turbo video

In article ,
Byron J. Covey wrote:
Just in case that I am right:
I know that a turboprop airplane can easily cost twice as much as a
piston plane of the same size. But this fact could only explain a
relative rareness of turboprop airplanes among aerobatic planes. What
it cannot explain is their (next to?) absence, since experience shows
that if there is a will there is a way, and some or another team of
people should always be able to adquire one of these planes.


Just a SWAG, but I would think that the Turbo Raven cost about 6 times what
a good Edge 540 would cost. Sponsorship before construction would be
important.

Larry Ellison, CEO of Oracle, and owner of many big boy toys, is
also a fan of aviation. The story goes that he was talking with
Wayne Handley and Sean Tucker after some airshow, and they hatched
the idea of the Turbo Raven. Cost isn't much of an issue for Larry
Ellison, since he is way up there on the various 'richest people'
lists.

Another post mentioned the difference between aerobatics and
competition aerobatics. The T-6A and various other trainers are
aerobatic turboprops, but they don't have to worry about staying
in the competition aerobatic box, which is quite tiny. The cost of
a turboprop, and the size of the box are probably the main reasons
they aren't used on competition planes. The maintenance requirements
on the turboprop would probably also be an issue.

The Turbo Raven was just a show plane, in the same category as the
jet powered Waco. Fun to watch, but totally ridiculous.

John
--
John Clear - http://www.panix.com/~jac

Turbines are not more difficult to maintain. In fact the maintenance is much
lower on a turbine (on a per-hour basis). The cost of the overhaul is quite
different though! However, the TBO is much better for a turbine. Overhaul on
my turbine is about US$235,000 but I get 3000 hours out of it. It's quite a
bit more expensive than other turbines, but you still are in the US$100,000
zone for an overhaul of a 600hp+ engine.

How much would a 600hp piston engine cost to overhaul?

"John Clear" wrote in message
...
In article ,
Byron J. Covey wrote:
Just in case that I am right:
I know that a turboprop airplane can easily cost twice as much as a
piston plane of the same size. But this fact could only explain a
relative rareness of turboprop airplanes among aerobatic planes. What
it cannot explain is their (next to?) absence, since experience shows
that if there is a will there is a way, and some or another team of
people should always be able to adquire one of these planes.


Just a SWAG, but I would think that the Turbo Raven cost about 6 times
what
a good Edge 540 would cost. Sponsorship before construction would be
important.

Larry Ellison, CEO of Oracle, and owner of many big boy toys, is
also a fan of aviation. The story goes that he was talking with
Wayne Handley and Sean Tucker after some airshow, and they hatched
the idea of the Turbo Raven. Cost isn't much of an issue for Larry
Ellison, since he is way up there on the various 'richest people'
lists.

Another post mentioned the difference between aerobatics and
competition aerobatics. The T-6A and various other trainers are
aerobatic turboprops, but they don't have to worry about staying
in the competition aerobatic box, which is quite tiny. The cost of
a turboprop, and the size of the box are probably the main reasons
they aren't used on competition planes. The maintenance requirements
on the turboprop would probably also be an issue.

The Turbo Raven was just a show plane, in the same category as the
jet powered Waco. Fun to watch, but totally ridiculous.

John
--
John Clear - http://www.panix.com/~jac

(John Clear) wrote in message ...
(cut)
Larry Ellison, CEO of Oracle, and owner of many big boy toys, is
also a fan of aviation. The story goes that he was talking with
Wayne Handley and Sean Tucker after some airshow, and they hatched
the idea of the Turbo Raven. Cost isn't much of an issue for Larry
Ellison, since he is way up there on the various 'richest people'
lists.

As you concede yourself, when it comes to aerobatic airplanes there
exists a source of financing which generallty doesn´t exist for
private airplanes: Sponsoring. Therefore, the cost argument in itself
can only explain the relative scarcity of turboprop engines in private
aircraft, but not the near absence of turboprop engines in aerobatic
aircraft.


Another post mentioned the difference between aerobatics and
competition aerobatics. The T-6A and various other trainers are
aerobatic turboprops, but they don't have to worry about staying
in the competition aerobatic box, which is quite tiny. The cost of
a turboprop, and the size of the box are probably the main reasons
they aren't used on competition planes.

If the competition aerobatic box tends to be too small for turboprop
planes, then it is inconceivable why they do not install a greater
competition box for turboprop planes.

The maintenance requirements
on the turboprop would probably also be an issue.

The Turbo Raven was just a show plane, in the same category as the
jet powered Waco. Fun to watch, but totally ridiculous.

John

Well now, this jet powered Whacko is nothing but a piston biplane
with a turbojet strapped to its belly. And this turbojet engine has a
bent exhaust pipe - kind of like a turboprop. As long as I haven´t
seen more data on this plane or seen it fly, I won´t believe that this
setup has much more than decorative value.

And now you come and compare this thing with .... a classical
turboprop plane? Sorry, but that´s what I would call ridiculous. You
know as well as I do, that turbomachinery rules the airwaves - exept
for a relative scarcity among private airplanes and a next to absence
among aerobatic aircraft. And this is clearly a non trivial fact which
requires a cogent explanation.

Peter H.

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.

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.

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. 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. 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. And you wouldn't put a piston
in a commuter airliner.

-j-

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 don´t 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 don´t 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 can´t help feeling that you guys are trying to sell
me apples for oranges on this issue.


Peter

In article ,
Peter Holm wrote:

As you concede yourself, when it comes to aerobatic airplanes there
exists a source of financing which generallty doesn´t exist for
private airplanes: Sponsoring. Therefore, the cost argument in itself
can only explain the relative scarcity of turboprop engines in private
aircraft, but not the near absence of turboprop engines in aerobatic
aircraft.

Airshow aerobatics have sponsorships. Competition aerobatics don't have
as much in the way of sponsorships except at the highest levels. Even
with sponsorships, there is a big difference between a $50K Lycoming
and a $500K+ PT-6.

The Turbo Raven was just a show plane, in the same category as the
jet powered Waco. Fun to watch, but totally ridiculous.

Well now, this jet powered Whacko is nothing but a piston biplane
with a turbojet strapped to its belly. And this turbojet engine has a
bent exhaust pipe - kind of like a turboprop. As long as I haven´t
seen more data on this plane or seen it fly, I won´t believe that this
setup has much more than decorative value.

I've seen it fly, and it does some pretty impressive vertical climbs.

Some stats on the plane are available at:
http://www.franklinairshow.com/jetstats.htm

There is also video on that site, doesn't show much of the vertical
though.

John
--
John Clear - http://www.panix.com/~jac