Is anyone out there designing a scale PBY Catalina?

I was wondering if anyone else was designing (or maybe even progressed
to building) a homebuilt aircraft based on the PBY Catalina? The
reason I ask is that I have been thinking of designing one for some
time. Now that I have 1 year to go before finishing my BS in ME, I
have decided to begin working on a conceptual design.
Hopefulley I'll get around to posting some of my newer PBY stuff on my
website before too long.

I'd like to see what you guys (and gals) think of my idea. Basically I
want an adventure/bush/recreational aircraft. There are a lot of
single engine amphibs out there around 100-200hp, so I'm not going to
design something that basically already exists. What I want these
aircraft wouldn't be able to do anyway. I am looking to build
something where there is nothing very similar to it. It would be
similar size to a Widgeon, but how many of those do you see around.
I'd like to see a C185 or Beaver owner consider buying one of these. I
also don't want to go through the nosebleed the seawind went through
(basically design/build it right the first time and no BS).

I won't be building everything exactly to scale, and it will be made
of mostly composite materials (glass, CF, some kevlar, foam/balsa,
epoxy). You could call it an evolution of a PBY-6A with the R-2600
conversion. I have narrowed down the size that I am going to build.
50% scale. This puts us at 52' WS and 4750 gross, and a pair of
160-200 hp engines. My minimum goals (on 200 hp) are 2000 lbs useful
load, stall w/flaps 49 mph, 75% cruise 167 mph, takeoff from water in
under 900 feet, and have a 1500 statute mile range. I want this
aircraft to be affordable to build and operate (not RV-4 affordable,
but affordable for its size). So far my powerplant of choice is the
deltahawk diesel (although one could put whatever they wanted in for
an engine, many choices around 160-200 hp). A pair of 200hp diesels
would give this PBY the same fuel burn that a 300hp lycoming would
(about 14-16 gph). That's it in a nutshell. Whatchya think? Sound
cool?

PBY was only US warplane (not counting single engine observation) that did
not have flaps!
"Tom Osmundson" wrote in message
m...
I was wondering if anyone else was designing (or maybe even progressed
to building) a homebuilt aircraft based on the PBY Catalina? The
reason I ask is that I have been thinking of designing one for some
time. Now that I have 1 year to go before finishing my BS in ME, I
have decided to begin working on a conceptual design.
Hopefulley I'll get around to posting some of my newer PBY stuff on my
website before too long.

I'd like to see what you guys (and gals) think of my idea. Basically I
want an adventure/bush/recreational aircraft. There are a lot of
single engine amphibs out there around 100-200hp, so I'm not going to
design something that basically already exists. What I want these
aircraft wouldn't be able to do anyway. I am looking to build
something where there is nothing very similar to it. It would be
similar size to a Widgeon, but how many of those do you see around.
I'd like to see a C185 or Beaver owner consider buying one of these. I
also don't want to go through the nosebleed the seawind went through
(basically design/build it right the first time and no BS).

I won't be building everything exactly to scale, and it will be made
of mostly composite materials (glass, CF, some kevlar, foam/balsa,
epoxy). You could call it an evolution of a PBY-6A with the R-2600
conversion. I have narrowed down the size that I am going to build.
50% scale. This puts us at 52' WS and 4750 gross, and a pair of
160-200 hp engines. My minimum goals (on 200 hp) are 2000 lbs useful
load, stall w/flaps 49 mph, 75% cruise 167 mph, takeoff from water in
under 900 feet, and have a 1500 statute mile range. I want this
aircraft to be affordable to build and operate (not RV-4 affordable,
but affordable for its size). So far my powerplant of choice is the
deltahawk diesel (although one could put whatever they wanted in for
an engine, many choices around 160-200 hp). A pair of 200hp diesels
would give this PBY the same fuel burn that a 300hp lycoming would
(about 14-16 gph). That's it in a nutshell. Whatchya think? Sound
cool?

From: (Tom Osmundson)
Date: 6/10/2004 12:55 AM Central Daylight Time
Message-id:

I was wondering if anyone else was designing (or maybe even progressed
to building) a homebuilt aircraft based on the PBY Catalina? The
reason I ask is that I have been thinking of designing one for some
time. Now that I have 1 year to go before finishing my BS in ME, I
have decided to begin working on a conceptual design.
Hopefulley I'll get around to posting some of my newer PBY stuff on my
website before too long.

I'd like to see what you guys (and gals) think of my idea. Basically I
want an adventure/bush/recreational aircraft. There are a lot of
single engine amphibs out there around 100-200hp, so I'm not going to
design something that basically already exists. What I want these
aircraft wouldn't be able to do anyway. I am looking to build
something where there is nothing very similar to it. It would be
similar size to a Widgeon, but how many of those do you see around.
I'd like to see a C185 or Beaver owner consider buying one of these. I
also don't want to go through the nosebleed the seawind went through
(basically design/build it right the first time and no BS).

