# Reggiane RE-2007 - What if?



## DAVIDICUS (Mar 26, 2005)

Does anyone know what performance the RE-2007 was expected to have if the Junkers Jumo 004 turbojet had been made available?

Can you share any info whatsoever on this plane?

As always, thanks.


----------



## kiwimac (Mar 27, 2005)

Davidicus,

Couple of sites, first one:

http://tanks45.tripod.com/Jets45/Histories/Re2007/Re2007.htm



> Engine: 1x Junkers Jumo 004 turbojet
> Wing Span: 9.5 m
> Length: 9 m
> Height: 2.93 m
> ...




Second one:









> Specifications
> Engine 1x Junkers Jumo 004 turbojet
> Max Speed 1,050 kph
> Ceiling 15,000 m
> ...



Source: http://www.comandosupremo.com/Re2007.html

Kiwimac


----------



## the lancaster kicks ass (Mar 27, 2005)

man i hate metric...........


----------



## DAVIDICUS (Mar 27, 2005)

Kiwimac,

Whoa. According to the site, it could do 652mph. 

That seems a wee bit optomistic. 

Good info though, thanls.


----------



## CharlesBronson (Mar 27, 2005)




----------



## DAVIDICUS (Mar 27, 2005)

Charles,

No doubt from a scary dream of an allied pilot.


----------



## delcyros (Apr 1, 2005)

The high speed figures are suspect. The high ceiling and the range, too. With the fuel consumption of a Jumo-004, the weaponry and the weights in mind I see no justification for these high numbers. But I might be wrong in this. The slightly swept back wing could allow a crit mach between 0.85 and 0.9, depending on aspect ratio and so on. 652 mp/h are theoritcly possible at low altitudes, only. At this altitudes, the drag by air is huge, I doubt that the 890 Kp thrust of a single Jumo-004 B could overcome the drag at 550-580 mp/h at low altitudes. The thrust/weight ratio of the Re-2007 would be at around 0.288-0.310, this is quite a very good number and close to P-80 and He-162 (...and better than the Me-262, Ar-234 B and Meteor MK III). 
However, an amazing plane, looking very advanced!


----------



## the lancaster kicks ass (Apr 1, 2005)

yes but you have to remember by the time it would have entered service the meteor would be at the Mk.6 to 8 stage when it could take out anything out there, and we'd have other designs as well...........


----------



## delcyros (Apr 1, 2005)

The Meteor MK IV was great (superior to the Me-262 A), indeed. But it saw service from late 1945 on. F MK VI and F MK VIII are even later planes. Pretty late or isn´t it? And I doubt that a twin engined Meteor could match a single engined Re-2007 (or a single engined P80 or He-162). And in late 1945/early 1946 you could have to deal with a Jumo-004 H driven Re-2007, which could easily exceed 600 mp/h...
The D.H. Vampire on the other hand would be a hard match, agreed.


----------



## the lancaster kicks ass (Apr 1, 2005)

ok firstly when refering to the meteor and most other post war planes you use arabic numerals not roman (so it's the Mk.8 not Mk.VIII), and secondly the meteor was very manouverable, morso than the vampire which was a ground attack jet, the meteor even took the world speed record being the first aircraft past 600mph, i don't know what timespan we're loking at for the RE-2007 for it to come into service but for the meteor to reach 600mph we're not looking that far past WWII..........


----------



## delcyros (Apr 1, 2005)

My mistake with the numbers.
Well, Lanc, the first plane to exceed 600 mp/h in level flight was the Me-163 A. It reached 1003,4 Km/h (roghly 623 mp/h) in late 1941. Hey, it was faster than the Meteor MK IV at it´s world breaking flight! Even with brute force you cannot push the speed of any Meteor beyond 620 mp/h. No matter what´s the engine. 
As far as I know the manoverability of the Meteor depends on the speed. At low speeds it could outturn the Vampires, at high speeds I am sure that it would have been outturned even by a Me-262.


