Favorite plane never built (or perhaps as a prototype).

[aqhoffman]

Ditto on the B-35 Flying Wing, but for late war deployment in the Pacific where its range and payload would exceed that of the B-29. Initial contracts specified late 1943 delivery of the first prototype. WW2 B-35 production might have been possible if this project had a higher priority, perhaps to augment and be the immediate successor of the B-29 with the B-32 cancelled?

However, my other favorite that never made it into full production is the Republic XF-12 Rainbow. Republic XF-12 Rainbow - WikipediaView attachment 764064

I was literally coming into this thread to post this answer (the XF-12 that is). What a beauty.

This a great documentary on it.
View: https://www.youtube.com/watch?v=ZTy0zyfP6KI

 

[GrauGeist]

MAIN reason Concorde/Tu144/Boeing SST failed was economic, pure and simple. It couldn't be justified even as a corporate/national image booster.

Ozone was just the media whipping boy of the day, with spray cans, refining plants, and conifer forests all sharing the blame in the activist movements.

The effects the SSTs had on the upper atmosphere was actually a real thing.

Aside from the public hand-wringing over the ozone issue and sonic booms, NASA and the ESA were taking note of it to the point of conducting some pretty serious studies.

Here's a PDF report from NASA on the subject:

https://ntrs.nasa.gov/api/citations/20205009400/downloads/CR-20205009400.pdf

 

[TM06]

I've always been a fan of the Italian Series 6 fighters; The Fiat G.56, Reggiane Re.2006 and Macchi C.207. Functionally they were the G.55, Re.2005 and C.205 with the DB 603 engine in place of their DB 605. The G.56 had a few (2 or 3 I think?) prototypes built and the Re.2006 was only missing its engine, with the C.207 being a development of the C.206 - hence the number discrepancy. The G.56 in particular was so impressive that Hermann Göring proposed it to Hitler and Galland as the replacement for the Bf 109.
Despite only being fitted with basic DB 603's making ~1,750 hp, they had superprop level performance and would've been absolute monsters had they been mass produced. I dream of the possibilities of them being fitted with the 2,800 hp DB 603N.

 

[tomo pauk]

Despite only being fitted with basic DB 603's making ~1,750 hp, they had superprop level performance and would've been absolute monsters had they been mass produced.

(my bold)
Please, do tell.

 

[Shortround6]

I find of wonder if they tried for max speed on the way back to airfield. If they run out of fuel they can glide back?

 

[TM06]

(my bold)
Please, do tell.

The G.56 had an official top speed of 688 kmh / 428 mph - but Captain Valentino Cus reached a top speed of 708 kmh / 440 mph - and a climb rate of I believe 22 m/s?
The Re.2006 had a slated top speed of 750 kmh / 466 mph and likely would've had similar climb rate to the G.56 as the base planes had extremely similar climb rates.
The C.207 is the least well-known with very little data as it was made too close to the armistice and wasn't as promising as the others, so it probably is a step below the other two. It was the most heavily armed however, with 4 x 20 mm cannons instead of the 3 x 20 mm cannons of the others (a little supurflous if you ask me).
I define "superprop" as a purely piston-engined aircraft capable of 700 km/h in level flight with a climb rate of at least 20 m/s, an armament layout with a burst mass of ~3.5 kg/s and a weight under 5,500 kg (10,000 kg for twin-engined aircraft) - although this one can be waived relatively easily - and the Series 6 fighters fall into this camp comfortably.
The G.56 is actually available in War Thunder, and it's one of my personal favourite aircraft to fly.

 

[tomo pauk]

The G.56 had an official top speed of 688 kmh / 428 mph - but Captain Valentino Cus reached a top speed of 708 kmh / 440 mph - and a climb rate of I believe 22 m/s?

Any source that proves that the bigger and draggier G.56 was faster than the Fw 190D-9, on about the same power?

The Re.2006 had a slated top speed of 750 kmh / 466 mph and likely would've had similar climb rate to the G.56 as the base planes had extremely similar climb rates.

'Slated' top speed is a dead giveaway. The XP-39 have had the slated top speed of 390-400 mph, but that never happened. Same for 370 mph Beaufighter, or the 460 mph Typhoon.

I define "superprop" as a purely piston-engined aircraft capable of 700 km/h in level flight with a climb rate of at least 20 m/s, and the Series 6 fighters fall into this camp.

Allied aircraft (Merlin Mustang, P-47s with wi and 150 grade, Tempest, Spitfire XIV) were actually making 700 km/h in 1944 in service.
The superprops like the P-51H, Sea Fury, (Sea) Hornet, Ta 152 (at least when outfitted with all of the bells and whistles), Spiteful and post-war Spitfires, P-47M and N were in the 750 km/h zone, for actual service.

