I built that airplane..All the RedHawks. I worked there from the beginning until the last RedHawk was completed. Like you said, great idea before its time.
And, as I said, priced before its time, hence the lack of buyers. An off-the-shelf four cylinder Mercedes oil burner shouldn't price out like a factory overhauled Rolls Royce M 250 turboprop.
@leonpano I have been looking at BMW engines for aircraft for a while now. The M57 was a great engine although rare now. The B57 is less ideal, but still a good option. Engines manufactured around the year 2000 were the best for aircraft. Engines produced now are far more complex for emissions etc that just aren't applicable to use in aircraft.
I saw a video of a cropduster (air tractor) severely modified to run a V12 diesel TRUCK engine. Running on Jet A, it was a real showpony, and could do a ballistic climb :)
Not a truck engine. Red V12 is made in Germany and no airplane is flying with a truck engines are cast iron. Engine swap is a major change and requires an STC from the FAA.
Just to be accurate it is "injectors instead of spark plugs" the glow plugs are more analogous to a choke for cold starting. Rudolf Diesel Invented timed injection. He did not invent high compression...
I've always dreamed of a diesel powered turbine in the Cessna 172's. No mixture levers, no magneto's, no carb heat, just a single throttle lever. Throw that baby and fly. I flew a 2000 model Skyhawk 172R for training but had to stop due to blackout spells.
I fly the CD-155 variants (155 HP max), out of a fleet of about 8 aircraft (F172Ms mosty, some F172N). Those outperform our traditional Lycoming-equipped 172M, according to pilots who fly both. The diesel 172s are the workhorses on airshows and open days, carrying passengers around on short sightseeing flights. The constant-speed 3-blade propeller gives a good acceleration on takeoff. There is no POH-limitation on climb, it could be 100% in all climbs, although we also throttle back to 85% at safe altitude, with all obstacles left behind. The diesel 172 is remarkably nice for long cross-country flights as well, because it has a high operational ceiling (FL180), so for me it is much easier to climb high and cruise fast in the rarer and cooler air. The basic empty weights are a concern though, like for all Cessnas with 2300 lbs MTOM, because the well-equipped aircraft are heavy, and I always run calculations on how we fit passengers, baggages and the fuel for each leg. But if you don't need to carry a lot of useful load, e.g., just do a long powerline or gas pipe aerial survey, you can enjoy unpleasantly long flights with the Long Range tanks in some of the aircraft, in excess of 6-7 hours in the airplane, due to the low consumption at economic cruise (55%-65% power). Here is a playlist of my adventures with the diesel 172s. ruclips.net/p/PL0xNTmAtxEUcOYS1cDb7FLmzW3XYVOxv4 At 3:37, just a minor thing, but for the precision nazis: AED = Auxilary Engine Display, CED = Compact Engine Display.
You are correct that CED stands for Compact Engine Display. The Normal Procedures Card from Cochise College (who originally owned all 6 of these planes) recommends climb at 85% and cruise at
@@grafhilgenhurst9717 aha, so It's a (precautionary) recommendation from the former operator/owner, and not a factory/manufacturer limitation. Basically then it's the same situation for both of us. Thanks for the the clarification, and also thank you for the video!
@@grafhilgenhurst9717 - Yet you stated it like an operation constraint, as though it WAS in the POH. I fly these in a school and we climb at 100% and have done for 9 years with perfect engine health and no issues. You want to get up quickly with these engines, as that's where they perform best.
Hi ! im preparing for 172TD exams , i would like to ask ,are the V speeds different compare to AVGASS / 172R ? cause in the 172TD POH , i couldnt find any V speeds apart from Vy , thanks !
@@karann4335 You should somehow find these speeds under SPEEDS FOR NORMAL OPERATION. I never flew the normal Avgas version, but my friends who do, they fly it in a similar manner, same speeds. The airframe is the same, aerodynamically it's the same aircraft. Perhaps the climb speeds are slightly different due to the better power-->thrust efficiency of the variable pitch propeller on the diesel variants.
WHY hasn’t THIS been a thing? Diesels..done right, are VERY efficient, economical AND POWERFUL. Again, done right it COULD’VE BEEN a very popular powerplant.
They also last a long time given proper care. I've got a well known brand of pickup truck that has a diesel engine. It's 18 years old and recently achieved the half million mile mark and runs great. Fuel economy as a daily driver is decent at 17-18 mpg.
I recently had the chance to fly the Robin DR401 with this CD-155engine. This plane is wooden and therefore lighter than the C172, so the payload penalty is insignificant. The engine was fantastic. Efficient, the constant speed prop gives lots of power. I believe that now where the engine belongs to Continental, it finally gets the marketing power it deserves.
Very nice, thanks. I have bet my life on diesels quite a bit in the past. Having them in my boat on ocean passages. I put over 20,000 hrs on mine with very minor issues. I know that this is different but if you give a diesel clean fuel, and air, it will run and run. I ran mine at times, 24 hrs a day, only shutting down to check vitals.
Here's a comment about clean fuel. In the 70's(?), Mexico got s bunch of money from the U.S. the govt in Quintana Roo started pushing back the jungle in order to develop land. My buddy took several 2 week trips to help them develop an irrigation system. He said there was tons of equipment scattered on a gravel road that led into the jungle. When the project stopped, the jungle grew back. He flew over the area and went to explore several nearby lumps in the jungle. What he found was Cats, some with paint still on the tracks, abandoned. With so much inoperative new stuff, he things they quit because of dirty fuel. He saw many empty/partial rusty barrels laying around. He set up a program to bring all those machines back, but the Mex national he was working with got assassinated. After that he never went back. Side note: As they built a road into the jungle, any rock they found was crushed to make gravel. He said they tore down many ancient Aztec artifacts and fed them into a rock crusher...which was still there..inoperative.
@@obsoleteprofessor2034 my brother and father had a farm in Belize in the 70s and early 80s and there was a lot of that going on. Mostly Americans and a lot of them were from Texas looking for oil and they knew absolutely nothing about working in the jungle. Same with Guatemala in the Peten’ region.
In 2008, I had to be trained on Cessna diesel 172 and Cessna 208 Caravan as maintenance instructor for the Iraqi Air Force. Funny thing is the main reason why Iraq wanted diesel powered 172 is avgas 100LL was not practicible but jet fuel could be used if diesel was not available. I did not get to be around those 172's as I spent nearly all my time working the King Air 350.
