# World War II Aircraft New Production



## turbopower87 (Feb 21, 2009)

Hello.


I was wondering if it would be possible for someone who had enough time and money to build from scratch new airframes? 

For aircraft where there are only a few remaining (or none at all  ), wouldn't it be possible? 

Take, for example, the Dornier Do 335. There is only one remaining. IMO, this is a crying shame.

Wouldn't it be possible to use the blueprints (and if still extant, dies and molds) to reproduce these aircraft? Heck, I bet you could even get the serial numbers to be a continuation. 

Do the blueprints and records for these planes exist, or is this just wishful thinking?


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## ONE_HELLCAT (Feb 21, 2009)

There are people that do that, and sometimes the original molds and dies are still available. Most of these are for museums like the one in San Diego. When I visited they were building from scratch a P-26 Peashooter. They found a company that had one of the radio components sitting in storage. They also built a new Gee Bee. These guys build the planes to the exact specifications of the original to near flyable condition.

I believe there's a company that's building new flyable Me-262s with modern engines, too. There's a video of one on YouTube


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## turbopower87 (Feb 21, 2009)

yes, but can you build an exact replica (besides things that are impossible or unsafe)?

The aircraft i'm asking about would be flying examples, that would look like they rolled off the factory floor in 1944.

An yes, I did see the ME 262s. Very, very cool!!!


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## GrauGeist (Feb 21, 2009)

There's a few companies that I know of, that are making brand new aircraft.

One company is Flug Werk, that makes brand new Fw190s and P-51 aircraft, thier site is in both German and English.

Another would be the Texas Airplane Factory, who started the Me262 project but sold that to Classic Fighter Industries. They were planning on producing a Nakajima Ki-43 Oscar based on thier experience in restoration of a number of the Ki-43s in the past.

And of course, Legend Flyers - Stormbirds coverage (formely Classic Fighter Industries), who is producing the Me262 A-1c and Me262 B-1c and A/B1-c (these designations were given officially by Messerschmitt).


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## 109ROAMING (Feb 21, 2009)

Interesting links GG!

somewhat controversal subject ,IMO I can certainly see why people would want to do this and I fully respect them ,If I had the choice I'd put the money to finding the original crashed examples and getting them airworthy again

in 100 years we'll still be able to make new aircraft but the ones out there now will be lost


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## GrauGeist (Feb 22, 2009)

I agree, 109, definately.

One of the problems you'll run into though, is money. Most of these new projects are based on thier ability to sell.

Everyone knows what a P-51D or a Fw190 is...but a Do335 or He280 for example, is a relative unknown as far as WWII appeal goes. Same would go for any number of aircraft that were limited in production or large in size. These most likely will never be made because of thier cost and don't rate high in public appeal.

Recovering wrecks is a noble passion, but so much time has passed now, that the chances of a successful recovery/restoration is becoming very limited. The intact P-38 they just found in the UK would be a prime example. Had they found that 20 years ago, it may have had a chance like Glacier Girl from Greenland. Restoring an original machine can have a brutal price tag, though. Especially if it's a rare one that has little in the way of available parts.

So I think we're going to be seeing more of the popular aircraft being reproduced as time goes by, because a reproduction warbird would be cheaper to make/purchase and considered as safer to operate on a regular basis. 

When I say "safer to operate", I'm referring to the worries people have about the older aircraft having metal fatigue, engine failure, etc...


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## 109ROAMING (Feb 22, 2009)

Very true ,Some good points there

I would agree


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## Captain Dunsel (Feb 24, 2009)

I was working at a GE branch that sold aircraft engines when the 262's were started. I had a conversation with some of the sales team that was working on that project, amongst others. When I asked how they thought it might look when word got out that GE was building engines for Nazi fighter planes, the looks on their faces was priceless! 

I suggested that I thought the idea was worth backing, but they might consider being ready to counter any such commentary, should it arise....that got a lot of nervous nodding!

CD


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## SoD Stitch (Feb 24, 2009)

I have often thought that if I became a stinkin' rich millionaire (billionaire?) I would scratch-build a two-seat Do 335 _Pfeil_; THAT would be cool! Of course, I may not be able to use DB 603's, I might have to use Merlins, but I still think it'd be cool. Anybody know what the average fuel consumption of a Merlin is? It's gotta be over 100 GPH.


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## Elvis (Feb 24, 2009)

turbopower87 said:


> yes, but can you build an exact replica (besides things that are impossible or unsafe)?
> 
> The aircraft i'm asking about would be flying examples, that would look like they rolled off the factory floor in 1944.
> 
> An yes, I did see the ME 262s. Very, very cool!!!


