In several of my previous columns, I have proposed that part of the problem with general aviation is the lack of new technology in piston-powered aircraft.
The fact that the engines are based on 1930s and 1940s technology means that many of today’s future pilots do not relate to their operating systems.
I proposed that manufacturers adapt technology from the automotive world to new aviation engines. I have received a lot of responses. The two most common are “Do you know how much that will cost?” and “Pilots prefer the old tried and proven engines.”
This reminds me of when I was a boy growing up on a farm in the 1950s. A friend of my father worked for John Deere, so we had JD tractors. In the 1950s JD still produced just 2-cylinder tractors like it always had. But by the end of the decade, the company’s biggest tractor had a 470 cubic inch, 2-cylinder engine with 6.125-inch pistons that produced 70 hp.
Company officials knew they were at the limit for their design and that, in the future, farms would get bigger and farmers would demand more horsepower. So the company “bet the farm” on designing a completely new line of tractors and engines.
When the new tractors were introduced in 1960, many of the old farmers went out and bought up the remaining inventory of the old tractors because they felt the new tractors would not be as dependable as the old models. But within a short time, the new generation of tractors became industry leaders and John Deere went from a contender to the market leader.
Now I know that the ag industry is larger than the GA industry, but the principle is the same. When a company builds a better product, people will buy it if it offers significant improvements in performance, economy, and dependability.
Unfortunately, no one has offered an improved technology piston engine, at least not until now.
The concern over what it would cost to develop and certify a new technology engine is very real. But I think the bigger question is “what is the cost of not updating engine technology for GA piston engines?’
The other big question is “why are small companies like Rotax, Adept, EPS, Graflight, P2M, and Delta Hawk working on new technology engines and Lycoming and Continental are not working on them?”
I know that Continental is selling a diesel engine, but that was developed by another company, so it is just a rebrand.
On that point, a number of years ago, Continental received a large grant from the government to develop a Jet-A powered piston engine for GA aircraft. It built several prototypes of a 2-stroke opposed 4-cylinder diesel engine. It was expensive and had a few drawbacks and died when the government money went away.
Then a German company took an existing diesel engine, put a simple prop drive system on it, and got it certified. Now Continental is selling them.
The problems are not that hard. The thought process is where the problem is.
If you wanted to adapt an automotive spark ignition engine, a reduction gear system would be needed, but these are already available in the TIGO-540 and the TIARI engine.
Next, you would select a higher horsepower engine and de-rate it so that it would live at the higher load factor service needed in an aircraft. Since there is a gear reduction system, there would not be the prop load factor on the rear main bearing like that in a direct drive engine.
Additionally, the engine would be liquid cooled, which would greatly reduce wear and strain.
And the engine could use modern automotive oils, which would all but eliminate rusting and greatly increase the load carrying ability over aviation oils.
There are many more advantages to new technology in engines, such as better fuel economy, easier starting, no pre-heating, lower cost fuel, lower emissions, easier operation, quieter and smoother operation. I could go on, but I think we all understand the need for newer technology.
And us old guys will switch to the new designs once they become available and are proven.
I do not know exactly how many dollars it would cost to develop a new technology engine, but I do know that the cost of not updating is really costing general aviation many new pilots and possibly its future.
Why not move to a small turbine engine? A 450 shp engine like the Rolls-Royce B417F derated to between 200-300 shp would make a great reliable, safe, and relatively economic for power produced option for GA aircraft.
Speaking of new technologies, at some point it will be possible to completely 3D-print a carbon-fiber airframe. Hopefully that will decrease the cost of manufacture to the point that small aircraft become affordable for the average middle-class person.
I wholeheartedly agree, Ben.
Several years ago, I was ‘hot’ to buy a light sport airplane and actually test flew the first RV-12 that had a Garmin avionics suite. I liked it but it had the 912ULS engine. I asked Van why he didn’t put the 912iS engine in it. Answer: “I’d have to redesign the cowling.” Well … I walked away from it because I wanted the increased range and reliability of the iS engine. NOW, he’s seen the proverbial light and one is available. Problem is … MY flying years are now coming to an end and I cannot justify the cost. Maybe if a used one showed up … ?? So I soldier on with my venerable C172.
