Heated fuel tanks, insulated fuel lines, clogged in-line filters? I appreciate that you can buy winterized diesel but what effect does that have on price?

[leemind]

TechHead,

When people here talk about Diesel Helicopters they are talking about reciprocating engines (i.e. piston engines) powered by Jet-A1. Jet A1 has a freezing point of -47 Deg C and doesn't wax up like road diesel so is a non-issue.

Gaseous,

That is a scary thought for this industry... one stroke of the pen to double fuel costs... You can picture the scenario... JetA1 for "export" (i.e. international airlines) will remain the same, but any fuel used purely for within the UK (i.e. 99% of our domestic helicopter industry) will be taxed at the same rate as Avgas.... arrrrgggg

[Gaseous]

You can picture the scenario... JetA1 for "export" (i.e. international airlines) will remain the same, but any fuel used purely for within the UK (i.e. 99% of our domestic helicopter industry) will be taxed at the same rate as Avgas.... arrrrgggg

You got it in one, except that the UK government wants to see the end of tax free JetA1 globally. This is a tougher nut to crack than simply the domestic market - but that would be a start.

The background to my observation was a memo passed on to me about 2 years ago emanating from HM treasury addressing this issue and also the environmental 'implication' of tax free fuel.:yuk:

Government's position is it does not like the idea of tax free fuel and wants to end it but ICAO rules are a big obstacle.

I'll see if I can find the note and post it up.

[alicopter]

Hi all, I am new to this forum and would like to thank you all for the really interesting and good quality content. Happy New Year to all of you and your family. Keep safe.
My question is about the DeltaHawk's 180/200HP 2 strokes diesel engines.
Does anyone know if they are nearing certification for vertical mounting and what is your opinion as one of them as a replacement of Lycoms on light pistons ships? (mainly in self built/kits units such as Safaris/Cabris etc...)... I cannot get fresh news on the net... but going diesel seems really interesting. Any other suppliers? Cheers. Al

[fly911]

ILA 2010: A look at a new innovative EADS helicopter design - YouTube

[Graviman]

Not sure about status of deltahawk without checking website:

DeltaHawk Diesel Engines (http://www.deltahawkengines.com/)


Another very competant design to watch is the Wilsch AirMotive (also a 2 stroke design):

wilksch.net (http://wilksch.net/)


One development that really caught my eye a while back was Cubewano Diesel rotary:

Cubewano (http://www.cubewano.com/)

These last guys are a clever spin-off from the Norton/UAV rotary with a clever combustor design to handle either diesel or kerosine. Designs large enough for private helicopters are on hold pending DOD funding, which is a great pity IMHO.


Or you could fit a Perkins and sacrifice a little payload... :O

Perkins (http://www.perkins.com)

[Graviman]

Must admit to holding out there to see if anyone else would bite...

Actually the guys to watch are:

Startseite (http://www.austroengine.at/)

Because of this

http://www.austroengine.at/cms/upload/Technical_Data/AE_300_Technical_Data.pdf

and this

STEYR MOTORS and Austro Engine form development partnership for 280hp 6-cylinder aircraft engine | STEYR MOTORS NA (http://www.steyr-motors.com/na/news/news-single/steyr-motors-and-austro-engine-form-development-partnership-for-280hp-6-cylinder-aircraft-engine/b3cba3e7eddf7ed04ee7fd0811f582aa/)

Very neat installation in Diamond DA-42 which was on display at Helitech.

[stringfellow]

firstly i apologise for not reading the whole thread but on the recent safety course i sat next to frank robinson (i was gobsmacked when he turned up for lunch, but on the course thats what he does) and he said one major regret was not completing a diesel r44. but in his own words he just could not get the darn weight down!!! mr robinson is crazy about low weight machines and simplicity.

its close to his heart lets hope so one day.

[Graviman]

Yes, he also mentioned this at his talk at the R.A.S. (London). Diesel helicopters will come, particularly with the rate of development at Austra Engine.