----------



## DAVIDICUS (Apr 1, 2005)

An excerpt from my earlier post above.

"It is interesting to note that the two Jumo 004B engines were sent to Italy, but were said to have been sold for scrap in Milan immediately after the collapse of the German forces in Italy."

Apparently, by January 1944, they were just waiting for the engine so they could finish.


----------



## delcyros (Apr 1, 2005)

Has anybody noticed that the first Re-2007 picture looks more like a slightly modified F-86 Sabre? 
I have some doubts about the engines. They may have been sent to italy but they would have been of limited worth for a Re-2007 project. The Jumo engineers at Dessau were ordered to take some parts from inside of the engine and put them on it. This drasticly changed it´s shape. Original 60 cm in diameter would change to an oval of 60 x 80 cm. Surprisingly the industrie wasn´t informed by this change (and surely not Caproni). This is why the Horten brothers had to redesign their Ho-IX jet plane as soon as they got their engines (in mid 1944). I estimate that this would happen to the Re-2007, too. Esspecially if it was designed around a Jumo-004.


----------



## DAVIDICUS (Apr 1, 2005)

I think you meant to say the F-86 looks like a slightly modified Re 2007!


----------



## delcyros (Apr 1, 2005)

Umm, I am nearly sure that the artist had a F-86 in mind. Look at the exhaust or the canopy. No italian design or isn´t it?


----------



## DAVIDICUS (Apr 1, 2005)

A drawing from the design boards of the Re-2007


----------



## the lancaster kicks ass (Apr 2, 2005)

oh god if CC reads this he's gonna claim that the designers of the F-86 copied the italains an he'll try and use the fact that the F-86 was so goo dto claim the RE-2007 would have been amazing and i'll get really annoyed.........

thans for pointing that out guys........


----------



## red admiral (Apr 2, 2005)

Aircraft designers often arrive at similar solutions to the same problems, so their aircraft look decidedly similar. It doesn't look much like a F86 apart from the general configuration. Its an artist's impression anyway, not the real thing. The tail definitely looks Italian though.


----------



## delcyros (Apr 2, 2005)

It is going to be even more suspect with this drawing. The canopy don´t fit to the artists picture (who actually took a F-86/F-84 canopy and not the italian one). This underlines that he was very much influenced by the F-86. I see more problems in this design: With the jet engine moved into the center of the fuselage there is no space for the fuel tanks left. Calculate the average fuel consumtion of a Jumo 004 B (around 1,44 Kg/(100 %thrust)sec.) and the given range you would need between 1000 kg and 1350 kg fuel (depends on altitude and drag). Where should it been placed in this design? In the wings? Impossible, such a small wing cannot bear the complete fuel, even if it bears only one third of that fuel the wing would become very thick (increasing drag and reducing critical Mach speed).


----------



## the lancaster kicks ass (Apr 2, 2005)

and incresing drag further, that's a very good point del...........


----------



## delcyros (Apr 4, 2005)

That´s it, Lanc. With increasing drag you loose speed (and range). I believe that the Re-2007 would need a new fuselage design (since the Jumo-004 doesn´t fit) or beeing replaced by BMW-003 A2 (with less weight and less sustainable thrust) powerplants. Both would need considerable time (and thus also delaying the development of the Re-2007, so a timeframe between mid 45/late 45 and early 46 for ti´s deployment would be possible). 
The given range is overrated a lot, the Re-2007 would more probably have a comparable range with the He-162 than anything else (at best).
The speed is also overrated. The drag produced by the canopy and (thick?) wings would be quite large, even with slightly swept back wings. I really don´t see why it should have a comparable speed to the soviet MiG-15 / La-150 (which also are small and light weighted planes) while it lacks so much thrust?! A speed between 520 and 570 mp/h is more probable than a speed between 600 and 650 mp/h.


