Available aircraft engines: What's out there in diesels?

[Aesquire]

I think if there was a significant demand for long range, slow light aircraft, we'd see more diesels developed. Wonder if it's possible to have some kind of mechanical backup for FADEC, or a system that really doesn't need much of a battery when the alternator is working.

The older 12 valve, 6 cylinder Cummings engines found in Dodge pick up trucks used a mechanical fuel injection system. Proven, the problems are known and easy to fix/prevent, and lots of power can be extracted if you don't care about clouds of smoke. Only one wire to connect to the ignition switch, and another to the starter. So, yes, full authority analog engine control, with One Lever, the throttle, is easy to make, relatively. Poor choice, as is for an airplane, as it masses over 800 pounds.

However, the reason everyone uses computers today, is pollution. Control of the combustion event, fuel injection timing and amount, gives better mileage, and cleaner air.

 

[Twodeaddogs]

speaking of engines that start on one fuel and switch to another, like the old TVO engines, Mazda have an engine that starts with spark plugs on petrol but then changes to "dieseling", still on petrol, but with no ignition firing. the fuel burn is said to be much reduced.

 

[Chilton]

The no GPU requirement for the diesel Diamond aircraft came in after the incident described before. I am also awary of at least one diesel powered cessna which ended up in the North Atlantic on a delivery flight with an electrical issue which took out the fadec.

We looked at the thielert conversion a few years ago for our C206 fleet due to tthe price difference between JetA and avgas, fortunately we did not go ahead as thielert went under with the first conversions in the workshop! Our reason for not doing it was mostly about electric dependency and sectors which can be over an hour from an alternate!

 

[Twodeaddogs]

...and the whole point of diesel is that it needs no electrics to stay running, yet fitting a FADEC introduces the possibility of failure. Why not have the fuel solenoid on a seperate circuit?

 

[Chilton]

Almost my exact words to the Thielert sales rep, but I think my suggestion was that they remove the electrical dependency entirely before I would consider it safe.

 

[tspear]

So for those who are stating the electric ignition or injection system are too risky.
When do you switch to an all electric airplane? Electric motor has many fewer parts and a lower failure rate than any ICE engine.
Further, batteries although less understood in the general sense, have both fewer failure points and less risk of failure than fuel systems.

Tim (could not resist)

 

[Mad MAC]

So for those who are stating the electric ignition or injection system are too risky.
When do you switch to an all electric airplane? Electric motor has many fewer parts and a lower failure rate than any ICE engine.
Further, batteries although less understood in the general sense, have both fewer failure points and less risk of failure than fuel systems.

Tim (could not resist)

Current engine failure rate on electric aircraft was the same as piston engine aircraft last time I saw numbers (most failures were controller / battery related I think).

 

[wsimpso1]

Gemini Diesel.

 

[Richard6]

So for those who are stating the electric ignition or injection system are too risky.
When do you switch to an all electric airplane? Electric motor has many fewer parts and a lower failure rate than any ICE engine.
Further, batteries although less understood in the general sense, have both fewer failure points and less risk of failure than fuel systems.

Tim (could not resist)

Tim - I think that when you include the controller for the motor, you will see that there are hundreds if not thousands of more parts in the controller than in a piston engine.

Richard