I watched the Iraqi Air Force flight the c130e, it was the must scariest thing I ever seen. They were all over the place when landing, I was waiting for them to crash as they bounced multiple times across the runway.
We converted 6 of these in our fleet. Had lots of problems with leaking radiators. Ours where rated 155 hp and had a great take off performance with an auto CSU and third prop. The nose tends to be heavy in the flare & the glide performance is reduced. I found them ok, but preferred the IO360...
When I got endorsed in the 182, my flight instructor said that I would not want to fly anything smaller. He was right. A 172 is a nice plane, don't get me wrong. However, pretty much all the issues with a 172 were solved with the 182. You can actually put 4 people in a 182 and fly it. Don't ever try that with a 172. You won't rub elbows in a 182 with a co pilot, and the old saying does seem to ring true. If you can put it into the 182 and still get the doors to close, you'll get it airborne and fly it.
@@grafhilgenhurst9717 Interesting that you mentioned the 152. I started my flight training in a 152. After a decent pay raise at work, I moved up into a 172. Seemed like a huge upgrade. Now I'm into a 182 RG. Another improvement. I also dabbled in a Warrior. Every aircraft has it's pros and cons. But for long distance comfort, a 182 with extended range fuel tanks is hard to beat. )
Another overlooked benefit of a Jet-A/diesel powered version is the increased safety in the event of a fuel leak. You can put out a lit match in a jar of Jet-A or diesel. Try that with Av-Gas...
@@rogertycholiz2218 Its Gasoline. Diesel also explodes in the combustion chamber, but it is due to the heat and compression of the air at the moment the fuel is injected, no spark plugs. Diesel and Jet-A also burn a bit more slowly. The higher compression ratio of a diesel leads to greater efficiency and greater torque at lower RPMs. Diesel/Jet-A is also slightly higher in energy content than Gasoline per equivalent quantity.
@@pawo007 Neither "explodes" in normal operation. One other contributor to efficiency in a diesel is that they are not throttled. Pumping losses can be huge in a petrol engine.
In Cento a Town near Ferrara in Italy there is the VM ENGINES. They built diesel engines for automotive and experimental one for aviation, very interesting.Greeting from Rome 🇮🇹
From what I've read and seen, there are a number of different diesel engines for various aircraft -- some are rated for Jet-A or No. 2 automotive diesel interchangeably, which saves even more money if you have a diesel pump for trucks on the apron (that fuel was, before the Russian invasion of Ukraine, about half the price of Jet-A -- might still be, I don't track aircraft fuel costs). Also, some don't require continuous glow plug power (i.e. use the plugs only for starting) so can run with complete electrical failure (injectors are mechanical). Some of those, however, have an operating restriction for outside air temp not below 0 F (-18 C) because compression won't reliably ignite the fuel if the air is colder. IIRC, those are air cooled, so don't weigh any more than the gasoline engine they replace (the Redhawk, with a converted automobile engine, has a heavier block/head and liquid cooling adding to the weight).
You make some good points.However compression ignition will operate way below -18C.Mechanical injection hasn't been used on diesel engines for a long time most common rail injectors are solenoid operated the timing and duration of the operating pulse being determined by the engine ECU.The ECU receives it's cue from a number of sensors,mostly all are 'hall effect' but consist of cam and crank position sensors, throttle position sensor (potentiometer) and intake airflow sensor(hot wire filament).
The Continental (and Snecma) air-cooled diesels look similar to their petrol counterparts, but are indeed about 40-50 kg heavier, due to the forces experienced by a diesel engine.
Actually, Cessna stopped production of the 172 in 1986. Production resumed in Independence, Ks. in 1996 and continues there to this day. They also produced the 182 and 206 there.
I did some design review of the original FADEC electronic controller with Thilert, I think it was in the late 1980s or early 90s. I designed and the company I worked for built some electronic test equipment to test the FADEC through the extremes of temperature and vibration that they would see in operation as a prelude to a potential partnership with airframe and powerplant manufacturers.
my flight school air harmony flies about 6 of these and I love them especially the throttle. Its a little bit different in the normal 172 layout but it flies so smooth, would def reccomend this aircraft!
The Hawk XP was made from 1977 to 1981 with the IO360 de-rated to 195 hp with constant speed prop. We had a 1979 that was great for our hot high altitude airport, basically the same as the USAF T-41 except theirs had fixed pitch prop.
If I understand this correctly, it will have longer endurance than a gas engine and possibly a longer range as well. The lower-powered engine might not show as much increase in range due to a slower cruise speed.
FYI Cessna XP has a 215 hp Continental engine. We have one with us registered as VT IJS . The Cessna S has the 180 hp Lycomming fuel injected engine. 160 hp has the same 180 hp but derated engine
General aviation is in the stone age from an engineering point of view. A mercedes turbo diesel (or any other modern turbocharged automotive engine for that matter) which is found in nearly every taxi cab in Germany is way more advanced, refined and reliable than any lycoming piston engine would ever be, at literally a fraction of the cost.
The Jet A and Jet A1 specifications do not have a cetane number requirement as it has no relevance to operation in gas turbines. As a consequence a diesel cycle piston engine cannot be optimised in the way that ground diesel engines can be as a result of a consistent minimum cetane number.
Back in the 1950s the writer Nevil Shute wrote a novel about the Berlin Airlift, and part of the story had a designer who developed a Diesel engine for the larger transport aeroplanes involved in the airlift. I don’t think that titanium, which would be essential for some of the more highly-stressed components, had become frequently used in industry.
Prior to WW2 and during the war, Germany had a number of Diesel-powered aircraft, e.g. the Blohm & Voss BV 138 flying boat, or the elegant float plane B&V HA 139 with two-stroke Jumo 205A Diesel engines, each rated @600 H.P. on take-off.
This I have to see. An airplane with a Diesel engine would be heavier so as to add more weight to the airplane. But on the other hand, Diesel engines use fuel which provides more power per quantity than the same amount of aviation fuel --- which would make for less fuel needed and a smaller fuel tank. So one of either could win out.
I used to check out pilots on a PA28 fitted with the original Thielert engine an found it to be a lot less foolproof than the old fashioned engines. Overheating was a big issue, especially on a hot day when a climb speed around 90 kts or more was necessary to keep the temperature down. One can easily figure out what the resulting climb performance was. But also overspinning turned out to be a problem after a few hundred hours, especially while applying t/o or climb power. Sadly the aircraft crashed due to engine failure (luckily nobody was hurt). I don't know what happened to it afterwards.