Not sure if its going to be a "flying" example (although that would be very, very cool), but I think they're trying to do this in Finland, with a B-239.


Elvis


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## Elvis (Feb 24, 2009)

SoD Stitch said:


> I have often thought that if I became a stinkin' rich millionaire (billionaire?) I would scratch-build a two-seat Do 335 _Pfeil_; THAT would be cool! Of course, I may not be able to use DB 603's, I might have to use Merlins, but I still think it'd be cool. Anybody know what the average fuel consumption of a Merlin is? It's gotta be over 100 GPH.


I know this kinda goes against the subject here, but what if you were to build it 1/2-3/4 scale.
This might allow you to use a pair of Falconer V-12's for power.
Might be just as cool and an easier project to pull off.



Elvis


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## turbopower87 (Feb 28, 2009)

what I mean is, is it theoretically possible? 

Is there an archive somewhere that has a bunch of me 109 blueprints and info?

....?


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## Heinz (Feb 28, 2009)

It's possible but like anything that is manufactured it needs to be financially viable. Making every single component from scratch with plans or not is an extremely lengthy and expensive process. I think with years to come some more replicas will be needed as airframes age but for the time lets enjoy our 'genuine' warbirds and continue our tribute to the brave men who have served for their countries.


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## model299 (Feb 28, 2009)

turbopower87 said:


> what I mean is, is it theoretically possible?
> 
> Is there an archive somewhere that has a bunch of me 109 blueprints and info?
> 
> ....?



ANYTHING is possible engineering wise, *if you have enough money.* Much harder, but not impossible if there's only one example left, as the owner of said example is usually loath to allow any degree of dis-assembly.


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## BombTaxi (Feb 28, 2009)

turbopower87 said:


> yes, but can you build an exact replica (besides things that are impossible or unsafe)?



If you set out to build a replica 'except for things that are impossible or unsafe', you aren't setting out to build an exact replica in the first place. And the provisos you have cited will inevitably lead to historically inaccurate details being included anyway. There will be differences in avionics, for example - I believe I am right in saying that WWII fighters did not carry transponders like modern GA aircraft. Materials technology has also moved on, and while old materials and techniques can be used, in certain areas there will probably be a requirement or necessity to build with more modern stuff. And of course, I would anticipate few of these replicas carrying a fully functional armament package, so the replica would not be 'exact' in that sense, either.


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## Clay_Allison (Feb 28, 2009)

I like the 75-80% replicas, good performance from a V-8 or V-6 without the need for 1000 horsepower.


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## drgondog (Feb 28, 2009)

Short answer - yes, providing you have a complete set of prints and specifications or a complete airframe that you are willing to tear down to re-engineer the airframe, component by component. If you are re-engineering you must re-produce all the necessary design drawings, lines drawings and tooling designs to produce the stamping dies, drill fixtures and jigs for sheet metal assemblies, etc.

That is the easy part. Next you have to have the design documents for every GFE part (pumps, instruments, engine, etc) or OEM sources which can provide THAT part or you must build them yourself.

Next, somewhat easier if you are buildiing only one - is the tooling to stamp out contour parts, ribs, jogs in stringers, bend beams, longerons, etc. You need to build the Fixtures and Jigs to keep the airframe integrity per alignment and lines.

All of the above (except for OEM sourcing) is part of the Non-Recurring Cost at the front end of every airframe design

Some things you will NOT find as original - like a tire or hose clamp, etc so you will just have to procure the closest fit and suitable to size and spec.

I'm sure I have overlooked some stuff that may or may not be necessary (like Stability and Control, Structures and Aerodynamics Analysis) but you might assume that since the airplane once flew as designed that your 100% reproduction with respect to shape, material, fastners, castings/forgings, etc will also. You would soon find out.

I would just guess that reproducing One D0 335 would cost $50-$100 million, and if you were designing for mass production - add about the same amount to set up plant and tailored tooling, dies, fixtures, machine tools, and hire/train design, manufacturing and Service organization behind it.


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## Clay_Allison (Feb 28, 2009)

SoD Stitch said:


> I have often thought that if I became a stinkin' rich millionaire (billionaire?) I would scratch-build a two-seat Do 335 _Pfeil_; THAT would be cool! Of course, I may not be able to use DB 603's, I might have to use Merlins, but I still think it'd be cool. Anybody know what the average fuel consumption of a Merlin is? It's gotta be over 100 GPH.


You may have to use turboprops.