----------



## the lancaster kicks ass (Apr 4, 2005)

yeah i mean that's a huge speed for a plane like that........


----------



## cheddar cheese (Apr 5, 2005)

the lancaster kicks ass said:


> oh god if CC reads this he's gonna claim that the designers of the F-86 copied the italains an he'll try and use the fact that the F-86 was so goo dto claim the RE-2007 would have been amazing and i'll get really annoyed.........
> 
> thans for pointing that out guys........



You read me like a book


----------



## the lancaster kicks ass (Apr 5, 2005)

i know you too well.........


----------



## red admiral (Apr 6, 2005)

The Speed figure might not be as far off as you think. If you look at the other Italian fighters, G.55 et al, they were doing 400+mph on only 1500hp. There were other designs, e.g. the SAI 207/403 that could do 400mph on only 750hp. This would leave me to believe that the Italians have very clean airframes.


----------



## the lancaster kicks ass (Apr 6, 2005)

yes but think how much heavier this jet would be...........


----------



## cheddar cheese (Apr 6, 2005)

Weight shouldnt really have much to do with top speed. Just look at the P-47, for example.


----------



## the lancaster kicks ass (Apr 6, 2005)

yes but the P-47 also had a hugely powerfull engine...........

and as a car man you should know that weight has allot to do with speed...........


----------



## cheddar cheese (Apr 6, 2005)

No, as a car man I know that weight kills acceleration and handling. Top Speed is largely unaffected.


----------



## the lancaster kicks ass (Apr 6, 2005)

ok well take into account pewer to weight ratios..........


----------



## cheddar cheese (Apr 6, 2005)

Again, more to do with acceleration and handling 8)


----------



## delcyros (Apr 6, 2005)

Bring it back to aerodynamic drag. The calculation looks quite similar to the early Messerschmitd speed estimations of the Me-P.1101, which wered in general about 50 mp/h higher. A correct mathmatical solution for high subsonic and transsonic speeds (including compressability effects) wasn´t found earlier than january 1945 (by means of DFS). And again: thicker wings increase the drag, so you have to choose: either greatly reduce the range or reduce speed and range moderatly. This leaves the Re-2007 in a difficult situation. As would the needed redesign of the fuselage because of the larger Jumo-004 B engines. Larger fuselage diameter also increase the drag and weight. At least the low thrust of a single Jumo-004 B makes any speed over 600 mp/h very questionable. Extremely clean lines and thin, swept back wings would be needed, the area rule and a very small airframe would be necessary, too. I cannot see these details in the Re-2007 design...


----------



## the lancaster kicks ass (Apr 7, 2005)

nor can i...........


----------



## cheddar cheese (Apr 7, 2005)

The drawing on the first page depicts swept-back wings.


----------



## red admiral (Apr 7, 2005)

The problem is that most of the pictures are artist's impressions not technical drawings. Now if we had technical drawings, then we could maybe get somewhere. The Caproni-Campini also has thin wings, but huge range.


----------



## the lancaster kicks ass (Apr 7, 2005)

ok i can't actually find the "Caproni-Campini", what's it's proper designation? but if it's like the rest of the Caproni familyit'll have big fuel tanks and more engines, each engine having better fuel economy, do you realise we're simply sayin it'd have thin wings if it's gonna go fast, but thin wings also mean that less fuel can be carried as none can be carried in the wings and they produce less lift than a thicker wing, however if it's gonna get more range the wings'll have to get thicker to produce more lift, incresing drag and slowing her down...................


----------



## cheddar cheese (Apr 7, 2005)

Go to the first page of "Best Jet of WW2" that bronze created in the polls section and look at the bottom. I tried pasting it but my interent spazzes every time I try.