 

[TM06]

Any source that proves that the bigger and draggier G.56 was faster than the Fw 190D-9, on about the same power?

Here's the official data sheets done on the G.56.

Notice that these graphs are with a DB 603A making only 1,510 hp, the G.56 piloted by Valentino Cus likely had the full 1,750 hp DB 603.

'Slated' top speed is a dead giveaway. The XP-39 have had the slated top speed of 390-400 mph, but that never happened. Same for 370 mph Beaufighter, or the 460 mph Typhoon.

I'm inclined to believe the Re.2006's top speed on this one. The base Re.2005 had a top speed of 628 kmh / 390 mph, slightly faster than the G.55 (623 kmh / 387 mph) and slightly slower than the C.205V (642 kmh / 399 mph).
There was a modified Re.2005 prototype designated MM.495 that was fitted with a DB 605A-1 with MW50 and a new VDM 3-bladed propeller. This relatively minor modification was enough to propel the aircraft to 720 kmh / 447 mph at 7,300 metres. If these changes were all it took to give it that top speed, the one predicted for the Re.2006 doesn't look very unrealistic IMO.

Allied aircraft (Merlin Mustang, P-47s with wi and 150 grade, Tempest, Spitfire XIV) were actually making 700 km/h in 1944 in service.
The superprops like the P-51H, Sea Fury, (Sea) Hornet, Ta 152 (at least when outfitted with all of the bells and whistles),Spiteful and post-war Spitfires were in the 750 km/h zone, for actual service.

700 kmh was the number I settled on after much consideration regarding how to define a superprop, as it would open the door for a few more aircraft I'd consider worthy for the title. I can share the spreadsheet I made with the help of a friend for superprop fighter aircraft if you desire.

 

[Frog]

Northrop F-20 Tigershark.

 

[tomo pauk]

Notice that these graphs are with a DB 603A making only 1,510 hp, the G.56 piloted by Valentino Cus likely had the full 1,750 hp DB 603.

Thank you for the data

Here is the power chart for the DB 603A:



IOW, running the 603A at 2700 rpm and the max boost as per the chart, the G.56 will have at disposal ~1620 PS at the rated altitude of 5700 m (or at ~7 km with max ram?, ie. at max speed) instead of 1510. Is the extra 110 HP enough for more than 20 km/h speed increase stipulated?

The 1750 HP is the take off power, while the max power was about 1850 PS, but at 2 km (~3 km with max ram?).

I'm inclined to believe the Re.2006's top speed on this one. The base Re.2005 had a top speed of 628 kmh / 390 mph, slightly faster than the G.55 (623 kmh / 387 mph) and slightly slower than the C.205V (642 kmh / 399 mph).

I'm not inclined to believe that a 5 km/h faster base fighter can became a 50-70 km/h faster fighter because the new type of the same engines are installed in both aircraft.

There was a modified Re.2005 prototype designated MM.495 that was fitted with a DB 605A-1 with MW50 and a new VDM 3-bladed propeller. This relatively minor modification was enough to propel the aircraft to 720 kmh / 447 mph at 7,300 metres.

I'd again ask for the sources.

700 kmh was the number I settled on after much consideration regarding how to define a superprop, as it would open the door for a few more aircraft I'd consider worthy for the title. I can share the spreadsheet I made with the help of a friend for superprop fighter aircraft if you desire.

If you want to share your stuff, I'm 100% okay.

 

[tomo pauk]

Here's the official data sheets done on the G.56.

Looking the data sheet more carefully, last date on it is in September in 1943, and 1st dates are in May of 1943. The 1st flight of the G.56 happened in 1944.

 

[TM06]

I'm not inclined to believe that a 5 km/h faster base fighter can became a 50-70 km/h faster fighter because the new type of the same engines are installed in both aircraft.

From what I understand, the Re.2005 was extremely aerodynamically efficient with quite a sophisticated wing design - with a few quotes here and there describing it as "aerodynamically perfect". Perhaps It has something to do with that? Maybe lack of drag compared to the G.56 or cleaner lines. I'm not entirely sure, however it definitely would be above the 700 km/h mark regardless.

I'd again ask for the sources.

These are the ones I have at the moment, there's some manuals linked with the aircraft but I can't seem to find PDF's for them.

If you want to share your stuff, I'm 100% okay.

Here you go. Just be wary that some of the planes weren't fully built and that this is by no means a complete list.

 

[tomo pauk]

From what I understand, the Re.2005 was extremely aerodynamically efficient with quite a sophisticated wing design - with a few quotes here and there describing it as "aerodynamically perfect". Perhaps It has something to do with that? Maybe lack of drag compared to the G.56 or cleaner lines. I'm not entirely sure, however it definitely would be above the 700 km/h mark regardless.