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## drgondog (Feb 28, 2009)

SoD Stitch said:


> I have often thought that if I became a stinkin' rich millionaire (billionaire?) I would scratch-build a two-seat Do 335 _Pfeil_; THAT would be cool! Of course, I may not be able to use DB 603's, I might have to use Merlins, but I still think it'd be cool. Anybody know what the average fuel consumption of a Merlin is? It's gotta be over 100 GPH.



The fuel consumption ranged from about 48gph leaned out in steady cruise around 1900-2300 rpm, 30-34"hg, and then about 250gph at WEP at 3000 rpm/67".

Cruise consumption and settings varied on weight and altitude for max efficiency - and depended on whether you want loiter time or range.


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## Glider (Feb 28, 2009)

A new Spitfire was built around 2-3 years ago. Which goes to show that with plenty of Money anything is possible


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## pbfoot (Feb 28, 2009)

drgondog said:


> The fuel consumption ranged from about 48gph leaned out in steady cruise around 1900-2300 rpm, 30-34"hg, and then about 250gph at WEP at 3000 rpm/67".
> 
> Cruise consumption and settings varied on weight and altitude for max efficiency - and depended on whether you want loiter time or range.


Rule of thumb is a GPM


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## Elvis (Mar 1, 2009)

drgondog said:


> The fuel consumption ranged from about 48gph leaned out in steady cruise around 1900-2300 rpm, 30-34"hg, and then about 250gph at WEP at 3000 rpm/67".


That's a 149 GPH average........SoD Stitch nailed it. It IS over 100 GPH! 







Elvis


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## Nightwitch (Mar 1, 2009)

I'm kind of surprised nobody has mentioned the new Yak-3's and Yak-9's being produced in Russia with the original plans and moulds. There's a lot of those around now, and cheap for a WWII warbird at about $300k.


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## drgondog (Mar 1, 2009)

Elvis said:


> That's a 149 GPH average........SoD Stitch nailed it. It IS over 100 GPH!
> 
> 
> 
> ...



Elvis - no.

A typical mission profile is take off at max power, climb at reduced setting to cruise altitutue, cruise in a straight line for 200 miles, R/V with bombers and cruise in an Ess pattern, because the bombers are 75-100mph slower than 51 cruise speed, during escort. If no German fighters encountered, all the fuel consumption except take off will be 60gph or less.

Most fights were less than 5 minutes of WEP so that would only use up 15-20 gallons.


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## drgondog (Mar 1, 2009)

Nightwitch said:


> I'm kind of surprised nobody has mentioned the new Yak-3's and Yak-9's being produced in Russia with the original plans and moulds. There's a lot of those around now, and cheap for a WWII warbird at about $300k.



I know the guys that own them, love them.


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## drgondog (Mar 1, 2009)

pbfoot said:


> Rule of thumb is a GPM



Pb - It's either/or. 

I don't do cross country flight plan based on per minute fuel consumption.

Specific fuel consumption as an efficiency factor, for example, is expressed in units of pound mass per hour per Hp. - but whatever works for you is the one you should use.


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## pbfoot (Mar 1, 2009)

drgondog said:


> Pb - It's either/or.
> 
> I don't do cross country flight plan based on per minute fuel consumption.
> 
> Specific fuel consumption as an efficiency factor, for example, is expressed in units of pound mass per hour per Hp. - but whatever works for you is the one you should use.


That was the rule of thumb so I've been told by


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## drgondog (Mar 1, 2009)

If you have an egt/cht package and trying to lean out an engine for best fuel consumption - most of those will display in gpm. If you see an engine spec or are looking at efficiency comparisons those will normally be gallons per hour per hp.

Specific fuel consumption: Definition from Answers.com

Just because it is 'my way' doesn't mean everyone has to agree - but efficiency in context of specific fuel consumption is as stated in the 'answers' link above.


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## FLYBOYJ (Mar 1, 2009)

pbfoot said:


> That was the rule of thumb so I've been told by



And what type of aircraft?


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## Bill G. (Mar 1, 2009)

Here is a problem that is going to be hitting the warbird fliers hard sooner or later, that is ENGINES!

No one is making the big inlines or radial engines. There is only a finite supply of engines. You can only rebuild these engines so many times. There are parts that just aren't made anymore. 

With an unlimited budget you could make the blocks, crankshafts, pistons, camshafts and other big parts. All the tooling for making these key parts are gone.

An airplane can be made from scratch, but the power plant is going to be the problem. 

Or am I wrong?

Bill G.


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## Clay_Allison (Mar 1, 2009)

Bill G. said:


> Here is a problem that is going to be hitting the warbird fliers hard sooner or later, that is ENGINES!
> 
> No one is making the big inlines or radial engines. There is only a finite supply of engines. You can only rebuild these engines so many times. There are parts that just aren't made anymore.
> 
> ...


