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Comment by TylerE | Hacker News Reader

It's an impressive achievement, but I would say the true beauty of good engineering is in being the best while also keeping costs under control. Getting 50-80% more performance isn't hard when you cost 5x as much (or more).

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And most true in aviation. With enough funds you can buy some very magical things. But it isnt a bush plane if it cannot be fixed in the bush. Things like turbines and carbon fiber dont lend themselves to repair in an actual field.

Carbon:

One of the most popular high performance light bush planes at the moment: https://en.wikipedia.org/wiki/CubCrafters_Carbon_Cub_EX

Turbines:

The money makers: https://en.wikipedia.org/wiki/De_Havilland_Canada_DHC-3_Otte... (plus it's twin cousin)

https://en.wikipedia.org/wiki/Sherpa_Aircraft_Sherpa

So these aren't bush planes?

Edit: further, there's nothing inherent to carbon or turbines that make them unsuitable for the backcountry. Turbines are generally more reliable and have fewer moving parts. There's nothing on them that you can't fix with bailing wire that you can on a piston engine. The Wilga is overwhelmingly aluminum monocoque but if you need to fix the cowling (the main carbon part) some speed tape will do as it's not really load bearing. The cessna I took my checkride in was probably missing half it's cowling bolts :/

Not to mention all the Basler-converted turbine DC-3s, many of which are still flying into the least hospital places on earth (like Antartica) at almost 90 years old.

My worry with a turbine on a bushplane would be the potential for it to ingest gravel / sand / rocks etc.

Surely a prop is better suited for this? You could even carry a spare "just in case".

Piston engines have air intakes too. A 600ish HP turbine is also moving a lot less air than you probably think.. it's not a high-bypass jet on an airliner.

Small/medium sized turbines are used all the time on helicopters, which routinely see backwoods operation.

These are turbo-props. The jet bit is only a power supply to turn a propeller. It doesn't provide thrust like in a 747 or military jet. Its air intake is covered by a filter system just like any piston engine. For a given fuel consumption, the amount of air moving in/out of a turbine engine is roughly proportional to a piston engine.

They certainly do push the limit of what I'd call a bushplace. Are we going to define anything that lands on grass a bushplane? They operate in the woods, but can they actually live in the woods? Turbines need to be sent away for servicing and are very expensive. They cannot be disassembled or inspected without things like bore scopes. These are the planes that service logging camps, commercial operations, and fly back to aerodromes. They aren't the romantic planes servicing trappers or individual prospectors, the ones that sleep under a tarp most nights.

The exact same thing is true of any certified piston engine but on a shorter time table. Piston engine need to be removed and overhauled at the factory every 2000 hours and if a prop blade grazes the ground or hits a bush it needs to be removed, fully disassembled and have a die penetration test done at a minimum.

Also, a bush plane is, by definition, any logistics aircraft that doesn't need a runway which those very much fall into.

Carbon fiber can be fixed in the bush. What's special about turbines that makes the not field repairable? Nobody is fixing engine cores of any type without flying in parts anyway.

If anything turbines are probably better... I mean, worse if something actually goes wrong probably but there's less to go wrong.

The thing is that turbines are incredibly reliable compared to piston engines. The PT6 in particular is known for reliability. Compare the TBO (time between overhauls) on the IO-540 piston engine originally at 1200 to 2000 hours depending on application to the TBO for the PT6A turbine which is 6000 to 9000 hours depending on model and application. In any case, fixing an aircraft engine in the bush is not really a thing, the concern is forced landings due to engine failure.

In airline service engines are monitored and inspected and overhauls are done when there is evidence that it is needed. One CFM-56 on a 737 went over 40,000 hours before being removed from the airplane for rebuild.

The extreme reliability of turbine engines is why they permit twin engine airliners to operate on routes that could require up to 370 minutes of single engine operation. That is, the FAA considers the risk of a second engine failure is acceptable for over six hours. [0]

[0] https://en.wikipedia.org/wiki/ETOPS

This is an expensive plane, but $1M isn't that expensive for a plane. It's would be like buying a $80k car.

It's very expensive for a 4 seater.

The current most popular 4-seater, the Cirrus SR22 goes for about $600k-750k new depending on options.

Even the turbine-power Lancair Evolution comes in right around $1M, and that's for a fully certified-factory built aircraft.

The aircraft in the OP is an expirimental (e.g. you can't make money using it) aircraft and the quoted price did not include hundreds or thousands of hours of labor.

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