Electrically Powered Ultralight Aircraft

On Wed, 08 Aug 2007 07:20:22 -0700, wrote in
.com:


I have not seen any significant flight duration claim on the Sonex,
which speaks well for the design team.

I really hate to burst your bubble but, from the Sonex link above.

"Initial top speeds will reach approximately 130 mph, and endurance is
expected to range between 25-45 minutes or longer, depending upon power
usage on each individual flight."- Hide quoted text -

- Show quoted text -

I also read that but "Expected to be" isn't a claim and 45 minutes is
not what I would call significant duration.

Would you characterize 12 seconds ad significant?

http://www.thewrightbrothers.org/fivefirstflights.html
The First Flight, spanning some 120 feet in 12 seconds. The next
flight, Wilbur’s first flight on the 17th, extended to some 175
feet in 13 seconds and a landing was accomplished with no damage
to The Flyer. Orville’s second attempt that day, and his last one
in The Flyer, carried him just over 200 feet in 15 seconds and
ended with a safe landing. At noon, Wilbur took-off on the last
and the longest flight which The Flyer would ever make, and flew
for 852 feet, staying aloft for 59 seconds.

On Aug 8, 8:35 am, Larry Dighera wrote:
On Wed, 08 Aug 2007 07:20:22 -0700, wrote in
.com:



I have not seen any significant flight duration claim on the Sonex,
which speaks well for the design team.

I really hate to burst your bubble but, from the Sonex link above.

"Initial top speeds will reach approximately 130 mph, and endurance is
expected to range between 25-45 minutes or longer, depending upon power
usage on each individual flight."- Hide quoted text -

- Show quoted text -

I also read that but "Expected to be" isn't a claim and 45 minutes is
not what I would call significant duration.

Would you characterize 12 seconds ad significant?

http://www.thewrightbrothers.org/fivefirstflights.html
The First Flight, spanning some 120 feet in 12 seconds. The next
flight, Wilbur's first flight on the 17th, extended to some 175
feet in 13 seconds and a landing was accomplished with no damage
to The Flyer. Orville's second attempt that day, and his last one
in The Flyer, carried him just over 200 feet in 15 seconds and
ended with a safe landing. At noon, Wilbur took-off on the last
and the longest flight which The Flyer would ever make, and flew
for 852 feet, staying aloft for 59 seconds.

I guess I should have clarified that my comments refer to the here and
now where 12 seconds and\or 45 minutes are both insignificant in terms
of useful flight duration. While any duration is important the first
time achieved it will only become marketable when it has reached a
practical use point. Hopefully today's developments will lead to
something in the future that is but for now they are interesting
engineering experiments. Most people should and do applaud the efforts
while some think the future is already here. For those adventurers we
have $100,000 cars and underpowered trikes available right now.
I'm going to hold off for a little while longer.

Larry Dighera wrote:
On Wed, 8 Aug 2007 08:12:37 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in
:

They obviously don't make a 100HP motor of the type you showed or
you would have quoted it's specs.


Take a look at the ~75 HP electric motor installed in the Sonex Waiex:
http://www.sonexaircraft.com/news/im...irventure07/e-
flight_5947.jpg

Exclusive of the two black boxes, the Sonex motor sure doesn't appear
to weigh any where near the 1,118 lbs motor you found. My guess would
be under 100 lbs. It is custom built for/by Sonex, so I'm not able to
quote its specifications.

You don't really believe Sonex is using an electric motor that weighs
any where near 1,118 lbs, do you. The entire empty weight of the
Waiex is only ~620 lbs with a gross weight of 1150 lbs.

Of course I don't. But they might as well be at this point becuse the
electric motor they have has never been off the ground.

I wish the Sonex guys well and will praise the hell out of them if they do
what they are trying to do. But, as I said in a earlier post, I just don't
see this big of a technological leap coming from a company whose last major
enginnering feat was converting a VW engine for aircraft.