CNC machining is getting cheaper and easier. I believe a day is coming where you will be able to email the specs to a custom machinist and have their computer tell their milling machines what to do and have it crank out a Merlin for you.


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## pbfoot (Mar 2, 2009)

FLYBOYJ said:


> And what type of aircraft?


Spit as mentioned earlier and don't forget to convert as it's imperial


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## drgondog (Mar 2, 2009)

Clay_Allison said:


> CNC machining is getting cheaper and easier. I believe a day is coming where you will be able to email the specs to a custom machinist and have their computer tell their milling machines what to do and have it crank out a Merlin for you.



Absolutely true. Ditto 603/605 for 109. 

Crankshaft is the focus because of tolerances required, Block and pistons much easier. The supercharger is also a pretty complex bag of high precision parts


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## Clay_Allison (Mar 2, 2009)

drgondog said:


> Absolutely true. Ditto 603/605 for 109.
> 
> Crankshaft is the focus because of tolerances required, Block and pistons much easier. The supercharger is also a pretty complex bag of high precision parts


If you aren't building an armored replica (and there is no reason to put armor on it) You could go cheap on the supercharger or just leave it off. 

Any full size civillian replica will be on the order of 1000 pounds lighter than the original.


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## drgondog (Mar 2, 2009)

Clay_Allison said:


> If you aren't building an armored replica (and there is no reason to put armor on it) You could go cheap on the supercharger or just leave it off.
> 
> Any full size civillian replica will be on the order of 1000 pounds lighter than the original.



Clay -not sure about the latter statement. IIRC the only armor was behind the seat ~ trapezoidal shape of ~ 5/16" hardened steel. Off hand I can't recall any other 'stuff' we removed from our 51 other than fuselage tank (plus structure, plumbing, original radios and frame for radios) so that the TF51D mod could be performed. 

If you keep single seat and civilian it up by getting rid of fuse tank and armor maybe you save 100 pounds (assuming no fuel)? What else do you have in mind


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## Clay_Allison (Mar 2, 2009)

drgondog said:


> Clay -not sure about the latter statement. IIRC the only armor was behind the seat ~ trapezoidal share of ~ 5/16" hardened steel. Off hand I can't recall any other 'stuff' we removed from our 51 other than fuselage tank (plus structure, plumbing, original radios and frame for radios) so that the TF51D mod could be performed.
> 
> If you keep single seat and civilian it up by getting rid of fuse tank and armor maybe you save 100 pounds (assuming no fuel)? What else do you have in mind


Guns? Ammo? 84 pounds a gun, half an ounce per round.


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## KrazyKraut (Mar 2, 2009)

SoD Stitch said:


> I have often thought that if I became a stinkin' rich millionaire (billionaire?) I would scratch-build a two-seat Do 335 _Pfeil_; THAT would be cool! Of course, I may not be able to use DB 603's, I might have to use Merlins, but I still think it'd be cool. Anybody know what the average fuel consumption of a Merlin is? It's gotta be over 100 GPH.



That'd be cool. However there would still be some things to iron out, so you'd end up not only rebuilding but finishing the design. Nevertheless it would be awesome. I guess you could use a lower range turboprop to eliminate a lot of problems and keep sfc down.


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## drgondog (Mar 2, 2009)

Clay_Allison said:


> Guns? Ammo? 84 pounds a gun, half an ounce per round.



Then make the statement to include not just armored but also armament.

The M2 was ~69 pounds/M2, 1 lb per 3 rounds/with links ~ 5oz each. 

So, if you yank the 50s and ammo from a New P-51B you strip 420 pounds of linked 50 cal plus 276 pounds of M2.

For the D it's 627 pounds of linked ammo plus 414 pounds of M2

Source Mustang by Gruenhagen - page 190

(and yes, I haver seen 'civilian' 51s with both real and 'decommissioned' 50's. Class III license still works (for uncertain future).


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## Clay_Allison (Mar 2, 2009)

drgondog said:


> Then make the statement to include not just armored but also armament.
> 
> The M2 was ~69 pounds/M2, 1 lb per 3 rounds/with links ~ 5oz each.
> 
> ...


Note in my original post I said civillian "replica". I just realized you might be thinking I was talking about restored real warbirds. 

Besides the 1000 pounds of "armament" (should have been more specific) and the back armor, I think that many other lighter components could be included in the plane. See the carbon fiber "Grand Mustang" for an extreme example.


