Basler's in Oshkosh: http://www.baslerturbo.com/bt_67_overview.html


I worked on a number of DC-3's in the late 80's. I refitted electronics
on two that came out of Chile that had the original command
communication equipment from the second world war, incuding the arc-5
units, bc 348 and the BC610 transmitter. I still have the telegraph key
somewhere in my collection of stuff.
The DC-3 could work out of smaller airports and was a compariaatively
inexpensive aircraft to own and operate. A decent cargo DC-3 was
running about 150,000 dollars and would haul about 9000 lbs payload.
They came with a number of different engines, including the R1820
Wright, R1830 PW and the R2000 PW on the R4-d7 military aircraft.
There was one outfit that put a pair of turboprops on a DC-3 and upped
the useful load and gross weight of the aircraft.

John

Wow, I've read for years that the VW was not a good conversion, but I didn't
realize it was that bad.




Anybody who wants to see the details of my planes...
the plans and builders manual are at:

http://www.matronics.com/photoshare/...006/index.html
Scroll down to the Plans download - or the manual download.
Heck, splurge and get both!


Photo CD of construction log web site and lots of pictures...
http://www.matronics.com/photoshare/...et.03.04.2006/

Warning Will Robinson! - MOBY BIG Zip file...


I didn't download your big file but I see some photos on the Web of the
Texas Parasol. I see it's made of 6061 aluminum angle and tube. How do you
stick it together, TIG welding?

--
Ed Huntress



Rivets, Ed!
AD-470 type driven rivets.

While 6061-T6 can be welded, such would never do a fuselage truss.
That sweet curve would turn into a series ov straight chords.

Ug...

"cavelamb himself" wrote in message
...



Wow, I've read for years that the VW was not a good conversion, but I
didn't realize it was that bad.




Anybody who wants to see the details of my planes...
the plans and builders manual are at:

http://www.matronics.com/photoshare/...006/index.html
Scroll down to the Plans download - or the manual download.
Heck, splurge and get both!


Photo CD of construction log web site and lots of pictures...
http://www.matronics.com/photoshare/...et.03.04.2006/

Warning Will Robinson! - MOBY BIG Zip file...


I didn't download your big file but I see some photos on the Web of the
Texas Parasol. I see it's made of 6061 aluminum angle and tube. How do
you stick it together, TIG welding?

--
Ed Huntress

Rivets, Ed!
AD-470 type driven rivets.

While 6061-T6 can be welded, such would never do a fuselage truss.
That sweet curve would turn into a series ov straight chords.

Ug...

Yeah, that's why I wondered. I couldn't picture welds that wouldn't make a
mess.

But the frame members appear to meet at points, as in a tubular space frame.
How do you get rivets in there? How many rivets pin a typical joint?

--
Ed Huntress

Ed Huntress wrote:
"cavelamb himself" wrote in message
...



Wow, I've read for years that the VW was not a good conversion, but I
didn't realize it was that bad.




Anybody who wants to see the details of my planes...
the plans and builders manual are at:

http://www.matronics.com/photoshare/...006/index.html
Scroll down to the Plans download - or the manual download.
Heck, splurge and get both!


Photo CD of construction log web site and lots of pictures...
http://www.matronics.com/photoshare/...et.03.04.2006/

Warning Will Robinson! - MOBY BIG Zip file...


I didn't download your big file but I see some photos on the Web of the
Texas Parasol. I see it's made of 6061 aluminum angle and tube. How do
you stick it together, TIG welding?

--
Ed Huntress

Rivets, Ed!
AD-470 type driven rivets.

While 6061-T6 can be welded, such would never do a fuselage truss.
That sweet curve would turn into a series ov straight chords.

Ug...


Yeah, that's why I wondered. I couldn't picture welds that wouldn't make a
mess.

But the frame members appear to meet at points, as in a tubular space frame.
How do you get rivets in there? How many rivets pin a typical joint?

--
Ed Huntress



Extruded angle - mated on the flat faces.

The vertical members attach to the outside (vertical) longeron flange,
the horizontal members attach to the horizontal flange.

Everything attaches on the inside face of the longeron - well, except
the landing gear cross bars / lift strut attach points (a pair of 1-1/4"
extruded angle pieces) that are bolted underneath the longs.

Edge margin is a little iffy with 3/4" flanges, but the 1/8" thickness
(each) is more than adequate metal to hold a rivet.
It's not like riveted thin sheet metal.
More like Lugs.

Some use two 1/8" rivets per joint - some use a single 5/32 or 3/16.
I've done them both ways.

It produces a very rigid, fairly light weight structure that is very
robust.

For example, a Graham Lee Nieuport fuselage the weight increase is
about 6 to 8 pounds.

A very slight factor compared to the structural integrety, low cost
and ease of construction afforded by extruded angle construction.


Richard

"cavelamb himself" wrote in message
...
Ed Huntress wrote:
"cavelamb himself" wrote in message
...



Wow, I've read for years that the VW was not a good conversion, but I
didn't realize it was that bad.




Anybody who wants to see the details of my planes...
the plans and builders manual are at:

http://www.matronics.com/photoshare/...006/index.html
Scroll down to the Plans download - or the manual download.
Heck, splurge and get both!