My instructors warn me that on a hot day in TN, overheating is a real concern. They have me climb out at 85 knots, 85% power and 500 fpm. But sometimes it's more like 80 knots or 300 fpm. And watch for water temp or oil temp going into the yellow!
The 172S was not considered the XP. That title belongs to the R172K. It was literally marked as Hawk XP. It came from the factory with a 210hp motor derated to 195hp
Ideal for extended navs. For flying club training, with say 8 starts for 1 hour flights every day the increased maintenance costs are a distinct disadvantage.
Thanks. Great information. I’ve been flying since 1981 and didn’t know all that history about the 172. And I think he’s right that the design was ahead of it’s time. And why didn’t they make the engine with the same 160 HP? Seems like a mistake.
Because they started with an auto engine, they were stuck with some operating parameters. The engine is not able to be overhauled; it is replaced, at hefty expense, thus the conservative operation.
@@UncleKennysPlace Of course it can be overhauled, they're just not certified for aviation usage that way. For the same engine in a Mercedes car, you can buy a remanufactured engine right off the shelf.
I never understood why diesel engines are not mainstream in GA. Usually diesel engines provide a lot of torque for their displacement. With a constant speed prop i will take torque over horsepower any day. Plus Jet-A and Diesel fuel is available everywhere.
Someday. Reliable automotive based diesels tend to be quite a bit heavier than gasoline engines with similar power. The volume of GA sales makes the cost of designing and certifying a specialized light aviation diesel a bad bet. So far. Take a step or two up from C172 class aircraft and pure turbines have long since taken over. Using a generous definition of "step", of course. :-)
Harsh torsional oscillations typical on diesels due to compression ratio and pressures are rough on props..especially constant speed units. All aviation diesels are heavier due to construction and require larger mass-damper units. In other countries where 100LL is difficult, sub 300 HP engines that can run on jet A have more utility. Second is maintenance. If it isn't Lycoming or Continental, you must find an FBO.
Compare this engine to a Rotax 915 iS and you'll understand. The Rotax weighs far less (around 100 pounds less), its very fuel efficient (about the same GPH) and it burns less expensive fuel. The max continuous power for the Rotax is also the same as the max TO power for the diesel.
They should reconsider. Look at Diamond aircraft out of Austria. They are using shakers in their aircraft and they claim its the best for engine choice.
It did not take a genius to know this Redhawk is under powered. Fully loaded, even with 150HP, the 172 climb like the Spirit of St Louis just took off from NY on its way to Paris. Every redesign of most airplanes , HP get an increase, Who in their right mind would cut 10% power on an airplane that is already marginal and wondered why it is not popular !
It was a legitimate gamble. Maintaining or even potentially surpassing reliability while significantly cutting operating costs?? Yes please! An entry level workhorse is not what buyers go for, when seeking out high performance.
Very interesting, I wonder if there is enough power to equip with retractable gear. I ask this because in Australia transit distances are far greater than in the US and most of our farmers have aircraft, bottomline cost savings are always pure profit and accelerated depreciation makes capital cost to reduce consumables very attractive.
Here in North-Karelia in Finland, two guys were testing a helicopter with a diesel engine. I was quite promising, but tests ended with a malfunction and an accident. And then they had not enough financial to continue.
A few years ago a diesel powered powered survey Cessna 172 dropped into our skydive airfield. The crew explained they had an endurance of about eight hours without landing. Now I've logged eight hours in a day, that's the legal limit, but at least I had breaks. Surprised diesels are not more popular in GA.
Demand was not there because of keeping it a big secret. I never heard of this airplane until today. If you want to sell you MUST advertise, get the word out and get everyone excited. That is if you really want to sell a product.
The 180hp Centurion model (2 of which are fitted to the Diamond DA62) would not fit inside the 172s cowling. The 135 model is underpowered but the CDI 155 model is more than adequate for a 172 and outperforms the 180hp Lycoming in every phase, other than initial climb from sea level to 1500'.
Curious what kind of weight difference between the gas & diesel models... I’m going to go out on a limb here and bet the diesel weighs considerably more, considering it was designed for a car
A little research shows the Continental CD-155 Diesel weighs 295#, the Lycoming IO-360 weighs 296-332#. So weight is similar, but power to weight favors the gas engine, at least at low altitudes.
Damn, a 172 or 182 with retractable gear would be the business! I would love to be able to toss in the wife and dogs and run up to see family. I would love to see what the aftermarket would come up with for these, take a Cessna, shoehorn in a R2.8 Cummins, sprinkle in some tuning, and finish with a stupid amount of boost!
The conversion price in 2016 was over $250k, much of which is just the price of the engine. Continental is mum about the price of a new engine, but word is around $80k for the CD 155 (155 hp). The price of the CD 170 (170 hp) is likely closer to $100k, so Red Hawk is right when they say the concept was ahead of its time. A largely off-the-shelf Mercedes four-banger shouldn't cost as much as an M-250 turboprop engine. Actually, Red Hawk meant their pricing was price was ahead of its time, so it is not surprising that few opted for the TDI engine. There wasn't enough potential fuel and maintenance savings to offset the huge purchase price. Personally I'd love to have a jet-A-burning 220 hp turbodiesel in my Mooney, because the Continental engine powering it is outmoded, expensive, thirsty and fragile, but unless somebody figures out how to produce affordable alternatives, I'm stuck with it. Lycoming still trumpets its 205 HP DEL-120, but it is non-certified, drone-only. Continental is selling TDI aerodiesels, but as mentioned, the price is prohibitive. Austro's mercedes-based TDI engines are proving to have good reliability and longevity, but again price is the stopper. While it is nearly impossible to find the retail price online, the only aircraft that uses it, the Diamond DA62 uses two of them and retails north of $1.3 million. And so the dream continues, unrequited.
@@grafhilgenhurst9717 I don't know much about planes but would additional power make up for a little more weight? I cant find the weight of the om604 4 cylinder, I know the om606 6 cylinder weighs around 490 lbs. 4 cylinder is like 90hp stock while the om606 is making 190hp and can take 600hp+ on stock internals with a few small mods and a bigger turbo + injection pump. I know the 4 cylinders have also been modified I don't know how much they can make off the top of my head though. I'm assuming theres gotta be some rules to engine modifications though. Im surprised diesel planes didnt catch on, they can be extremely reliable and not needing to adjust fuel sounds, easier to turbo charge.