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## pbfoot (Mar 2, 2009)

drgondog said:


> Clay -not sure about the latter statement. IIRC the only armor was behind the seat ~ trapezoidal shape of ~ 5/16" hardened steel. Off hand I can't recall any other 'stuff' we removed from our 51 other than fuselage tank (plus structure, plumbing, original radios and frame for radios) so that the TF51D mod could be performed.
> 
> If you keep single seat and civilian it up by getting rid of fuse tank and armor maybe you save 100 pounds (assuming no fuel)? What else do you have in mind


the radio equipment and IFF was probably 100lbs+/-


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## drgondog (Mar 2, 2009)

pbfoot said:


> the radio equipment and IFF was probably 100lbs+/-



Right, but we added most of that back - after removing the fuselage tank, ecept for IFF - but the civilian version today would have a lot lighter radios/radar/rnav combo.. maybe 50 pounds +/- between old/new?


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## drgondog (Mar 2, 2009)

Clay_Allison said:


> Note in my original post I said civillian "replica". I just realized you might be thinking I was talking about restored real warbirds.
> 
> Besides the 1000 pounds of "armament" (should have been more specific) and the back armor, I think that many other lighter components could be included in the plane. See the carbon fiber "Grand Mustang" for an extreme example.



I did think you meant 'restored' not re-designed from ground up to take advantage of composites and remove armament.

If we assume than only the external lines are sacred I would speculate that a really good turbo prop/composite design could be built that is a lot lighter than 1500 pound reduction.

Rivets are a high percentage of bare airframe total weight. If you wanted to reduce the airframe to some ultimate G load capability below 11-12 then even more weight could be extracted from wing and tail structure.


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## Clay_Allison (Mar 2, 2009)

drgondog said:


> I did think you meant 'restored' not re-designed from ground up to take advantage of composites and remove armament.
> 
> If we assume than only the external lines are sacred I would speculate that a really good turbo prop/composite design could be built that is a lot lighter than 1500 pound reduction.
> 
> Rivets are a high percentage of bare airframe total weight. If you wanted to reduce the airframe to some ultimate G load capability below 11-12 then even more weight could be extracted from wing and tail structure.


If you used a turboprop, that would be another 1000 pounds right there. Compare the weight of a Merlin to the T-55 used on the "grand mustang".

I worry about preserving the original lines on on the reproductions if you use turboprops, since they were designed to have so much weight forward of the firewall. How do you balance that and make it look the same. Extra fuel tank?


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## Captain Dunsel (Mar 2, 2009)

Just remember one thing when you discuss removing weight. You have to keep the CG where it belongs. There's a saying in R/C models that nose heavy planes my fly poorly, but tail heavy planes only fly once.

CD


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## drgondog (Mar 2, 2009)

Clay_Allison said:


> If you used a turboprop, that would be another 1000 pounds right there. Compare the weight of a Merlin to the T-55 used on the "grand mustang".
> 
> I worry about preserving the original lines on on the reproductions if you use turboprops, since they were designed to have so much weight forward of the firewall. How do you balance that and make it look the same. Extra fuel tank?



I don't know how much a T-55 or PT6A weighs but they would trash the original lines. Where can I find figures for weights and lengths of either engine?

The extra fuse tank when full actually moved the cg too far back. I would be more inclined (for civilian/lower structural design target) to put ballast near tail wheel bulkhead - which would be fixed weight rather than the variable weight of fuel in the fuse tank - and a much larger 'arm' from the cg so the ballast could be much lower weight.

Dunsel is right about aft cg. When cg is too far forward you usually don't have enough H. Stabilizer to get off the ground (or very poorly) in lower speed range.


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## Clay_Allison (Mar 2, 2009)

drgondog said:


> I don't know how much a T-55 or PT6A weighs but they would trash the original lines. Where can I find figures for weights and lengths of either engine?
> 
> The extra fuse tank when full actually moved the cg too far back. I would be more inclined (for civilian/lower structural design target) to put ballast near tail wheel bulkhead - which would be fixed weight rather than the variable weight of fuel in the fuse tank - and a much larger 'arm' from the cg so the ballast could be much lower weight.
> 
> Dunsel is right about aft cg. When cg is too far forward you usually don't have enough H. Stabilizer to get off the ground (or very poorly) in lower speed range.


The T-55 weaighs 540 pounds and gives 1450 horses.

As for the CG, that was what the second half of my post was about, you will constantly have to be refiguring how much weight you are taking away and where the CG will go. That's a careful process if you want to make it look like the same plane from 50 feet away.