Photo CD of construction log web site and lots of pictures...
http://www.matronics.com/photoshare/...et.03.04.2006/

Warning Will Robinson! - MOBY BIG Zip file...


I didn't download your big file but I see some photos on the Web of the
Texas Parasol. I see it's made of 6061 aluminum angle and tube. How do
you stick it together, TIG welding?

--
Ed Huntress

Rivets, Ed!
AD-470 type driven rivets.

While 6061-T6 can be welded, such would never do a fuselage truss.
That sweet curve would turn into a series ov straight chords.

Ug...


Yeah, that's why I wondered. I couldn't picture welds that wouldn't make
a mess.

But the frame members appear to meet at points, as in a tubular space
frame. How do you get rivets in there? How many rivets pin a typical
joint?

--
Ed Huntress

Extruded angle - mated on the flat faces.

The vertical members attach to the outside (vertical) longeron flange,
the horizontal members attach to the horizontal flange.

Everything attaches on the inside face of the longeron - well, except
the landing gear cross bars / lift strut attach points (a pair of 1-1/4"
extruded angle pieces) that are bolted underneath the longs.

Edge margin is a little iffy with 3/4" flanges, but the 1/8" thickness
(each) is more than adequate metal to hold a rivet.
It's not like riveted thin sheet metal.
More like Lugs.

Some use two 1/8" rivets per joint - some use a single 5/32 or 3/16.
I've done them both ways.

It produces a very rigid, fairly light weight structure that is very
robust.

For example, a Graham Lee Nieuport fuselage the weight increase is
about 6 to 8 pounds.

A very slight factor compared to the structural integrety, low cost
and ease of construction afforded by extruded angle construction.

That's interesting, and surprising. So, many of those members are held
together with a single rivet.

I'd like to see that one in a finite-element analysis program.

--
Ed Huntress

On Sun, 30 Sep 2007 21:14:03 +0100, David Billington
wrote:



Ed Huntress wrote:

"David Billington" wrote in message
...


Ed Huntress wrote:

"David Billington" wrote in message
o.uk...

Ed Huntress wrote:

"Jman" wrote in message
glegroups.com...

I think I'd rather take the train or bus thanks.......


http://seattletimes.nwsource.com/htm...boeing111.html

http://findarticles.com/p/articles/m..._n8765992/pg_4

I wrote articles almost identical to those 25 years ago. IIRC, the
L-1011 had a carbon-fiber tailfin, as well. And the other story is the
same old, same old for the high-performance composites business. Very
little appears to have changed.

A lot of people don't realize how much epoxy is used throughout the
structure of an airliner. They probably don't want to know. d8-)

However, they also don't know how much fatigue becomes a problem in
all-aluminum aircraft that were designed over the last few decades.
DC3's are still flying because the engineers didn't know what a
reasonable safety margin was. Now they know, and the life of those
planes is finite.

--
Ed Huntress

I was told by late father, who was in the aerospace industry in the UK
and later US as a stress analyst, maybe 25 years ago that one of the
reasons the DC3 kept flying because you could still get fuselages and
wings. When the life of the wings was up you bought new ones and the same
with the fuselage. I expect like many planes the airframe life is also
re-evaluated after actual service conditions have been experienced and
extended or otherwise revised.

I think that's true, but I flew in DC3's in Canada's Northwest Territories
that still had fabric-covered control surfaces. Those were *old* DC3's,
and it was only 20 years ago that I flew in them.

If fabric covered what was the structure of the control surfaces made of?.
I don't know much about wood structures so don't know if they suffer from
fatigue.


I don't know for sure, but most likely they were steel tubing. That was the
most common way to build a whole airplane in the 1930s, before the
aluminum-skinned construction became common, and it was used for small
planes as well, including the Piper Cub, the Aeronca Champion, and so on,
into the '50s and some into the '60s. Today, homebuilts are often made that
way in the US. My understanding is that amateur-welded steel tube frames are
not allowed for homebuilts in Europe, correct?


The control surfaces on a DC-3 were constructed of an aluminum frame
covered with fabric. A not uncommon method of construction for their
time.

To the best of my knowledge there were no "spare" wings or fuselages
for the DC-3. Like any other aircraft if there was damage it was
repaired.

In Viet Nam when we mounted the Mini Guns in the DC-3 (C-47) we found
that many of the fuselage formers that supported the floors were
corroded to the extent that it was thought that they would not support
the recoil of the guns. The formers were simply removed and new ones
fabricated in the field and riveted into place.

Bruce in Bangkok
(brucepaigeATgmailDOTcom)

wrote in message
...

snip


The control surfaces on a DC-3 were constructed of an aluminum frame
covered with fabric. A not uncommon method of construction for their
time.

To the best of my knowledge there were no "spare" wings or fuselages
for the DC-3. Like any other aircraft if there was damage it was
repaired.

In Viet Nam when we mounted the Mini Guns in the DC-3 (C-47) we found
that many of the fuselage formers that supported the floors were
corroded to the extent that it was thought that they would not support
the recoil of the guns. The formers were simply removed and new ones
fabricated in the field and riveted into place.

