New Planes from old companies

Mike Rapoport wrote:

Since most of the new airplanes and all of the new high performance single
engine designs are composite. Metal is a great material for airplanes but
it is difficult to produce perfect shapes with in the thin sheets used in
light aircraft. If you want to get more performance from your new design it
is going to need ripple free compound curves over the entire fusilage and
this is really hard to achieve with .025 sheetmetal. In other catagories,
like utility aircraft, it doesn't seem (to me anyway) that a new design is
going to offer much more than current planes like the 182 or 206.

The auto companies seem to have found ways to do this, and Audi even
does this with aluminum. Yes, you need some internal structure to
provide stiffness, but these structures can be easily stamped or
hydroformed as well as the skin. Just look inside a car that has had
the interior stripped, or look under your hood or trunk lid. This
technology is readily available, it has just never made its way into
light aircraft.


Matt

It is hard to do with real thin sheets. Cars are closer to Boeings than
Cessna's. There is a method used by Piaggio where the skin is sucked into a
mold and the structure is rivited on, but this process is fairly expensive
and, of course, the Piaggio has much thicker skins anyway.

Mike
MU-2


"Matt Whiting" wrote in message
...
Mike Rapoport wrote:

Since most of the new airplanes and all of the new high performance
single engine designs are composite. Metal is a great material for
airplanes but it is difficult to produce perfect shapes with in the thin
sheets used in light aircraft. If you want to get more performance from
your new design it is going to need ripple free compound curves over the
entire fusilage and this is really hard to achieve with .025 sheetmetal.
In other catagories, like utility aircraft, it doesn't seem (to me
anyway) that a new design is going to offer much more than current planes
like the 182 or 206.

The auto companies seem to have found ways to do this, and Audi even does
this with aluminum. Yes, you need some internal structure to provide
stiffness, but these structures can be easily stamped or hydroformed as
well as the skin. Just look inside a car that has had the interior
stripped, or look under your hood or trunk lid. This technology is
readily available, it has just never made its way into light aircraft.


Matt

Mike Rapoport wrote:
It is hard to do with real thin sheets. Cars are closer to Boeings than
Cessna's. There is a method used by Piaggio where the skin is sucked into a
mold and the structure is rivited on, but this process is fairly expensive
and, of course, the Piaggio has much thicker skins anyway.

It is harder with thin sheet, but I don't know I would say it is hard in
an absolute sense. I believe that the Venture kit plane had its wing
skins stretch formed and they are aircraft thickness. The reality
remains that the sheet metal techniques and technology being used today
in aircraft production is essentially unchanged from about 60 years ago.
Other industries have moved on to more modern methods, but aircraft
manufacturers have not. They may have good reasons for this,
certification costs, insurance, initial capital costs, etc., but the
fact remains.

Composite construction is great for low volume items as the tooling is
very inexpensive compared to large metal stamping dies. However, for
high volume production, composites actually aren't superior to metals in
general. Once you have the tooling in place, you can product finely
shaped metal parts at rates that composite makers can only dream of.
And you don't have to deal with the environmental hazards that
composites pose.

I'd love to see an all metal airplane designed and built by one of the
big auto makers. It would be nothing like a Cessna or Piper and likely
would be indistinguishable from a Lancair.


Matt

Ahh yes, sufficient volume.


"Matt Whiting" wrote in message
...
Dude wrote:

I would say you took his comments in a way not intended.

I have to wonder about the wisdom of a metal fuselage for a new small
piston plane anymore though. Wings, sure, but not the fuselage. The
composites would seem to have too many advantages. At least until
someone can make more progress in ways to get more curves, and more
strength, with less money than is currently happening in the metal world.
Which, someone likely will.

Actually, technology exists to hydroform metal into large and compound
curved shapes. It would be easy to eliminate almost all of the rivets in
both the fuselage and wings with modern metal forming technology. I can't
imagine a new design that would use the rib and skin methods developed
more than 60 years ago. A truly modern metal airplane could look just as
smooth as a composite and probably be even cheaper to produce given
sufficient volume to justify the tooling costs.


Matt

" This is a great expectation for a hobby, but not for a business! :-)

Yes, and when you reach a certain point in life, isn't it great that you can
make a business your hobby?

