Smutny wrote in message . ..
The Australian Roulettes fly the PT-6 as well as a few other countries
I can't think of at the moment. Brazil perhaps? But one has to
remember, what aerobatic teams do, and what happens in an aerobatic
competition aren't identical.
So it appears. Thanks for the tip about the Roulettes, but all the
images I could find of them in the web were just about formation
flight. No torque rolls etc.
I do envy John Clear a lot for having seen (live, on top!) an
aerobatic turboprop plane strut its stuff. I might never get to see
this in my life perhaps not even on a video. And this to me is
rather disapointing, whether you understand that or not.
The competition box is one size for all competitions, 1000 square
meters. Changing it would require sancitioning from the FAI. But
creating different sized boxes for different aircraft neutralizes the
spirit behind the competition.
Airshows on the other hand, boxes are determined mainly by the venue.
The idea that the competition aerobatic box might be too small for
turboprop planes came up in this thread, presumably based on the
hypothesis that the throttle lag of an aerobatic turboprop plane
would hamper its agility of flight in comparison to a piston plane.
But as nametab has pointed out on 9-17 in this thread, and I think he
is right, is that throttle lag is not likely to be a problem for
single spool turbine motors. Small turboprops are double spool, though
not coaxial but in series (one turbine shaft and one independent power
shaft).
Therefore, the idea that the competition box might be too small for a
turboprop plane is, like next to everything else on this thread, based
on nothing but speculation. So I repeat: What would be needed here is
the testimony of a pilot who has actually flown aerobatics with a
turboprop plane.
One of the reasons you don't see many more turbine GA aircraft is
partly due to the lack of certified small turbines. There is a
growing number of turbine homebuilts. Comp Air and Lancair being two
that offer kits designed for them. I've also seen an article on a
turbine RV-4 in Sport Aviation not too long ago. As time goes on,
cheaper and smaller turbines will probably have a greater presence in
the GA market.
I donīt think that the general aviation market has a lot of relevance
for aerobatic planes. The abundance of turbine planes (not only
turboprop) in general aviation is far higher than in aerobatics.
Don't know what the economics are though, how much
does a hot section cost compared to overhauling a piston engine? And
what does that translate to per hour costs?
No need to get hostile over all this, Holm. Turbines are not the
end-all, be-all of aviation.
Of course not. There are ramjets, and perhaps some day there will be
scramjets. But when it comes to aviation, I cannot think of any
advantage of piston engines over turbine engines besides their price
and their fuel efficiency (I know of people who actually think that
the maintaineance for turbine engines costs even less than for piston
engines).
Jets, turboprops and pistons all have
thier strengths and weaknesses. And their appropriate application.
Aviation pistons right now are just at the top of thier game when it
comes to hardcore aerobatic aircraft.
(cut)
But this is exactly what I donīt understand.
I am perfectly aware of the fact that under certain circumstances a
more primitive technology can have advantages over a more advanced
technology dedicated to the same task. An example in case would for
instance be police officers patroling park and beach areas on bicycles
instead of in police cars. But whenever this happens, there exists a
cogent explanation for that circumstance. And a cogent explanation -
preferrably from someone who talks from experience - is what is
missing in this thread so far.
So why should, of all cases, aerobatics be one of those examples where
a comparatively primitive (engine) technology would have the edge over
a more sofisticated one? Why should the aim in aerobatics be to only
make the aircraft lighter, but not to make the motor stronger and
lighter at the same time? Why should an aircraft which cannot fly a
sustained torque roll be better for aerobatics than an aircraft which
can? After all, the relative lack of power of piston planes is
responsible for the fact that a torque roll is often confused with a
tail slide.
This remains an obvious paradox at least on this thread - which
requires something more than speculations for a convincing
explanation. And I canīt help feeling that you guys are trying to sell
me apples for oranges on this issue.
Peter
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