----------



## the lancaster kicks ass (Apr 7, 2005)

wow, an un-armed plane doing 375kmph, now i'm scared


----------



## delcyros (Apr 8, 2005)

...it is true that we don´t have any construction charts, but there is a possibility to determine how probable a speed of 650 mp/h is as long as the design is driven by a single Jumo-004 B.
Jumo-004 B: weight: 742 kg (~1600 lbs), thrust: 890 kp (1958 lbs)
Let´s say we have a very clean airframe and a featherweighted design (comparable to a He-162). The increasing drag at speeds close to Mach 1 would force the designers to greatly increase the engine thrust (at a drag factor of 0.9):
550 mp/h ~ 2000 lbs thrust
600 mp/h ~ 3500 lbs
650 mp/h ~ 6000 lbs
this is a roughly estimation but it can be verified:
Ar-234 C with four BMW-003 allowed a top speed of 562 mp/h (~drag factor of around 2,6)
Me-262 a with two Jumo-004 B allowed a top speed of
max. 540 mp/h (~drag factor 1.8 )
P-80 would allow a top speed of 577 mp/h with roughly 4000 lbs thust (~drag factor 1.3)
The Ho-IX V2 (twin engined jet) flying wing (LOW DRAG!) design allowed a top speed of 607 mp/h (drag factor ~ 1.0) Ta-183 (hypothetical) with a single He-S011 B (1300 kp or 2860 lbs) would allow around 597 mp/h. This indicates a drag factor of around 0.88
Which drag factor allows the Re-2007 with 2000 lbs thust to reach 650 mp/h in level flight? Can tell you: 0.26 !!! Impossible.
This would rather indicate a few stabilizers around a single Jumo-004 B (and even this is questionable) and surely no plane. Even the F-86 and Mig-15 hardly match a drag factor of around 0.75-0.8!
For 600 mp/h, a drag factor of around 0.5 would be necessary (still highly unprobable, maybe a single engined flying wing design?).
For 550 mp/h a drag factor of around 0.9 (which still is very good) would be necessacy. This is possible, but questionable (not to count compressability effects).


----------



## Civettone (May 29, 2006)

I'm terribly sorry but the Re.2007 is a myth. A post-war development by Reggiane to allow his company to stay in business. 

Kudos to the many members who immediately became suspicious of the Italian design and especially the overrated performance stats. 

Information comes from the rather well known Max Cappone. Take a look at this website: http://cloud.prohosting.com/hud607/uncommon/aircraft/re2005/re2007.html

Kris


----------



## Twitch (May 30, 2006)

I put up a pic of this plane before http://www.ww2aircraft.net/forum/aviation/italian-bombers-3022-4.html?highlight=Re-2007 and cheddar cheese said it was never a design concept. How come not saying so now?

Here's the background I gave on it. BTW it was to use a PAIR of 004Bs

REGGIANE 
Early Italian jet experimentation with indigenous power plants, such as the Caproni-Campini N.1 that used a 900 HP Isotta-Fraschini piston engine and ducts to produce jet thrust, were lackluster but Italy almost had a potent jet. The 1943 Reggaine Re-2007 was to use the Junker Jumo 004B with 1,980 lbs. thrust.

The open exchange of ideas and material between Germany and Italy saw interesting applications in the aviation field such as using Daimler-Benz piston engines on Italian prototypes. When the Jumo was seen as a possible source of power Reggaine laid out a small fighter design. For the time, right before Italy’s capitulation, the craft looked quite a lot like contemporary Reggaine piston engine fighters, which makes sense. Even the classic Reggaine tail was present on the horizontally oval-shaped 29.5-foot fuselage. Though the tail was non-swept the wings spanning 31.1 feet did have a slight sweep.
A certain Hauptmann (Captain) Bohm, was the Luftwaffe's senior engineer at the Reggiane plant, but even he was unable to obtain a positive decision concerning the supply of the two Junkers Jumo 004B's which had been promised by the Berlin. On January 7, 1944, Reggaine engineer Roberto Longhi wrote to Count Caproni, requesting that he intervene with the Germans as design work had diminished. Much of the rear fuselage, wing spars, ribs, undercarriage and the cockpit were already built but because of the inability to obtain adequately detailed dimensional specifications about the engine work once again halted.
In October 1944 the finished components were transported to the Caproni plant at Taliedo, where they remained until the end of the war. They were ultimately shipped to the US. The two Jumo 004B engines were sent to Italy, but were allegedly sold for scrap in Milan immediately after the withdrawal of German forces in Italy.