Helicopters in the short term have to be designed around the current fleet of heavy Avtur JP8 burning diesel engines. You either push up rotor radius and solidity ratio, and drop rrpm to keep cruise speed. Or sacrifice a little of the efficiency gain by generating more downwash to lift that heavy engine. A challenge yes, but not unsurmountable. Cars went from about 5% to 50% diesel sales in roughly a decade, so I would say that diesel helicopters will be mainstream in a simar timeframe.

[Graviman]

TEOS 440shp diesel V12 (using Steyr M16 componentry):

http://www.teos-engineering.com/mbFiles/documents/article-aviation-week-space-technology-20120213-54218.pdf

GRC4: Integration of a Diesel Engine on a Light Helicopter | Clean Sky (http://www.cleansky.eu/content/interview/grc4-integration-diesel-engine-light-helicopter)

http://www.teos-engineering.com/mbFiles/images/galeries/thumbs/800x600/integration-of-the-v12-in-an-aircraft-cawlings_504310233.jpg

TEOS POWERTRAIN ENGINEERING - Diesel aircraft engine (http://www.teos-engineering.com/experience/diesel-aircraft-engine/index.html)

I'll be keeping a close eye on this one...

[HueyDog]

firstly i apologise for not reading the whole thread but on the recent safety course i sat next to frank robinson (i was gobsmacked when he turned up for lunch, but on the course thats what he does) and he said one major regret was not completing a diesel r44. but in his own words he just could not get the darn weight down!!! mr robinson is crazy about low weight machines and simplicity.


Oddly enough I had a similar discussion with Frank Schweizer a few years ago right after they had sold Schweizer Helicopters to Sikorsky. Today Sikorsky is barely interested in even continuing the production of the 300C series, even less interested in sinking any money into diesel powered light helicopters.

[Helinut]

The taxation risk is such a big issue with diesel applications in light aviation that any major corporation contemplating major development will be very cautious about jumping in and spending real money, it seems to me.

It is more likely that there is an incentive if Avgas disappears, which it probably will, given time.

You would not want to bank your pension on an aviation diesel industry, I suggest.

[Graviman]

Helinut, the engines should more accurately be referred to as compression ignition (C.I.) engines. They are burning jet A1 for which there is a ready untaxed supply. The main modification over a diesel burning CI engine is a fuel pump modified to use the sump oil and special injectors to cope with the reduced lubricity of kerosine.

[Graviman]

Must admit that I was suprised at the timescale of developing the Jet A1 burning V12 diesel (TEOS/Austro/Steyr) and then installing it in an EC120. This time last year the thinking was that first flight would be later this year.

http://www.ainonline.com/sites/default/files/uploads/310_dieselpicture2.jpg

Diesel On Track To Replace Turboshafts On Light Helicopters | Aviation International News (http://www.ainonline.com/aviation-news/hai-convention-news/2013-03-04/diesel-track-replace-turboshafts-light-helicopters)

Any news?

[Ian Corrigible]

Graviman,

AIN provided another update in this year's Heli-Expo show dailies: Europe’s diesel demonstrator to fly this year (http://www.ainonline.com/aviation-news/hai-convention-news/2014-02-23/europes-diesel-demonstrator-fly-year)

The modified EC120 iron bird (which includes an airframe) is located at the Airbus Helicopters factory in Marignane, France. Testing began last November, after extensive engine trials took place on a dedicated test bench earlier last year. No particular difficulty has been encountered since the beginning of the test phase, project officer Sébastien Dubois told AIN. Iron bird testing will continue this quarter.

The engine will then be installed on the flight-test aircraft. Modifications for the installation began late last year. Ground trials are planned to begin in the third quarter and the first flight is expected to take place later in 2014. The first flight was previously scheduled for April 2014.
The diesel-powered EC120 was originally touted for a flight in 2011 (http://www.ainonline.com/aviation-news/2011-03-03/eurocopter-delays-diesel-powered-ec120).

There's a dedicated thread on the project here (http://www.pprune.org/rotorheads/325863-ec120-diesel.html).

I/C