That's my kind of airplane. d8-)

--
Ed Huntress

Ed Huntress wrote:
wrote in message
...

snip

The control surfaces on a DC-3 were constructed of an aluminum frame
covered with fabric. A not uncommon method of construction for their
time.

To the best of my knowledge there were no "spare" wings or fuselages
for the DC-3. Like any other aircraft if there was damage it was
repaired.

In Gann's book "Flying Circus", he mentioned a DC-2 1/2,
A DC-3 with a DC-2 wing on one side.

In Viet Nam when we mounted the Mini Guns in the DC-3 (C-47) we found
that many of the fuselage formers that supported the floors were
corroded to the extent that it was thought that they would not support
the recoil of the guns. The formers were simply removed and new ones
fabricated in the field and riveted into place.

That's my kind of airplane. d8-)

--
Ed Huntress

Ted Frater wrote:

john wrote:


David Billington wrote:



Ed Huntress wrote:

"David Billington" wrote in
message ...


Ed Huntress wrote:

"Jman" wrote in message
ups.com...

I think I'd rather take the train or bus thanks.......


http://seattletimes.nwsource.com/htm...boeing111.html


http://findarticles.com/p/articles/m..._n8765992/pg_4



I wrote articles almost identical to those 25 years ago. IIRC, the
L-1011 had a carbon-fiber tailfin, as well. And the other story is
the same old, same old for the high-performance composites
business. Very little appears to have changed.

A lot of people don't realize how much epoxy is used throughout the
structure of an airliner. They probably don't want to know. d8-)

However, they also don't know how much fatigue becomes a problem in
all-aluminum aircraft that were designed over the last few decades.
DC3's are still flying because the engineers didn't know what a
reasonable safety margin was. Now they know, and the life of those
planes is finite.

--
Ed Huntress

I was told by late father, who was in the aerospace industry in the
UK and later US as a stress analyst, maybe 25 years ago that one of
the reasons the DC3 kept flying because you could still get
fuselages and wings. When the life of the wings was up you bought
new ones and the same with the fuselage. I expect like many planes
the airframe life is also re-evaluated after actual service
conditions have been experienced and extended or otherwise revised.



Parts for the DC3/ C47 were easy to come by and most of the parts were
stock items. Since the military had over 10,000 C-47s there were plenty
of spare parts available. The DC3 itself was a very simple aircraft,
not like todays flying electronic boxes. There were many variations
depending on how the airline ordered the plane. The Pan Am ones had the
biggest fuel tanks. You would almost never find any major structural
cracks in the wings like you do with later jet aircraft. If you ever
check an AD (sirworthness directive) list for a 747 you would probably
not fly in one. There is a number of them that list cracks in the main
spars of the wing and not to let them get bigger than a certain number
of inches.








I think that's true, but I flew in DC3's in Canada's Northwest
Territories that still had fabric-covered control surfaces. Those
were *old* DC3's, and it was only 20 years ago that I flew in them.

If fabric covered what was the structure of the control surfaces made
of?. I don't know much about wood structures so don't know if they
suffer from fatigue.



The frame of the control surface was all metal.





They just stood up a lot longer. They also had severely reduced load
capacities because of the overbuilding.

In the science museum in London there is a section of a 747 fuselage.
It's quite surprising how thin the outer shell is, looks to be about
2.5mm from memory. Not that I have a problem with that as with a
background in engineering I know some damn good people design these
things and the 747 is a strong aircraft judging from the bits that has
fallen off them and they still kept flying.\



The 747 was a well designed aircraft. It had triple redundant systems
on all critical systems. The one engineer that I knew that was heavily
involved in the design of that plane told me that they estimated a
mechanical failure rate leading to a crash worked out to 1.3 aircraft
in 20 years. The plane has a rate better than that, The crash of the
one in Japan was due to improper maintenace. The others were from pilot
errors or bombs and rockets.

There are still plenty of DC-3 flying, a lot of them are used in the
Bahamas, West Indies and south florida. There was one that had been
going over our place late in the evening, sounded like it had R1820
Wright engines on it, 9 cylinders with 200 cubic inch each you can tell
the difference.


John




Seems like a lot of very interesting reminising going on!!
hope you dont mind me adding a bit.
I was lucky to get my emgineering training on Sunderland Flying boats
and then converted to Shackleton 1 and 2. at RAF kinloss.
A little while ago!.
However its all been so worth while, when hang gliding started in
1976 here in the UK, it was just what I wanted to do.
Finished up representing the BHGA at the CAA in London on the air
management group.
Met some very good people.
Now we have some 800 yds away from here a microlite field.
there they have the 3 axis under 500kgs fixed wing 2 seaters. they turn
finals over the house.
Now they have all steel tube welded fuselages with ali main spars inthe
wings with wooden ribs and fabric cover on all surfaces.
One gronund looped on take off recently and the tubes bent in all sorts
of places but none of the welds let go.
Definately the CAA dont allow home welding.!!
Ed, do you know the book by Ernest Gahn Fate is the Hunter? surely you must?
Also you have a plaque of mine from some time ago. Hope all is well
with you.
Ted Frater Dorset UK.

Still have all my hardware and kit.

.


Ever work on a Pembroke (sp)? I was working on one when I hit the
little lever on the yoke. It sounded like a tractor trailer was
standing next to the aircraft. The lever was for the air brakes. That
plane had air brakes to stop the ground roll.