Keeping with the Italian lust for compact planes of high maneuverability the Re-2007 was that weighing just 7,788 lbs. loaded compared to around 14,000 lbs. for the Me 262. Its pair of 004Bs was buried in the fuselage for a very post-war look. The pilot’s bubble canopy sat adjacent to the leading edge of the wings.

Maximum speed was estimated to be about 630 MPH while a range of 931 miles was estimated. Four 20 mm MG 151 cannon were to be the armament.

This jet was quite standard in every way and specifications seem legitimate.


----------



## Twitch (May 30, 2006)

I put up a pic of this plane before http://www.ww2aircraft.net/forum/aviation/italian-bombers-3022-4.html?highlight=Re-2007 and cheddar cheese said it was never a design concept. How come not saying so now?

Here's the background I gave on it. BTW it was to use a PAIR of 004Bs

REGGIANE 
Early Italian jet experimentation with indigenous power plants, such as the Caproni-Campini N.1 that used a 900 HP Isotta-Fraschini piston engine and ducts to produce jet thrust, were lackluster but Italy almost had a potent jet. The 1943 Reggaine Re-2007 was to use the Junker Jumo 004B with 1,980 lbs. thrust.

The open exchange of ideas and material between Germany and Italy saw interesting applications in the aviation field such as using Daimler-Benz piston engines on Italian prototypes. When the Jumo was seen as a possible source of power Reggaine laid out a small fighter design. For the time, right before Italy’s capitulation, the craft looked quite a lot like contemporary Reggaine piston engine fighters, which makes sense. Even the classic Reggaine tail was present on the horizontally oval-shaped 29.5-foot fuselage. Though the tail was non-swept the wings spanning 31.1 feet did have a slight sweep.

A certain Hauptmann (Captain) Bohm, was the Luftwaffe's senior engineer at the Reggiane plant, but even he was unable to obtain a positive decision concerning the supply of the two Junkers Jumo 004B's which had been promised by the Berlin. On January 7, 1944, Reggaine engineer Roberto Longhi wrote to Count Caproni, requesting that he intervene with the Germans as design work had diminished. Much of the rear fuselage, wing spars, ribs, undercarriage and the cockpit were already built but because of the inability to obtain adequately detailed dimensional specifications about the engine work once again halted.

In October 1944 the finished components were transported to the Caproni plant at Taliedo, and stayed there until the end of the war. They were ultimately shipped to the US. The two Jumo 004B engines were sent to Italy, but were allegedly sold for scrap in Milan immediately after the withdrawal of German forces in Italy.

Keeping with the Italian lust for compact planes of high maneuverability the Re-2007 was that weighing just 7,788 lbs. loaded compared to around 14,000 lbs. for the Me 262. Its pair of 004Bs was buried in the fuselage for a very post-war look. This layout was proposed by Yokosuka for the R2Y2 Keiun jet bomber. The pilot’s bubble canopy sat adjacent to the leading edge of the wings.

Maximum speed was estimated to be about 630 MPH while a range of 931 miles was estimated. Four 20 mm MG 151 cannon were to be the armament.