I won't be building everything exactly to scale, and it will be made
of mostly composite materials (glass, CF, some kevlar, foam/balsa,
epoxy). You could call it an evolution of a PBY-6A with the R-2600
conversion. I have narrowed down the size that I am going to build.
50% scale. This puts us at 52' WS and 4750 gross, and a pair of
160-200 hp engines. My minimum goals (on 200 hp) are 2000 lbs useful
load, stall w/flaps 49 mph, 75% cruise 167 mph, takeoff from water in
under 900 feet, and have a 1500 statute mile range. I want this
aircraft to be affordable to build and operate (not RV-4 affordable,
but affordable for its size). So far my powerplant of choice is the
deltahawk diesel (although one could put whatever they wanted in for
an engine, many choices around 160-200 hp). A pair of 200hp diesels
would give this PBY the same fuel burn that a 300hp lycoming would
(about 14-16 gph). That's it in a nutshell. Whatchya think? Sound
cool?


I decided several years ago to design a half scale A-10 that would accomodate
someonne my size. After years of learning, drawing, calculating etc I have an
aircraft that will fly rather nicely except for that li'l ole ducted fan thing.

I use MicroStation for the drawings, trust me, you will need either CAD or a
room full of A size paper.

My point is I think you will find all kinds of neat stuff that will make you
work and rework your estimates.

If you make it amphibian as the original is the gear alone will weigh a bunch.
For the useful load you suggest I think you would have problems with 2x200 hp
engins if one flakes out on take off.

Having said that I think it's a neat idea, I did mention a scale PBY as an idea
a year or two ago in this NG, and I wish you all the luck.

Dan, U.S. Air Force, retired

On 9 Jun 2004 22:55:41 -0700, (Tom Osmundson)
wrote:

I was wondering if anyone else was designing (or maybe even progressed
to building) a homebuilt aircraft based on the PBY Catalina? The
reason I ask is that I have been thinking of designing one for some
time. Now that I have 1 year to go before finishing my BS in ME, I
have decided to begin working on a conceptual design.
Hopefulley I'll get around to posting some of my newer PBY stuff on my
website before too long.

I'd like to see what you guys (and gals) think of my idea. Basically I
want an adventure/bush/recreational aircraft. There are a lot of
single engine amphibs out there around 100-200hp, so I'm not going to
design something that basically already exists. What I want these
aircraft wouldn't be able to do anyway. I am looking to build
something where there is nothing very similar to it. It would be
similar size to a Widgeon, but how many of those do you see around.
I'd like to see a C185 or Beaver owner consider buying one of these. I
also don't want to go through the nosebleed the seawind went through
(basically design/build it right the first time and no BS).

I won't be building everything exactly to scale, and it will be made
of mostly composite materials (glass, CF, some kevlar, foam/balsa,
epoxy). You could call it an evolution of a PBY-6A with the R-2600
conversion. I have narrowed down the size that I am going to build.
50% scale. This puts us at 52' WS and 4750 gross, and a pair of
160-200 hp engines. My minimum goals (on 200 hp) are 2000 lbs useful
load, stall w/flaps 49 mph, 75% cruise 167 mph, takeoff from water in
under 900 feet, and have a 1500 statute mile range. I want this
aircraft to be affordable to build and operate (not RV-4 affordable,
but affordable for its size). So far my powerplant of choice is the
deltahawk diesel (although one could put whatever they wanted in for
an engine, many choices around 160-200 hp). A pair of 200hp diesels
would give this PBY the same fuel burn that a 300hp lycoming would
(about 14-16 gph). That's it in a nutshell. Whatchya think? Sound
cool?

Cool idea!

You may want to consider revising some combination of horsepower,
useful load, and gross weight, as 320hp would be a dog hauling around
4750lbs.

For a few reference points: the 160hp Twin Comanche has a gross
weight of 3700lbs and is a much cleaner airplane than a PBY. A Piper
Seneca with 200hp/side has a gross of about 4500. The final version
of the PBY had 1700hp engines, pushing around 40,000lbs.

Weight/HP ratios:
TwinComanche: 11.56
Seneca II: 11.25
PBY: 11.76
Your scale PBY: 14.384-11.875 (320-400hp)

-Nathan

In the early 1970's while stationed at the Pentagon a bunch of us worked on
scaling various WWII aircraft.

It became immediately obvious that there were were two things we could NOT
scale: the pilot and the engines.

Pilot-relative scaling was the most productive in that designing an airframe
just large enough to accomodate the pilot usually afforded a wider range of
engine options.