John

"Jim Stewart" wrote in message
.. .
Ed Huntress wrote:
wrote in message
...

snip

The control surfaces on a DC-3 were constructed of an aluminum frame
covered with fabric. A not uncommon method of construction for their
time.

To the best of my knowledge there were no "spare" wings or fuselages
for the DC-3. Like any other aircraft if there was damage it was
repaired.

In Gann's book "Flying Circus", he mentioned a DC-2 1/2,
A DC-3 with a DC-2 wing on one side.

Is this serious? Was it intended for flying in circles?

--
Ed Huntress

Ed Huntress wrote:

"cavelamb himself" wrote in message
...

Ed Huntress wrote:

"cavelamb himself" wrote in message
...



Wow, I've read for years that the VW was not a good conversion, but I
didn't realize it was that bad.




Anybody who wants to see the details of my planes...
the plans and builders manual are at:

http://www.matronics.com/photoshare/...006/index.html
Scroll down to the Plans download - or the manual download.
Heck, splurge and get both!


Photo CD of construction log web site and lots of pictures...
http://www.matronics.com/photoshare/...et.03.04.2006/

Warning Will Robinson! - MOBY BIG Zip file...


I didn't download your big file but I see some photos on the Web of the
Texas Parasol. I see it's made of 6061 aluminum angle and tube. How do
you stick it together, TIG welding?

--
Ed Huntress

Rivets, Ed!
AD-470 type driven rivets.

While 6061-T6 can be welded, such would never do a fuselage truss.
That sweet curve would turn into a series ov straight chords.

Ug...


Yeah, that's why I wondered. I couldn't picture welds that wouldn't make
a mess.

But the frame members appear to meet at points, as in a tubular space
frame. How do you get rivets in there? How many rivets pin a typical
joint?

--
Ed Huntress

Extruded angle - mated on the flat faces.

The vertical members attach to the outside (vertical) longeron flange,
the horizontal members attach to the horizontal flange.

Everything attaches on the inside face of the longeron - well, except
the landing gear cross bars / lift strut attach points (a pair of 1-1/4"
extruded angle pieces) that are bolted underneath the longs.

Edge margin is a little iffy with 3/4" flanges, but the 1/8" thickness
(each) is more than adequate metal to hold a rivet.
It's not like riveted thin sheet metal.
More like Lugs.

Some use two 1/8" rivets per joint - some use a single 5/32 or 3/16.
I've done them both ways.

It produces a very rigid, fairly light weight structure that is very
robust.

For example, a Graham Lee Nieuport fuselage the weight increase is
about 6 to 8 pounds.

A very slight factor compared to the structural integrety, low cost
and ease of construction afforded by extruded angle construction.


That's interesting, and surprising. So, many of those members are held
together with a single rivet.

I'd like to see that one in a finite-element analysis program.

--
Ed Huntress



Agreed - it would be interesting!
Let me see it when you are done. ok?

Richard

On Mon, 01 Oct 2007 18:02:01 -0700, Jim Stewart
wrote:

Ed Huntress wrote:
wrote in message
...

snip

The control surfaces on a DC-3 were constructed of an aluminum frame
covered with fabric. A not uncommon method of construction for their
time.

To the best of my knowledge there were no "spare" wings or fuselages
for the DC-3. Like any other aircraft if there was damage it was
repaired.

In Gann's book "Flying Circus", he mentioned a DC-2 1/2,
A DC-3 with a DC-2 wing on one side.

I suppose that anything is possible but I have seen DC-2's and they
were substantially different from DC-3's. The most noticeable was that
they were covered with much smaller sections of aluminum and (IIRC)
used brazer head rivets instead of flush rivets...... but it was a
long time ago.


In Viet Nam when we mounted the Mini Guns in the DC-3 (C-47) we found
that many of the fuselage formers that supported the floors were
corroded to the extent that it was thought that they would not support
the recoil of the guns. The formers were simply removed and new ones
fabricated in the field and riveted into place.

That's my kind of airplane. d8-)

--
Ed Huntress



Bruce in Bangkok
(brucepaigeATgmailDOTcom)

wrote:
On Mon, 01 Oct 2007 18:02:01 -0700, Jim Stewart
wrote:


Ed Huntress wrote:

wrote in message
...

snip

The control surfaces on a DC-3 were constructed of an aluminum frame
covered with fabric. A not uncommon method of construction for their
time.

To the best of my knowledge there were no "spare" wings or fuselages
for the DC-3. Like any other aircraft if there was damage it was
repaired.

In Gann's book "Flying Circus", he mentioned a DC-2 1/2,
A DC-3 with a DC-2 wing on one side.


I suppose that anything is possible but I have seen DC-2's and they
were substantially different from DC-3's. The most noticeable was that
they were covered with much smaller sections of aluminum and (IIRC)
used brazer head rivets instead of flush rivets...... but it was a
long time ago.


In Viet Nam when we mounted the Mini Guns in the DC-3 (C-47) we found
that many of the fuselage formers that supported the floors were
corroded to the extent that it was thought that they would not support
the recoil of the guns. The formers were simply removed and new ones
fabricated in the field and riveted into place.