----------



## delcyros (May 30, 2006)

Now, let´s assume two Jumo-004 B4would give enough thrust to accelerate the plane to 630 mp/h (I don´t know but let´s believe for the moment):

weight for
two Jumo-004B4 (dry):
3.268 lbs. (1.484 Kg) 
additional necessary engine equipment (including lubes, controll and others):
473 lbs. (215 Kg) -extrapolated from He-162 engines (BMW003 is LIGHTER than Jumo 004)
weight 4 MG 151/20:
370 lbs. (168 Kg)
ammo (100 rpg -which is comparably low):
220 lbs. (100 Kg)
fuel for 20 min. full powered flight at low level*:
1.881 lbs. (854.4 Kg)
fuel for engine test, taxiing, take off and accelerating:
462 lbs (210 Kg)
equipment and pilot:
266 lbs. (121 Kg, again taken from He-162)
---------------------------------------------
loadings:
6.942 lbs (3.152 Kg)

loaden weight RE 2007:
7.788 lbs. (3.537 Kg)

TOTAL WEIGHT AIRFRAME RE-2007:
---- 848 lbs. or 385 Kg----
For comparison: airframe weight for He-162A1(originally without structural enforcements): 1836.5 lbs (834 Kg) 


I conclude that the airframe strength is insufficiant to carry these loads.
The range with the given loaden weight of the airframe would rather indicate a severe design failure. With two Jumo-004 B I would expect the loaden weight for a twin engined RE-2007 to be at least 10.000 - 12.000 lbs.
The drag factor necessary to achieve 630 mp/h with two Jumo-004 B is ~ 0.82, which is a lot better than anything in it´s timeframe (esspecially for twin engined jets). However, I cannot exclude for sure that such a speed could be achieved with this specific powerplant but I do vote for the variant with higher probability; ~600 mp/h (+-15 mp/h) for a featherweighted, twin jet engined design such as a RE-2007.


*equals 170-210 miles range at 100% and sea level or at best ~500 miles range at 60% and very high altitude (fuel for take off, accelerating and climb to altitude not included)


----------



## SM79Sparviero (May 31, 2006)

According to most of the historical sources Re-2007 was a post-war design ( 1947-1949).
It is quite strange, anyway, that acording to Anthony Kay 's "German jet engines and gas turbine development", pag 85 , ""Italy was interested inusing Jumo 109-004 B to power her first jet fighter, Caproni-Reggiane Re-2007".

It is not strange, on the contrary, that most of historical papers about italian industrial production during the war not only aeronautical but also about armored vehicle is lost, and that industrial leaders , technicians but also workmen frequently deny the existence of a particular industrial project:if you had worked to an aeronautical project during the fascist period in particular during 1943-43 it was commonly interpreted as an ACTIVE COLLABORATION with na nazi-fascist regime. This was sufficient to get a bullet while you were coming home by bike, as happened to Engineer Gobbato who had managed the construction of Db-601 engines on licence in Alfa Romeo.

Here is the letter "riservatissimo-personale"= "personal, top secret" from Eng. Bobbato to Count Caproni , with the request of two jumo engines. If someone wants, I can translate it.


----------



## Dogwalker (May 31, 2006)

The Re.2007 (assuming the existance of the project during the war) was not a twin engined aircraft, but a single engined one, as you can see in the famous post-war cutaway ( http://tanks45.tripod.com/Jets45/Histories/Re2007/Re2007.htm ).
It's projected prestations were greately inflated. In the mid fifties, Sergio Stefanutti's AERFER Sagittario II, had the same weight and prestations of those projected for the Re.2007 (2500 kg, 1050 km/h), but to achieve them, he used a RR Derwent engine, with 1600 kg thrust (179% that of a Jumo 004 B). Wiewing at the very clean line of this aircraft, I don't believe Longhi could do something so better in the forties.





Some of Max Cappone's objections to te existance of the project during the war (as the words of Commander De Prato, or the "impossibility" to use parts of the fuselage of Re.2006 to fit a jet engine) seems specious to me but, at the best, they never hope to wiew one Re.2007 fly first of the end of the war.
The major part, if not all, of the italian's aircraft projects started after 8 september 1943 (not those started first, but not yet ready at the day of the armistice) had, as principal objective of the ingeneers, that of not being deported to Germany and, as principal objective of the owners, that of having something ready for the post-war era. Producing usable aircrafts, was not really an objective. Re.2007 is not an exception.