The PBY was among several pilot-relative designs. With the pilots head in the
pylon, the thing came out with a span of about 34' and, at least on paper,
could fly with a pair of C-85's.

The C-130 (with four VW engines!) came out looking pretty good... on paper.

I don't think any of the scaled designs ever flew although. The
engine-relative P-38 may have done so. All of Kelly Johnson's designs
scaled-down rather well.

-R.S.Hoover

Nathan: Several of us including a P.E have set around the table talking
about the same thing. Diesel engines great for the lagoon hopping out in
the So. Pacific. I even approached one of Burt Rutan's test pilots and told
him to get Burt working on the idea..??
I think the idea is neat.. We spent 8 years out in the Pacific in the
Marshall islands and the type of ship you are playing with would be the
thing to have. Better than a sailboat.
Stu Fields
"Nathan Young" wrote in message
...
On 9 Jun 2004 22:55:41 -0700, (Tom Osmundson)
wrote:

I was wondering if anyone else was designing (or maybe even progressed
to building) a homebuilt aircraft based on the PBY Catalina? The
reason I ask is that I have been thinking of designing one for some
time. Now that I have 1 year to go before finishing my BS in ME, I
have decided to begin working on a conceptual design.
Hopefulley I'll get around to posting some of my newer PBY stuff on my
website before too long.

I'd like to see what you guys (and gals) think of my idea. Basically I
want an adventure/bush/recreational aircraft. There are a lot of
single engine amphibs out there around 100-200hp, so I'm not going to
design something that basically already exists. What I want these
aircraft wouldn't be able to do anyway. I am looking to build
something where there is nothing very similar to it. It would be
similar size to a Widgeon, but how many of those do you see around.
I'd like to see a C185 or Beaver owner consider buying one of these. I
also don't want to go through the nosebleed the seawind went through
(basically design/build it right the first time and no BS).

I won't be building everything exactly to scale, and it will be made
of mostly composite materials (glass, CF, some kevlar, foam/balsa,
epoxy). You could call it an evolution of a PBY-6A with the R-2600
conversion. I have narrowed down the size that I am going to build.
50% scale. This puts us at 52' WS and 4750 gross, and a pair of
160-200 hp engines. My minimum goals (on 200 hp) are 2000 lbs useful
load, stall w/flaps 49 mph, 75% cruise 167 mph, takeoff from water in
under 900 feet, and have a 1500 statute mile range. I want this
aircraft to be affordable to build and operate (not RV-4 affordable,
but affordable for its size). So far my powerplant of choice is the
deltahawk diesel (although one could put whatever they wanted in for
an engine, many choices around 160-200 hp). A pair of 200hp diesels
would give this PBY the same fuel burn that a 300hp lycoming would
(about 14-16 gph). That's it in a nutshell. Whatchya think? Sound
cool?

Cool idea!

You may want to consider revising some combination of horsepower,
useful load, and gross weight, as 320hp would be a dog hauling around
4750lbs.

For a few reference points: the 160hp Twin Comanche has a gross
weight of 3700lbs and is a much cleaner airplane than a PBY. A Piper
Seneca with 200hp/side has a gross of about 4500. The final version
of the PBY had 1700hp engines, pushing around 40,000lbs.

Weight/HP ratios:
TwinComanche: 11.56
Seneca II: 11.25
PBY: 11.76
Your scale PBY: 14.384-11.875 (320-400hp)

-Nathan

"Kathryn & Stuart Fields" wrote in message
...

Nathan: Several of us including a P.E have set around the table talking
about the same thing. Diesel engines great for the lagoon hopping out in
the So. Pacific. I even approached one of Burt Rutan's test pilots and
told
him to get Burt working on the idea..??
I think the idea is neat.. We spent 8 years out in the Pacific in the
Marshall islands and the type of ship you are playing with would be the
thing to have. Better than a sailboat.

I recall a French series of nature documentaries filmed in Patagonia etc.
featuring a huge amphibian twin-engined aircraft, sort of a flying
combination of a house, a boat and an airplane. I wish I could find the
name of the series.
Kumaros
It's all Greek to me

Yes, the PBY never had flaps, but I'm going to put some 30% chord
fowler flaps over about 70% of the span. Should be pretty close to
STOL then with a good power to weight ratio.

I've got access to Catia V5, so I'm ok there. I have more experience
using ProE wildfire, but that's what I got. :-)

The gear will weigh a lot, and I want to make sure it is up to rough
fields. I think it can be reasonable in weight if one puts enough time
into it.