That's my kind of airplane. d8-)

--
Ed Huntress




Bruce in Bangkok
(brucepaigeATgmailDOTcom)


I believe this is the story you are refering to...

Yankee Ships in China Seas: Adventures of Pioneer Americans in the
Troubled ...

"But by the time he got there, things had happened. Fearful that more
Jap bombers would return to finish of! the damaged before if could be
repaired. Woods and his crew and his coolie helpers had dragged the DC3
off the field and three miles down the road to hide it in a clump of
bamboo trees. Within an hour after they had completed their camouflage
job, a flight of seven Jap bombers returned and spent nearly an hour
looking for the wounded Douglas before giving up and winging away. On
the second and third days flights totaling up to 50 bombers scoured the
countryside around Siufu, some of them diving to within 200 feet of the
boys and the ship huddled under the bam-boo without finding a trace of
the Douglas.
'That third night the two skippers, Woods and Sweet, and their crews
fitted the DC2 wing to the DC3 and put the ship in technical order.
Meanwhile the coolies filled in the bomb craters to make a runway.
Working desperately against time, just as the first gray light of day
came threading through the trees, Woods took the 1 €j or! with its
unbalanced monoplane and Sweet fol-lowed him with the DC3. Four hours
later both landed safely in Hong Kong.


By Daniel M. Henderson
http://books.google.com/books?id=xFa...7gCd-dpkB3KvCk

"cavelamb himself" wrote in message
...
Ed Huntress wrote:

snip


But the frame members appear to meet at points, as in a tubular space
frame. How do you get rivets in there? How many rivets pin a typical
joint?

--
Ed Huntress

Extruded angle - mated on the flat faces.

The vertical members attach to the outside (vertical) longeron flange,
the horizontal members attach to the horizontal flange.

Everything attaches on the inside face of the longeron - well, except
the landing gear cross bars / lift strut attach points (a pair of 1-1/4"
extruded angle pieces) that are bolted underneath the longs.

Edge margin is a little iffy with 3/4" flanges, but the 1/8" thickness
(each) is more than adequate metal to hold a rivet.
It's not like riveted thin sheet metal.
More like Lugs.

Some use two 1/8" rivets per joint - some use a single 5/32 or 3/16.
I've done them both ways.

It produces a very rigid, fairly light weight structure that is very
robust.

For example, a Graham Lee Nieuport fuselage the weight increase is
about 6 to 8 pounds.

A very slight factor compared to the structural integrety, low cost
and ease of construction afforded by extruded angle construction.


That's interesting, and surprising. So, many of those members are held
together with a single rivet.

I'd like to see that one in a finite-element analysis program.

--
Ed Huntress

Agreed - it would be interesting!
Let me see it when you are done. ok?

Aack! With the simple FEA program that I use, it would take me a week just
to enter the data, if the program would handle it at all. (What's the
modulus and radius of gyration for those sections? Tear-out strength versus
shear strength for the location of rivet holes? My God...)

That's where the fancy and expensive CAD programs with integrated FEA
modules are worth their salt. I don't have one.

But I'll make some guesses: The structure probably is very rigid; that's a
function of geometry and elastic modulus rather than strength. As for
strength, the individual elements probably do OK in tension, if the rivets
are sized right and their locations provide enough tear-out strength. My
question is how they do in compression. Non-tubular sections usually don't
do well in resisting buckling. I suspect that is the primary failure mode
for most loadings.

However, it's probably scaled well enough that it's plenty strong in
practice.

--
Ed Huntress

Ed Huntress wrote:

High-strength adhesives in general have very high shear strength but poor
peel and cleavage strength. The rivets are there to keep the edges of the
aluminum from separating and loading the glue line in either peel or
cleavage.

That's the way it is.
Think of the rivet more to serve as a fixture while the glue is curing and
giving security for peel-off.


Nick
--
The lowcost-DRO:
http://www.yadro.de

Ed Huntress wrote:
"cavelamb himself" wrote in message
...

Ed Huntress wrote:


snip

But the frame members appear to meet at points, as in a tubular space
frame. How do you get rivets in there? How many rivets pin a typical
joint?

--
Ed Huntress

Extruded angle - mated on the flat faces.

The vertical members attach to the outside (vertical) longeron flange,
the horizontal members attach to the horizontal flange.

Everything attaches on the inside face of the longeron - well, except
the landing gear cross bars / lift strut attach points (a pair of 1-1/4"
extruded angle pieces) that are bolted underneath the longs.

Edge margin is a little iffy with 3/4" flanges, but the 1/8" thickness
(each) is more than adequate metal to hold a rivet.
It's not like riveted thin sheet metal.
More like Lugs.

Some use two 1/8" rivets per joint - some use a single 5/32 or 3/16.
I've done them both ways.

It produces a very rigid, fairly light weight structure that is very
robust.

For example, a Graham Lee Nieuport fuselage the weight increase is
about 6 to 8 pounds.

A very slight factor compared to the structural integrety, low cost
and ease of construction afforded by extruded angle construction.


That's interesting, and surprising. So, many of those members are held
together with a single rivet.

I'd like to see that one in a finite-element analysis program.

--
Ed Huntress

Agreed - it would be interesting!
Let me see it when you are done. ok?