I suspect the 6 cylinder would be too heavy in the nose of a Cessna. If only they got 180 hp from the 4 cylinder, it would be competitive with the current Lycoming. @@lemons3738
You clearly don't know anything about turbo-normalizing. The CDI 155 engine outperforms the 180hp Lycoming in all phases except a narrow initial climb stage of about 1000 feet. At just 6000 feet a Lycoming 180hp is only delivering 133hp, due to density. The CDI 155 delivers 155hp from 0 AGL to 12,000'.
@@lutomson3496 A) Diesels absolutely do not (inherently) produce more torque than gasoline engines, this only happens when a diesel engine is run with significantly higher manifold pressure. B) Torque is not power, it cannot be used as a substitute for power. Aircraft need to have a good power to weight ratio in order to fly.
Other than the reduced fuel burn rate and the novelty of having a "knockity-knock" powerplant, I'm not seeing a lot of advantage to a Diesel-powered aircraft at this time. Yes, jet-A is cheaper than 100LL or other avgas formulations, but as noted, not every airport has jet-A. The reduced horsepower at takeoff would be bothersome, especially at MTOW. More concerning are the restrictions on continuous cruise power. Who needs that?
I am told to keep an eye on the oil temp, that will go from green to yellow if exceeding 85kts on climb out. Also to climb at 80, not 85. So far it has worked.
The Diamond DA40 NG does quite well with its diesel engine. Not sure what you mean by "knockity-knock" - - these diesel engines run far smoother and quieter than the 1950s-tech gasoline piston engines are. More reliable as well. No mixture control, no fouled plugs, no hot-start issues, dual redundant FADECs. Even the widely-used Lycoming IO-360 has restrictions on cruise power. Not only is Jet-A cheaper, but fuel burn is also 50% less! That's huge, especially now with Brandon's price hike. 100LL was
not if you fly a Cessna Citation :) but yes, it's a true story. Whereever I fly with a diesel powered Cessna 172, there is always a shocked " are you completely out of your stupid mind???" kind of look on everyone's face when I sheepishly ask for jet fuel :D On a more serious note, one has to be EXTREMELY careful about preventing accidental refueling with Avgas. It's labellet Jet-A1 only all over the wing leading edge, the fuel caps etc, but still..
My left ear enjoyed this video
🤣
Same here lmao
My mono speaker in my smartphone worked nicely 👍
Ah but wait !
At 3:00 you can enjoy full stereo for a while 🤭
"By the 1980's they invented....stereo, but it broke a minute later "
I built that airplane..All the RedHawks. I worked there from the beginning until the last RedHawk was completed. Like you said, great idea before its time.
And, as I said, priced before its time, hence the lack of buyers. An off-the-shelf four cylinder Mercedes oil burner shouldn't price out like a factory overhauled Rolls Royce M 250 turboprop.
@@htschmerdtz4465 If you use 30% less fuel isnt it worth it.
@@chippyjohn1 the turbo prop is way more powerful and reliable
@@chippyjohn1I think newer car engine would be better like BMW car engines(better to enchanted with 48V system)
@leonpano I have been looking at BMW engines for aircraft for a while now. The M57 was a great engine although rare now. The B57 is less ideal, but still a good option. Engines manufactured around the year 2000 were the best for aircraft. Engines produced now are far more complex for emissions etc that just aren't applicable to use in aircraft.
I love the stenciling on the outside of the plane, and I love that they had a sense of humor and nailed it.
I love this plane!!! I have everything diesel, even my lawn mower, and I didn't realize I could get a diesel Cessna!!!
I saw a video of a cropduster (air tractor) severely modified to run a V12 diesel TRUCK engine. Running on Jet A, it was a real showpony, and could do a ballistic climb :)
Not a truck engine. Red V12 is made in Germany and no airplane is flying with a truck engines are cast iron. Engine swap is a major change and requires an STC from the FAA.
Pretty sure that was BMW v12 diesel
Just to be accurate it is "injectors instead of spark plugs" the glow plugs are more analogous to a choke for cold starting. Rudolf Diesel Invented timed injection. He did not invent high compression...
I've always dreamed of a diesel powered turbine in the Cessna 172's. No mixture levers, no magneto's, no carb heat, just a single throttle lever. Throw that baby and fly. I flew a 2000 model Skyhawk 172R for training but had to stop due to blackout spells.
The Cessna 208 Caravan 🐪is a single-engine turboprop
Just flew one of them at KJWN. Easy run-up, very quiet and smooth.
Did the first 20-25 hours of my PPL in Red Birds 101-103 ...I didn't know how amazing that fuel burn was until started flying standard 172's.
I fly the CD-155 variants (155 HP max), out of a fleet of about 8 aircraft (F172Ms mosty, some F172N). Those outperform our traditional Lycoming-equipped 172M, according to pilots who fly both. The diesel 172s are the workhorses on airshows and open days, carrying passengers around on short sightseeing flights. The constant-speed 3-blade propeller gives a good acceleration on takeoff. There is no POH-limitation on climb, it could be 100% in all climbs, although we also throttle back to 85% at safe altitude, with all obstacles left behind.
The diesel 172 is remarkably nice for long cross-country flights as well, because it has a high operational ceiling (FL180), so for me it is much easier to climb high and cruise fast in the rarer and cooler air. The basic empty weights are a concern though, like for all Cessnas with 2300 lbs MTOM, because the well-equipped aircraft are heavy, and I always run calculations on how we fit passengers, baggages and the fuel for each leg. But if you don't need to carry a lot of useful load, e.g., just do a long powerline or gas pipe aerial survey, you can enjoy unpleasantly long flights with the Long Range tanks in some of the aircraft, in excess of 6-7 hours in the airplane, due to the low consumption at economic cruise (55%-65% power).
Here is a playlist of my adventures with the diesel 172s. ruclips.net/p/PL0xNTmAtxEUcOYS1cDb7FLmzW3XYVOxv4
At 3:37, just a minor thing, but for the precision nazis: AED = Auxilary Engine Display, CED = Compact Engine Display.