I've been looking at safety issues right off the bat with this
concept. I've already went through NTSB stuff on the Catalina as well
as other types, like the seawind. So I've been documenting problems
such as the nose wheel doors on the catalina collapsing causing a
nose-over in the water. You mention loosing an engine might be a
problem with 2x200 hp. I had been looking at the power loading of
several twins and have noticed many with similar power loading. In
fact a 1997 PA-34 Seneca V has 2 engines rated 200 hp continuous (220
for TO) with a gross of 4750 lbs, but a stall speed of 70 mph. But you
do bring up a good point about SE performance, and that's one thing I
will keep an eye on.

Thanks for your comments! Keep em coming!
Tom



I decided several years ago to design a half scale A-10 that would accomodate
someonne my size. After years of learning, drawing, calculating etc I have an
aircraft that will fly rather nicely except for that li'l ole ducted fan thing.

I use MicroStation for the drawings, trust me, you will need either CAD or a
room full of A size paper.

My point is I think you will find all kinds of neat stuff that will make you
work and rework your estimates.

If you make it amphibian as the original is the gear alone will weigh a bunch.
For the useful load you suggest I think you would have problems with 2x200 hp
engins if one flakes out on take off.

Having said that I think it's a neat idea, I did mention a scale PBY as an idea
a year or two ago in this NG, and I wish you all the luck.

Dan, U.S. Air Force, retired

Yes, the PBY never had flaps, but I'm going to put some 30% chord
fowler flaps over about 70% of the span. Should be pretty close to
STOL then with a good power to weight ratio.

I've got access to Catia V5, so I'm ok there. I have more experience
using ProE wildfire, but that's what I got. :-)

The gear will weigh a lot, and I want to make sure it is up to rough
fields. I think it can be reasonable in weight if one puts enough time
into it.

I've been looking at safety issues right off the bat with this
concept. I've already went through NTSB stuff on the Catalina as well
as other types, like the seawind. So I've been documenting problems
such as the nose wheel doors on the catalina collapsing causing a
nose-over in the water. You mention loosing an engine might be a
problem with 2x200 hp. I had been looking at the power loading of
several twins and have noticed many with similar power loading. In
fact a 1997 PA-34 Seneca V has 2 engines rated 200 hp continuous (220
for TO) with a gross of 4750 lbs, but a stall speed of 70 mph. But you
do bring up a good point about SE performance, and that's one thing I
will keep an eye on.

Thanks for your comments! Keep em coming!
Tom



I decided several years ago to design a half scale A-10 that would accomodate
someonne my size. After years of learning, drawing, calculating etc I have an
aircraft that will fly rather nicely except for that li'l ole ducted fan thing.

I use MicroStation for the drawings, trust me, you will need either CAD or a
room full of A size paper.

My point is I think you will find all kinds of neat stuff that will make you
work and rework your estimates.

If you make it amphibian as the original is the gear alone will weigh a bunch.
For the useful load you suggest I think you would have problems with 2x200 hp
engins if one flakes out on take off.

Having said that I think it's a neat idea, I did mention a scale PBY as an idea
a year or two ago in this NG, and I wish you all the luck.

Dan, U.S. Air Force, retired

Yes, the PBY never had flaps, but I'm going to put some 30% chord
fowler flaps over about 70% of the span. Should be pretty close to
STOL then with a good power to weight ratio.

I've got access to Catia V5, so I'm ok there. I have more experience
using ProE wildfire, but that's what I got. :-)

The gear will weigh a lot, and I want to make sure it is up to rough
fields. I think it can be reasonable in weight if one puts enough time
into it.

I've been looking at safety issues right off the bat with this
concept. I've already went through NTSB stuff on the Catalina as well
as other types, like the seawind. So I've been documenting problems
such as the nose wheel doors on the catalina collapsing causing a
nose-over in the water. You mention loosing an engine might be a
problem with 2x200 hp. I had been looking at the power loading of
several twins and have noticed many with similar power loading. In
fact a 1997 PA-34 Seneca V has 2 engines rated 200 hp continuous (220
for TO) with a gross of 4750 lbs, but a stall speed of 70 mph. But you
do bring up a good point about SE performance, and that's one thing I
will keep an eye on.

Thanks for your comments! Keep em coming!
Tom



I decided several years ago to design a half scale A-10 that would accomodate
someonne my size. After years of learning, drawing, calculating etc I have an
aircraft that will fly rather nicely except for that li'l ole ducted fan thing.

I use MicroStation for the drawings, trust me, you will need either CAD or a
room full of A size paper.

My point is I think you will find all kinds of neat stuff that will make you
work and rework your estimates.

If you make it amphibian as the original is the gear alone will weigh a bunch.
For the useful load you suggest I think you would have problems with 2x200 hp
engins if one flakes out on take off.

Having said that I think it's a neat idea, I did mention a scale PBY as an idea
a year or two ago in this NG, and I wish you all the luck.

Dan, U.S. Air Force, retired