Aack! With the simple FEA program that I use, it would take me a week just
to enter the data, if the program would handle it at all. (What's the
modulus and radius of gyration for those sections? Tear-out strength versus
shear strength for the location of rivet holes? My God...)

That's where the fancy and expensive CAD programs with integrated FEA
modules are worth their salt. I don't have one.

But I'll make some guesses: The structure probably is very rigid; that's a
function of geometry and elastic modulus rather than strength. As for
strength, the individual elements probably do OK in tension, if the rivets
are sized right and their locations provide enough tear-out strength. My
question is how they do in compression. Non-tubular sections usually don't
do well in resisting buckling. I suspect that is the primary failure mode
for most loadings.

However, it's probably scaled well enough that it's plenty strong in
practice.

--
Ed Huntress



Yep. On all counts.

It's basically South Texas Farm Technology.
Nothing fancy - but it works out very well.

As an aside, the Boeing F4B2 series were built this way too.
Not a whole lot of new stuff under this old sun...


As for compression of non-tubular sections, you are absolutely
right again.

One fellow proposed turning the longerons inside out.

Makes sense from one point of view.

With the open angle to the outside the fabric has a natural chamfer
the length of the longerons. Makes for a nicely faired edge.

The internal structure is then mated up 3/4" inside the skin - lot less
chance of touching it when sanding the finish (ooppss!!) and cutting
a hole in the fabric. (howcom this darned spot keeps getting bigger?)

But with the angle open side facing outside the compression strength is
seriously reduced. The flanges open a lot easier than they close...

Other than a few guys using aluminum tube tail wheel legs, there has
never been a structural issue.

Richard

On Mon, 1 Oct 2007 21:16:18 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:

"Jim Stewart" wrote in message
. ..

In Gann's book "Flying Circus", he mentioned a DC-2 1/2,
A DC-3 with a DC-2 wing on one side.

Is this serious? Was it intended for flying in circles?

Perfect for the Reno races, wot? With the shorter wing, it would miss
the pylons easier, too.

There's only a ten foot difference in wingspans but a 47 s/f area, so
I'm wondering how much of that is in fuselage width.

--
They also serve who stand and weld.
--David Weber, On Basilisk Station.

Ed Huntress wrote:

"Jim Stewart" wrote in message
.. .

Ed Huntress wrote:

wrote in message
...

snip

The control surfaces on a DC-3 were constructed of an aluminum frame
covered with fabric. A not uncommon method of construction for their
time.

To the best of my knowledge there were no "spare" wings or fuselages
for the DC-3. Like any other aircraft if there was damage it was
repaired.

In Gann's book "Flying Circus", he mentioned a DC-2 1/2,
A DC-3 with a DC-2 wing on one side.


Is this serious? Was it intended for flying in circles?

--
Ed Huntress


Field expedient to get a damaged aircraft to a better location for
repairs.

Only wing available was DC2 parts.

I recall reading that a very large wrench was grafted onto the control
yoke, to offset some of the requirement to keep the smaller wing level.

A product of a very different time!

The mechanics, and the airplane both!

Cheers
Trevor Jones

"cavelamb himself" wrote in message
...

It's basically South Texas Farm Technology.
Nothing fancy - but it works out very well.

Richard, what in your opinion is the best engine for a small parasol
monoplane like this?

--
Ed Huntress

Light miniature aircraft(LMA) in florida used rivet bonded alum square tube
in the homebuilt aircraft. Dick Schreder used bonded alum with foam ribs in
several of his kitted sailplanes. Bede used bonded wing modules (glass) that
slid over a tubular alum spar. Pat

Ed Huntress wrote:

"cavelamb himself" wrote in message
...

It's basically South Texas Farm Technology.
Nothing fancy - but it works out very well.


Richard, what in your opinion is the best engine for a small parasol
monoplane like this?

--
Ed Huntress



Rotax 503 - 2 stroke 50 horse - air cooled - with electric start.
Bare engine is 67 pounds - figure about 80 all up.
http://www.ultralightnews.ca/rotax503/rotax503specs.htm


For guys 250 pounds, consider a 582. 64 horesies at about 96 pounds.
http://www.ultralightnews.ca/rotax58...edatasheet.pdf

It's heavier with water cooling, but the extra power helps.
The temps are better regulated for long runs at high power.

AND, they sound and feel like turbines, are geared for a LONG
(72 or better) propeller.

I'd not go for an automatic oiler.
Mix the oil in the gas like any self respecting weed eater.

As for them being two stroke engines - yes they are.
Turbine like smooth operation and power.

But the really big issue is weight.
That 2180 VW weighed in at a bit over 200 pounds and cost
over $4000 to build.

Yes, it had electric start and alternator - but 200 pounds
for what is essentially a 40 horse engine - even with the
initial big engine attitude - seems excessive to me.

Richard

Larry Jaques wrote:

On Mon, 1 Oct 2007 21:16:18 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"Jim Stewart" wrote in message
...


In Gann's book "Flying Circus", he mentioned a DC-2 1/2,
A DC-3 with a DC-2 wing on one side.

Is this serious? Was it intended for flying in circles?


Perfect for the Reno races, wot? With the shorter wing, it would miss
the pylons easier, too.