----------



## Twitch (Jun 1, 2006)

The problem with neophytes and armchair engineers deciding what performance is or is not possible ascribed to blueprints done by experienced aero designers is worthless. As we all know the process of ANY aircraft reaching combat flight status from an initial design concept is a multi-faceted one. Every plane design is reworked and improved before metal is cut. Flight testing then brings out other modifications desired and prototypes evolve accordingly.

For anyone on forums like these to decide whether a design concept is valid simply is wrong and flawed as the final product will be different. And to pass judgement on preliminary designs from aero engineers with sucessful, proven in combat aircraft experience is sheer folly. We must be aware that basic design concepts and air ministry requirements from any country do not reflect final products.


----------



## Dogwalker (Jun 1, 2006)

Twitch said:


> We must be aware that basic design concepts and air ministry requirements from any country do not reflect final products.


That's sure and, surely, Re.2007 (if existant) could be a great aircraft even reaching "only" 900 or 950 km/h instead 1050, or weighting 3000 kg instead 2500. A lot of good aircrafts gained some weight passing from the paper to the production, or achieved prestations that are not the expected ones.


----------



## red admiral (Jun 1, 2006)

Power = Force * Velocity

Drag ~ constant * Velocity^2

Force = mass * acceleration

At maximum speed there is acceleration so sum of forces = 0

Total Force = 0

(Power / Velocity) - (Constant * Velocity^2) = 0

Power / Velocity = Constant * Velocity^2

Power = Constant * Velocity^3

Power^1/3 * Constant, k = Velocity

The constant value, k varies from aircraft to aircraft and is a measure of how aerodynamic the airframe is. 

Me 262, 870kph with 2x900kg 004B engines
k = 870 / 1800^1/3 = 71.5
He 162, 890kph with 1x910kg BMW engine
k = 890 / 910^1/3 = 91.8
For 1050kph with the Re 2007 with 1x004B engine
k = 1050 / 900^1/3 = 108.8

Its not that unreasonable considering the similar size to He162, the incorporation of the engine inside the fuselage and the swept wing. Now if only they'd use the afterburner from the CC.2....


----------



## delcyros (Jun 1, 2006)

That´s it. I think, despite some arguable points we do all agree that the RE 2007
cannot be a twin engined jet because of weight considerations. A single engined RE 2007 could fit the weights well. It´s performance do remain unknown but the figures are suspicious because of several reasons. Things are not that easy (the rapid drag increase at Mach 0.75 and higher is a serious problem) but the drag difference between Me-262 and He-162 (the latter beeing a lighter but otherwise comparable plane to the RE 2007) is 20.3 according to Red Admiral, while the diference between He-162 and RE 2007 is 17. Such an improvement is suspicious, both planes are ultralightweighted (weight does also play a role, a lightly loaden plane is faster than with heavier loadings), the RE 2007 beeing heavier by 20%! Swept wing may cause a significant drag reduction but do more have an effect on critical Mach numbers (they do not delete drag, they do only shift drag to another speed region). The He-162 already has a very high critical Mach number (thanks to it´s thin airfoils), we don´t know much about the crit Mach figure of the RE 2007. But what else is important for a fighterplane?
Beside of speed it is thrust to weight ratio.
With a single Jumo 004B the RE 2007 as proposed will have a ratio of 0.25. That´s significant lower than any ww2 fighter jets:

Me-262: 0.275
P-80: 0.28
Meteor MK III: 0.28
He-162: 0.3
Bell P 59: 0.44 (with 2 x GE Ia)

Acceleration, climb, take off distance would suffer.
(Only the Ar-234B fully loaden with bombs has a lower thrust to weight ratio)


----------



## delcyros (Jun 2, 2006)

The problem I see with the drag figures posted are the altitudes. I again checked my books for this. The performance of the Jumo drops in altitude, 890 Kp thrust are at sea level only. The drag also is dependend on air density and Mach fraction. Both are neglected.