You are correct that CED stands for Compact Engine Display. The Normal Procedures Card from Cochise College (who originally owned all 6 of these planes) recommends climb at 85% and cruise at
@@grafhilgenhurst9717 aha, so It's a (precautionary) recommendation from the former operator/owner, and not a factory/manufacturer limitation. Basically then it's the same situation for both of us. Thanks for the the clarification, and also thank you for the video!
@@grafhilgenhurst9717 - Yet you stated it like an operation constraint, as though it WAS in the POH. I fly these in a school and we climb at 100% and have done for 9 years with perfect engine health and no issues. You want to get up quickly with these engines, as that's where they perform best.
Hi ! im preparing for 172TD exams , i would like to ask ,are the V speeds different compare to AVGASS / 172R ? cause in the 172TD POH , i couldnt find any V speeds apart from Vy , thanks !
@@karann4335 You should somehow find these speeds under SPEEDS FOR NORMAL OPERATION. I never flew the normal Avgas version, but my friends who do, they fly it in a similar manner, same speeds. The airframe is the same, aerodynamically it's the same aircraft. Perhaps the climb speeds are slightly different due to the better power-->thrust efficiency of the variable pitch propeller on the diesel variants.
WHY hasn’t THIS been a thing? Diesels..done right, are VERY efficient, economical AND POWERFUL. Again, done right it COULD’VE BEEN a very popular powerplant.
They also last a long time given proper care. I've got a well known brand of pickup truck that has a diesel engine. It's 18 years old and recently achieved the half million mile mark and runs great. Fuel economy as a daily driver is decent at 17-18 mpg.
Perhaps weight is the issue but I agree it would be ideal. Might need gears to use the torque or a special prop.
@@zxggwrt Might be an issue with fuel waxing at cooler climates/altitudes/Latitudes
Diamond has several diesel airplanes; they are the only company with a reasonably large production.
@@mattw8809 They seem to use airliner fuel (JET A) and airliners are flying everywhere, in all climates withouth (unmanageable) fuel issues.
I recently had the chance to fly the Robin DR401 with this CD-155engine. This plane is wooden and therefore lighter than the C172, so the payload penalty is insignificant. The engine was fantastic. Efficient, the constant speed prop gives lots of power. I believe that now where the engine belongs to Continental, it finally gets the marketing power it deserves.
Very nice, thanks. I have bet my life on diesels quite a bit in the past. Having them in my boat on ocean passages. I put over 20,000 hrs on mine with very minor issues. I know that this is different but if you give a diesel clean fuel, and air, it will run and run. I ran mine at times, 24 hrs a day, only shutting down to check vitals.
we powered our house in Belize for 10 years on an old Lister. 650 RPMs 24 seven.
ruclips.net/video/ivTeSedkYbU/видео.html
Here's a comment about clean fuel. In the 70's(?), Mexico got s bunch of money from the U.S. the govt in Quintana Roo started pushing back the jungle in order to develop land. My buddy took several 2 week trips to help them develop an irrigation system. He said there was tons of equipment scattered on a gravel road that led into the jungle. When the project stopped, the jungle grew back. He flew over the area and went to explore several nearby lumps in the jungle. What he found was Cats, some with paint still on the tracks, abandoned. With so much inoperative new stuff, he things they quit because of dirty fuel. He saw many empty/partial rusty barrels laying around. He set up a program to bring all those machines back, but the Mex national he was working with got assassinated. After that he never went back. Side note: As they built a road into the jungle, any rock they found was crushed to make gravel. He said they tore down many ancient Aztec artifacts and fed them into a rock crusher...which was still there..inoperative.
@@obsoleteprofessor2034 my brother and father had a farm in Belize in the 70s and early 80s and there was a lot of that going on. Mostly Americans and a lot of them were from Texas looking for oil and they knew absolutely nothing about working in the jungle. Same with Guatemala in the Peten’ region.
In 2008, I had to be trained on Cessna diesel 172 and Cessna 208 Caravan as maintenance instructor for the Iraqi Air Force. Funny thing is the main reason why Iraq wanted diesel powered 172 is avgas 100LL was not practicible but jet fuel could be used if diesel was not available. I did not get to be around those 172's as I spent nearly all my time working the King Air 350.
I watched the Iraqi Air Force flight the c130e, it was the must scariest thing I ever seen. They were all over the place when landing, I was waiting for them to crash as they bounced multiple times across the runway.
We converted 6 of these in our fleet. Had lots of problems with leaking radiators. Ours where rated 155 hp and had a great take off performance with an auto CSU and third prop. The nose tends to be heavy in the flare & the glide performance is reduced. I found them ok, but preferred the IO360...
IO360, bullet proof
@@brett6690 Almost . best wishes from Barry Seal.
Actually, Cessna began production of the 172 in Independence, Ks. in '96
My left ear really enjoyed this video.
When I got endorsed in the 182, my flight instructor said that I would not want to fly anything smaller. He was right. A 172 is a nice plane, don't get me wrong. However, pretty much all the issues with a 172 were solved with the 182. You can actually put 4 people in a 182 and fly it. Don't ever try that with a 172. You won't rub elbows in a 182 with a co pilot, and the old saying does seem to ring true. If you can put it into the 182 and still get the doors to close, you'll get it airborne and fly it.
I felt the same way going from a 152 to a 172!😅
@@grafhilgenhurst9717 Interesting that you mentioned the 152. I started my flight training in a 152. After a decent pay raise at work, I moved up into a 172. Seemed like a huge upgrade. Now I'm into a 182 RG. Another improvement. I also dabbled in a Warrior. Every aircraft has it's pros and cons. But for long distance comfort, a 182 with extended range fuel tanks is hard to beat. )
I like flying my C172N with CD-155 from South Florida. 5gph gives me 105 kias.
Love the Kenny Wayne Sheppard music.. Blue On Black is a great tune..
Another overlooked benefit of a Jet-A/diesel powered version is the increased safety in the event of a fuel leak. You can put out a lit match in a jar of Jet-A or diesel. Try that with Av-Gas...
pawo007 ~ Gosoline explodes in the combustion chamber, unlike diesel that does not.
@@rogertycholiz2218 Its Gasoline. Diesel also explodes in the combustion chamber, but it is due to the heat and compression of the air at the moment the fuel is injected, no spark plugs. Diesel and Jet-A also burn a bit more slowly. The higher compression ratio of a diesel leads to greater efficiency and greater torque at lower RPMs. Diesel/Jet-A is also slightly higher in energy content than Gasoline per equivalent quantity.
