Let’s develop the F5F / XP-50 fighter aircraft.

[davebender]

Historically this aircraft received little attention from the U.S. Army and USN. Each service ordered a single prototype and it appears both services rejected further development before the end of 1941.

Like the German Fw-187 the F5F offered superior performance using aircraft engines available during the late 1930s. IMO both aircraft were missed opportunities that could have been in mass production during 1940.

My F5F wish list.
Start development and order prototypes during 1936.
…..Concurrent with German Fw-187.
…..Engines are available at that early date.
…..Aircraft should be in mass production during 1940.

2 x Wright R1820 or P&W R1830 radial engines.
…..Similar size / weight / power output. Lowest bidder gets engine contract.
…..Power egg mount to allow quick engine change.
…..Different engine variants for high altitude (i.e. bomber escort) and CV medium/ low altitude.
…..These engines were relatively inexpensive. During 1942 you could probably purchase two R1830 engines for the same price as a single R2800 engine.

4 x nose mounted .50cal MG.
…..WWII era U.S. aircraft have no other available weapon.
…..Four in the nose are probably worth six or eight in the wings. Two 20mm cannon would be better but this will work.

Single seat fighter is primary version. However other variants are possible.

300 gallons internal fuel. This fighter should have excellent range / endurance.

What would your version of the F5F look like?

 

[Shortround6]

What would your version of the F5F look like?

A lot like an F4U.

 

[rank amateur]

You mean, gull wings, 2 R2800's and a bouncy undercarriage?
Perhaps if we were to ask the Vought company to take over development but historically that is not likely yo happen.

 

[Shortround6]

I mean historically both were ordered at the same time. Guess what, One big radial with the cockpit behind has a lot less drag than two radials with the cockpit in a 3rd body/fuselage. Turbo's on the XP-50 aren't going to get sorted out any sooner than the turbos on the P-38 and B-17. Two stage mechanical supercharger on the R-1830 had problems too. 2 stage engines (either turbo or mechanical) need inter-coolers and ducts, in other words a number of cubic feet of interior space. The list goes on......and on.....and on.....

 

[GregP]

The B-17 DID get sorted out and was a viable high-altitude bomber, perhaps not in 1940, but it got tehre So would have the XP-50. I think the main change from what WAS would be to size it for the smaller engines, and I think it COULD have been done quite well.

People tend to denigrate the twin versus the single but, when an engine fails, I MUCH rather be in the twin! Centerline guns would have been a great help and I'd go with 5 or 6, and keep the tricycle landing gear since it worked quite well. I have always disliked the placement of oil tanks in the engine compartment, and would have mounted it inside the wing BEHIND the firewall such that bullet holes would NOT cause oil to leak onto the exhaust headers. That is, I'd route the exhaust such that oil spilling vertically downward would not hit the hot pipes.

 

[R Pope]

F5F has been a favorite of mine since the old bubble gum card days. Cannons, drop tanks and some work on the undercarriage would have made it a winner, I think.

 

[davebender]

If you are going to wait until 1938 then developing the F4U is probably a better choice.

Development of the F5F can begin during 1936 (or perhaps even earlier) because R1830 engines were available during the early 1930s. Long before you can consider any fighter aircraft design powered by the R2800 engine.

 

[Shortround6]

And without warping time WHICH R-1830 and R-1820 engines were available?

Not the 1200hp ones. Not the 1100hp ones. Even 1000hp in 1935/36 was skating on thin ice. The F3F-2/3 used a 950hp R-1820 as did the first Brewster F2A's

Single speed superchargers were all there was. Army P-30A turbo charged aircraft he first of which made its maiden flight on 17 December 1935, with deliveries to service units starting on 28 April 1936, used a single stage turbo. The turbo delivered air to the carburetor and there was NO engine driven supercharger.

The Navy was just ordering the FIRST monoplane aircraft for US carrier use, the Devastator.

BTW the first drawings/requests for the F5F involve the use of the smaller R-1535 engines for better pilot view and streamlining. The larger engines were resorted too when P&W stopped development of the R-1535 engine.

Odds are that any work done on an "early" F5F would have to be thrown out as the level of knowledge of aeronautics, structures and engines (propulsion) advanced from 1935-1938. One writer claims that all the F5F contributed to the F7F was how NOT to do things.

 

[tomo pauk]

...

What would your version of the F5F look like?

Can we use the V-1710?