I found only one plane to have similar layout, weights and thrust ratios: It never flew. The BV P 211.01 project was a proposal for the Volksjäger competition which in the end was won by the He-162. For a number of weeks the BV P 211.01 was acknowledged as the better plane but it lost in the end.
A comparison with the RE 2007 is enlighting:

Both planes weight around 3.500 Kg
Both planes are driven by a single, low performance jet engine (BMW 003 or Jumo-004)
Both planes have a swept back, low wing configuration.
The BV P 211.01 is 32Kg lighter, has a 90 Kp inferior engine, has 750 Kg fuel and a 30 degrees swept back wing (armament 2 x 30mm MK 108).
Both planes have a long air intake (which results in 6-8% thrust loss according to tests with Jumo-004 B and Me-262 with intake pipes) but only the RE 2007 also has a long exhaust pipe (resulting in additional 5-7% loss in thrust). Odds are that both planes would fare comparably, how is the claculated speed for the BV P 211.01?
Can tell You: 860 Km/h @ 8.000 m. (~540 mp/h). Wind tunnel tests proved that the swept back wing did not made a big difference with the single Jumo-004B powerplant. I cannot imagine how the RE 2007 could reach 600 mp/h. 550 +-15 mp/h is more plausible, 600 mp/h might be achievable with a 1.200 Kp Jumo 004 E powerplant.


----------



## DAVIDICUS (Jun 22, 2006)

Civettone, I think you may be right. A myth.


----------



## Civettone (Feb 1, 2007)

I love Italian WW2 aircraft and especially appreciate the Reggiane 200* family.

But the Re 2007 story can be put together with the Ju 390 mission to the US or the 16 Hellcats shot down by a Japanese Ki-100. Great stories that catch and feed our imagination...

One element from the link I quoted stands out: _The drawings and technical description were done after the war. The technical description, dated January 7th 1944, is written on Reggiane official paper but it’s the type of paper used by Reggiane in the post war years. The drawings were done by Mr. Cometti and, as stated by Mr. Cometti himself, they have done immediately after the end of the war in Europe (May 45)._

In any case, it's one thing to draw a jet fighter, it's another thing to actually develop and build one. Longhi didn't have the know-how nor the resources to continue with the Re 2007. Especially the given performance stats (speed, range) combined with the heavy armament and the unnecessary swept-back wing make it clear that Longhi didn't have sufficient knowledge of jet aircraft technology.


_Final considerations
1st. If built the RE 2007 could be considered the best jet fighter not only of WWII but also of the late 40s and good enough in the early 50s.
2nd. Having a quick look to the know cross section it’s easy to understand that it was impossible to use a RE 2006 frame in order to build the RE 2007. The wing is different, due to the arrowed and sweeped profile, and the fuselage is designed to fit a turbojet engine, quite different from a piston engine. So the opinion that the 2006 second prototype frame was used for the 2007 prototype is a fable written by someone for sure not expert of aeronautical things.
3rd. Com. De Prato says a quite interesting thing about the non existence of RE 2007. In the relatively little Reggiane environment it would been have impossible to hide such an important project and no designer or technician or test pilot remember anything about that. For sure we can exclude that such an operation could be done just by Ing. Longhi all alone._
Kris


----------



## bigZ (Feb 1, 2007)

From what I have read the Re 2007 was a post war myth that was published in some magazine. If I can remember whereiread this I will copy the the quote and list source.


----------



## Parmigiano (Feb 2, 2007)

Well, this may put another seal on the topic.

The site is dedicated to Reggiane, and for those who does not understand a word of Italian the summary is: there is NO minimal evidence that something like the RE2007 ever existed, as a prototype or project.

The whole topic is an after-war myth

http://www.geocities.com/CapeCanaveral/Launchpad/2569/RE2007.html


----------