Carl

"Dude" wrote in message
news

I can't figure out how it will get very large unless Sport pilots are
allowed under the class B umbrella. I know they are not allowed in the
Bravo, but can they go under? Can the LSA's go into B with a PP as PIC?
Is
that all decided?

Sport pilots *can* fly into all classes of controlled airspace with just a
logbook endorsement. See http://www.sportpilot.org/becoming/ for full
details.


They are not overcharging, they are not being discriminating enough. This
has too affects. One, it raises claims because it does not discourage the
use of poorly designed planes. Two, it reduces overall safety by the same
mechanism.


I think you may be grossly overestimating the variability of safety here.
While one can find interesting point cases of disparity (such as night IFR
in Mooneys vs. other makes) overall I suspect the deltas just aren't that
significant. Likewise it may be that accidents are distributed pretty evenly
throughout the pilot community. Other than an obvious period in the first
couple of hundred hours and when transitioning to a new type, it may be that
accident pilots-to-be look just like the rest of us most of the time. It's a
sobering conclusion. Every time we read about an accident we want to find
something that we can say "well I wouldn't have done THAT," when it's more
like "there but for the grace of God..."

Best,
-cwk.

"Matt Whiting" wrote in message
...
Mike Rapoport wrote:
It is hard to do with real thin sheets. Cars are closer to Boeings than
Cessna's. There is a method used by Piaggio where the skin is sucked
into a mold and the structure is rivited on, but this process is fairly
expensive and, of course, the Piaggio has much thicker skins anyway.

It is harder with thin sheet, but I don't know I would say it is hard in
an absolute sense. I believe that the Venture kit plane had its wing
skins stretch formed and they are aircraft thickness. The reality remains
that the sheet metal techniques and technology being used today in
aircraft production is essentially unchanged from about 60 years ago.
Other industries have moved on to more modern methods, but aircraft
manufacturers have not. They may have good reasons for this,
certification costs, insurance, initial capital costs, etc., but the fact
remains.

Composite construction is great for low volume items as the tooling is
very inexpensive compared to large metal stamping dies. However, for high
volume production, composites actually aren't superior to metals in
general. Once you have the tooling in place, you can product finely
shaped metal parts at rates that composite makers can only dream of. And
you don't have to deal with the environmental hazards that composites
pose.

I'd love to see an all metal airplane designed and built by one of the big
auto makers. It would be nothing like a Cessna or Piper and likely would
be indistinguishable from a Lancair.


Matt


I agree with your above statements except for the implied notion that there
is a high volume market for any airplane.

Mike
MU-2

Mike Rapoport wrote:

"Matt Whiting" wrote in message
...

Mike Rapoport wrote:

It is hard to do with real thin sheets. Cars are closer to Boeings than
Cessna's. There is a method used by Piaggio where the skin is sucked
into a mold and the structure is rivited on, but this process is fairly
expensive and, of course, the Piaggio has much thicker skins anyway.

It is harder with thin sheet, but I don't know I would say it is hard in
an absolute sense. I believe that the Venture kit plane had its wing
skins stretch formed and they are aircraft thickness. The reality remains
that the sheet metal techniques and technology being used today in
aircraft production is essentially unchanged from about 60 years ago.
Other industries have moved on to more modern methods, but aircraft
manufacturers have not. They may have good reasons for this,
certification costs, insurance, initial capital costs, etc., but the fact
remains.

Composite construction is great for low volume items as the tooling is
very inexpensive compared to large metal stamping dies. However, for high
volume production, composites actually aren't superior to metals in
general. Once you have the tooling in place, you can product finely
shaped metal parts at rates that composite makers can only dream of. And
you don't have to deal with the environmental hazards that composites
pose.

I'd love to see an all metal airplane designed and built by one of the big
auto makers. It would be nothing like a Cessna or Piper and likely would
be indistinguishable from a Lancair.


Matt



I agree with your above statements except for the implied notion that there
is a high volume market for any airplane.

I made no such implication. My comment about "initial capital costs"
was actually in recognition that the volume available may not be
sufficient to warrant the tooling costs for stamping dies. However,
given that tooling costs have dropped a lot with the advent of CAD and
CNC, I do wonder if it might be possible even with Cirrus-like volume.
I don't know, but I do wonder. :-)


Matt