 

[Shortround6]

The B-17 DID get sorted out and was a viable high-altitude bomber, perhaps not in 1940, but it got tehre So would have the XP-50. I think the main change from what WAS would be to size it for the smaller engines, and I think it COULD have been done quite well.

It was around 1942 that the army got the turbos sorted out, or early 1943. The turbos themselves were not the problem but the turbo controls and management philosophy.
The army started by using a turbo control setup that measured the exhaust pressure (back pressure) before the turbine nozzles and adjusted the waste gate/s accordingly to keep a constant value of pressure at that point. speed of the turbine and compressor affected how much pressure the inlet of the carburetor was getting. A simple idea but perhaps too simple. There were a lot of problems including freezing of the sensor line leading to run away turbos as the plane descended. Changing the management philosophy to one that measured the pressure of the intake in front of the carburetor and adjusted to wastegate/s to keep that value, even if more difficult from a mechanical/electrical point of view, made for a more reliable system that was easier for the pilots to manage. Bombers gained and lost height much slower than fighters and had the flight engineer to assist so what was acceptable performance in bomber might not be acceptable in a fighter.

 

[Shortround6]

Can we use the V-1710?

A Navy Blue P-38?????

 

[tomo pauk]

Nope, the 'metal, pre (Sea) Hornet' would be a correct answer

 

[davebender]

F5F prototypes and production aircraft would use the newest version available. Just as Spitfires were powered by the newest available version of the RR Merlin engine and Me-109s were powered by the newest available version of the DB601 / DB605 engine.

 

[wuzak]

Nope, the 'metal, pre (Sea) Hornet' would be a correct answer

Or a Supermarine Type 327?

 

[The Basket]

Funny looking thing. But why then wasnt it developed? Musta been a reason.

F7F development seems to state the F5F as a dead end as you dont rip a winning design and start again.

 

[Shortround6]

F5F prototypes and production aircraft would use the newest version available. Just as Spitfires were powered by the newest available version of the RR Merlin engine and Me-109s were powered by the newest available version of the DB601 / DB605 engine.

Which gets back to my question doesn't it?
You want to "start" work several years early, the engine models used in the prototype F5F and XP-50 were not available several years earlier and even switching to the R-1830 doesn't give you a 1200hp engine several years earlier. 109 started with the Jumo 210, a 1936/37/38 F5F would have a 750-950hp engine instead of the 1200hp engines used in the 1940/41 prototypes.

 

[davebender]

1,200 hp engines are not mandatory for F5F prototypes and the initial production version.

 

[wuzak]

1,200 hp engines are not mandatory for F5F prototypes and the initial production version.

I think what he is suggesting is that the performance came about because it was fitted with 1200hp engines. With earlier, lower powered engines the performance would be less, and possibly would have seen the project cancelled.

 

[Shortround6]

Wuzak has the idea. The early engines are lighter than the later ones but only by 100-150lbs. A 10% loss of engine weight (not plane weight) vs a 20% reduction in the power to weight ratio of the whole plane? and that is for 950hp engines. The cowling and streamlining/cooling of air cooled engines was also making steady progress at this time. In 1935/36 few aircraft, if any, used adjustable cowl flaps (including the Hughes H-1 record setter). See this picture of a 1935/36 Grumman R-1820 installation.

Mr. Bender is asking for everything Grumman learned working on the early F4F to be available to them several years earlier. While both the Devastator and Vindicator did use cowl flaps the Vindicator used a steel tube fuselage with fabric covering for a good part of it's length.

Grumman may have been able to design a twin fighter in 1935-7 but I doubt it could have been developed INTO the F5F as we know it.

 

[Shortround6]

Wuzak has the idea. The early engines are lighter than the later ones but only by 100-150lbs. A 10% loss of engine weight (not plane weight) vs a 20% reduction in the power to weight ratio of the whole plane? and that is for 950hp engines. The cowling and streamlining/cooling of air cooled engines was also making steady progress at this time. In 1935/36 few aircraft, if any, used adjustable cowl flaps (including the Hughes H-1 record setter). See this picture of a 1935/36 Grumman R-1820 installation.

View attachment 209220

Mr. Bender is asking for everything Grumman learned working on the early F4F to be available to them several years earlier. While both the Devastator and Vindicator did use cowl flaps the Vindicator used a steel tube fuselage with fabric covering for a good part of it's length.

Grumman may have been able to design a twin fighter in 1935-7 but I doubt it could have been developed INTO the F5F as we know it.