If and when it happens it will be either a bunch of guys from MIT or Cal
Tech or as the offshoot of a much more profitable electric motor project.

Larry Dighera wrote:
On Wed, 08 Aug 2007 07:20:22 -0700, wrote in
.com:


I have not seen any significant flight duration claim on the Sonex,
which speaks well for the design team.

I really hate to burst your bubble but, from the Sonex link above.

"Initial top speeds will reach approximately 130 mph, and endurance
is expected to range between 25-45 minutes or longer, depending
upon power usage on each individual flight."- Hide quoted text -

- Show quoted text -

I also read that but "Expected to be" isn't a claim and 45 minutes is
not what I would call significant duration.

Would you characterize 12 seconds ad significant?

http://www.thewrightbrothers.org/fivefirstflights.html
The First Flight, spanning some 120 feet in 12 seconds. The next
flight, Wilbur's first flight on the 17th, extended to some 175
feet in 13 seconds and a landing was accomplished with no damage
to The Flyer. Orville's second attempt that day, and his last one
in The Flyer, carried him just over 200 feet in 15 seconds and
ended with a safe landing. At noon, Wilbur took-off on the last
and the longest flight which The Flyer would ever make, and flew
for 852 feet, staying aloft for 59 seconds.


I would now but when the best previous powered flight it was ZERO in both
time and distance anything 0 was significant. And, unfortunately, for the
electric powered airplane folks they have to be compared at least to what I
can build in my garage and attach a 1960's vintage Corvair engine too.

Sonex's electric airplane especially has to be judged against that criteria
because they already make a plane that I can build in my garage and hang a
Corvair engine on.

Darrel Toepfer wrote:
"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote:

Why should I. I'm not the one making the claim.

But your the "bubble burst"r... ;-)

Exactly! To have the guys bubble fixed he needs to be the one that keeps an
eye out for the flight.

On Wed, 8 Aug 2007 10:48:40 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in
:

Larry Dighera wrote:
On Wed, 8 Aug 2007 08:12:37 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in
:

They obviously don't make a 100HP motor of the type you showed or
you would have quoted it's specs.


Take a look at the ~75 HP electric motor installed in the Sonex Waiex:
http://www.sonexaircraft.com/news/im...irventure07/e-
flight_5947.jpg

Exclusive of the two black boxes, the Sonex motor sure doesn't appear
to weigh any where near the 1,118 lbs motor you found. My guess would
be under 100 lbs. It is custom built for/by Sonex, so I'm not able to
quote its specifications.

You don't really believe Sonex is using an electric motor that weighs
any where near 1,118 lbs, do you. The entire empty weight of the
Waiex is only ~620 lbs with a gross weight of 1150 lbs.

Of course I don't. But they might as well be at this point becuse the
electric motor they have has never been off the ground.

The motor was apparently designed by Bob Boucher. He also designed
the motors Dr. Paul MacCready used to fly across the English channel
solely under power from the sun, and other successful AeroVironment
electrically powered aircraft commissioned by NASA. If anyone can
design a proper electric motor for aviation, Mr. Boucher should be
able to; he has the past successes to prove it.

I wish the Sonex guys well and will praise the hell out of them if they do
what they are trying to do. But, as I said in a earlier post, I just don't
see this big of a technological leap coming from a company whose last major
enginnering feat was converting a VW engine for aircraft.

If and when it happens it will be either a bunch of guys from MIT or Cal
Tech or as the offshoot of a much more profitable electric motor project.


Perhaps.

On Wed, 8 Aug 2007 10:55:38 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote in
:

Larry Dighera wrote:
On Wed, 08 Aug 2007 07:20:22 -0700, wrote in
.com:


I have not seen any significant flight duration claim on the Sonex,
which speaks well for the design team.

I really hate to burst your bubble but, from the Sonex link above.