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## pbfoot (Mar 2, 2009)

Clay_Allison said:


> The T-55 weaighs 540 pounds and gives 1450 horses.
> 
> As for the CG, that was what the second half of my post was about, you will constantly have to be refiguring how much weight you are taking away and where the CG will go. That's a careful process if you want to make it look like the same plane from 50 feet away.


Check out the Piper Pa48 Enforcer with was a Turbo powered P51 designed for possible use in Viet Nam


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## Clay_Allison (Mar 2, 2009)

pbfoot said:


> Check out the Piper Pa48 Enforcer with was a Turbo powered P51 designed for possible use in Viet Nam


well aware of it and its Cavalier ancestry. I hate wingtip tanks though, lol.


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## Marcel (Mar 3, 2009)

Here in the Netherlands, someone is building a real, flying replica of the Fokker G.I. We have several Fokker replica's in Lelystad, like a beautiful F.2 with original engine! This year, the MLM will get a B339 Buffalo replica, don't know if it'll be able to fly, though. So I would say it's very well possible to build an airframe of WWII if the money and dedication is there.


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## drgondog (Mar 3, 2009)

Clay_Allison said:


> The T-55 weaighs 540 pounds and gives 1450 horses.
> 
> As for the CG, that was what the second half of my post was about, you will constantly have to be refiguring how much weight you are taking away and where the CG will go. That's a careful process if you want to make it look like the same plane from 50 feet away.



I am curious as to why you seem to think I am not acquainted with airframe design issues? 

My comment about the extra fuselage tank as a possible solution (not one easily accepted) is that absent installation data for the T-55 and the ducting, intakes, shaft design and overall length of the engine - there isn't much information to assume that you should consider put a new fuel cell forward of the firewall if the T-55 is lighter than the Merlin)... and adding an extra cell to the fuselage aft of the cg just makes the problem worse.

If the T-55 package is heavier than the Merlin package then either extending the aft fuselage (i.e. like the Fw 190D-9) to move the tail further away is one solution, expanding the fuselage fuel cell or adding aft ballast are other possible solutions. 

To keep the same general lines as the Mustang and maintain existing stablity and control parameters you probably would add ballast near the tailwheel area. (much greater moment arm from cg than existing fuel cell - therfore less mass required) 

I had in mind that the T-55 installation with ducting, removal of all the radiator/oil cooler/structure aft of the original Mustang cg would probably have approximately the same effect but asked you to provide details as the article I read about the Enforcer was vague on this.

Your info of 540 pounds for T-55 seems low (does that include intake and exhaust ducting, new engine mounts, same center of mass as Merlin, etc) but for the moment I assume it correct.

Assume the T-55 is 1000 pounds lighter than the Merlin as you state, and that the center of mass of the new engine package isn't too much different from Merlin package - 

Then one possible solution (not a happy one) is that you have to consider moving the T-55 forward by extending the airframe more forward of the firewall than in the original P-51. 

By rough calculation the Merlin at ~ 1650 pounds is ~ 1100 pounds (and 3x the weight) more than your figure for the T-55. That means that the center of mass for the T-55 has to be moved 3x distance from CG in comparison to the distance to the center of mass of the Merlin to compensate for 1/3 the weight. Already a stupid idea

But if you did create room in front of firewall, you do not want to add a fuel cell forward of the cg to compensate for the aft cg issue that installing the lighter engine created. When you burn that fuel you also effectively move the resultant cg aft, and are in a possible world of hurt stability wise.

So, the easier solution is to reject the lighter engine package and stay with Merlin or Allison

Looking at the Enforcer pic, Piper definitely did not extend forward airframe - at least by much. The implication is that either the overall installation of the T-55 resulted in nearly the same weight as the Merlin package or they were able to remove a lot of mass aft of the cg (unlikely) to compensate for lighter engine... or the T-55 is so much shorter that the designers were able to push the center of mass of the engine forward and place ~ 1500 pounds of useful weight foreward of firewall/aft of T-55 (unlikely given exhaust ducting requirements of turbo prop).

What is your theory?


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## Clay_Allison (Mar 3, 2009)

drgondog said:


> I am curious as to why you seem to think I am not acquainted with airframe design issues?
> 
> My comment about the extra fuselage tank as a possible solution (not one easily accepted) is that absent installation data for the T-55 and the ducting, intakes, shaft design and overall length of the engine - there isn't much information to assume that you should consider put a new fuel cell forward of the firewall if the T-55 is lighter than the Merlin)... and adding an extra cell to the fuselage aft of the cg just makes the problem worse.
> 
> ...


