P 2012 STOL

[Eagle_]

I recently heard Tecnam is now building an STOL variant of the P2012. For this application they have selected the (375 hp) Continental GTSIO-520-S Instead of the (375 hp) Lycoming TEO-540. Does anyone know why they reverted to the use of a geared engine while every other manufacturer has abandoned them some time ago? I would get it if you wanted a 400+ hp piston so the prop turns slower while the engine can spin faster, does this maybe have an advantage for STOL capability as well? Also curious why they went with a Continental instead of a Lycoming for this in general but I suppose that’s just about who made them a better price offer…

 

[GeorgeC]

The Helio Courier went the geared route too.

 

[Eagle_]

Some variants yes, but it’s no longer in production. And neither are the 435 and 480 engine models. There are a lot of planes in the past that used geared engines. But I haven’t seen a new aircraft with a geared Lyco or Conti since the 80’s. I’m specifically avoiding mentioning the little rotaxes here too; they’re all geared.

 

[Bell206]

But I haven’t seen a new aircraft with a geared Lyco or Conti since the 80’s.

FYI: as you probably know the geared engine gives you the best of both worlds when it comes to optimum prop and engine performance. Perhaps Tecnam needs those combined performance/power bands to make their design achieve true STOL performance? Regardless, the death nell of the opposed geared engine wasn't so much the design but how it was operated. Operate a geared engine like a direct drive engine and you'll put it in an early grave.

 

[Piperonca]

FYI: as you probably know the geared engine gives you the best of both worlds when it comes to optimum prop and engine performance. Perhaps Tecnam needs those combined performance/power bands to make their design achieve true STOL performance? Regardless, the death nell of the opposed geared engine wasn't so much the design but how it was operated. Operate a geared engine like a direct drive engine and you'll put it in an early grave.

Didn't know that...why?

 

[Eagle_]

FYI: as you probably know the geared engine gives you the best of both worlds when it comes to optimum prop and engine performance. Perhaps Tecnam needs those combined performance/power bands to make their design achieve true STOL performance? Regardless, the death nell of the opposed geared engine wasn't so much the design but how it was operated. Operate a geared engine like a direct drive engine and you'll put it in an early grave.

Makes me wonder why they didn’t include a fadec this time

 

[William Pete Hodges]

I can think of one good reason... What if they are swinging a larger diameter prop? DIA x RPM translates to prop tip speed. If the prop is larger than 72 inches the prop RPM must be reduced. Bigger props make more thrust, very important for STOL operations.
Just a thought.

 

[Bell206]

Didn't know that...why?

In general, geared engines are designed to operate at a higher RPM (3000+) then direct drive engines. If you operate geared engines at those lower RPMs (<2400) it causes a number of issues internally and externally with the engine which lead to premature failure. Its always been said that if the GO-300 had a dual tach showing the prop RPM and engine RPM, the engine would have been a deal changer.

Makes me wonder why they didn’t include a fadec this time

Probably because the G520 is off-the-shelf and would have required additional certification.