@@pawo007 Neither "explodes" in normal operation. One other contributor to efficiency in a diesel is that they are not throttled. Pumping losses can be huge in a petrol engine.
@@UncleKennysPlace yap . try not to spill my beer. Looks like Panthers r gona make the playoffs this year.
In Cento a Town near Ferrara in Italy there is the VM ENGINES. They built diesel engines for automotive and experimental one for aviation, very interesting.Greeting from Rome 🇮🇹
They also have absolutely massive problems in the Ram trucks in the US.
I *NEVER* heard of these diesel powered Cessnas prior to watching this video.
From what I've read and seen, there are a number of different diesel engines for various aircraft -- some are rated for Jet-A or No. 2 automotive diesel interchangeably, which saves even more money if you have a diesel pump for trucks on the apron (that fuel was, before the Russian invasion of Ukraine, about half the price of Jet-A -- might still be, I don't track aircraft fuel costs). Also, some don't require continuous glow plug power (i.e. use the plugs only for starting) so can run with complete electrical failure (injectors are mechanical). Some of those, however, have an operating restriction for outside air temp not below 0 F (-18 C) because compression won't reliably ignite the fuel if the air is colder. IIRC, those are air cooled, so don't weigh any more than the gasoline engine they replace (the Redhawk, with a converted automobile engine, has a heavier block/head and liquid cooling adding to the weight).
You make some good points.However compression ignition will operate way below -18C.Mechanical injection hasn't been used on diesel engines for a long time most common rail injectors are solenoid operated the timing and duration of the operating pulse being determined by the engine ECU.The ECU receives it's cue from a number of sensors,mostly all are 'hall effect' but consist of cam and crank position sensors, throttle position sensor (potentiometer) and intake airflow sensor(hot wire filament).
@@eugeneoreilly9356 The ones I've seen with temp restrictions are rated for Jet-A. Higher ignition point than highway diesel, as I recall.
The Continental (and Snecma) air-cooled diesels look similar to their petrol counterparts, but are indeed about 40-50 kg heavier, due to the forces experienced by a diesel engine.
Actually, Cessna stopped production of the 172 in 1986. Production resumed in Independence, Ks. in 1996 and continues there to this day. They also produced the 182 and 206 there.
I did some design review of the original FADEC electronic controller with Thilert, I think it was in the late 1980s or early 90s. I designed and the company I worked for built some electronic test equipment to test the FADEC through the extremes of temperature and vibration that they would see in operation as a prelude to a potential partnership with airframe and powerplant manufacturers.
Canada’s producing a V 12 Beaver airplane looks pretty nice
my flight school air harmony flies about 6 of these and I love them especially the throttle. Its a little bit different in the normal 172 layout but it flies so smooth, would def reccomend this aircraft!
I flew all of the planes in this video they all flew amazingly N172TM was my favorite one
The Hawk XP was made from 1977 to 1981 with the IO360 de-rated to 195 hp with constant speed prop. We had a 1979 that was great for our hot high altitude airport, basically the same as the USAF T-41 except theirs had fixed pitch prop.
My favourite song blue on black
If I understand this correctly, it will have longer endurance than a gas engine and possibly a longer range as well. The lower-powered engine might not show as much increase in range due to a slower cruise speed.
But you keep the power at altitude, whereas the non turbo gas engine loses power with altitude, so it evens out.
1200 PIC hours on these. Proud Thielert flyer. ;)
FYI Cessna XP has a 215 hp Continental engine. We have one with us registered as VT IJS . The Cessna S has the 180 hp Lycomming fuel injected engine. 160 hp has the same 180 hp but derated engine
215 hp must go like a rocket!
Excellent research and writing. Very interesting and well done video. Thanks.
Lots of useful information. Good graphics. Well done. Thank you 😊
I would love to have this plane! I think I'd repaint it w/ new graphics though, lol.
Me too!
The idiotic graphics were off-putting.
Thank you very much, for this excellent video with useful informations. Peace with you from Eu :-)
General aviation is in the stone age from an engineering point of view. A mercedes turbo diesel (or any other modern turbocharged automotive engine for that matter) which is found in nearly every taxi cab in Germany is way more advanced, refined and reliable than any lycoming piston engine would ever be, at literally a fraction of the cost.
Manufacturers don't wanna spend the r+d money for better engines
I’m INTERESTED! 👍🏼
The Jet A and Jet A1 specifications do not have a cetane number requirement as it has no relevance to operation in gas turbines. As a consequence a diesel cycle piston engine cannot be optimised in the way that ground diesel engines can be as a result of a consistent minimum cetane number.
ruclips.net/video/ivTeSedkYbU/видео.html
I LOVE the T-handle throttle! Would be awesome if one could convert their avgas Cessna to that throttle!
Actually, I love all the instrumentation!
Cessna did study making this an engine option, then cancelled the plan without comment.
Really cool setup
Back in the 1950s the writer Nevil Shute wrote a novel about the Berlin Airlift, and part of the story had a designer who developed a Diesel engine for the larger transport aeroplanes involved in the airlift. I don’t think that titanium, which would be essential for some of the more highly-stressed components, had become frequently used in industry.
Prior to WW2 and during the war, Germany had a number of Diesel-powered aircraft, e.g. the Blohm & Voss BV 138 flying boat, or the elegant float plane B&V HA 139 with two-stroke Jumo 205A Diesel engines, each rated @600 H.P. on take-off.
This I have to see. An airplane with a Diesel engine would be heavier so as to add more weight to the airplane. But on the other hand, Diesel engines use fuel which provides more power per quantity than the same amount of aviation fuel --- which would make for less fuel needed and a smaller fuel tank. So one of either could win out.
I flew in Vietnam 🇻🇳 1968-1971 let me tell you the experience is a lot different when your under heavy artillery gunfire.
One of my instructor flew a Birddog in Viet Nam. If they found bullet holes, they would put tape over them, and then go fly. I can't begin to imagine!
I used to check out pilots on a PA28 fitted with the original Thielert engine an found it to be a lot less foolproof than the old fashioned engines. Overheating was a big issue, especially on a hot day when a climb speed around 90 kts or more was necessary to keep the temperature down. One can easily figure out what the resulting climb performance was. But also overspinning turned out to be a problem after a few hundred hours, especially while applying t/o or climb power. Sadly the aircraft crashed due to engine failure (luckily nobody was hurt). I don't know what happened to it afterwards.