There's only a ten foot difference in wingspans but a 47 s/f area, so
I'm wondering how much of that is in fuselage width.

--
They also serve who stand and weld.
--David Weber, On Basilisk Station.

No, they were trying to escape the Japaneese.

patrick mitchel wrote:

Light miniature aircraft(LMA) in florida used rivet bonded alum square tube
in the homebuilt aircraft. Dick Schreder used bonded alum with foam ribs in
several of his kitted sailplanes. Bede used bonded wing modules (glass) that
slid over a tubular alum spar. Pat



Sure, but none of that really means anything unless you know WHY.

"cavelamb himself" wrote in message
...
Ed Huntress wrote:

"cavelamb himself" wrote in message
...

It's basically South Texas Farm Technology.
Nothing fancy - but it works out very well.


Richard, what in your opinion is the best engine for a small parasol
monoplane like this?

--
Ed Huntress

Rotax 503 - 2 stroke 50 horse - air cooled - with electric start.
Bare engine is 67 pounds - figure about 80 all up.
http://www.ultralightnews.ca/rotax503/rotax503specs.htm


For guys 250 pounds, consider a 582. 64 horesies at about 96 pounds.
http://www.ultralightnews.ca/rotax58...edatasheet.pdf

It's heavier with water cooling, but the extra power helps.
The temps are better regulated for long runs at high power.

AND, they sound and feel like turbines, are geared for a LONG
(72 or better) propeller.

I'd not go for an automatic oiler.
Mix the oil in the gas like any self respecting weed eater.

As for them being two stroke engines - yes they are.
Turbine like smooth operation and power.

But the really big issue is weight.
That 2180 VW weighed in at a bit over 200 pounds and cost
over $4000 to build.

Yes, it had electric start and alternator - but 200 pounds
for what is essentially a 40 horse engine - even with the
initial big engine attitude - seems excessive to me.

Richard

Thanks, Richard. That seems to be the opinion of a lot of people.

--
Ed Huntress

On Sep 30, 10:00 am, "Ed Huntress" wrote:
However, they also don't know how much fatigue becomes a problem in
all-aluminum aircraft that were designed over the last few decades. DC3's
are still flying because the engineers didn't know what a reasonable safety
margin was. Now they know, and the life of those planes is finite.

Overdesigned aircraft can have a ridiculously long airframe life.

The B-52's airframe service life runs through ****ing 2040 by current
military planning. Can you believe that? The kids flying them will be
in an airplane made when their great-grandparents were kids or not
even born. It'll be a timespan equivalent to the military still using
Wright flyers. But not exactly the same, because even in 2040 there
still won't be another airplane that'll do everything a B-52 does.

"Tim Shoppa" wrote in message
ups.com...
On Sep 30, 10:00 am, "Ed Huntress" wrote:
However, they also don't know how much fatigue becomes a problem in
all-aluminum aircraft that were designed over the last few decades. DC3's
are still flying because the engineers didn't know what a reasonable
safety
margin was. Now they know, and the life of those planes is finite.

Overdesigned aircraft can have a ridiculously long airframe life.

The B-52's airframe service life runs through ****ing 2040 by current
military planning. Can you believe that? The kids flying them will be
in an airplane made when their great-grandparents were kids or not
even born. It'll be a timespan equivalent to the military still using
Wright flyers. But not exactly the same, because even in 2040 there
still won't be another airplane that'll do everything a B-52 does.

Yeah, when you study fatigue you learn that the margins are really very slim
between limited life and extremely long life. The curves climb (or fall off,
if the curve represents time to failure) sharply; I don't know what they are
mathematically, but there's some positive exponent in there.

Aluminum is particularly nasty in that regard. Fortunately aluminum fatigue
has been studied and researched to beat hell because of the aircraft
applications, and there is little guesswork in applying the calculations
today.

--
Ed Huntress

Ed Huntress wrote:

"Tim Shoppa" wrote in message
ups.com...

On Sep 30, 10:00 am, "Ed Huntress" wrote:

However, they also don't know how much fatigue becomes a problem in
all-aluminum aircraft that were designed over the last few decades. DC3's
are still flying because the engineers didn't know what a reasonable
safety
margin was. Now they know, and the life of those planes is finite.

Overdesigned aircraft can have a ridiculously long airframe life.

The B-52's airframe service life runs through ****ing 2040 by current
military planning. Can you believe that? The kids flying them will be
in an airplane made when their great-grandparents were kids or not
even born. It'll be a timespan equivalent to the military still using
Wright flyers. But not exactly the same, because even in 2040 there
still won't be another airplane that'll do everything a B-52 does.


Yeah, when you study fatigue you learn that the margins are really very slim
between limited life and extremely long life. The curves climb (or fall off,
if the curve represents time to failure) sharply; I don't know what they are
mathematically, but there's some positive exponent in there.

Aluminum is particularly nasty in that regard. Fortunately aluminum fatigue
has been studied and researched to beat hell because of the aircraft
applications, and there is little guesswork in applying the calculations
today.

--
Ed Huntress



The C-130 is another aircrft that will be around for a long time. On
the newer aircraft a lot of the parts are titanimum rather than
aluminum. On the older aircraft intergranular corrosion was a ongoing
problem. I was told it was from improper heat treating of the aluminum.
The aluminum would turn to a white powdery substance, mainly on heavier
aluminum pieces.


