I’m a bit confused by compressed air starting ? That’s no good in the air if you, for what ever reason need to attempt to restart an engine and you’ve not got enough air charged up to do it??
These days general aviation is going much the same way as cars with smaller more economic and cleaner engines.
When you can buy a whole car for £20k it doesn’t make sense that your aircraft engine that was designed in the 60s with a displacement of 6+ litres and only 160hp should be costing £50k that said aircraft engines no matter what are not cheap but they don’t need to be that big or heavy and they can be smaller, lighter and more powerful which is what Rotax are doing with their engines.
I don’t know much about the cross 4 but I suspect firstly as an air cooled Diesel engine it would have had to be an iron construction. So very heavy, then it would have been two Stoke so notoriously dirty emissions wise. And again a fully mechanical engine tends to be more simple/dumb which means no clever management of the engine resulting in sub optimal running configurations, and remember a car ending might go from 0-3000feet altitude but a plane engine needs to be able to manage the fuel air mix maybe up to 17,000-20,000 feet if carrying O2
The concept is genius but I’m assuming there were a lot of problems they’ve not been able to overcome.
The hawk engines you mentioned seem to have hit a similar wall having not made it into any sort of series production and only found there way into a few prototypes.
The only real advantage to a turbine is massive reliability as there are so few moving parts, also power, they don’t produce massive power on a little plane but for there size you can double your power for half the size and weight. They are much better on noise and of course vibrations but the costs are just insane. Something like a kit built Vans RV 10 might cost £50 for the aircraft but a turbine engine is going to be double that, versus £40k for a conventional new lycoming.
Something like that cross 4 or cross 8 would need some sort of aircraft designed around it, what I love though is the radial engine appearance.
These days general aviation is going much the same way as cars with smaller more economic and cleaner engines.
When you can buy a whole car for £20k it doesn’t make sense that your aircraft engine that was designed in the 60s with a displacement of 6+ litres and only 160hp should be costing £50k that said aircraft engines no matter what are not cheap but they don’t need to be that big or heavy and they can be smaller, lighter and more powerful which is what Rotax are doing with their engines.
I don’t know much about the cross 4 but I suspect firstly as an air cooled Diesel engine it would have had to be an iron construction. So very heavy, then it would have been two Stoke so notoriously dirty emissions wise. And again a fully mechanical engine tends to be more simple/dumb which means no clever management of the engine resulting in sub optimal running configurations, and remember a car ending might go from 0-3000feet altitude but a plane engine needs to be able to manage the fuel air mix maybe up to 17,000-20,000 feet if carrying O2
The concept is genius but I’m assuming there were a lot of problems they’ve not been able to overcome.
The hawk engines you mentioned seem to have hit a similar wall having not made it into any sort of series production and only found there way into a few prototypes.
The only real advantage to a turbine is massive reliability as there are so few moving parts, also power, they don’t produce massive power on a little plane but for there size you can double your power for half the size and weight. They are much better on noise and of course vibrations but the costs are just insane. Something like a kit built Vans RV 10 might cost £50 for the aircraft but a turbine engine is going to be double that, versus £40k for a conventional new lycoming.
Something like that cross 4 or cross 8 would need some sort of aircraft designed around it, what I love though is the radial engine appearance.