My instructors warn me that on a hot day in TN, overheating is a real concern. They have me climb out at 85 knots, 85% power and 500 fpm. But sometimes it's more like 80 knots or 300 fpm. And watch for water temp or oil temp going into the yellow!
This may be the way of the future due to the fact that 100LL is going to go away at some point.
The 172S was not considered the XP. That title belongs to the R172K. It was literally marked as Hawk XP. It came from the factory with a 210hp motor derated to 195hp
Ideal for extended navs. For flying club training, with say 8 starts for 1 hour flights every day the increased maintenance costs are a distinct disadvantage.
Thanks. Great information. I’ve been flying since 1981 and didn’t know all that history about the 172. And I think he’s right that the design was ahead of it’s time. And why didn’t they make the engine with the same 160 HP? Seems like a mistake.
Because they started with an auto engine, they were stuck with some operating parameters. The engine is not able to be overhauled; it is replaced, at hefty expense, thus the conservative operation.
@@UncleKennysPlace Of course it can be overhauled, they're just not certified for aviation usage that way. For the same engine in a Mercedes car, you can buy a remanufactured engine right off the shelf.
Hope somebody puts a Cummins in a plane...
It would have to be purpose built no small airplane could cope with the weight
@@catsbyondrepair Yes, a 5.9 Cummins weighs 1100-1200 pounds's. It was Klind of a a Joke...
@@patriotpioneer it can be done radial engines weight about the same and a Cummins can produce 1000 horse power reliably
@@catsbyondrepair Interesting
Super cool! Thanks for sharing!
I fles a diesel 172 more than 5 years ago!
left ear is loving this
I`ll stay with my Saratoga 2 TC. 06. Oh ! Yeah. 😉
And who wouldn't!
Thank you for that informative video !
This diesel engine in the Velocity V-Twin might just be a good match.
I never understood why diesel engines are not mainstream in GA. Usually diesel engines provide a lot of torque for their displacement. With a constant speed prop i will take torque over horsepower any day. Plus Jet-A and Diesel fuel is available everywhere.
Someday. Reliable automotive based diesels tend to be quite a bit heavier than gasoline engines with similar power. The volume of GA sales makes the cost of designing and certifying a specialized light aviation diesel a bad bet. So far. Take a step or two up from C172 class aircraft and pure turbines have long since taken over. Using a generous definition of "step", of course. :-)
Harsh torsional oscillations typical on diesels due to compression ratio and pressures are rough on props..especially constant speed units. All aviation diesels are heavier due to construction and require larger mass-damper units.
In other countries where 100LL is difficult, sub 300 HP engines that can run on jet A have more utility.
Second is maintenance. If it isn't Lycoming or Continental, you must find an FBO.
Compare this engine to a Rotax 915 iS and you'll understand. The Rotax weighs far less (around 100 pounds less), its very fuel efficient (about the same GPH) and it burns less expensive fuel. The max continuous power for the Rotax is also the same as the max TO power for the diesel.
Great video. Very informative.
I flew the 172-JTA for a while in Hawai’i. I think they sold it. It was also discontinued.
misspelled dickson in the end - Dickson, TN
I am a total fan !
Would LOVE to know more !
I'm all about making more of them happen !
The 915 iS is a far better option.
They should reconsider. Look at Diamond aircraft out of Austria. They are using shakers in their aircraft and they claim its the best for engine choice.
ruclips.net/video/ivTeSedkYbU/видео.html
Glo plugs are so ancient, direct injection would not even burn cleaner but extra power and fuel consumption.
It did not take a genius to know this Redhawk is under powered. Fully loaded, even with 150HP, the 172 climb like the Spirit of St Louis just took off from NY on its way to Paris. Every redesign of most airplanes , HP get an increase, Who in their right mind would cut 10% power on an airplane that is already marginal and wondered why it is not popular !
It was a legitimate gamble. Maintaining or even potentially surpassing reliability while significantly cutting operating costs?? Yes please!
An entry level workhorse is not what buyers go for, when seeking out high performance.
Very interesting, I wonder if there is enough power to equip with retractable gear. I ask this because in Australia transit distances are far greater than in the US and most of our farmers have aircraft, bottomline cost savings are always pure profit and accelerated depreciation makes capital cost to reduce consumables very attractive.
Here in North-Karelia in Finland, two guys were testing a helicopter with a diesel engine. I was quite promising, but tests ended with a malfunction and an accident. And then they had not enough financial to continue.
Howdy in Finland. My mother was from Tempere.
A few years ago a diesel powered powered survey Cessna 172 dropped into our skydive airfield. The crew explained they had an endurance of about eight hours without landing. Now I've logged eight hours in a day, that's the legal limit, but at least I had breaks.
Surprised diesels are not more popular in GA.
It's an expensive retrofit and a Lycoming can be overhauled for less than half the price, that's why.
Turbo diesels..it’s about time…
Demand was not there because of keeping it a big secret. I never heard of this airplane until today. If you want to sell you MUST advertise, get the word out and get everyone excited. That is if you really want to sell a product.
Thank you 🙏
This makes me want to learn how to fly
I think Redhawk fell short by not providing the similar 180hp diesel engine.
The 180hp Centurion model (2 of which are fitted to the Diamond DA62) would not fit inside the 172s cowling. The 135 model is underpowered but the CDI 155 model is more than adequate for a 172 and outperforms the 180hp Lycoming in every phase, other than initial climb from sea level to 1500'.
I wonder if there are issues with the fuel gelling at altitude. Is it heated in some way (either with the engine coolant, or electrically)?
One of those big gauges, the AED or CED has fuel temperatures. There are parameters to stay "in the green". Not heated, though.
Curious what kind of weight difference between the gas & diesel models... I’m going to go out on a limb here and bet the diesel weighs considerably more, considering it was designed for a car
A little research shows the Continental CD-155 Diesel weighs 295#, the Lycoming IO-360 weighs 296-332#. So weight is similar, but power to weight favors the gas engine, at least at low altitudes.
Great informative video thanx
While these planes run on Jet-A, could they run on standard diesel fuel?
Apparently yes, but Jet A is available at most airports.
Yes, ruclips.net/video/ivTeSedkYbU/видео.html
Has the boost been raised for this application? I'd imagine it would be.
Excellent, thank you.