John

On Tue, 02 Oct 2007 13:31:12 -0700, Tim Shoppa
wrote:

On Sep 30, 10:00 am, "Ed Huntress" wrote:
However, they also don't know how much fatigue becomes a problem in
all-aluminum aircraft that were designed over the last few decades. DC3's
are still flying because the engineers didn't know what a reasonable safety
margin was. Now they know, and the life of those planes is finite.

Overdesigned aircraft can have a ridiculously long airframe life.

The B-52's airframe service life runs through ****ing 2040 by current
military planning. Can you believe that? The kids flying them will be
in an airplane made when their great-grandparents were kids or not
even born. It'll be a timespan equivalent to the military still using
Wright flyers. But not exactly the same, because even in 2040 there
still won't be another airplane that'll do everything a B-52 does.


However, there have been some fairly extensive modifications made to
the B-52, like replacing all the stress panels on the bottom of the
wing, removing, repairing and replacing all of the heating,
pressurization ducting in the airplane.

In addition there are continuous "tech order modifications" made to
any airplane during its service life. these can range from something
as simple as installing bolts in the opposite direction so the nuts
are more accessible (B-50) to replacing major components.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

Ed Huntress wrote:
"cavelamb himself" wrote in message
...

Ed Huntress wrote:


"cavelamb himself" wrote in message
...


It's basically South Texas Farm Technology.
Nothing fancy - but it works out very well.


Richard, what in your opinion is the best engine for a small parasol
monoplane like this?

--
Ed Huntress

Rotax 503 - 2 stroke 50 horse - air cooled - with electric start.
Bare engine is 67 pounds - figure about 80 all up.
http://www.ultralightnews.ca/rotax503/rotax503specs.htm


For guys 250 pounds, consider a 582. 64 horesies at about 96 pounds.
http://www.ultralightnews.ca/rotax58...edatasheet.pdf

It's heavier with water cooling, but the extra power helps.
The temps are better regulated for long runs at high power.

AND, they sound and feel like turbines, are geared for a LONG
(72 or better) propeller.

I'd not go for an automatic oiler.
Mix the oil in the gas like any self respecting weed eater.

As for them being two stroke engines - yes they are.
Turbine like smooth operation and power.

But the really big issue is weight.
That 2180 VW weighed in at a bit over 200 pounds and cost
over $4000 to build.

Yes, it had electric start and alternator - but 200 pounds
for what is essentially a 40 horse engine - even with the
initial big engine attitude - seems excessive to me.

Richard


Thanks, Richard. That seems to be the opinion of a lot of people.

--
Ed Huntress



You are welcome, Ed.

Thanks for your interest.

Richard

On Tue, 02 Oct 2007 17:02:28 -0400, john
wrote:



Ed Huntress wrote:

"Tim Shoppa" wrote in message
ups.com...

On Sep 30, 10:00 am, "Ed Huntress" wrote:

However, they also don't know how much fatigue becomes a problem in
all-aluminum aircraft that were designed over the last few decades. DC3's
are still flying because the engineers didn't know what a reasonable
safety
margin was. Now they know, and the life of those planes is finite.

Overdesigned aircraft can have a ridiculously long airframe life.

The B-52's airframe service life runs through ****ing 2040 by current
military planning. Can you believe that? The kids flying them will be
in an airplane made when their great-grandparents were kids or not
even born. It'll be a timespan equivalent to the military still using
Wright flyers. But not exactly the same, because even in 2040 there
still won't be another airplane that'll do everything a B-52 does.


Yeah, when you study fatigue you learn that the margins are really very slim
between limited life and extremely long life. The curves climb (or fall off,
if the curve represents time to failure) sharply; I don't know what they are
mathematically, but there's some positive exponent in there.

Aluminum is particularly nasty in that regard. Fortunately aluminum fatigue
has been studied and researched to beat hell because of the aircraft
applications, and there is little guesswork in applying the calculations
today.

--
Ed Huntress



The C-130 is another aircrft that will be around for a long time. On
the newer aircraft a lot of the parts are titanimum rather than
aluminum. On the older aircraft intergranular corrosion was a ongoing
problem. I was told it was from improper heat treating of the aluminum.
The aluminum would turn to a white powdery substance, mainly on heavier
aluminum pieces.


John

Well, I've worked on C-47's (DC-3) that were built before I was born
and the only examples of corrosion was in the floor stringers where
liquids had been spilled. The thinner sheetmetal was 2024 alclad and
the larger forgins/castings aren't heat treated as far as any tech
manual I read specified. In fact the major problem we found in
maintaining them, 30-some years after they were manufactured was tech
order specifications for metals - leaded bronze bushings for example -
that the A.F. no longer normally stock.

What most people don;t realize that throughout an airplane's life
there are continually inspections, updates and modifications being
made which may range from replacing a hose to modifying or replacing a
major fitting. In some cases an entire fleet is grounded until a
specific bolt is replaced or some other modification made.

In addition all mechanical components are changed after specified
operating times regardless of whether they are causing problems or
not. If you maintained your car the same way it would last a lifetime.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)