5 ms·

Kerosene/JP-8 is great in a jet but it's not going to get you very far in a piston prop.

formerly_proven 5y ago
There is no particular reason why you can't put a diesel engine in a plane and indeed there are a number of diesel engines certified for just that.
- xyzzyz 5y ago
  There are few technical reasons, to be sure, but there are plenty of economic and business reasons. The most popular engines in general aviation are Continental/Lycoming ones, and these are based on what, 50+ years old basic designs? Automotive industry have developed significantly better piston engines in last few decades, in terms of power to weight ratio, fuel efficiency, MTBF and service interval. However, the nature of the field, its relative niche quality, and regulatory framework make it difficult to adapt and adopt them in general aviation. There has been recent attempt to do it, with diesel engines from German automotive industry, but they are facing a lot of very real problems, for example, lack of maintenance infrastructure.
  - mschuster91 5y ago
    > but they are facing a lot of very real problems, for example, lack of maintenance infrastructure. Comprehensive government regulation would create such an infrastructure. When the government says "in 5 years we will disallow creation of new airframes that use leaded gas, and in 10 years there will be no more leaded gas sold, and in 15 years additives will be illegal", everyone knows what's on the horizon - and you can bet that there will be engine vendors selling modification kits and maintenance infrastructure, since now everyone knows that there will be a massive market coming up as everyone has to adapt to the new rules if they want to keep flying!
    - xyzzyz 5y ago
      > Comprehensive government regulation would create such an infrastructure. Or, it would destroy small engine general aviation. > and you can bet that there will be engine vendors selling modification kits and maintenance infrastructure, since now everyone knows that there will be a massive market coming up as everyone has to adapt to the new rules if they want to keep flying! What if, you know, people can't adapt? What if people can't afford to replace their 40 years old aircrafts with sparkling new ones, costing 5-10 times much? Sure, some of them will, but there are many hobbyists who can afford loan payments and insurance on a plane worth $100k, but couldn't do the same on one worth $500k. Yes, this would stop emissions of TEL, sure, but at tremendous cost. Is that cost worth it? To our (and FAA, and EPA) best knowledge, probably not, as lead emissions from GA have much different characteristic than the ones from cars.

There is no particular reason why you can't put a diesel engine in a plane and indeed there are a number of diesel engines certified for just that.

xyzzyz 5y ago
There are few technical reasons, to be sure, but there are plenty of economic and business reasons. The most popular engines in general aviation are Continental/Lycoming ones, and these are based on what, 50+ years old basic designs? Automotive industry have developed significantly better piston engines in last few decades, in terms of power to weight ratio, fuel efficiency, MTBF and service interval. However, the nature of the field, its relative niche quality, and regulatory framework make it difficult to adapt and adopt them in general aviation. There has been recent attempt to do it, with diesel engines from German automotive industry, but they are facing a lot of very real problems, for example, lack of maintenance infrastructure.
- mschuster91 5y ago
  > but they are facing a lot of very real problems, for example, lack of maintenance infrastructure. Comprehensive government regulation would create such an infrastructure. When the government says "in 5 years we will disallow creation of new airframes that use leaded gas, and in 10 years there will be no more leaded gas sold, and in 15 years additives will be illegal", everyone knows what's on the horizon - and you can bet that there will be engine vendors selling modification kits and maintenance infrastructure, since now everyone knows that there will be a massive market coming up as everyone has to adapt to the new rules if they want to keep flying!
  - xyzzyz 5y ago
    > Comprehensive government regulation would create such an infrastructure. Or, it would destroy small engine general aviation. > and you can bet that there will be engine vendors selling modification kits and maintenance infrastructure, since now everyone knows that there will be a massive market coming up as everyone has to adapt to the new rules if they want to keep flying! What if, you know, people can't adapt? What if people can't afford to replace their 40 years old aircrafts with sparkling new ones, costing 5-10 times much? Sure, some of them will, but there are many hobbyists who can afford loan payments and insurance on a plane worth $100k, but couldn't do the same on one worth $500k. Yes, this would stop emissions of TEL, sure, but at tremendous cost. Is that cost worth it? To our (and FAA, and EPA) best knowledge, probably not, as lead emissions from GA have much different characteristic than the ones from cars.