Italians were certainly free to describe their aircraft the way they wanted
IMO - if the 630 km/h Re.2005 was "aerodynamically perfect", the 645 km/h fast MC.205V would've been probably above perfect, no?

These are the ones I have at the moment, there's some manuals linked with the aircraft but I can't seem to find PDF's for them.

Here you go. Just be wary that some of the planes weren't fully built and that this is by no means a complete list.

Thank you for the excerpts and the table.
You will hopefully understand my skepticism for the 720 km/h speed figure for the Re.2005 that was tested with MW 50.

 

[TM06]

Italians were certainly free to describe their aircraft the way they wanted
IMO - if the 630 km/h Re.2005 was "aerodynamically perfect", the 645 km/h fast MC.205V would've been probably above perfect, no?

They were Italian-made, of course they were perfect! All things are possible with faith in Il Duce!
In all seriousness, I believe those remarks are referring to things other than its top speed. The C.205V was certainly fast, but it ranked as only 'average' in the type test and mock dogfights Germany did with the Series 5 fighters + the Bf 109 and Fw 190 A-5. Perhaps the manoeuvrability was less than stellar, which would definitely put it in a bad light given how the other two Series 5 fighters could turn with Spitfires.
The main weakness was its mediocre high altitude performance, which only became more apparent when compared to the G.55 and Re.2005 which were excellent at high altitudes. They tried to fix this with the C.205N Orione variant, but apparently this version was liked even less by the pilots and Regia Aeronautica, as the increased weight drastically increased its time-to-climb by over two minutes for most altitudes and its top speed tanked as well.

 

[tomo pauk]

In all seriousness, I believe those remarks are referring to things other than its top speed. The C.205V was certainly fast, but it ranked as only 'average' in the type test and mock dogfights Germany did with the Series 5 fighters + the Bf 109 and Fw 190 A-5. Perhaps the manoeuvrability was less than stellar, which would definitely put it in a bad light given how the other two Series 5 fighters could turn with Spitfires.

That makes a lot of sense.

 

[dedalos]

The c205 veltro was excellent. The g55 was equal at low/mid altitude but superior at high altitude with its bigger wings. It also had more potential to receive the Db603
The re2005 had the most advanced skin and wing construction but it was tiny with no plenty room for development. I have also read the mw50 tested re2005 , but they also concluded that a stronger Airframe was required.
In my opinion 708 km/h for the g56 is quite reasonable with fully rated db603
The similarly powered fw190 v13 on the same engine had speed over 710km/h. The D9 was at 685km/h being bigger ,heavier and draggier
The g56 was lighter, and with excellent clean airframe and without the engine gap. I don't know it's wing profile .

 

[Shortround6]

The c205 veltro was excellent. The g55 was equal at low/mid altitude but superior at high altitude with its bigger wings. It also had more potential to receive the Db603
The re2005 had the most advanced skin and wing construction but it was tiny with no plenty room for development.

The Re 2005 had wing about 20% larger than the C205 Veltro. 220sqft to 181sqft. The G.55 had 227 sq ft.
This is just the size of the wing and not the size/cross section of the fuselage or ability to carry weight.

The Fiat was still in production (or at least still being offered for sale) in 1954 as the G.59 with a Merlin 500 engine. With four Hispano cannon it was supposed to do 368mph at 6200meters. The two seat trainer was faster but only had a single .50 cal in each wing. The G.59 had 480 liters of internal fuel, two of four tanks in the fuselage. the trainer had 370 liters. Five tanks all in the wing. Small drop tanks were available.
Still wondering about how long a DB 603 powered version could stay in the air

 

[GrauGeist]

The G.56 was a prototype.

It was the G.55 that caught the attention (and was field tested) of the RLM.

 

[TM06]

The G.56 was a prototype.

It was the G.55 that caught the attention (and was field tested) of the RLM.

Both caught the attention of the RLM. In fact, part of the reason why the G.55 was so intriguing and appealing was due to the G.56 being a reasonable possibility.
Hermann Göring proposed it to Hitler and Galland as an easier alternative to the Me 209-II and Me 309, stating that Germany could not afford to make such radical changes to the Bf 109 and that Germany should take over production. Of course this didn't exactly go to plan, given the situation in Italy.

 

[spicmart]

Here you go. Just be wary that some of the planes weren't fully built and that this is by no means a complete list.

In the twin engine category I would include for Germany the Ta 154A (Jumo 213E) and an, albeit hypothetical, Fw 187 (DB 605).
And where is the Ta 152C?
For Britain there was also the Westland Whirlwind.