"Initial top speeds will reach approximately 130 mph, and endurance
is expected to range between 25-45 minutes or longer, depending
upon power usage on each individual flight."- Hide quoted text -

- Show quoted text -

I also read that but "Expected to be" isn't a claim and 45 minutes is
not what I would call significant duration.

Would you characterize 12 seconds ad significant?

http://www.thewrightbrothers.org/fivefirstflights.html
The First Flight, spanning some 120 feet in 12 seconds. The next
flight, Wilbur's first flight on the 17th, extended to some 175
feet in 13 seconds and a landing was accomplished with no damage
to The Flyer. Orville's second attempt that day, and his last one
in The Flyer, carried him just over 200 feet in 15 seconds and
ended with a safe landing. At noon, Wilbur took-off on the last
and the longest flight which The Flyer would ever make, and flew
for 852 feet, staying aloft for 59 seconds.


I would now but when the best previous powered flight it was ZERO in both
time and distance anything 0 was significant. And, unfortunately, for the
electric powered airplane folks they have to be compared at least to what I
can build in my garage and attach a 1960's vintage Corvair engine too.

Sonex's electric airplane especially has to be judged against that criteria
because they already make a plane that I can build in my garage and hang a
Corvair engine on.


Electrically powered flight is in its infancy just as powered flight
was in 1903.

Larry Dighera wrote:


Electrically powered flight is in its infancy just as powered flight
was in 1903.

That matters not. It still has to be compared to what it is supposed to
replace. Would you want an electric car that was the technological equal to
this? http://www.ausbcomp.com/~bbott/cars/cugnot.jpg.

The otherside of that is that we can expect to wait until 2110 for electric
flight to catch up to where we are now with gasoline powered flight.

Would you characterize 12 seconds ad significant?

http://www.thewrightbrothers.org/fivefirstflights.html
The First Flight, spanning some 120 feet in 12 seconds. The next
flight, Wilbur’s first flight on the 17th, extended to some 175
feet in 13 seconds and a landing was accomplished with no damage
to The Flyer. Orville’s second attempt that day, and his last one
in The Flyer, carried him just over 200 feet in 15 seconds and
ended with a safe landing. At noon, Wilbur took-off on the last
and the longest flight which The Flyer would ever make, and flew
for 852 feet, staying aloft for 59 seconds.

In 1903 it was but times change...

Tony

On Tue, 07 Aug 2007 17:51:27 GMT, "Neil Gould"
wrote in
:

Recently, Larry Dighera posted:
[...]
I'm thinking there would be necessity for some means of conducting the
heat from the engine to a remote heat exchanger, and the resulting
complexity and weight increase would negatively impact the potential
advantages of a Stirling aviation engine. In any event, in addition
to the Stirling engine and its fuel, a heat exchanger of some type
needs to factored into the weight, cost, performance, and efficiency
equations.

Of course, but I don't see a lot of reason why that couldn't be
incorporated into the overall design. My point is that heat exchangers
need not be heavy, and could probably double as structural and/or
aerodynamic components, further reducing (and possibly enhancing) their
impact.

How would you get the heat from the Stirling engine to the heat sink?
If you use liquid coolant, it would be heavy and prone to leaks.

There might be one advantage to using Sterling external combustion
engines for aviation: the use of atomic energy as a fuel source if
the weight of the lead shielding were not too great. Imagine an
aircraft that effectively never runs out of fuel! There'd be no
more fuel exhaustion mishaps.

One downside would be the hazardous materials that could be
dispersed in a crash.

There are a lot of down sides to atomic power, but NASA uses it to
power Stirling engines in space.

Understandable, but their expectation is that catastrophic destruction
would disperse the nuclear material harmlessly. That can't be presumed for
light aircraft.

If the rocket detonated in the atmosphere, it might not be so
harmless. I would guess the reactor is jacketed with sufficient
strength to preclude its destruction. Presumably, that could be done
for a Stirling aircraft engine also.