Damn, a 172 or 182 with retractable gear would be the business! I would love to be able to toss in the wife and dogs and run up to see family. I would love to see what the aftermarket would come up with for these, take a Cessna, shoehorn in a R2.8 Cummins, sprinkle in some tuning, and finish with a stupid amount of boost!
I could live without the retractable gear, but a constant speed prop is a nice feature!
@@grafhilgenhurst9717 I only said retractable gear because I think it looks slick when wheels up.
Great video!
Much greatful thnx 🙏🤲👍👍
The conversion price in 2016 was over $250k, much of which is just the price of the engine. Continental is mum about the price of a new engine, but word is around $80k for the CD 155 (155 hp). The price of the CD 170 (170 hp) is likely closer to $100k, so Red Hawk is right when they say the concept was ahead of its time. A largely off-the-shelf Mercedes four-banger shouldn't cost as much as an M-250 turboprop engine. Actually, Red Hawk meant their pricing was price was ahead of its time, so it is not surprising that few opted for the TDI engine. There wasn't enough potential fuel and maintenance savings to offset the huge purchase price. Personally I'd love to have a jet-A-burning 220 hp turbodiesel in my Mooney, because the Continental engine powering it is outmoded, expensive, thirsty and fragile, but unless somebody figures out how to produce affordable alternatives, I'm stuck with it.
Lycoming still trumpets its 205 HP DEL-120, but it is non-certified, drone-only. Continental is selling TDI aerodiesels, but as mentioned, the price is prohibitive. Austro's mercedes-based TDI engines are proving to have good reliability and longevity, but again price is the stopper. While it is nearly impossible to find the retail price online, the only aircraft that uses it, the Diamond DA62 uses two of them and retails north of $1.3 million. And so the dream continues, unrequited.
Have you thought about putting a Porsche engine in your Mooney? Just kidding.
One of the planes shown was a Skylane.
Wonder why cessna decided against a production version?
Oh shit I came here to watch a video about diesel engines and I saw a picture of one my flight schools planes (N46188).
To borrow from a Groucho Marx quote, 'I would never want to fly on a plane that has me as its pilot!'
Great video for my deaf left ear
some of the mercedes diesels can make a lot of power when modified. Wonder if they could get the om606 3.0 6 cylinder turbo diesel to work with it.
Might be a bit heavy. Great engine, though!
@@grafhilgenhurst9717 I don't know much about planes but would additional power make up for a little more weight?
I cant find the weight of the om604 4 cylinder, I know the om606 6 cylinder weighs around 490 lbs. 4 cylinder is like 90hp stock while the om606 is making 190hp and can take 600hp+ on stock internals with a few small mods and a bigger turbo + injection pump. I know the 4 cylinders have also been modified I don't know how much they can make off the top of my head though. I'm assuming theres gotta be some rules to engine modifications though.
Im surprised diesel planes didnt catch on, they can be extremely reliable and not needing to adjust fuel sounds, easier to turbo charge.
I suspect the 6 cylinder would be too heavy in the nose of a Cessna. If only they got 180 hp from the 4 cylinder, it would be competitive with the current Lycoming. @@lemons3738
I believe the lower HP engine is why it did not catch on. Pilots want more power, not less!
And it limits the ability to take on a back seat passenger, as well.
You clearly don't know anything about turbo-normalizing. The CDI 155 engine outperforms the 180hp Lycoming in all phases except a narrow initial climb stage of about 1000 feet. At just 6000 feet a Lycoming 180hp is only delivering 133hp, due to density. The CDI 155 delivers 155hp from 0 AGL to 12,000'.
normal pilot need only cheapen gasoline not power important.
Diesels produce more torque then a comparable gas engine..wondering why that torque cant be maximized vs hp..
@@lutomson3496 A) Diesels absolutely do not (inherently) produce more torque than gasoline engines, this only happens when a diesel engine is run with significantly higher manifold pressure. B) Torque is not power, it cannot be used as a substitute for power. Aircraft need to have a good power to weight ratio in order to fly.
Check out the Skylark
Very cool
Other than the reduced fuel burn rate and the novelty of having a "knockity-knock" powerplant, I'm not seeing a lot of advantage to a Diesel-powered aircraft at this time. Yes, jet-A is cheaper than 100LL or other avgas formulations, but as noted, not every airport has jet-A. The reduced horsepower at takeoff would be bothersome, especially at MTOW.
More concerning are the restrictions on continuous cruise power. Who needs that?
I am told to keep an eye on the oil temp, that will go from green to yellow if exceeding 85kts on climb out. Also to climb at 80, not 85. So far it has worked.
The Diamond DA40 NG does quite well with its diesel engine. Not sure what you mean by "knockity-knock" - - these diesel engines run far smoother and quieter than the 1950s-tech gasoline piston engines are. More reliable as well. No mixture control, no fouled plugs, no hot-start issues, dual redundant FADECs.
Even the widely-used Lycoming IO-360 has restrictions on cruise power.
Not only is Jet-A cheaper, but fuel burn is also 50% less! That's huge, especially now with Brandon's price hike. 100LL was
@@grayrabbit2211
@@AZVIDS It was under $2.50 here for most of 2020 and didn't go above $2.50 until Jan 2021. KFMY.
@@grayrabbit2211 Modern gasoline engines would be a far better option. Running on mogas would save a bundle.
Very nice.
Is there a higher horse power unit available for this engine out there?
Yes, the CD155
@@johannesb. Do you know what HP its rated at?
@@Aerocommander1991 155
@@Aerocommander1991 I fly one
Has anyone put one of the Austro 168 hp engines used on the DA-62 on a C172?
The Austro engines use cast iron blocks. They are much heavier. They are rebuildable while this example is not.
not ideal too heavy engine lot better if engineers plan lot better lightweight engine, less weight and more power and less gasoline need.
@@mattivirta ruclips.net/video/ivTeSedkYbU/видео.html
The straight tail looks better.
I'll bet you get some raised eyebrows when you ask for Jet-A in a Cessna.
not if you fly a Cessna Citation :) but yes, it's a true story. Whereever I fly with a diesel powered Cessna 172, there is always a shocked " are you completely out of your stupid mind???" kind of look on everyone's face when I sheepishly ask for jet fuel :D On a more serious note, one has to be EXTREMELY careful about preventing accidental refueling with Avgas. It's labellet Jet-A1 only all over the wing leading edge, the fuel caps etc, but still..
@@rnzoli or 208 caravan ... Salute sir