I know that you know what you're talking about. I was just saying that I wasn't playing "mad scientist" without considering the ramifications. Honestly I was more interested in knowing your theory since I didn't have one, but given what you've told me I'd say the ducting weighed nearly enough to compensate for the engine weights and the lightening aft of the CG took care of a bit more. 

BTW. 540 is dry weight, standalone, I couldn't get a number for installed weight.

For another turboprop mustang, check out the carbon fiber Grand Mustang


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## drgondog (Mar 3, 2009)

Clay_Allison said:


> I know that you know what you're talking about. I was just saying that I wasn't playing "mad scientist" without considering the ramifications. Honestly I was more interested in knowing your theory since I didn't have one, but given what you've told me I'd say the ducting weighed nearly enough to compensate for the engine weights and the lightening aft of the CG took care of a bit more.
> 
> BTW. 540 is dry weight, standalone, I couldn't get a number for installed weight.
> 
> For another turboprop mustang, check out the carbon fiber Grand Mustang



Clay - the thing that confused me on the first article I read on the Enforcer was a stated gross weight of 14,500+ pounds and I was trying to figure out where they put it!


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## Clay_Allison (Mar 3, 2009)

drgondog said:


> Clay - the thing that confused me on the first article I read on the Enforcer was a stated gross weight of 14,500+ pounds and I was trying to figure out where they put it!


TURBOKART Here's where I got the weight listing. Also an ad for one for sale claiming the same shipping weight.


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## drgondog (Mar 3, 2009)

Clay_Allison said:


> TURBOKART Here's where I got the weight listing. Also an ad for one for sale claiming the same shipping weight.



No problem. No desparation required. I make mistakes.


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## Elvis (Mar 6, 2009)

Re: Clay Allison's "Turbokart" link.

I noticed, in the stats at the bottom of the page, for the Lycoming T53-L-13B Turboshaft Engine, that one of the things listed was Compression Ratio ("_Compression Ratio: 7.2:1 at 25,600 rpm_").

......

How does one achieve a c.r. rating for a turbine engine?
Is this a comparison of atmospheric air pressure to compressed air pressure?

...   



Elvis


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## Clay_Allison (Mar 9, 2009)

Elvis said:


> Re: Clay Allison's "Turbokart" link.
> 
> I noticed, in the stats at the bottom of the page, for the Lycoming T53-L-13B Turboshaft Engine, that one of the things listed was Compression Ratio ("_Compression Ratio: 7.2:1 at 25,600 rpm_").
> 
> ...


No idea. It was the result of a Google search, but like I said there was one for sale that listed the same shipping weight on another site so I had some verification.


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## drgondog (Mar 10, 2009)

Elvis said:


> Re: Clay Allison's "Turbokart" link.
> 
> I noticed, in the stats at the bottom of the page, for the Lycoming T53-L-13B Turboshaft Engine, that one of the things listed was Compression Ratio ("_Compression Ratio: 7.2:1 at 25,600 rpm_").
> 
> ...



Elvis - the compression ratio is the ratio of the internal, compressed, air pressure at the final stage of turbine blade compression at the combustion chamber - to the ambient air pressure in the freestream in front of the engine.


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## Elvis (Mar 12, 2009)

So its a comparison of atmospheric air pressure to compressed air pressure.

Ok, I thought that had to be it.
Thanks for defining that drgondog....and Clay, sorry if it seemed my question was pointed towards you.
I wasn't neccessarily asking you only, but rather, I was only asking for a definition of that particular stat, as it applies to that particular instance, to whomever could define it.

Thanks again, guys.




Elvis


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## Hollywood (Jun 21, 2009)

If you are looking at Warbird Reproductions Claus Colling @ Flugwerk will build you a Fw190D with Allison power that looks FANTASTIC and just like the original for less than they are asking for the Grand Mustang...........


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## gjs238 (Jun 23, 2009)

With unlimitless funds, not only would it be great to build flying replicas, but build them they way we sometimes speculate about in our what-if posts.

Build a P-38 with Merlins.
P-39 with turbocharger, or with Merlin.
Etc.


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## Junkers88A1 (Jun 25, 2009)

nice thread  here is a picture of the newbuildt Fw 190 D-9 ( its now in Florida for final assembly )

and i really like the newbuildt better than using originals when it comes to flying..as one said in here..in 100 years we can always make new aircrafts..BUT ( my opinion ) if we fly all originals the next 100 years it will only be replicas left for history to see.. keep the originals on ground.. atleast the few with combathistory.. so we dont loose them in some stupid accident..then they are gone forever. to me it means a lot more to go and see the actual Memphis belle.. a real Fw 190, a spitfire, anything with combat history in a museum than seeing some newmade replica..but on airshows its the shape that counts.. ( for me ) so a replica in the air and the original on the ground is good enough for me.. what would have happened if the memphis belle took to the air..and crashed and burned.. i dont even want to think about it.. but seeing liberty belle and others ( those are ofcourse original B-17 but a LOT is rebuild ) in the air..i love that..but its not a combat veteran.. so i would love to still see originals in the air ( like P-51` s and so on ) but not those few left that saw action...