There is little reason why an engine like the 912iS or it’s larger brethren couldn’t power a simple GA airplane and the cost would approach gbigs magical $100K number. IF the FAA would only step aside for any GA airplane flown recreationally under a reasonable weight … say 3,000 lbs or that MOSAIC number of 3,600 lbs. Build such an airplane and “they” will come. Ever dollar over $100K and you lose business. Simple as that. $200K+ LSA’s sell in small numbers for that reason. When the FlyCatcher was $100K, they were selling like hotcakes at Airventure. Proof positive !!
I’ve commented on this before.
My thoughts are to design new heads for the existing engines, which have proven reliability, the most important requirement.
Designing water cooled heads and adding multiport fuel injection and electronic ignition would bring these engines to the current technology. The EFI and EI are available now for experimental engines, adapted from auto race engines.
I fly a ’61 Cessna 175B with the geared TCM GO-300, and it has proved to be powerful, efficient and reliable.
TT is ,3500+ hrs and this engine makes 180 HP at 3,200 rpm, spinning an 84 in. prop at 2,400 rpm.
It will cruise at 145 mph on 9 gph, good for a draggy Cessna. ROC is 1,000+ fpm up to 10,000 ft.!
The ‘new’ engines are still based on the older designs. If we get piston diesels that will be good enough for now. Aircraft engines have to deal with altitude and temperatures that cars do not. And everything on an aircraft is hand-made. Thus the expense. The electrics coming are also going to be limited until a truly new revolutionary battery appears.
Still, there are new designs with fantastic futures like the hovering, drone-like products enabled by new micro-motor technology. And we will see fly-by-wire in GA as the next ‘big thing’ that may eventually include fully auto-landing or assist-landing capability. But lets get serious…the chase is to just get into the air under $100k for a new aircraft…and eventually get panels that don’t break the bank and don’t scare the old-analog instrument guys.
You are correct! It is smaller companies producing these new engines.
P2M has 2 engines and both are turbodiesels. It has racing as its heritage. When you can buy a fully installed engine that produces 150 hp and uses only 5 gph or 250 hp and uses only 10 gph or 300 hp and uses less than 14 gph at full power, you have game changing technology. These engines are for sale now as experimental until certified.
The EPS Graflight V8 is a 601 lb dry weight TDI that should be certified by years end. They won’t sell any though till certified. But excellent engine.
The Adept engine uses 1/3 fewer parts as they’ve used 3D printing extensively and in doing so use maybe 20% less fuel than a comparable Lycoming or Continental engine. Plus have a gear reduction unit that they believe has a 20,000 hour TBO. Not bad. They too can be purchased while they become certified.
The best bang for the buck are the P2M engines. I expect all 3 companies will be at Oshkosh. Everyone may want to check these new engines out. All three appear to be worth the money.
Automotive engine technology today is so advance that I find no logical reason why Continental or Lycoming don’t implement this into their engine designs. Perhaps regulations or economics are holding them back?
Ben, Right on. So, I got back into GA in 2018… my last flight in my logbook was 1980 !
I vowed I would buy a plane with two things in mind; 1) safety, and, 2) good economy. I purchased the Flight Design with the Rotax 912 Is. I burn 3.5 gals/hour in cruise, and, I can see traffic, weather, and A/P… and if all of that fails me, I have a parachute. So, I stayed true to my goals.
To your comment about engine technology. In my humble opinion, it is all “about the money”. GA is still a shrinking market in the West, there is a growing one in Asia, but, that’s another story. We cannot produce enough Buyers of new airplanes to excite the Lycomings and the Conti’s because new aircraft are way beyond most people’s budget. They can buy new RV’s, but they cannot afford $100,000/seat new aircraft.
I believe that the electric engine will be the game changer GA needs. Rotax spurred new airplane purchasing #’s because they fit in 2 seat aircraft and they are reliable. The LSA market and the Rotax grew up together. Now Rotax has introduced the bigger engine which has spurred 4 seat models. Good.
But E-engines will drive the cost of the engines… and the OPERATION cost WAY down. The E-engine, once the battery life question gets figures out will be the demand creator GA desperately needs. We have to be patient and wait for the magical 5 hours battery (a wickedly hard balance of Electrical, Chemical and Mechanical Engineering). The 2 seater E will then become the 4 seater and so on… it will be the 1950’s jet age all over again.
Thanks, Andrew