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## GrauGeist (Jun 25, 2009)

They're making new Doras?

Very cool!

I know Flugwerks is making the A series, are they making the Dora as well?


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## Junkers88A1 (Jun 25, 2009)

yes Flug Werk is making the doras as well  and they look awsome 
here is a few more pictures of it 

i really like how they have remade the whole engine so it fits and how they made the exhaustpipes so they come out on the right place ( low ) as the engine is not original.. dont remember right now who made the engine..


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## gumbyk (Jun 25, 2009)

Clay_Allison said:


> CNC machining is getting cheaper and easier. I believe a day is coming where you will be able to email the specs to a custom machinist and have their computer tell their milling machines what to do and have it crank out a Merlin for you.



Clay, we're almost there already. TVAL, here in New Zealand can make you a new WW1 aircraft , complete with new engine. I would guess that there will come a time when you can do the same with WW2 aircraft.
Oberursel Reproduction | The Vintage Aviator

Especially interesting is the fact that they are using a rapid prototyping machine to create almost immediate sandcasts for items. So, I guess, if you sent them a CAD drawing, they could turn out a cast model for you.


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## GrauGeist (Jun 25, 2009)

Junkers88A1 said:


> yes Flug Werk is making the doras as well  and they look awsome
> here is a few more pictures of it
> 
> i really like how they have remade the whole engine so it fits and how they made the exhaustpipes so they come out on the right place ( low ) as the engine is not original.. dont remember right now who made the engine..


Outstanding!

I am glad to see such an interest in bringing the old warbirds back (including the rarer types), who would have ever thought that they'd be making a brand new Dora even 20 years ago?

Thanks for posting those great photos!


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## Aaron Brooks Wolters (Jun 25, 2009)

WHOA!!!!!!! That's cool as %#[email protected]#.


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## fritzie 101 (Jun 30, 2009)

many restorations are already almost complete rebuilds any way.They're restoring planes now that would've been impossible to restore 10 to 20 years ago. Cost and lack of origional engines has always been the main problems blocking new builds but if you have enough money you can build just about anything. and by the way the Dora is really cool. (sorry about the photo quality it was enlarged from an image the size of a postage stamp .Flugwerk can build anairplane that's been extinct for 60 +yrs but they can't post decent pictures on their website? )


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## turbopower87 (Jul 5, 2009)

With all of the rapid prototyping machines and CAD stuff, wouldn't it be easier to rebuild an entire engine now? Just think, if you rebuilt the DB 600, that engine and it's derivatives could be used in the me 109, me 110, me 210, do 335, ta 152... the list goes on. 

Do the necessarily blueprints and technical specs still exist for this?


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## Clay_Allison (Jul 9, 2009)

turbopower87 said:


> With all of the rapid prototyping machines and CAD stuff, wouldn't it be easier to rebuild an entire engine now? Just think, if you rebuilt the DB 600, that engine and it's derivatives could be used in the me 109, me 110, me 210, do 335, ta 152... the list goes on.
> 
> Do the necessarily blueprints and technical specs still exist for this?


I know it would upset a lot of people, but probably the best engine to clone and CNC machine an all new reproduction of is an Allison V-1710. There are more of them around, more is known about them, they have been experimented with more than any other engine postwar because of their availability. They could be sold with ratings up to 1750 horsepower. Flugwerk uses the old ones in their Fw-190 IIRC and that's a radial platform. I don't see any reason why some interior cheating couldn't get it into practically anything.


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## turbopower87 (Jul 10, 2009)

What about the DB 601? The Germans made 10s of thousands of them.

Do the records and blueprints still exist? I mean come on, the Germans are supposed to be meticulous about things like that.


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## GrauGeist (Jul 10, 2009)

turbopower87 said:


> What about the DB 601? The Germans made 10s of thousands of them.
> 
> Do the records and blueprints still exist? I mean come on, the Germans are supposed to be meticulous about things like that.


They also made thousands of Bf109 aircraft, but few exist today.

In the chaos of the final months of the war, much of the German's records were lost. Factories and cities were bombed and in some places, like Berlin for example, the street fighting was brutal, causing alot of destruction to buildings.


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